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1
Tuzun, Alev. "Integrating plant oils in benzoxazine chemistry." Doctoral thesis, Universitat Rovira i Virgili, 2015. http://hdl.handle.net/10803/319708.
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Les polibenzoxazines son una classe relativament nova de resines fenòliques termoestables que posseeixen interessants propietats per a la indústria electrònica, automobilística, aerospacial i d’adhesius. Les seves possibilitats superen a les dels sistemes fenòlics clàssics, novolaques i resols, principalment en que no necessiten catalitzador per portar a terme el seu curat i no alliberen volàtils de condensació durant el mateix. Els monòmers benzoxazina es preparen habitualment per combinació de fenols i amines amb formaldehid mitjançant una condensació tipus Mannich. Aquesta química ofereix una elevada flexibilitat en el disseny estructural, fet que permet la utilització de gairebé qualsevol fenol i amina sigui comercial o sintètica. En aquesta tesi es persegueix la incorporació de derivats d’olis vegetals en monòmers i polímers precursors de polibenzoxazines per a que actuïn com a blocs flexibles. En concret, ens hem centrat en l’àcid 10-undecenoic i els seus derivats com a productes derivats de l’oli de resí, un oli vegetal no comestible. La incorporació d’aquest esquelet alifàtic, apart de d’incorporar productes derivats de fonts renovables a aquest tipus de polímers ha premés la preparació de materials flexibles. La rigidesa és una de les principals limitacions de las resines benzoxazina convencionals. Aquests objectius generals s’han aplicat a (i) monómers bis-benzoxazina sintetitzats a través de reaccions d’hidrosililació, (ii) monòmers bis-benzoxazina sintetitzats a través de reaccions d’auto-metátesi, i (iii) polímers que contenen grups benzoxazina en la cadena principal sintetitzats per polimerització de metátesi ADMET.Las polibenzoxazinas son una clase relativamente nueva de resinas fenólicas termoestables que poseen interesantes propiedades para la industria electrónica, automovilística, aerospacial y de adhesivos. Sus posibilidades superan a los sistemas fenólicos clásicos, novolacas y resoles, principalmente en que no necesitan catalizador y no liberan volátiles de condensación durante su curado. Los monómeros benzoxazina se preparan habitualmente por combinación de fenoles y aminas con formaldehído vía una condensación tipo Mannich. Esta química ofrece una elevada flexibilidad en el diseño estructural por lo que permite la utilización que casi cualquier fenol o amina sea comercial o sintética. En esta tesis se persigue la incorporación de derivados de aceites vegetales como bloques flexibles en monómeros y polímeros precursores de polibenzoxazinas. En concreto, nos hemos centrado en el ácido 10-undecenoico y sus derivados como productos derivados del aceite de ricino, un aceite vegetal no comestible. La incorporación de este esqueleto alifático, aparte de incorporar las fuentes renovables a este tipo de polímeros ha permitido la preparación de materiales flexibles. La rigidez es una de las principales limitaciones de las resinas benzoxazina convencionales. Estos objetivos generales se han aplicado a (i) monómeros bis-benzoxazina sintetizados por reacción de hidrosililación, (ii) monómeros bis-benzoxazina sintetizados por reacción de auto-metátesis, y (iii) polímeros que contienen grupos benzoxazina en la cadena principal sintetizados por polimerización de metátesis ADMET
Polybenzoxazines are a relatively new class of thermosetting phenolic resins which possess properties of interest for several technological industries such as electronic, automobile, aerospace, and adhesives. Polybenzoxazine possibilities surpass those of the classical phenolic resins, novolacs and resoles, mainly because do not require a catalyst and eliminate condensation products release problems during curing. Benzoxazine monomers are classically prepared combining phenols and amines with formaldehyde via a Mannich-type condensation. Interestingly, this chemistry offers a tremendous flexibility in structural design allowing the use of almost any commercially available or synthetic phenol or amine. This thesis pursues the incorporation of plant oil derivatives as flexible segments into polybenzoxazine monomeric and polymeric precursors. In particular, we have focused on 10-undecenoic acid and its derivatives which are valuable renewable materials derived from non-edible castor oil. The incorporation of this aliphatic skeleton of fatty acids, apart from bringing biobased character to these materials, has allowed preparing inherently tough and flexible cured systems. Inflexibility is one of the main limitations of convetional polybenzoxazine resins. These general objectives were applied to three groups of polybenzoxazine precursors: (i) bis-benzoxazine monomers obtained by hydrosilylation reaction, (ii) bis-benzoxazine monomers obtained by self-metathesis reaction, and (iii) main chain benzoxazine polymers obtained by acyclic diene metathesis polymerization.
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Clark, Amanda. "Melaleuca Alternifolia Concentrate (MAC): A Plant-Derived Anticancer Agent." Thesis, Griffith University, 2013. http://hdl.handle.net/10072/367678.
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Natural products historically represent a source of clinically approved drugs that have contributed significantly to anticancer drug development. In particular, essential oils represent a group of advantageous anticancer candidates as not only can they be produced in large quantities in a cost-effect manner but they also exhibit minimal toxicity. Melaleuca alternifolia Concentrate (MAC) is an extract prepared from the native Australian plant M. alternifolia (also a common source of Tea Tree Oil). Melaleuca oils are commonly used products, primarily utilised and investigated for their antimicrobial activity. However, over the last 2 decades, a continued stream of evidence has been produced pertaining to the anticancer potential of Melaleuca oil and its constituents. Previous studies reported Melaleuca oils to exhibit anticancer activity in vitro against a range of cancer cell lines, including melanoma, liver, leukaemia, lung, breast, and prostate cancer. However, much still remains to be discovered and elucidated about the Melaleuca oils, TTO and MAC. This thesis investigated the hypothesis that MAC represented an effective anticancer agent with immunomodulatory activity.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
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Wang, Haoran. "Development of Sustainable Polymer Coatings from Plant Oils." University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1596420480124218.
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Zhu, Lin. "Development of elastomers and elastomeric nanocomposites from plant oils." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 275 p, 2006. http://proquest.umi.com/pqdweb?did=1068271741&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Don, Pedro K. N. "Insecticidal activity of plant oils against stored product pests." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38289.
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Pan, Xiao. "Novel Biobased Resins using Sucrose Esters of Plant Oils." Diss., North Dakota State University, 2011. https://hdl.handle.net/10365/29636.
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Interest in using renewable raw materials to prepare biobased monomers, polymers, and materials is rapidly increasing. The goal of the research described is to develop branched polyesters of plant oil fatty acids, using different core pol yo ls (i.e. sucrose, dipentaerythritol, and tripentaerythritol) and plant oils (i.e. linseed, safflower, and soybean), into curing systems that have potential uses in applications such as coatings, composites, and adhesives. This study is mainly focused on the use of sucrose as the core
polyol in the soyate resins. Sucrose esters and their derivatives have a compact structure, high density, and high functionality-double bonds, epoxides, or hydroxyls. When considering the use of sucrose
ester compounds to form cross linked materials, the rigid core of sucrose can potentially impart hardness to the thermoset, and the high functionality can lead to rapid gelation and high cross link density. Thus, these novel biobased resins using sucrose esters of plant oils have the potential to be a significant advance in biobased resin technology, as well as to be competitive with the conventional petroleum-based resins.
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Chander, Anuj Kumar. "Characterisation and oxidative stability of speciality plant seed oils." Thesis, Aston University, 2010. http://publications.aston.ac.uk/15797/.
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The past decade has seen an influx of speciality plant seed oils arriving into the market place. The need to characterise these oils has become an important aspect of the oil industry. The characterisation of the oils allows for the physical and chemical properties of the oil to be determined. Speciality oils were characterised based on their lipid and fatty acid profiles and categorised as monounsaturated rich (oleic acid as the major acyl components e.g. Moringa and Marula oil), linoleic acid rich (Grape seed and Evening Primrose oil) or linolenic acid rich (Flaxseed and Kiwi oil). The quality of the oils was evaluated by determining the free fatty acid content, the peroxide value (that measures initial oxidation) and p-anisidine values (that determines secondary oxidation products containing the carbonyl function). A reference database was constructed for the oils in order to compare batches of oils for their overall quality including oxidative stability. For some of the speciality oils, the stereochemistry of the triacylglycerols was determined. Calophyllum, Coffee, Poppy and Sea Buckthorn oils stereochemistry was determined. The oils were enriched with saturated and/or a monounsaturated fatty acids at position sn-1 and sn-3. The sn-2 position of the four oils was esterified with a polyunsaturated and/or a monounsaturated fatty acid indicating that they follow a typical acylation pathway and no novel acylation activity was evident from these studies (e.g enrichment of saturates at the sn-2 position). The oxidative stability of the oils was evaluated at 18oC and 60oC and the effect of adding a-tocopherol at commercially used level i.e 750ppm was assessed. The addition of 750ppm of a-tocopherol at 18oC increased the oxidative stability of Brown flax, Moringa, Wheat germ and Yangu oils. At 60oC Brown Flax, Manketti and Pomegranate oil polymerised after 48 hours. The addition of 750ppm a-tocopherol delayed the onset of polymerisation by up to 48 hours in Brown Flax seed oil. Pomegranate oil showed a high resistance to oxidation, and was blended into other speciality oils at 1%. Pomegranate oil increased the oxidative stability of Yangu oil at 18oC. The addition of Pomegranate oil to Wheat germ oil at 60oC, decreased the peroxide content by 10%. In Manketti and Brown Flaxseed oil at elevated temperatures, Pomegranate oil delayed the onset of polymerisation. Preliminary studies of Pomegranate oil blending to Moringa and Borage oil showed it to be more effective than a-tocopherol for certain oils. The antioxidant effects observed following the addition of Pomegranate oil may be due to its conjugated linolenic acid fatty acid, punicic acid.
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Smith-Palmer, Mary Alison. "The antimicrobial properties of plant essential oils against foodborne pathogens." Thesis, Queen Margaret University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327082.
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Butler, G. D. Jr, D. L. Coudriet, and T. J. Henneberry. "Effect of Plant-Derived Oils on Sweetpotato Whitefly on Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208378.
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Cottonseed oil applied to cotton repelled sweetpotato whitefly (SPW) adults up to 8 days in greenhouse tests. Soybean oil (5 %) resulted in reduced numbers of adults and numbers of eggs laid. SPW egg hatch was reduced 84% after treatment with 10% crude cottonseed oil solutions as measured by the number of first instar larval emergence. Also, numbers of whitefly larvae were reduced 99, 91 and 83% on day 6 following treatment with 10% cottonseed oil, S and 1.5% soybean oil, respectively. Negligible plant leaf phytotoxicity occurred from the plant-derived oil treatments.
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Pinho, Joao Paulo Melo de. "Estudo das propriedades antiespasmÃdicas e miorrelaxantes do Ãleo essencial de Ocimum Micranthum em traquÃias isoladas de ratos wistar." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5665.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorOcimum. micranthum Willd. à uma planta popularmente conhecida como alfavaca de folha miÃda ou estoraque sendo utilizada na medicina popular no tratamento de gripe, resfriados, febre, tosse, bronquites, nas infecÃÃes intestinais e estomacais, nas otites e como estimulante e carminativa. O presente estudo teve como objetivo mostrar a atividade do Ãleo essencial de Ocimum micranthum e seu principal constituinte, o cinamato de metila, em traquÃias isoladas de ratos Wistar. Foi evidenciado que tanto o OEOM quanto o cinamato de metila, nas concentraÃÃes de 1-1000 Âg/mL, nÃo interferem no tÃnus basal, no entanto sÃo capazes de reverter a resposta contrÃtil induzida por cloreto de potÃssio e carbacol com CI50 de 112 e 128,2 Âg/mL (para o OEOM) e 308 e 100 Âg/mL (para o cinamato de metila) respectivamente. . A concentraÃÃo de 100 Âg/mL OEOM, quando adicionada antes do agente contrÃtil, à capaz de atenuar a resposta mÃxima do KCl em traquÃias de ratos naÃve, fato que nÃo ocorreu quando a contraÃÃo foi induzida por carbacol na presenÃa de nitrendipina. Adicionalmente, em animais submetidos a modelos de asma pela OVA, o OEOM se mostrou mais ativo em animais desafiados do que apenas sensibilizados. Portanto, o mecanismo envolvido nos efeitos miorrelaxante e antiespasmÃdico do OEOM Ã, pelo menos em parte, devido à sua aÃÃo preferencial nos canais de cÃlcio operados por voltagem (VOCC). Seu principal constituinte, o cinamato de metila, parece estar envolvido nos efeitos miorrelaxantes do OEOM.
The Ocimum. micranthum Willd. is a plant popularly known as âalfavaca-de-folha-miÃdaâ or âestoraqueâ and is used in folk medicine to treat flu, colds, fever, cough, bronchitis, stomach and intestinal infections, ear infections and as stimulant and carminative. This study aimed to show the activity of its essential oil (EOOM) and of its main constituent, methyl cinnamate, in rat isolated trachea. It was shown that both the OEOM and methyl cinnamate (1-1000 Âg/mL) did not change the basal tone, but they were able to reverse the contractile response induced by potassium chloride or carbachol with IC50 of 112 and 128.2 Âg/mL (for EOOM) and 308 and 100 μg/mL (for methyl cinnamate), respectively. At 100 Âg/mL, added before the contractile agent, EOOM attenuated maximal response to KCl in trachea from naÃve rats. This effect did not occur when contraction was induced by carbachol in the presence of nitrendipine. Additionally, in animals subjected to an ovalbumin-sensitized model of asthma, EOOM was more active in challenged than in sensitized animals. In conclusion,th e myorelaxant and antispasmodic effects of the EOOM are due to its preferential action on voltage-operated calcium channels. Its major constituent, methyl cinnamte, appears to be involved in the pharmacological effects of the EOOM.
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Montero, de Espinosa Meléndez Lucas. "Plant oils as renewable precursors of thermosetting and flame retardant polymers." Doctoral thesis, Universitat Rovira i Virgili, 2009. http://hdl.handle.net/10803/9039.
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El objetivo principal de esta tesis es la síntesis de polímeros empleando aceites vegetales como reactivos de partida. En la primera parte, se prepararon diferentes polímeros termoestables por modificación química de aceite de girasol alto oleico y posterior polimerización via aza-Michael y radicalaria. Se ha realizado un estudio exhaustivo del mecanismo de entrecruzamiento por reacción aza-Michael pudiéndose comprobar que variando la temperatura de entrecruzamiento y añadiendo un ácido de Lewis como catalizador se produce la formación de anillos de tipo quinolina como puntos de entrecruzamiento. En la segunda parte, se empleó aceite de girasol alto oleico para sintetizar polímeros entrecruzados con grupos funcionales fosforados que mostraron propiedades de retardancia a la llama. Se empleó la polimerización por metátesis acíclica de dienos (ADMET) para la síntesis de polímeros lineales y entrecruzados con grupos funcionales fosforados empleando ácido 10-undecenoico (derivado del aceite de ricino). Estos polímeros presentaron propiedades de retardancia a la llama. Como conclusión general, se puede afirmar que se emplearon aceites vegetales y sus derivados como reactivos para la síntesis de materiales poliméricos de manera satisfactoria.The main objective of this thesis is the synthesis of polymers using as starting reagents plant oil based chemicals. In the first part, different thermosetting polymers were synthesized through chemical modifications of commercial high oleic sunflower oil followed by cross-link via aza-Michael addition and radical polymerization. A thorough study of the aza-Michael cross-link reaction with model compounds showed that depending on the temperature and the presence of a Lewis acid catalyst quinoline rings can be formed as cross-link points. In the second part, high oleic sunflower oil was used for the synthesis of cross-linked polymers containing phosphorus functional groups via radical polymerization that showed improved flame retardancy. Acyclic diene metathesis (ADMET) polymerization was used for the synthesis of linear and cross-linked polymers with phosphorus containing functional groups using 10-undecenoic acid (castor oil derived). These polymers showed and improved flame retardancy. As a general conclusion, plant oils could be used as renewable reagents for the synthesis of linear and cross-linked polymers.
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Sugami, Yuitsu. "ALTERNATIVE DIESELS FROM PLANT OILS AND THEIR EVALUATION OF FUEL PROPERTIES." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225703.
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Lale, N. E. S. "Insecticidal activity of plant essential oils on Callosobruchus maculatus (F.) : (Coleoptera:Bruchidae)." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379315.
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Roesle, Philipp [Verfasser]. "The mechanism of the isomerizing alkoxycarbonylation of plant oils / Philipp Roesle." Konstanz : Bibliothek der Universität Konstanz, 2016. http://d-nb.info/1153425661/34.
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Gilling, Damian Henry. "THE EFFICACY OF NATURAL PLANT ANTIMICROBIALS AGAINST ESCHERICHIA COLI." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/205215.
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The number of foodborne disease outbreaks related to fresh produce has increased in recent years. This has coincided with a growing public demand for minimally processed fruits and vegetables. Effective produce sanitizers are therefore needed that are at least as effective as chlorine, currently the most commonly used sanitizer. Natural antimicrobials from plant extracts and essential oils are a possible alternative. These are highly effective and may also be used in situations in which chlorine is not advantageous; for instance, in situations in which chlorine has limited efficacy or because of concerns over the production of harmful by-products resulting from chlorine use. Plant derived essential oils have been shown to be antibacterial, antiviral, and antifungal. In this study we examined the use of natural antimicrobials from plant extracts and essential oils as possible alternative sanitizers. We examined these antimicrobials for their efficacy against Escherichia coli. In addition, since many of these natural compounds are believed to be membrane active, silver ions were added to some of the tests to assess the potential for synergy between the antimicrobials. Silver ions, although slow-acting on their own, often exhibit a synergistic antimicrobial effect when combined with other membrane active antimicrobials such as oxidizing agents. These studies reveal that plant derived antimicrobials are effective sanitizers with the potential to replace commonly used chlorine
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Sadek, Garboui Samira. "Plant-Derived Chemicals as Tick Repellents." Doctoral thesis, Uppsala universitet, Systematisk zoologi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9368.
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Ixodes ricinus is the main vector of Lyme borreliosis and Tick-borne encephalitis in Europe. Repellents provide a practical means of protection against tick bites and can therefore reduce transmission of tick-borne diseases. In laboratory tests, pieces of cloth treated with MyggA Natural® (a commercial insect repellent) or with the essential oils of Corymbia citriodora (30%), Lavandula angustifolia (1 and 30%), Pelargonium graveolens (1 and 30%), Hyptis suaveolens (10%), Salvadora persica, Pistacia atlantica, Juniperus phoenicea (20%) and methyl jasmonate (MJ) (0.5%, 1.0%, 2.0% and 5.0%) showed strong repellent activity against I. ricinus nymphs. In a tick-infested woodland in east-central Sweden, we tested by randomized, standardised methodology the potential anti-tick repellent activity of MyggA Natural® (roll-on), two concentrations of MyggA Natural® spray, RB86 (a commercially available insect repellent for horses), the essential oil of C. citriodora and three concentrations of MJ. Each substance was dissolved in acetone and applied separately to 1 m2 cloths which were then pulled over vegetation. Nymphal tick numbers on the cloths were recorded at 10-m intervals and differed significantly between treated cloths and the untreated control and also between collectors. Volatile compounds from fresh and dried leaves of H. suaveolens and the essential oils of H. suaveolens (from Laos and Guinea Bissau) and S. persica, P. atlantica and J. phoenicea (from Libya) were collected by solid phase micro-extraction (SPME) and the constituents were identified by gas chromatography - mass spectrometry (GC-MS). Two main sesquiterpene hydrocarbons in the H. suaveolens oil were β-caryophyllene and humulene. These were modified by oxidation and sulphidation to obtain effective tick repellent compounds with lower volatility. In all three oils from Libyan plants the main monoterpene hydrocarbons were α-pinene, sabinene, β-pinene, myrcene, α-phellandrene, 4-carene, β-phellandrene and γ-terpinene. The selected plant species contained numerous volatiles known to have insecticidal, acaricidal, and/or insect repellent properties.
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Marais, Christiaan De Wet. "The determination of cis and trans fatty acid isomers in partially hodrogenated plant oils /." Link to online version, 2007. http://hdl.handle.net/10019/399.
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Christian, Erik J. "Plant extracted essential oils as a contact fungicide seed treatment for organic corn." [Ames, Iowa : Iowa State University], 2007.
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Scott, Gillian. "The anti-inflammatory properties of n-3 fatty acids and dietary plant oils." Thesis, University of Edinburgh, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366042.
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Dorman, Hugh Jude Damien. "Phytochemistry and bioactive properties of plant volatile oils : antibacterial, antifungal and antioxidant activities." Thesis, University of Strathclyde, 1999. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21318.
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Aromatic and medicinal plants have been recognized since antiquity as possessing biological activities; chief amongst these are their antibacterial, antifungal and antioxidant properties. In this study, the chemical composition, the antimicrobial and in vitro antioxidant bioactivities the volatile oils extracted by hydrodistillation from aromatic and medicinal members of the plant families Geraniaceae: geranium (Pelargonium graveolens L'Herit); Lamiaceae: melissa (Melissa officinalis L.), monarda (Monarda citriodora var. citriodora Cerv. ex Lag.), oregano (Origanum vulgare ssp. hirtum (Link) Letsw.) and thyme (Thymus vulgaris L.); Myristicaceae: nutmeg (Myristica fragrans Houtt.); Myrtaceae: clove (Syzygium caryophyllus Gaertn.); Piperaceae: black pepper (Piper nigrum L.) and Umbelliferae: lovage (Levisticum officinalis L.) were investigated. The chemical percentage composition of the volatile oils extracted from black pepper, clove, geranium, lovage (from both leaf and stem material), melissa, monarda, nutmeg, oregano and thyme were analysed using gas chromatography and mass spectroscopy. The findings of these analyses confirmed that volatile oils from aromatic and medicinal members of different plant families are principally mixtures of mono- and sesqui- terpenoids compounds. Furthermore, oil samples extracted from species of the same plant family, samples sourced from different parts of the same plant and a commercial and authenticated volatile oil described as from the same species may exhibit different compositions, i.e. the percentage composition and variation in individual phytochemicals. A series of experiments were carried out in an attempt at assessing the antibacterial properties of black pepper, clove, geranium, melissa, nutmeg, oregano and thyme volatile oils and their main components. A collection of 25 test microorganisms [9 Gram-positive and 16 Gram-negative strains] including human, plant and veterinary pathogens and food spoilage organisms. All the volatile oils demonstrated some degree of antiseptic activity with the oils of oregano and thyme being particularly active. The phenyipropanoid eugenol and the phenolic constituents carvacrol and thymol were found to be strongly antiseptic. The antifungal activity of black pepper, clove, melissa, oregano and thyme volatile oils against the agriculturally important Aspergillus species Aspergillus flavus (Link) Fries and Aspergillus niger van Tieghen, and the Fusarium species Fusarium culmorum W.G. Smith was investigated. All the volatile oil samples demonstrated antifungal properties with variable degrees of efficacy across the concentration levels used in this study, with the volatile oils of oregano and thyme being particularly inhibitory. The in vitro antioxidant properties of the volatile oils of black pepper, clove, nutmeg, oregano and thyme and their major components were evaluated by using a method routinely used in this laboratory, a simplified plate diffusion technique for determining lipid antioxidant activity using linoleic acid/β-carotene. To investigate further the potential antioxidant activity of these plant extracts and their main components and characterise their underpinning mechanism of action, an attempt to develop and optimize current antioxidant screening techniques was carried out. These methods included a thiobarbituric reactive species assay, a conjugated diene assay and a free-radical trapping assay. Finally, a series of feeding trials were carried out to assess whether volatile oils feed at various concentrations prior to and during pregnancy can beneficially affect the compositional levels of major fatty acids in a maternal and foetal/neonatal model extracted from cholesteryl ester, triacylglyceride, free fatty acid and phosphoglyceride lipid fractions in an organ dependent manner. Particular focus centered upon the saturated fatty acids lauric, palmitic and stearic acids; the essential fatty acids[LA](18:2n-6) and α-linoleic [LA] (18:2n-6) and α-linolenic [ALA (18:3n-3) acids and the long chain polyunsaturated fatty acid metabolic derivatives, e.g. arachidonic acid [ARA] (20:4n-6), docosahexaenoic [DHA] (22:6n-3) and eicosapentnoic acid [EPA] (20:5n-3). The volatile oil of oregano was administered orally to female rats at 167mg Kgˉ¹; 334 mg Kgˉ¹ and 843 mg Kgˉ¹ concentration levels immediately prior to and during pregnancy to determine whether they affected the fatty acids composition in a variety of major maternal and neonatal organs. In addition to the aforementioned experiment, further feeding trails were carried out using the volatile oils of clove and nutmeg at a 5Oµg gˉ¹ concentration level.
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Murray, Andrew P. "Factors controlling the abundance and carbon isotopic composition of land-plant derived compounds in crude oils." Thesis, Curtin University, 1998. http://hdl.handle.net/20.500.11937/1100.
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This thesis describes a study in petroleum geochemistry and specifically of the application of Land-plant derived hydrocarbons to elucidating source matter type, depositional environment and thermal maturity of crude oils. Large volumes of petroleum have been generated from land-plant organic matter in many parts of the world, but especially in the Tertiary deltaic provinces of the USA, Canada, Africa, Southeast Asia, Australia and New Zealand. Compared to oils from other regions, these oils have a relatively complex pattern of biomarkers or molecular fossils, a feature reflecting the diversity of deltaic depositional environments and the advanced state of plant evolution during late Mesozoic and Tertiary time. The molecular and carbon isotopic composition of these oils is useful in identifying the character of their source beds and also in understanding the conditions that give rise to oil-prone sediments generally.Despite their widespread occurrence in oils and sediments, land-plant biomarkers have been used less frequently than compounds of algal origin as markers for source, depositional environment and thermal maturity. The present work sets out to extend the range of land-plant biomarker and isotope tools available to the petroleum geochemist and to provide a firmer foundation for some of the existing tools. A systematic study of the biomarker and n-alkane carbon-isotope composition of a set of late Mesozoic/Tertiary-age oils was carried out as a preamble to more focussed investigations. A comparison of the biomarker and n-alkane isotope data showed that parameters such as the oleanane/hopane ratio overestimate the higher plant contribution to marine deltaic oils. The abundance of bicadinane isomers was found to be much more variable than that of the oleananes, probably because of their close association with the highly resinous, dipterocarp hardwoods of Southeast Asia. However, small amounts of bicadinanes were found in an oil from outside the paleogeographic range of the dipterocarp family, indicating a more general source. Retention indices based on the regular hopane series were calculated for the main bicadinane and methyl bicadinane isomers and for a group of oleanoid triterpanes.Source rock depositional setting proved to be the primary control on the shape of the n-alkane isotope profile, with negatively sloping curves being characteristic of fluvio-deltaic and marginal lacustrine oils and flat or positively sloping curves typical of marine oils. The difference is probably related to the bacterial reworking of higher plant matter in the fluvio-deltaic environment. A slight isotopic anomaly at n-C(subscript)17 correlates with the abundance of algal-derived steranes and may indicate a minor marine contribution to the source of an fluvio-deltaic oil. A study of sediments from the South Sumatra Basin and New Zealand showed that the n-alkane isotope profile is determined mainly by source matter type and is little influenced by thermal maturity or depositional environment.Based on the results of the work described above, three aspects were chosen for further examination. These were: a) the factors controlling the carbon isotopic composition of n-alkanes and of resin-derived compounds in terrigenous oils; b) the influence of source, maturity and biodegradation on the abundance of bicadinanes, especially the effect of maturity on the isomer distribution, and c) the factors controlling the abundance of oleananes and rearranged oleananes in oils and Ancient sediments, especially the role of depositional environment.A preliminary study using sediments, from the Visayan Basin (Philippines) showed the bicadinane isomeric distribution to be sensitive to maturity. This suggested new maturity parameters which would be resistant to even severe biodegradation and largely immune to interference from diagenetic effects. A more detailed study of a marine-fluvio-deltaic depositional sequence from the South Sumatra Basin confirmed that the maturity indices based on bicadinanes and aromatic analogs were less subject to non-maturity influences than those based on the steranes and aromatic hydrocarbons. The values obtained for the bicadinane indices were compared with the maturity required for oil generation as estimated by kinetic modelling and with conventional maturity indicators such as sterane epimerisation and the methyl phenanthrene index. Values for several of the indices were also measured for 17 Tertiary-age oils from Southeast Asia, Papua New Guinea, New Zealand and Australia. The main bicadinane maturity indicator (BMI-1) continues to change into the oil window and hence is useful in ranking the relative maturity of oils as well as sediments. Values of BMI-1 for two oils having unusually low sterane maturities were found to be normal and, in the light of this observation, the conventional explanation for low sterane epimerisation of many Tertiary-age oils was critically evaluated.The oleananes, as markers for the angiosperms, provide valuable source and age information when present in an oil. Nevertheless, their abundance is not quantitatively related to the land plant input and indeed their presence results from a small "leak" in diagenetic processes leading primarily to aromatic oleanoids. Evidence is presented that contact of plant matter with seawater during early diagenesis enhances the expression of oleananes in a mature sediment or oil. Oleananes are absent or present at very low concentrations in samples from the base of an Eocene coal seam affected by post-depositional seawater intrusion. However, their abundance increases toward the top of the seam in correlation with % organic sulphur, dibenzothiophene/phenanthrene and the homohopane index. Similarly, in deltaic sediments from the South Sumatra Basin, oleanane/hopane is strongly correlated with indicators of marine influence such as C[subscript 27]/C[subscript 29] steranes and of oxic/anoxic conditions such as the homohopane index. In each case, increasing oleanane abundance is accompanied by a reduction in the extent of aromatisation and, for the South Sumatra Basin, the proportion of A-ring contracted oleananes. An angiosperm-derived Miocene coal from the Philippines, deposited under freshwater conditions, shows abundant aromatic oleanoids but no oleananes. These results show that oleananes need to be used with caution as age and source markers in fluvio- deltaic and lacustrine petroleum systems. On the other hand, their sensitivity to early diagenetic conditions may make them useful in locating effective source rocks in such systems.Compounds derived from plant resins are major components of some terrigenous oils. Although recent studies have elucidated the molecular structure of resinites, very little information was available on the carbon isotope composition of resinites prior to the present study. No carbon isotope studies of resin-derived compounds in oils had been performed. Hence, carbon stable isotope analyses were carried out on a set of modern and fossil resins of diverse origins and compound specific isotope analysis was used to characterise individual hydrocarbons in resin pyrolysates and oils derived from resinitic source matter. The results showed that "Class V' resinites derived from gymnosperms are enriched in the heavy carbon isotope compared with the angiosperm-derived "Class W' resinites. Furthermore, both the fossil resinites themselves and individual hydrocarbons derived from them are isotopically heavy compared with modern plant resins. The reasons for these differences and their implications for petroleum geochemical studies are discussed.
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McEwan, Michael. "The antifungal effects of plant essential oils and their production by transformed shoot culture." Thesis, University of Strathclyde, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246327.
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Marais, Christiaan De Wet. "The determination of cis and trans fatty acid isomers in partially hydrogenated plant oils." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/2628.
Full textAbstract:
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2007.Trans isomers are formed during the partial hydrogenation process of cis unsaturated fatty acids. The major source of trans fatty acids in the normal person's diet is from margarines and shortenings made from these partially hydrogenated plant and marine oils. In addition to influencing lipid risk factors for cardiovascular disease, trans fatty acids have also been implicated in breast cancer, and in poor fetal development and reduced early infant growth. In reality, trans fatty acids have been consumed for centuries, since they occur naturally in beef, mutton, butter, milk and other dairy products. Though it has been shown that these naturally occurring trans fatty acids have different effects on the health of humans. With the implementation of the new labelling law in South Africa, the trans fatty acids content of food items must be displayed on the food label. Therefore, it becomes necessary to optimise the analytical methodology for the determination of trans fatty acids in foods. Many publications have reported on the quantification of the total concentration of trans fatty acids in food samples, while less work has been done on the identification and quantification of the different cis and trans unsaturated fatty acid isomers found in foods made from partially hydrogenated oils. The objective of this study was to standardise and optimise an analytical technique to identify and quantify the different cis and trans mono-unsaturated fatty acid isomers in local margarines and bread spreads. Seeing that fatty acids are the group of lipids most commonly analysed by GLC and the availability of highly polar capillary columns bonded with cyanoalkyl polysiloxan phases, it was decided to use GLC for the identification and quantification of the different cis and trans isomers in a selected group of margarines. It was further decided to evaluate two BPX-70 capillary columns packed with cyanoalkyl polysiloxan phases. The one a 30 m BPX-70 capillary column, normally used for routine fatty acid analyses, and the other a 120 m BPX-70 capillary column.
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Hamid, Samiyah. "Production and purification of fatty acid methyl esters from plant oils of different origin." Thesis, University of Greenwich, 2011. http://gala.gre.ac.uk/8056/.
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Biodiesel production from plant oils has been studied since ca. 1900 and is now being widely adopted as a means to reduce carbon emissions in transport applications. Its properties are similar to those of fossil diesel fuel, thus allowing its use in diesel engines both pure and in mixtures with fossil diesel fuel. Biodiesel is obtained from vegetable oils or animal fats by a transesterification reaction whereby the triglycerides, contained in the oil or fat, react with a short chain alcohol in the presence of a catalyst. The products of the reaction are fatty acid methyl esters (biodiesel) and glycerol, obtained as two separate phases. However, current reaction efficiency using a homogeneous catalyst, such as sodium hydroxide, has various drawbacks. These include non-specificity leading to saponification, difficulty in isolating the catalyst from the fatty acid methyl esters, immiscibility of the catalyst with the reactants and incomplete transesterification. The aim of the research reported in this thesis is to provide a full description of the transesterification reaction. According to previously published methodologies, the transesterification of glycerol trioleate with sodium hydroxide should provide 97-98 % (w/w) conversion to the ester. However, the results reported, herein, indicated only 95.2% (w/w) ester content. To understand the differences in the results, the concentrations of sodium hydroxide and methanol were varied by using unrefined rapeseed oil. Results showed that the optimum reaction conditions to produce higher ester content (93.3% w/w) from unrefined rapeseed oil i.e. molar ratio of methanol/oil was 6:1 and 0.015 mol of sodium hydroxide at 60 min. The same results were obtained with various plants oils of different origin under similar reaction conditions, but no increase in the ester content was observed. The data suggested that the results were in accord with biodiesel specifications i.e. EN ISO 12937 and EN 14104. However, EN 14103 standard could not be met, perhaps due to the reversible nature of the reaction, higher acid value in the oil and other competing reactions of the triglycerides. It was not possible to achieve the ester content (%) according to EN 14103 standard if any moisture or free fatty acid was present in the oil or during the reaction. The failure to meet the required EN 14103 standards by using homogeneous catalytic systems paved the way for kinetics studies of the transesterification reaction. Heterogeneous catalysts offered the opportunity to study the reaction kinetics of the system because they can be separated rapidly from the reaction mixture by centrifugation. Various heterogeneous metal oxide catalysts were investigated. Strontium oxide was confirmed to be an effective catalyst but, contrary to expectations, similar catalytic activity was not observed for the other metal oxides. The experimental results obtained, by optimising reaction conditions using a heterogeneous catalyst were found to be 3% (w/w) SrO, 6:1 CH3OH/oil molar ratio at 120 min. Therefore, subsequent reactions were planned to carry out real-time kinetic studies using SrO as a catalyst. The application of refractometry allowed real-time kinetic studies of the transesterification reaction. The ester content obtained after transesterification were determined by gas chromatography and validated the results obtained by the refractometer method. This analytical method helped to improve the reaction conditions from 120 min to 90 min using 3% (w/w) SrO and 6:1 CH3OH/oil molar ratio to achieve 92% (w/w) ester content. During kinetic studies, using a heterogeneous catalyst, solubility issues were observed between oil, methanol and fatty acid methyl esters (FAMEs). Therefore, a phase solubility diagram was plotted to identify the miscible region. The transesterification reaction was conducted in the miscible region of a ternary phase diagram to overcome the phase limitation problems. The ester content obtained was higher than 98% (w/w) within 25-30 min depending on the concentration (% v/v) ratio of the reactants used. These results were encouraging in terms of using a heterogeneous catalyst since its use is limited to lower ester content (%) and longer reaction time.
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Pandey, S. "Regioselective rhodium catalyzed isomerizing hydroformylation and iron catalyzed hydroformylation of alkenes and plant oils." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2018. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/4487.
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Reyna-Granados, Javier Rolando. "Control of Foodborne Pathogenic Bacteria Using Natural Plant Antimicrobials." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/228511.
Full textAbstract:
Foodborne pathogens are a threat to public health worldwide. Because many consumers prefer natural compounds to synthetic additives, research on safe plant-derived compounds with antimicrobial activity against foodborne pathogens is vital. The aim of this investigation was to evaluate the antimicrobial activities of plant essential oils (oregano, cinnamon, lemongrass), their active components (carvacrol, trans-cinnamaldehyde, citral) and plant-extracts such as green tea, apple skin extract, black and decaffeinated black tea, grapes seed and pomace extracts against foodborne bacteria. Salmonella enterica serotype Typhimurium DT104, and serotype Newport, were selected conducting an antibiotic screening on 23 Salmonella isolates using seven antibiotics to determine antibiotic resistance. Listeria monocytogenes (strain 101M; beef and pork sausage isolate; resistant to antimicrobials in past investigations) was included to represent gram-positive bacteria. Escherichia coli O157:H7 virulent isolates (932- apple juice isolate; ATCC 35150- human isolate; F4637- sprouts isolate; used as a cocktail) were selected after conducting a Multiplex PCR over nine E. coli O157:H7 isolates to detect shiga-toxin 1 and 2 genes. All antimicrobials were evaluated in vitro in phosphate buffered saline. In general, all pathogens were more susceptible to essential oils and their active components, than powder extracts. The most active antimicrobials from each category were directly applied on foods. The activity of oregano oil (0.5%) and green tea (3%) was evaluated against S. Typhimurium on chicken and S. Newport on tomatoes and sprouts, and the results showed that oregano oil was more effective. In addition, baby spinach leaf samples inoculated with green fluorescent protein labeled S. Newport were examined under confocal scanning laser microscope before and after antimicrobial treatments. Antimicrobial experiments against L. monocytogenes on sprouts, ham and bologna, carvacrol at 0.5% and grape seed extract at 3% were used and carvacrol showed better activity. Antimicrobial activity against E. coli O157:H7 was tested on romaine lettuce, spinach and ground beef using oregano oil at 0.5% and green tea at 3%. Both compounds were effective showing no recovery of E. coli O157:H7 from lettuce and spinach; however, was not reduced in ground beef. Antimicrobial plant compounds have the potential for reducing foodborne pathogenic bacteria on/in various foods.
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Enns, Jennifer Emily. "The role of dietary fatty acids from plant-based oils in metabolic and vascular disease." Elsevier, 2012. http://hdl.handle.net/1993/30603.
Full textAbstract:
Dietary fat has long been implicated in the etiology of metabolic and cardiovascular disease, and both the amount of fat and the fatty acid composition of the diet play a role in disease progression. Although national health organizations have set guidelines for the recommended intake of dietary fats, questions remain regarding the optimal dietary lipid profile for maintaining health and improving disease conditions. Whether certain types of fatty acids from plant-based oils can improve metabolic and vascular disease has been studied and debated, but not fully determined. In this study, we investigated the role of dietary fatty acids from plant-based oils, and examined their effects on metabolic and vascular disease parameters.
Obese fa/fa Zucker rats were fed a diet containing flaxseed oil, which resulted in smaller adipocytes and decreased adipose tissue T-cell infiltration. Obese-prone Sprague Dawley rats were fed high-fat diets with different proportions of mono- and polyunsaturated fats. Changes were observed in adipose tissue levels of fatty acid synthase, adiponectin and fatty acid receptors GPR41 and GPR43, but other metabolic and inflammatory mediators in adipose tissue and serum remained stable.
A systematic review and meta-analysis on the impact of n3 fatty acids on major cardiovascular endpoints showed that little evidence exists to support their role in peripheral arterial disease. Then again, very few studies on this topic have been conducted. To address this research gap, a clinical trial was designed to investigate the effects of a dietary intervention on blood vessel properties in people with peripheral arterial disease. Participants in the Canola-PAD Study consumed 25 g/day of canola oil or a Western diet oil mixture as part of their usual diet for 8 weeks. Although the intervention altered phospholipid fatty acids, vascular function, the lipid profile and inflammatory markers stayed relatively stable.
Overall, this research demonstrates that dietary fatty acids from plant-based oils can be immunomodulatory, but at the physiological doses tested they are not potent mediators of functional changes in obesity or vascular physiology.October 2015
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Embaby, Mohamed GalalEldeen. "EFFECTS OF UNCONVENTIONAL PLANT OILS AND RUMEN ADAPTATION ON METHANE GAS EMISSION AND RUMEN FERMENTATION CHARACTERISTICS." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2353.
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The objectives of this work were to investigate the effects of unconventional oils rich in phenolic compounds and rumen adaption on methane (CH4) gas production and rumen fermentation characteristics under in vitro rumen conditions. For this purpose, two sets of trials were conducted. In the first trial, the effects of blackberry, blueberry, raspberry, pomegranate, black seed and hemp oils on CH4 production and fermentation were examined in three 24 h batch culture experiments. Treatments in each experiment consisted of control (no oil supplement), control plus corn oil, or control plus two of the unconventional oils. Oils were added to rumen cultures at 500 mg/L (equivalent to 3.3 g oil/kg of diet dry matter (DM)). After 24 h of incubation, CH4 production was not different between the control and the corn oil treatments. Of the six unconventional oils tested, only hemp and blueberry oils reduced (P<0.05) CH4 production by 9-16% relative to the control and corn oil treatments. No significant differences were observed between treatments in dry matter digestibility (DMD) or total volatile fatty acids (tVFA). Except for a reduction (P<0.05) in acetate concentration with the raspberry oil, and an increase (P<0.05) in valerate concentration with the pomegranate oil, all other treatments had similar VFA concentrations. In the second trial, the effects of adding oregano essential oil (OEO) to adapted and unadapted rumen cultures on CH4 production and rumen fermentation were evaluated under in vitro condition. Rumen cultures were obtained from continues culture fermenters fed a control diet or control diet plus OEO at 250 mg/day for 10 days. The addition of OEO decreased (P<0.05) ii CH4 production only in adapted cultures. Total VFA and acetate concentrations were greater (P<0.05) in the unadapted than adapted cultures and their concentrations decreased (P<0.05) with the addition of OEO particularly when added to the adapted cultures. Propionate concentrations were also greater (P<0.05) in the unadapted than the adapted cultures and concentrations decreased (P<0.05) with the addition of OEO. Dry matter degradability and total gas production decreased (P<0.03) with the addition of OEO in both cultures and total gas production tended (P<0.13) to be lower when added to the adapted cultures. In conclusion, our results showed that hemp and blueberry oils were moderately effective in reducing rumen CH4 formation without compromising rumen fermentation and digestibility. Oregano Essential oil addition negatively affected rumen fermentation in both adapted and unadapted cultures and the effect was greater in the adapted cultures. The greater effects of OEO on CH4 production in the adapted cultures most likely due to the lower fermentation efficiency in these cultures.
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Hodgson, Ian. "Growth, inhibition and pathogenicity of microorganisms in enteral nutrient solutions." Thesis, Open University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287009.
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Mokhtari-Fard, Ahmad Chemistry Faculty of Science UNSW. "Method development in electrospray ionisation fourier transform ion cyclotron resonance mass spectrometry study of plant oils - macadamia oil as a model." Publisher:University of New South Wales. Chemistry, 2008. http://handle.unsw.edu.au/1959.4/43114.
Full textAbstract:
A novel analytical method is developed to examine the chemical composition of plant oils by electrospray ionisation high-resolution Fourier transform ion cyclotron resonance mass spectrometry in both positive- and negative-ion modes. To date, this is the first reported application of this technique for the study of macadamia nut oil. Samples of macadamia nut oil from the Macadamia Integrifolia- Proteaceae family (smooth shell) are examined. The fatty acid profile of the oil is obtained by this mass spectrometric examination of the transesterified and hydrolysed oil samples. The Fourier transform ion-cyclotron resonance mass spectrometry results are compared to those obtained from similar samples using gas chromatography-mass spectrometry techniques. High performance liquid chromatography and Fourier transform ion cyclotron resonance mass spectrometry are used to separate and assign the isomers present in the methanol extract of the oils in separate experiments. Significant results in this study include: - The first observation and identity of a number of oxidised triacylglycerols in macadamia oil samples. - The first observation of oxidised and free fatty acids, measured directly in hydrolysed oil and in the methanol extract of macadamia oil. - High resolution Fourier transform ion cyclotron resonance mass spectrometry in broadband mode which enables isobars to be observed. - Esterified oil Fourier transform ion cyclotron resonance mass spectrometry results are consistent with our gas chromatography-mass spectrometry results and with the results of similar studies on macadamia oil in the literature. - A number of fatty acids with odd number of carbon atoms are observed in the oil. - In electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry of oils, the sample preparation is straightforward. The sample is dissolved in methanol or acetonitrile and the solution is introduced to the electrospray source directly. Introducing oil samples to the gas chromatograph-mass spectrometer needs the oils to be esterified prior to the analysis. - In this work, state-of-the-art mass spectrometry demonstrates distinct advantages in comparison to gas chromatography measurements such as direct identification of free fatty acids in oil samples, whereas this is not possible in gas chromatography-mass spectrometry due to the required esterification step prior to the analysis. - High performance liquid chromatography fraction collection is combined with Fourier transform ion cyclotron resonance mass spectrometry in off-line mode and found to improve the sensitivity, selectivity and signal to noise levels due to the lower number of compounds in each high performance liquid chromatography fraction compared to the methanol extract of macadamia oil sample. Also isomers of monoacylglycerols have been resolved using the high performance liquid chromatography technique.
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Murray, Andrew P. "Factors controlling the abundance and carbon isotopic composition of land-plant derived compounds in crude oils." Curtin University of Technology, Centre for Petroleum and Environmental Organic Geochemistry, 1998. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=10771.
Full textAbstract:
This thesis describes a study in petroleum geochemistry and specifically of the application of Land-plant derived hydrocarbons to elucidating source matter type, depositional environment and thermal maturity of crude oils. Large volumes of petroleum have been generated from land-plant organic matter in many parts of the world, but especially in the Tertiary deltaic provinces of the USA, Canada, Africa, Southeast Asia, Australia and New Zealand. Compared to oils from other regions, these oils have a relatively complex pattern of biomarkers or molecular fossils, a feature reflecting the diversity of deltaic depositional environments and the advanced state of plant evolution during late Mesozoic and Tertiary time. The molecular and carbon isotopic composition of these oils is useful in identifying the character of their source beds and also in understanding the conditions that give rise to oil-prone sediments generally.Despite their widespread occurrence in oils and sediments, land-plant biomarkers have been used less frequently than compounds of algal origin as markers for source, depositional environment and thermal maturity. The present work sets out to extend the range of land-plant biomarker and isotope tools available to the petroleum geochemist and to provide a firmer foundation for some of the existing tools. A systematic study of the biomarker and n-alkane carbon-isotope composition of a set of late Mesozoic/Tertiary-age oils was carried out as a preamble to more focussed investigations. A comparison of the biomarker and n-alkane isotope data showed that parameters such as the oleanane/hopane ratio overestimate the higher plant contribution to marine deltaic oils. The abundance of bicadinane isomers was found to be much more variable than that of the oleananes, probably because of their close association with the highly resinous, dipterocarp hardwoods of ++Southeast Asia. However, small amounts of bicadinanes were found in an oil from outside the paleogeographic range of the dipterocarp family, indicating a more general source. Retention indices based on the regular hopane series were calculated for the main bicadinane and methyl bicadinane isomers and for a group of oleanoid triterpanes.Source rock depositional setting proved to be the primary control on the shape of the n-alkane isotope profile, with negatively sloping curves being characteristic of fluvio-deltaic and marginal lacustrine oils and flat or positively sloping curves typical of marine oils. The difference is probably related to the bacterial reworking of higher plant matter in the fluvio-deltaic environment. A slight isotopic anomaly at n-C(subscript)17 correlates with the abundance of algal-derived steranes and may indicate a minor marine contribution to the source of an fluvio-deltaic oil. A study of sediments from the South Sumatra Basin and New Zealand showed that the n-alkane isotope profile is determined mainly by source matter type and is little influenced by thermal maturity or depositional environment.Based on the results of the work described above, three aspects were chosen for further examination. These were: a) the factors controlling the carbon isotopic composition of n-alkanes and of resin-derived compounds in terrigenous oils; b) the influence of source, maturity and biodegradation on the abundance of bicadinanes, especially the effect of maturity on the isomer distribution, and c) the factors controlling the abundance of oleananes and rearranged oleananes in oils and Ancient sediments, especially the role of depositional environment.A preliminary study using sediments, from the Visayan Basin (Philippines) showed the bicadinane isomeric distribution to be sensitive to maturity. This suggested new maturity parameters which would be ++
resistant to even severe biodegradation and largely immune to interference from diagenetic effects. A more detailed study of a marine-fluvio-deltaic depositional sequence from the South Sumatra Basin confirmed that the maturity indices based on bicadinanes and aromatic analogs were less subject to non-maturity influences than those based on the steranes and aromatic hydrocarbons. The values obtained for the bicadinane indices were compared with the maturity required for oil generation as estimated by kinetic modelling and with conventional maturity indicators such as sterane epimerisation and the methyl phenanthrene index. Values for several of the indices were also measured for 17 Tertiary-age oils from Southeast Asia, Papua New Guinea, New Zealand and Australia. The main bicadinane maturity indicator (BMI-1) continues to change into the oil window and hence is useful in ranking the relative maturity of oils as well as sediments. Values of BMI-1 for two oils having unusually low sterane maturities were found to be normal and, in the light of this observation, the conventional explanation for low sterane epimerisation of many Tertiary-age oils was critically evaluated.The oleananes, as markers for the angiosperms, provide valuable source and age information when present in an oil. Nevertheless, their abundance is not quantitatively related to the land plant input and indeed their presence results from a small "leak" in diagenetic processes leading primarily to aromatic oleanoids. Evidence is presented that contact of plant matter with seawater during early diagenesis enhances the expression of oleananes in a mature sediment or oil. Oleananes are absent or present at very low concentrations in samples from the base of an Eocene coal seam affected by post-depositional seawater intrusion. However, their abundance increases toward the top of the seam in correlation with ++
% organic sulphur, dibenzothiophene/phenanthrene and the homohopane index. Similarly, in deltaic sediments from the South Sumatra Basin, oleanane/hopane is strongly correlated with indicators of marine influence such as C[subscript 27]/C[subscript 29] steranes and of oxic/anoxic conditions such as the homohopane index. In each case, increasing oleanane abundance is accompanied by a reduction in the extent of aromatisation and, for the South Sumatra Basin, the proportion of A-ring contracted oleananes. An angiosperm-derived Miocene coal from the Philippines, deposited under freshwater conditions, shows abundant aromatic oleanoids but no oleananes. These results show that oleananes need to be used with caution as age and source markers in fluvio- deltaic and lacustrine petroleum systems. On the other hand, their sensitivity to early diagenetic conditions may make them useful in locating effective source rocks in such systems.Compounds derived from plant resins are major components of some terrigenous oils. Although recent studies have elucidated the molecular structure of resinites, very little information was available on the carbon isotope composition of resinites prior to the present study. No carbon isotope studies of resin-derived compounds in oils had been performed. Hence, carbon stable isotope analyses were carried out on a set of modern and fossil resins of diverse origins and compound specific isotope analysis was used to characterise individual hydrocarbons in resin pyrolysates and oils derived from resinitic source matter. The results showed that "Class V' resinites derived from gymnosperms are enriched in the heavy carbon isotope compared with the angiosperm-derived "Class W' resinites. Furthermore, both the fossil resinites themselves and individual hydrocarbons derived from them are isotopically heavy compared with modern plant resins. The reasons for ++
these differences and their implications for petroleum geochemical studies are discussed.
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Alamene, Azawei. "Effects of plant essential oils and biocontrol agents on the growth of, and mycotoxin production by, Aspergillus spp. on groundnut." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/28731/.
Full textAbstract:
Groundnut, Arachis hypogaea (L.), can be attacked by a range of pathogens, including Aspergillus species, which can cause accumulation of the mycotoxin aflatoxin. Although some success in controlling this pathogen has been achieved with application of fungicides, their use is not always feasible in developing nations like Nigeria. The aim of this study was, therefore, to evaluate naturally-occurring plant oils and BCAs with a past history of efficacy as alternatives to fungicides for reduction of Aspergillus infection and aflatoxin accumulation in groundnut. Aspergillus strains and thirteen different plant essential oils were tested. The oils were derived from clove, camphor, vanilla, garlic, galangal, green oregano, lemon grass, neem, ginger, basil, tea tree, thyme and onion. The biocontrol agents used were fungi Trichoderma harzianum strain T-22, T. asperellum and T. viride from a commercial biocontrol product, TUSAL, and bacteria Pseudomonas chlororaphis ssp. aureofaciens and Bacillus amyloliquefaciens (strains MBI600, 62P, and 66P). The identities of a strain of A. niger, isolated from Nigerian groundnut samples, and of T. asperellum and T. viride were confirmed by PCR amplification of DNA and sequence comparison to reference isolates in the GenBank database. Some of the plant oils (clove, camphor and vanilla) and biocontrol agents (Trichoderma strains) tested proved effective in inhibiting the A. flavus and A. niger strains used in the research, in both in vitro and in planta experiments. Improved seedling emergence in pathogen-contaminated compost and reduced post-harvest pod infection were observed. Combinations of the most active BCAs and EOs also provided disease suppression. ELISA analysis of aflatoxin B1 in treated, A. flavus-inoculated groundnut pods showed a reduction in toxin concentrations, to a level below that recommended by the European Commission of 15 ppb. Of the control agents tested, the most effective were T. harzianum T-22 as a BCA and probably clove oil as a plant extract. Commercial products based on Trichoderma are used world-wide. EOs, have, to date, had little use in control of Aspergillus infection of groundnut. It was also demonstrated that detection of asymptomatic A. flavus pod infection could be achieved by the traditional method of surface sterilisation and plating out, and by use of a LAMP assay to detect pathogen DNA. The latter could provide a rapid, portable method for A. flavus detection in harvested groundnut pods and could have application in both developed and developing nations. Since low resource growers in nations like Nigeria need alternative, low-cost methods for protecting groundnut from Aspergillus infection, to produce a nutritionally-valuable, high protein foodstuff low in toxin contamination, such alternative methods of disease control may have a future role to play in global food security. It may prove possible to extract antifungal components from appropriate, locally-sourced plant material in a cost-effective manner. However, whether the level of disease control and suppression of aflatoxin accumulation reported here was adequate for possible commercial application is unclear. Further evaluation, including field experiments, is required.
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Witt, Timo [Verfasser]. "Unsymmetric, Macrocyclic, and Ultra Long-Chain α,ω-Difunctional Building Blocks from Plant Oils / Timo Witt." Konstanz : KOPS Universität Konstanz, 2017. http://d-nb.info/1190565390/34.
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Butler, G. D. Jr, T. J. Henneberry, D. L. Coudriet, and M. Broza. "Greenhouse and Field Studies with Plant-Derived Oils for Control of the Sweet Potato Whitefly on Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/204506.
Full textAbstract:
Plant derived oils (cottonseed and soybean) in greenhouse and field studies were promising for sweet potato whitefly, Bemisia tabaci (Gennadius) control. Cotton seedlings treated with oil in the greenhouse repelled whiteflies up to 7 days and high mortality of treated larvae, pupae and adults occurred. In the field, application of crude cottonseed oil to cotton with high air-blast, ground spray equipment suppressed whitefly populations thoughout the season.
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Anthony, Jean-Paul. "The inhibitory properties, and mode of action, of plant essential oils and fruit extracts on protozoan parasites." Thesis, Queen Margaret University, 2008. https://eresearch.qmu.ac.uk/handle/20.500.12289/7382.
Full textAbstract:
The main aims and objectives of this study was to determine if plant essential oils (PEOs) and polyphenol-rich fruit extracts (PRFEs) could reduce the viability of Giardia duodenalis trophozoites, Trypanosoma cruzi epimastigotes and Cryptospordium parvum oocysts in vitro. All PEOs tested reduced epimastigote and trophozoite viability at a concentration of 0.02% v/v, with titrations of the PEOs showing a concentration dependant decrease in viability. The minimum inhibitory concentrations (MICs) of PEOs demonstrated that myrtle and elemi oil were the most active PEOs (trophozoites = 0.005% v/v; epimastigotes = 0.00125% v/v) with the terpenes, α-pinene and limonene, constituents of these oils, being responsible for their action. Incubation of palmarosa oil and its terpene, geraniol, with C. parvum oocysts caused the almost complete excystation of oocysts (in the presence of increased temperature and time), with geranium oil and its terpene, citronellol, being nearly as effective. PRFEs reduce trophozoite viability, with 4 members of the Rosaceae Family causing complete reduction at 167 μg ml-1, possibly through their ellagitannin content. Cloudberry extract was found to have an MIC comparable to the drug metronidazole (67 μg ml-1). The historical use of blueberries for the treatment of diarrhoeal diseases was demonstrated by the ability of blueberry PRFE, pressed juice and drink to kill trophozoites. Protein expression was both inhibited and upregulated in several proteins in whole cell lysates of PEO treated trophozoites, indicating a supplemental intracellular mode of action. Both PEOs and PRFEs cause morphological changes to epimastigotes and trophozoites through flagellar truncation and internalisation, swelling and rounding of the cell body, cytoplasmic condensation and the formation of large membrane protrusions. These indicate an action on the membrane itself with possible changes in osmoregulation. Both PEOs and PRFEs can be considered to be candidates for novel drug discovery for the treatments of cryptosporidiosis, giardiasis and American trypanosomiasis.
36
Miller, Andrew B. "Antimicrobial and Anticancer Activity of Essential Oils from Guatemalan Medicinal Plants." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2411.
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Guatemalan medicinal plants were collected and screened for the presence of essential oils using steam distillation. Oil was found in 63 species from 24 families and was tested in tube dilution assays for activity against Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Lactobacillus acidophilus and Candida albicans. Several essential oils were highly active with 20 instances of oils inhibiting the microbes at an MIC of 0.31 µl/ml. Oils were also tested against cancerous and established cell lines using a 15% (v/v) agar-media which was developed to improve essential oil solubility. Assays were performed against three cancer lines: Stomach (AGS: CRL-1739), Skin (A375: CRL-1619), Tongue (CAL27: CRL-2095) and an established Monkey Kidney cell line (Vero C 1008: CRL-1586). Assessment of viability was performed using the Neutral Red assay with results indicating that many of the oils significantly inhibited cancer cell lines in vitro with 24 individual instances producing an IC50 of 0.20 µl/ml or less. Therapeutic indices indicated that many of the highly inhibitory oils were more cytotoxic to cancerous cell lines than to the established cell line.
37
Azadmard-Damirchi, Sodeif. "Olive oil : phytosterols, tracing of adulteration with hazelnut oil and chemical interesterification /." Uppsala : Dept. of Food Science, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200736.pdf.
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Motsa, Nozipho M. "Essential oil yield and composition of rose-scented geranium (Pelargonium sp.) as influenced by harvesting frequency and plant shoot age." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08272007-180003.
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Machial, Cristina Maria. "Efficacy of plant essential oils and detoxification mechanisms in Choristoneura rosaceana, Trichoplusia ni, Dysaphis plantaginea and Myzus persicae." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/27244.
Full textAbstract:
The obliquebanded leafroller, Choristoneura rosaceana, and the rosy apple aphid, Dysaphis plantaginea are serious pests in apple orchards throughout North America, while the green peach aphid, Myzus persicae and the cabbage looper, Trichoplusia ni are serious pests in vegetable greenhouses. In an effort to reduce the impact of these pests on their respective crops, growers typically resort to multiple insecticide applications per year for the control of each pest. However, concerns regarding the risk of such pesticides to human and environmental health have led to renewed calls for the development of reduced risk pesticides.
In the following, 17 essential oils were screened against each pest species to identify those which could be used to develop novel essential oil-based insecticides and the most toxic of these were further evaluated to determine their LC50 and LD50 values. Patchouli oil was found to be among the most toxic to all four species. Thyme oil was also toxic to both C. rosaceana larvae and D. plantaginea adults, while citronella oil demonstrated high toxicity to D. plantaginea. Garlic and lemongrass oils were also identified as potential candidates for T. ni control and lavender oil was identified as the second most toxic essential oil to M. persicae.
Through this work, it was noted that there appeared to be a role for detoxification enzymes in detoxifying these essential oils. Accordingly, the detoxicative abilities of each insect and the potential role of patchouli oil in inducing these enzymes were assessed. Esterase activity was highest in M. persicae while glutathione S-transferase activity followed the order of M. persicae > D. plantaginea > C. rosaceana > T. ni. Cytochrome P450 activity was only detected in some samples, and consequently, results were less conclusive. The potential for incorporating these essential oils into an essential oil-based insecticide is discussed.
40
Motsa, Nozipho Mgcibelo. "Essential oil yield and composition of rose-scented geranium (Pelargonium sp.) as influenced by harvesting frequency and plant shoot age." Diss., University of Pretoria, 2007. http://hdl.handle.net/2263/27584.
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Eiasu, Bahlebi Kibreab. "Influence of soil water management on plant growth, essential oil yield and oil composition of rose-scented geranium (Pelargonium spp.)." Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-10172009-100336/.
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Saithai, Pimchanok. "Synthesis and characterization of bio-based copolymers from soybean oil and methyl methacrylate." Thesis, Montpellier, SupAgro, 2013. http://www.theses.fr/2013NSAM0008.
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L'objectif de ce travail était d'étudier l'impact du mode de préparation et de la formulation de bioplastiques transparents issus d'huile de soja sur leur structure et leurs propriétés thermiques et mécaniques. Nous nous sommes plus particulièrement intéressés à l'huile de soja époxydée (ESO), qui a ensuite été acrylée et co-polymérisée avec méthacrylate de méthyle (MMA) en présence ou non de nano-particules de dioxyde de titane. Deux méthodes de préparation d'ESO ont été comparées. La première a fait appel à une époxydation chimique en présence de peroxyde d'hydrogène et d'acide formique. L'acide sulfurique a été utilisé comme catalyseur pour la production de peracides, ces oxydants forts générant ensuite des époxydes par attaque des doubles liaisons des acides gras de l'huile. La seconde consistait en une époxydation chimio-enzymatique, les peracides étant alors générés dans des conditions douces de pH et de température par catalyse enzymatique en présence d'H2O2 et d'huile. Deux types de lipases ont été utilisées comme biocatalyseurs : la lipase de Candida antarctica (Novozyme 435) et la lipase/acyltransférase de C. parapsilosis. Un contrôle de la réaction a permis d'obtenir des produits à différents degrés d'époxydation (50 et 75 3 %). Les effets du mode d'époxydation, du degré d'acrylation et des teneurs en MMA et TiO2 sur les propriétés des bioplastiques obtenus ont été étudiés par FTIR, RMN 1D et 2D, DMTA, TGA et par mesure des propriétés mécaniques.Mots-clés : Biocomposite, Bioplatique, Nanocomposite, Huile de soja époxydée et acrylée (AESO), Dioxyde de titane (TiO2), Biocatalyse, LipaseThe aim of this research to study the effect the production method and the formulation of transparent soybean oil-based bioplastics on their structure and their thermal and mechanical properties. We focused on epoxidized soybean oil (ESO), that was acrylated and copolymerized methyl methacrylate (MMA) with and without titanium dioxide (TiO2). Two methods of ESO preparation were compared. The first used chemical epoxidation in the presence of H2O2 and formic acid, using sulfuric acid as a catalyst to produce peracids as strong oxydants for the epoxidation. The second one was a chemo-enzymatic method where the peracids were generated in mild conditions by an enzyme in the presence of H2O2. Two types of lipases were selected as biocatalysts for the chemo-enzymatic epoxidation: Novozyme®435 and a non-commercial lipase/acyltransferase (CpLIP2). The reaction was controlled so as to obtain different degrees of epoxidation (DOE), i.e. 50+/-3 mol% and 75+/-3 mol%, from both methods. Acrylated ESO (AESO) was chemically synthesized by acrylation of ESO and acrylic acid. Then AESO was copolymerized with MMA and cured to form a rigid polymer using 1 wt% of benzoyl peroxide as a free radical initiator. A nanocomposite was prepared by blending AESO-co-PMMA with 0.1-0.2 wt% nano-TiO2 (particle size 2-5 nm). The effect of degree of acrylation, MMA content and titanium dioxide content on structural, tensile and thermal properties of the obtained bioplastics were studied using Fourier transform infrared spectrometer (FTIR), 1D and 2D NMR, dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA) and mechanical properties determination
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ELOH, KODJO. "Exploration of New Oxidative Stress Nematicidal Compounds and Valorization of Satureja montana L. Essential Oils and Hydrolates as Plant Biopesticides." Doctoral thesis, Università degli Studi di Cagliari, 2019. http://hdl.handle.net/11584/260403.
Full textAbstract:
Plant diseases cause economic challenges because they are responsible for estimated pre- and
postharvest losses of 16–28% of crops yearly. Control is aimed at the use of chemical
protectants, which reduce or retard the growth of the pathogen population. Another option is
the use of resistant varieties, which reduce the pest population or increase recovery from injury
caused by the enemies. However, resistant varieties become susceptible after few years of
cultivation due to pathogen adaptation and evolution to cultivated varieties.
Research of new environmentally benign products active against pests and diseases are
required that control target organisms without harming the environment. In this thesis, I
evaluated for the first time the nematicidal activity of new synthesized maleimide derivatives
by structure-activity relationship (SAR), some selected haloacetophenones and transition metal
ions. I also developed a new method to assess the metabolome alteration induced by these
products on nematodes. Finally, I valorized a carvacrol chemotype domesticated plant of S.
montana by evaluating its activity on insects, Spodoptera littoralis, Myzus persicae and
Rhopalosiphum padi; and on the root-knot nematode Meloidogyne javanica.
The maleimide derivatives were easily synthesized in a one pot reaction; haloacetophenones
were commercially available and metal ions present as sulphate or nitrate salts. The tested
compounds showed strong nematicidal activity against Meloidogyne incognita, X. index and
G. pallida with EC50 values lower than 5 mg/L. I also found a synergism action between
maleimide and copper ion on one hand and between copper ions and tannins on the other hand.
A GC-MS metabolomics analysis showed that these compounds might induce oxidative stress
in nematodes by modifying the levels of fatty acids and acylglycerols. After a field experiment
and phytotoxicity assays, these first reported nematicidal compounds could be used in crop protection against nematodes.
S. montana essential oil (EO) chemical composition was influenced by the fertilizers applied
and the EO extraction method. Hence, the conventional agriculture plants showed a lower level
of p-cymene with a higher level of carvacrol while more than 20 compounds showed
significantly difference levels according to the method of extraction, laboratory or semiindustrial. The EOs and the organic phase of hydrolates with LC50 values of 20-65 µg/cm2
modified the feeding behavior of Spodoptera. littoralis. S. montana EOs repel Rhopalosiphon.
padi and Myzus. persicae with settlement inhibition LC50 values estimated at 25-60 µg/cm2.
The plant also inhibited the germination and growth of Lolium perenne at 10 mg/mL.
Furthermore, ethanol extracts of S. montana did not show any activity on the pests. However,
we successfully valorized the EO by product hydrolates on the insects and nematode.
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Amajuoyi, Ifeanyi Kingsley. "Behavior and elimination of pesticide residues during supercritical carbon dioxide extraction of essential oils of spice plants and analysis of pesticides in high-lipid-content plant extracts." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963029177.
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Duru, Betul. "Isolation Of A Bioactive Compound Hypericin From A Medicinal Plant Hyppericum Perforatum L. Using Basic Chromatography Methods." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/12604846/index.pdf.
Full textAbstract:
Medicinal plants which have been widely used in folk medicine are known to contain important biologically active compounds. Most of today&rsquos synthetic drug raw materials are to be prepared by using plant originated compounds as the starting material. Hypericum Perforatum is one of the medicinal plants that grows in Europe, Western Asia and Northern Africa and is distinguished by its golden yellow flowers. The common name of the plant is St. John&rsquo
s wort. From the time of the ancient Greeks down through the middle Ages, the plant was considered to be imbued with magical powers and was used to ward off evil and protect against disease. As a practical folk-remedy, it has been used widely to heal wounds, remedy kidney troubles, and alleviate nervous disorders, even insanity. In the last thirty years, Hypericum perforatum has undergone extensive clinical and laboratory testing. The extract of the flower is a red liquid that contains many biologically active compounds such as: naphtodianthrones (hypericin, pseudohypericin), phloroglucinols (hyperforin, adhyperforin), flavonoids (quercetin, hyperoside, quercitrin, isoquercitrin, rutin, campferol, myricetin, amentofloavone), procyanidins (procyanidin, catechin, epicatechin polymers) , tannins (tannic acid), essential oils (terpenes, alcohols), amino acids (GABA, Cysteine, glutamine, leucine, lysine, ornithine, praline, threonine), phenyl propanes (caffeic acid, chlorogenic acid), xanthones (keilcorin, norathriol), organic acids peptides and polysaccharides (other water soluble compounds). These compounds have previously been isolated using HPLC method. The aim of this study is to isolate the main biologically active compound groups of Hypericum Perforatum and simply characterize the compounds with TLC, UV-VIS spectroscopy, NMR spectroscopy using standard compounds as references.
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Schröder, Markus [Verfasser]. "GC/MS analysis of phytanic acid in milk as well as the unsaponifiable matter of plant oils after HSCCC fractionation / Markus Schröder." München : Verlag Dr. Hut, 2013. http://d-nb.info/1033041351/34.
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Lanzrath, Russell. "Antimicrobial effects of multifunctional ingredients with potential application for ready to eat meat and poultry products." Kansas State University, 2016. http://hdl.handle.net/2097/32884.
Full textAbstract:
Master of ScienceFood Science Institute
Elizabeth Boyle
Consumer demand for clean-label and 'all natural' food products has created the need to investigate antimicrobials derived from natural sources. Multifunctional ingredients are food additives that have multiple properties to reduce fat, limit salt, retard oxidation, increase water-holding capacity and inhibit bacterial growth in foods. Multifunctional ingredients that exhibit antimicrobial effects in meat and poultry products can facilitate consumers demand for clean and 'all natural' labels while reducing foodborne illness risk. Previous scientific research has shown that plant essential oils are known to contain active components to prevent oxidation in meat products, but emerging data have shown that these plant-based ingredients also contain antimicrobial properties. Plant essential oils such as basil oil has shown limited Salmonella Enteritidis inhibition in meat model systems and thyme oil has shown Listeria monocytogenes inhibition in low fat beef hotdogs. Intrinsic and extrinsic parameters of meat systems can alter the antimicrobial efficacy of plant essential oils. Although antimicrobial effects were observed with plant essential oils, effective usage levels may be limited to sensory characteristics in certain meat and poultry products. Natural extracts have shown potential antimicrobial properties in meat and poultry applications. Rosemary extract has been shown to suppress the growth of Enterobacteriaceae, Pseudomonas, and yeast and molds in fresh sausage. Grapefruit seed extract has shown inhibition against Campylobacter jejuni in poultry skin and meat models and E. coli O157:H7 in moisture enhanced beef homogenate models. The addition green tea extract in ground beef has been shown to reduce D-values while cooking and inhibit outgrowth of C. perfringens spores during extended chilling of cooked ground beef. Grape seed extract has been shown to reduce Listeria monocytogenes, E. coli O157:H7 and Salmonella Typhimurium populations in cooked lean ground beef stored for 9 days at 4°C. Scientific research findings for plant essential oils and extracts confirm that multifunctional ingredients are relevant to meat and poultry products as potential food additives to control undesirable pathogen and spoilage bacteria while meeting consumer demand for natural, clean-label ingredients.
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Smith, Zena Elizabeth Florence. "Characterisation of A-ring contracted triterpenoids in oils and shales : evidence for an alternative transformation pathway in the diagenesis of higher plant triterpenoids." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294960.
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Perignon, Marlène. "Compréhension et maîtrise de l'interestérification enzymatique d'huiles végétales sur les plans nutritionnel et technologique." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20136.
Full textAbstract:
La nutrition constitue l'un des facteurs déterminants du développement ou de la prévention de diverses pathologies. Parmi les trois classes de nutriments majeurs, les lipides alimentaires occupent une place essentielle dans cette relation nutrition-santé puisque leur déséquilibre qualitatif est impliqué dans l'incidence des maladies cardiovasculaires. L'importance de l'équilibre alimentaire justifie le développement de produits fonctionnels au profil nutritionnel amélioré. En parallèle, suite à la prise de conscience de l'impact environnemental de la production alimentaire, il est aujourd'hui important d'inscrire le choix des matières premières et des procédés dans une démarche de développement durable.Dans ce contexte, les travaux menés durant cette thèse concernent tout d'abord l'amélioration des propriétés nutritionnelles d'une matière grasse végétale tartinable par réduction de sa teneur en acides gras (AG) saturés délétères, mais également la limitation de son impact environnemental par réduction des ingrédients issus de la filière palme. La mise au point d'un procédé d'interestérification enzymatique vise à ajuster les propriétés rhéologiques du produit sans modifier le profil global en AG, et sans utiliser de solvants ou produits chimiques grâce à l'action d'un biocatalyseur (lipase). Ces travaux ont conduit au développement jusqu'au stade pilote d'un substitut interestérifié par voie enzymatique permettant de réduire la teneur en AG saturés délétères de 65% et l'utilisation de dérivés d'huile de palme de 70% tout en maintenant une fonctionnalité similaire au produit actuel. En parallèle, un procédé enzymatique à également été exploité dans l'étude d'une nouvelle méthode d'analyse de la régiodistribution : l'évaluation des sélectivités de la lipase de Rhizopus oryzae a montré son potentiel pour l'analyse de la position sn-2 des triacylglycérols contenant des AG à chaines moyennesNutrition is one of the main factors contributing to various diseases occurrence or prevention. Among the three major types of nutrients, dietary lipids are essential in this nutrition-health relationship since lipid disorder is associated with an increased risk of cardiovascular diseases. Thus, the importance of a healthy diet explains the development of functional foods with improved nutritional properties. Furthermore, with environmental impact of food production being a growing concern for consumers, selection of raw materials and processes should meet the requirements for sustainable development. In this context, this work concerns the improvement of the nutritional properties of a vegetable oil spread by reducing its unhealthy fatty acids (FA) content, but also the limitation of its environmental impact by minimizing the use of palm oil products. An enzymatic interesterification process has been developed to adapt rheological properties without modifying FA profile nor using solvents and chemical products by action of a biocatalyst (lipase). This work led to the pilot-scale development of an enzymatically interesterified substitute allowing to reduce the unhealthy FA content by 65%, and the use of palm oil products by 70% while keeping a functionality similar to the current product.At the same time, an enzymatic approach has also been used in the investigation of a new method for regiodistribution analysis. Thus, Rhizopus oryzae lipase appeared to be a good candidate for the sn-2 position analysis of triacylglycerols containing medium chain fatty acids
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Neto, José Alipio Faleiro. "Impacto de óleos essenciais de plantas brasileiras sobre parâmetros de fermentação ruminal, digestibilidade e balanço de nitrogênio em ovinos." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/10/10135/tde-14092015-105231/.
Full textAbstract:
Foram desenvolvidos cinco experimentos com o objetivo de avaliar o efeito do fornecimento de óleos essenciais sobre a fermentação ruminal e a digestibilidade dos nutrientes em borregos. No experimento I, avaliou-se um produto comercial tendo como princípio ativo óleo essencial de pimenta (Activo®), os tratamentos experimentais foram: controle negativo ração base (30% de volumoso e 70% de concentrado, % da MS); controle positivo - ração base adicionada com 25 mg de monensina sódica por kg de matéria natural e ração base adicionada com 100, 200 ou 300 ppm de Activo® (%MS). Nos quatro experimentos restantes, além dos tratamentos controle negativo e controle positivo descritos para o primeiro experimento, avaliou-se também a inclusão na dieta de 1,09; 2,18 ou 3,27 mL/kg de matéria seca (MS) de óleo essencial extraído do capim cidreira, Cymbopogon citratus (Experimento II); Óleo essencial extraído do fruto da aroeira-vermelha, Schinus terebinthifolius (Experimento III); Óleo essencial extraído do capim limão, Cymbopogon flexuosus (Experimento IV) ou óleo essencial extraído das folhas da aroeira vermelha; Schinus terebinthifolius (Experimento V). No experimento I, não houve efeito dos tratamentos sobre a concentração ruminal de ácidos graxos de cadeia curta (AGCC). No entanto, quando comparados ao controle positivo, o fornecimento de Activo® (%MS) aumentou o consumo de MS e reduziu a digestibilidade dos nutrientes. No experimento II, não houve efeito dos tratamentos sobre as características de fermentação ruminal, contudo, a digestibilidade da PB foi maior nas dietas contendo monensina sódica ou óleo essencial de capim cidreira em comparação ao tratamento controle. Nos experimentos III, IV e V, não observou-se efeito dos tratamentos sobre nenhuma das variáveis estudadas. Desta forma, os resultados mais promissores foram observados para o experimento com capim cidreira, devido ao benéfico observado sobre a digestibilidade da proteína bruta.Five experiments were developed in order to evaluate the effect of providing essential oils on ruminal fermentation and nutrient digestibility in lambs. In the first experiment (Experiment I) it was evaluated a commercial product having as active principle pepper essential oil (Activo®), the experimental treatments were: negative control - basal diet (30% roughage and 70% concentrate,% DM); positive control - basal diet plus 25 mg monensin per kg of natural matter (NM) and basal diet plus 100, 200 or 300 ppm Activo® (% DM). The remaining four experiments, besides of the treatments negative and positive control described in the first experiment, were also evaluated the inclusion in the diet 1.09; 2.18 or 3.27 mL/kg dry matter of essential oil extracted from West Indian lemongrass, Cymbopogon citratus (Experiment II); Essential oil extracted from the fruit of the Brazilian peppertree; Schinus terebinthifolius (Experiment III); essential oil extracted from Lemon grass; Cymbopogon flexuosus (Experiment IV) or essential oil extracted from the leaves of the Brazilian peppertree; Schinus terebinthifolius (Experiment V). In the first experiment, there was no effect of treatments on ruminal concentration of short-chain fatty acids (SCFA). However, when compared to the positive control, the supply of Activo® increased dry matter intake (DMI) and reduced nutrient digestibility. In the second experiment, there was no effect of treatments on ruminal fermentation characteristics, however, the digestibility of CP was higher in diets containing monensin or essential oil of lemon grass compared to the control treatment. In the experiments III, IV and V, there was no effect of treatments on any of the variables studied. Thereby, the most promising results were observed for the experiment with essential oil of lemon grass, because of the beneficial on the digestibility of crude protein.