Dissertationen zum Thema „Anthocyanes et activité antioxydante“
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Fargeix, Guillaume. „Étude des mécanismes d'oxydation de flavonoïdes en relation avec leur activité antioxydante : effets anti- et pro-oxydants dans l'inhibition de la peroxydation lipidique par les flavonoïdes“. Lyon 1, 2000. http://www.theses.fr/2000LYO10281.
Der volle Inhalt der QuelleM'be, Cho. „Procédés de production et influence des propriétés fonctionnelles des poudres de calices d’Hibiscus sabdariffa et de leurs fractions sur la formulation de boisson“. Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0274.
Der volle Inhalt der QuelleHibiscus sabdariffa (hibiscus) is a plant with edible calyxes containing polyphenol and anthocyanin molecules that are both antioxidant compounds and responsible for their attractive red color for consumers. These particularities constitute a good health potential that meets the current market demands, and an economic potential for industries. However, this tropical and seasonal plant whose water-rich calyxes are highly perishable, sensitive to humidity and heat, and whose the interesting molecules (anthocyanins) are heat-sensitive and unstable in aqueous medium. In this context, the calyx transformation into powder allows, besides optimizing the transport cost and storage space, to stabilize the calyxes by ensuring a long product shelf-life, and to improve the biomolecule accessibility. This allows to benefit to its health assets provided that the process is controlled. One of the best ways to preserve the calyx original nutritional properties (anthocyanin content, antioxidant activity) is to obtain minimally processed products by combining controlled oven-drying, grinding and fractionation by sieving. This process was studied in this work and the powder physicochemical properties (particle size and shape, structure, porosity, fiber proportion, anthocyanin content, antioxidant activity) and functional properties (flowability, reconstitution, biomolecule extractability) were systematically evaluated for drink formulation. The interest of such a process is the ease of its implementation applicable to all plants, the powder ease of use, the improvement of the biomolecule availability and accessibility. This work allows identifying the impact of sun-drying and grinding on the powder physicochemical properties, the latter impacting the functional properties. The substitution of sun-drying by controlled oven-drying and an additional fractionation by sieving preceded by grinding allowed improving the powder functional properties. These powder functional properties were singular and allowed to distinguish specific applications for each powder type (fine or coarse powders)
Garaudée, Sandrine. „Polyphénols : propriétés de complexation et activité antioxydante“. Université Louis Pasteur (Strasbourg) (1971-2008), 2004. http://www.theses.fr/2004STR13005.
Der volle Inhalt der QuelleThis phd manuscript presents an original and highly collaborative research work on norbadione a, a fungal pigment which was isolated from pisolithus arhizus. This study was undertaken in order to gain insight into complexation, exchange and accumulation of radionuclides (137cs) or heavy metals (cd(ii), ni(ii), pb(ii)). This subject required interdisciplinary expertise (mycology, natural products extraction and characterisation, organic traces analysis, physicochemistry) and was using the most recent developments of analytical methods (spectrophotometry, nmr, mass spectrometry, potentiometry, cyclic voltammetry). Our results were published in chemical communications, highlighted in nature and emphasised in different press articles (l'express, the guardian,. . . ). Our results revealed that in the p[h] range (between 6. 0 and 6. 5) which is typical for mushrooms, the major species of free norbadione a is the dienolate form. We showed that norbadione a was able to accumulate monovalent cations (cs+, k+, tl(i)) due to allosteric properties which favors the formation of bimetallic complexes. On the other hand, norbadione a forms mononuclear complexes with heavy metals like cd(ii), ni(ii) and pb(ii), the corresponding dinuclear analogs being less stable for electrostatic reasons. The natural dipotassic norbadione a complex exchanges its potassium cations with caesium or thallium(i), as shown by electrospray mass spectrometry. Finally, we determined for norbadione a an antiradicalar power comparable with that of the most abundant polyphenols present in fruits and vegetables and a moderate antioxidant activity
Marteau, Clémentine. „Activité antioxydante des phénols : mécanismes, cinétiques, effets de solvants et synergies“. Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10046.
Der volle Inhalt der QuellePerfumes are composed of molecules which are prone to autoxidation in the presence of oxygen. This oxidative degradation can lead to the loss of olfactory properties, the appearence of off-odours or colors and the formation of irritant or allergenic substances. The antioxidants addition is necessary to stabilize formulas. However, consumers distrust the synthetic antioxidants such as BHA or BHT which are or will be banned by future European directives. New alternatives must be found either by identifying the most efficient and the most harmless natural antioxidants, or by taking benefits from the synergies between antioxidants and other ingredients in the formula which are often observed but rarely understood. In this context, the three aims of this work were: to establish mechanisms of antioxidant action, alone or in mixture, to indentify the matrix effects on their efficiency and to rationalize synergies. The target molecule was a fragrant aldehyde (decanal) known to be very sensitive to oxygen and difficult to stabilize. Concerning antioxidants, the choice fell on phenols (synthetic, natural or "fragrant") which inhibit the free radical chain oxidation by transferring a H• to oxygen radical intermediates
Jourdes, Michaël. „Réactivité, synthèse, couleur et activité biologique d'ellagitannins C-glycosidiques et flavano-ellagitannins“. Bordeaux 1, 2003. http://www.theses.fr/2003BOR12721.
Der volle Inhalt der QuelleGreat red wines are generally aged in oak barrels for a period from 6 to 18 months, which contributes to improve their organoleptic quality. During this contact with wood in the barrel the wine solution extracts many substances including some C-glucosidic ellagitannins. During this work, we focused on the evolution of C-glucosidic ellagitannins in acidic medium leading to the formation of various products from nucleophilic substitution reactions with vescalagine and various nucleophilic species present in wine. The hemisynthesis of flavano-ellagitannins (acutissimins and epiacutissimins) was achieved via a nucleophilic substitution reaction between vescalagin and catechin and epicatechin in an acidic medium. Their identification and quantification in a red wine aged in oak barrel were carried out by HPLC-ESI-MS. The remarkable stereospecificity of these substitution reactions was examined by molecular modelling of the benzylic cation intermediate. The hemisynthesis of the first member of a new class of compounds called anthocyano-ellagitannins was achieved via a nucleophilic substitution reaction between vescalagin and malvidin. This new complex shows a bathochromic shift of about 15 nm compared to the maximum wavelength of the initial anthocyanin
Adje, Félix Anoh. „Production par procédés membranaires couplés d'extraits polyphénoliques de Carapa procera, Delonix regia et Hibiscus sabdariffa. Détermination des structures moléculaires et des activités antioxydantes“. Aix-Marseille 3, 2009. http://www.theses.fr/2009AIX30054.
Der volle Inhalt der QuelleThe extraction of the polyphenols of Carapa procera leaves, of Delonix regia flowers and of Hibiscus sabdariffa calyx was optimized at laboratory scale to obtain a red extracts rich in antioxidants. Anthocyanins, flavonols and phenolic acids of these 3 endemic plants from Ivory Coast were characterized by LC-MS and NMR for the first time in the 2 first plants and confirmed in the third. Water maceration, 12-16h time, of locally dried samples, 1hour time ultrasound-assisted maceration, microfiltration and concentration of the extracts at pilot plant scale allowed the production of 250L of microfiltrate/plant processed with average MFT flows of 100 to 200 L. H-1. M-2. B-1 at 0,6 bar, the volume concentration of the microfiltrates of 100 to 120 times with 16 and 20 L. H -1. M -2 fluxes at 40 bar and at 20°C and to produce powders by atomization, with a 5 to 10 % yield, of polyphenolic extracts (30 in 160 [micro]mol. L-1 AG eq), of which the antioxidant capacity was determined by DPPH and ABTS (from 8 to 30 mmol. L-1 AG eq for RO concentrates and from 220 to 500 mmol. G-1 TEAC for powders)
Muanda, François Nsemi. „Identification de polyphénols, évaluation de leur activité antioxydante et étude de leurs propriétés biologiques“. Thesis, Metz, 2010. http://www.theses.fr/2010METZ011S/document.
Der volle Inhalt der QuelleNatural substances from biomass plant have taken advantage of multiple interests in the biotechnology industries both in food, cosmetic and pharmaceutical. Between these compounds are found much of secondary metabolites which are mainly illustrated in therapeutics. Traditional medicines has used for long time plant materials for healing without knowing what had caused their actions, then studies of secondary metabolites are the subject of numerous studies based on in vitro and in vivo cultures of plant tissues. These include phenolic compounds, polyphenols, flavonoids, anthocyanins, tannins ... which are the subject of our study, compounds widely used in therapeutics as vasculoprotective, anti-inflammatory, enzyme inhibitors, antioxidant and anti free radical. Our work has brought the excerpts from six plants (Daniella oliveri, Desmodium adscendens, Ficus capensis, Securidaca longependuculata, Stevia rebaudiana, and Vitex doniana) traditionally used to treat many diseases in various parts of the world (America, Africa, Asia). The methodology developed for the analysis of these extracts has been applied for the determination of root exudates of Miscanthus x giganteus. The combination of some methods of chemical analysis, spectrophotometry (UV, NMR, MS), chromatography (TLC, CC, HPLC, GC-MS) and biology allowed us to evaluate quantitative and qualitative phenolic extracts from these plants materials. Further analysis helped to highlight the antioxidant capacity and anti-radical of these extracts. While biology tests were used for the evaluation of certain properties such as antimicrobial and anti inflammatory. The results of this work have allowed us to conclude that all plant extracts studied has very good antioxidant properties that may allow us to recommend them in biotechnology
Cerrati, Claude. „Composition lipidique foliaire de plantes de la région méditerranéenne. Caractérisation par couplage CG/SM et activité antioxydante“. Aix-Marseille 3, 1993. http://www.theses.fr/1993AIX30072.
Der volle Inhalt der QuelleBenbouguerra, Nawel. „Évolutions structurales et propriétés biologiques des polyphénols au cours de la maturation des baies de vitis vinifera“. Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTG041.
Der volle Inhalt der QuellePolyphenols belong to the family of secondary metabolites found in plants and mainly in grape berries. They play an important role in the protection of the plant against biotic and abiotic stresses. They have an impact on the organoleptic quality of certain foods such as those from grapes and are mainly known for their beneficial roles for human health. A global study on the phenolic composition and the biological activities (antioxidant, anti-inflammatory and anti-diabetes) of the phenolic extracts of the seeds and skins of three red grape varieties Merlot, Tannat and Syrah at different stages of maturation was carried out during this thesis. Seed extracts contain a higher content of phenolic compounds than skin extracts for all stages of ripening. The phenolic composition differs depending on the stage of maturity and the tissue of the grape berry (seed or skin). The antioxidant activity of the extracts was determined by spectrophotometric tests (DPPH, ABTS and FRAP) and electrochemical parameters. Anti-inflammatory activity was followed by the inhibition of ROS and NO production by stimulated RAW 264.7 cells. Anti-diabetic effect was determined by measuring the inhibition of the enzyme α-glucosidase activity. The biological activities are positively correlated with the content of flavanols and negatively correlated with the content of anthocyanins and stilbenes. The most important biological activities were measured before maturity for all the tests and in the three grape varieties studied
Tangsumranjit, Anothai. „Vectorisation à visée topique du palmitate d'ascorbyle : optimisation, étude de stabilité, activité antioxydante sur culture de kératinocytes“. Besançon, 2005. http://www.theses.fr/2005BESAA010.
Der volle Inhalt der QuelleThe stability and the antioxidant activity of ascorbyl palmitate (AP), a lipophilic antioxidant, were developed as a topical formulation by loading in biodegradable nanoparticles and by forming an inclusion complex with hydroxypropyl-β-cyclodextrin (HPβCD). AP loaded poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were prepared by interfacial polymer deposition following solvent displacement method. HPβCD-AP inclusion complex was prepared by flash evaporation method. The results showed that AP loaded PLA nanoparticles prepared from degassing distilled water exhibited the best protection for AP even being stored under atmosphere at 4°C. For in vitro antioxidant activity, AP loaded nanoparticles could effectively protect human keratinocyte (HaCaT) cells against both H2O2 and t-BHP induced cytotoxicity. Ln conclusion, PLA nanoparticles might have a potential as a good carrier for improving stability and antioxidant activity of AP
Hanbali, Mazen. „Composés hybrides w-alcanol / hydroquinone à activité neurotrophique. Synthèse et étude des propriétés physicochimiques et biologiques“. Phd thesis, Université Louis Pasteur - Strasbourg I, 2005. http://tel.archives-ouvertes.fr/tel-00116946.
Der volle Inhalt der QuelleUne approche thérapeutique novatrice serait l'utilisation de composés hybrides portant deux activités distinctes. Une activité neurotrophique permettant la neuro-régénération et une activité antioxydante assurant la neuro-protection en piégeant les radicaux libres.
Dans cet objectif, cinq séries de molécules hybrides combinant une chaîne grasse Ω-hydroxylée et des noyaux quinol ont été synthétisés. Les alcools gras quinoliques (QFA) C-alkylés, comportant des noyaux quinol polyméthoxylés, ont été obtenu par couplage de Sonogashira entre des arylbromures et des alcynes vrais. Les homologues N- ou O-alkylés ont été obtenus par des réactions de type SN2.
Les molécules synthétisés possèdent de très bonnes activités antioxydantes sous leurs formes déméthylés dépassant d'un facteur 100 l'activité antioxydante du Trolox®. Par ailleurs, le QFA15 portant une chaîne latérale à 15 atomes de carbones, est capable de promouvoir une croissance axonale très importante, aussi bien sur substrat permissif que sur substrat inhibiteur tel les protéines de myéline ou la Sema3A. Des études préliminaires du mécanisme d'action ont permis de conclure que le QFA15 sollicite les nucléotides cycliques.
Berahia, Tahar. „Comportement par couplage chromatographie gazeuse-spectrométrie de masse et activité antioxydante de polyméthoxyflavones : application aux huiles essentielles de Citrus sinensis“. Aix-Marseille 3, 1993. http://www.theses.fr/1993AIX30034.
Der volle Inhalt der QuelleAfoulous, Samia. „Valorisation des plantes médicinales d’origines africaines, évaluation et identification des molécules à activités biologiques (antioxydante, anticancéreuse et antimalariale, …)“. Toulouse 3, 2013. http://www.theses.fr/2013TOU30325.
Der volle Inhalt der QuelleCette thèse, avec financement CIFRE, a été réalisée au sein du laboratoire des IMRCP (UMR 5623) de l’Université Paul Sabatier (Université de Toulouse) en collaboration avec la Société Nat’Ex Biotech. Les travaux de cette thèse ont été focalisés sur l’étude phytochimique et criblage biologique de métabolites secondaires pour la recherche de nouvelle(s) molécule(s) bioactive(s). Dans ce cadre, deux plantes médicinales de la flore malgache ont été ciblées, Helichrysum gymnocephalum (Astéracées) et Cedrelopsis grevei (Ptaeroxylacées). En premier lieu, l’étude a porté sur l’identification des composés des deux huiles essentielles de ces plantes par GC-FID et GC-MS. Ensuite, les activités biologiques in vitro (activité antioxydante, activité péroxydation lipidique, activité antiinflammatoire (5-lipoxygénase), activité antipaludique (P. Falciparum, souche Columbia/FcB1), activité cytotoxique (sur cellules MCF-7), activité anti-Alzheimer (acétylcholinestérase) et activité antidiabétique (-amylase)) ont été étudiées pour les deux huiles essentielles. En deuxième lieu, une extraction successive, des solvants de polarité croissante, a été réalisée sur les deux plantes. La quantification chimique a été réalisée pour les composés phénoliques, les flavonoïdes, les tanins et les anthocyanes. De même, un criblage des activités biologiques a été fait notamment pour les activités antioxydante, péroxydation lipidique, anti-inflammatoire (5-lipoxygénase), antimycobactérienne (Mycobacterium tuberculosis H37Rv), cytotoxique (sur cellules MCF-7 et HTC 116), anti-Alzheimer (acétylcholinestérase) et antidiabétique (-amylase). Les extraits dichlorométhane et méthanol d’H. Gymnocephalum ont révélé une importante activité inhibitrice de la 5-lipoxygénase (CI50< 10 mg/L). La troisième partie a porté sur l’étude bio-guidée de l’extrait au dichlorométhane de d’H. Gymnocephalum pour l’activité inhibitrice de la 5-lipoxygénase. Un nouveau composé, appartenant à la famille des flavonoïdes, a été isolé et identifié pour sa structure chimique par UV, RMN 2D et spectrométrie de masse. Cette nouvelle substance bioactive a une activité inhibitrice de cette enzyme de l’ordre de CI50=0,51 mg/L, inférieure à celle de la molécule inhibitrice de référence, l’acide nordihydroguaiaretique (IC50=1,61 mg/L)
Chervin, Justine. „Etude de la spéciation chimique de la collection nationale de violettes et mise en place d'un agro-raffinage de la violette de Toulouse“. Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0119/document.
Der volle Inhalt der QuelleThe "Viola Tolosa" project aims to promote a plant produced in Occitanie region, the violet and especially the emblematic violet of Toulouse, essentially for non-food fields such as the chemistry of natural compounds and cosmetics. Violets belong to Viola genus including more than 500 species. Today, their uses are mainly limited to ornamental and culinary aspects. Nevertheless, the growing interest of the actors of the sector (industrials, growers and academicals) led the Occitanie region to implement the Viola Tolosa project entitled "Chemical speciation of the national collection of violets et establishment of an agro-refining of the violet of Toulouse ". It comprises four interdisciplinary aspects associating fundamental and applicative aspects. The characterization of the 100 or so plants in the violet collection owned by the Toulouse municipal greenhouses, including 80% identified by cultivar or vernacular names, was carried out through genetic and chemotaxonomic studies. A first genetic study based on internal transcribed spacers conducted to classify 58% of the collection as a species. This phylogenetic study was completed by chemotaxonomic studies of chemical profiles of flowers volatile fractions and non-volatile aerial parts of the collection. Discriminant analysis of orthogonal projection to latent structure model finally allowed indexation of 96% of all plants with a species name. Study of non-volatile secondary metabolites of leaves has also been undertaken to study the biological potential of violets, including antioxidant, antifungal and defense inducer. The detailed study of a hydroalcoholic extract of the violet of Toulouse allowed the identification of eight antioxidant compounds belonging to flavonoids and coumarins. Three of them have been characterized by 1D and 2D NMR and two were de novo dereplicated through molecular network. The application to the whole collection conducted to highlight six antioxidant compounds, including two coumarins and four flavonoids, predominant in two species. A species-activity relationship was therefore highlighted. Regarding antifungal activities carried out on five fungal strains, and defense inducer through the study of pathogenesis-related protein 1, the results are more ambiguous. However, some species showed better activity than others and this screening led to a strong hypothesis regarding the involvement of cyclotides. Finally, all this work led to the establishment of an identity card of violets of the collection (genetic identification, chemical profiling, et biological potential) et a semi-quantitative description of all the species is considered by combining chromatographic data based on corona detector et spectral data. Different methods of extraction (electroporation, microwaves, supercritical CO2 et hydroalcoholic extraction) corresponding to green chemistry precepts were then compared in order to select the one presenting the best compromise between cosmetic specifications et enrichment in molecules of interest, for technological transfer
Rezaire, Aïra. „Activité anti-oxydante, et caractérisation phénolique du fruit de palmier amazonien Oenocarpus bataua (patawa)“. Thesis, Antilles-Guyane, 2012. http://www.theses.fr/2012AGUY0573/document.
Der volle Inhalt der QuelleDue to its wealth in genetic resources, and to traditional uses, plant biodiversity issued from the Amazonian Basin is a real source of active process to valorize. The specie Euterpeoleracea Mart., usually called acai berry, which is experiencing a huge scientific interest, is the perfect example of valued natural bioactive resources from the geographic area. Scientific studies give it many biological properties, but the most known is its antioxidant property mainly due to its polyphenolic composition. In French Guiana, we can use the term “diversity” within the palm family with more than 75 species identified. Among them is a common species, Oenocarpus bataua Mart., called “Patawa”, mainly with alimentary properties but for which knowledge of phytochemical properties is until now very poor. The present research deals with determining the antioxidant activity of this palm fruit and with the identification of the polyphenols responsible for it.The uniqueness of this work lays in the study of the different tissue components of this fruit namely the mesocarp, the epicarp and mixing epicarp / mesocarp (MEM). In a first time, the most favorable extraction conditions of biomolecules (particularly of the epicarp and mesocarp) were defined using the DPPH test. The preliminary tests performed on those tissues taken separately, have led to select an acetone / water (70/30, v / v) to reveal, at best, the antioxidant capacity of each part of the fruit. An initial defatting step was necessary in the case of the study of the mesocarp. The confirmation of the antioxidant activity was carried out by other tests of chemical activity (TEAC, FRAP, ORAC), and was supplemented by the use of a bioassay (KRL) due to its more complete reaction mechanisms. Results point out that the most antioxidant tissue is the mesocarp that contains proanthocyanidins, phenolics of a chemical family known for its numerous biological activities.The same work was performed on tissues combined (overall result). The mixed solvent acetone / water, without initial defatting step, has been selected. The antioxidant capacity of fruit was compared to that of the Acai specie chosen as a reference. It turns out that acai extracts have antioxidant activity much greater than that of Patawa when tested vis-à-vis of ORAC and KRL. In contrary, mesocarp tissue has a greater antioxidant capacity than that of Acai. These results can be associated with the phytochemical composition of each fruit. The polyphenolic composition of the fruit of Patawa determined by UPLC / MSn, reflects the presence of anthocyanins, condensed tannins, stilbene and phenolic acids. This work, which deserves to be deepened, especially for the mesocarp tissue, opens new prospects for the use of Patawa fruit, especially the incorporation of phenolic compounds from the mesocarp in pharmaceutical formulations linked to the fields of Nutrition, of Cosmetics and Pharmaceuticals
Hadj, Salem Jamila. „Extraction, identification, caractérisation des activités biologiques de flavonoïdes de Nitraria retusa et synthèse de dérivés acylés de ces molécules par voie enzymatique“. Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL057N/document.
Der volle Inhalt der QuelleThe present work firstly consisted in studying the extraction and the identification of major flavonoids contained in Nitraria retusa leaves and evaluating their biological activities. Four flavonoids were identified in extracts and fractions: isorhamnetin, isorhamnetin-3-O-glucoside and the two isomers isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-robinobioside. The evaluation of the biological activities of extracts and fractions of N. retusa allowed to establish a linear relationship between their antioxidant and antiproliferative activities and their total flavonoids content, the most enriched exhibiting the highest activities. The nature of the flavonoids present in the extracts and fractions was shown to be important too. Thus, the strong xanthine oxidase inhibition activity and the high DPPH radical scavenging capacity observed for the chloroform fraction can be attributed to its high content in the aglycone flavonoid isorhamnetin, a structural analogue of quercetin which is well known for its antioxidant activities. In a second part, the enzymatic acylation of isoquercitrin as a model compound and isorhamnetin-3-O-glucoside was studied in order to improve their properties. The enzymatic acylation of isoquercitrin by fatty acid ethyl esters of different chain lengths, catalyzed by the lipase B of Candida antarctica, showed that the performance of the reaction is inversely proportional to the acyl donor chain length. Similar results were obtained when acylating the isorhamnetin-3-O-glucoside. The activities of isoquercitrin and isorhamnetin-3-O-glucoside esters were determined and compared to that of initial flavonoids. Esters exhibited higher antiproliferative towards Caco2 cells and xanthine oxidase inhibition activities than original compounds. Finally, this work led to a better understanding of the structure-activity relationship of flavonoids and their acylated derivatives
Chaaban, Hind. „Étude cinétique et modélisation des effets des traitements thermiques et de l’environnement physico-chimique sur la dégradation et l’activité antioxydante des flavonoïdes“. Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0065/document.
Der volle Inhalt der QuelleThe objectives of this thesis are to study the effects of a heat treatment and the physicochemical environment on the stability of 6 flavonoids of different structure and on the evolution of their antioxidant activity. The heat treatment conditions were as follows: (i) heating under isothermal conditions for 2 h at temperatures ranging from 30 to 130 ° C and (ii) heating under non-isothermal conditions by microcalorimetry (30 to 130 ° C, 4 ° C / hour). The flavonoids were solubilized in water. We found that the glycosylated flavonoids are more resistant than the aglyconic flavonoids. The calculated degradation activation energies also depend on the structure of the flavonoid. To degrade, glycosylated flavonoids require high energy relative to the aglycone form. Exposure to light was carried out for 15 days with and without oxygen, the experimental control being a dark storage with and without oxygen. The degradation of flavonoids is influenced by the presence of light and by the amount of oxygen. The molecules have a different sensitivity according to their structure, the following classification is obtained according to: naringine, ériodictyol then rutin, luteolin, luteolin 7-O-glucoside and finally the mesquitol. Indeed, the presence of a hydroxyl group at position 3 and a C2-C3 double bond reduces the stability of the flavonoids. Furthermore, it has been observed that, despite the total degradation of certain flavonoids by the heat treatment and the physical-chemical environment, the treated solutions retain an antioxidant activity
Ben, Rahal Neïla. „Extraction, identification et caractérisation des molécules bioactives de la graine et de l'huile de Silybum marianum. Étude de leurs activités antioxydante et antitumorale“. Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0137/document.
Der volle Inhalt der QuelleThe supercritical CO2 extraction demonstrates the benefits of green chemistry process comparing with the method of organic solvents extraction and depending to toxicity and pollution solvent degree. Organic solvents extraction shows the solvent extraction influence, so that the SC-CO2 extraction highlights different parameters including pressure, temperature, contact time between the plant matrix and CO2 SC, the average particle diameter and the addition of a cosolvent. Chromatographic analysis identified and quantified four flavonolignans (silychristin, silydianin, silybin, taxifolin) in seed extracts obtained by organic solvents and SC-CO2 with cosolvent. At 220 bar, silydianin (38.87 mg / g) and silybin (45.91 mg / g) have highest concentrations and at 40°C silychristin (31.97 mg / g), silydianin (38.87 mg / g) and silybin (45.91 mg / g) have the most important concentrations. The oily extracts obtained at 220 bar and 40°C of Silybum marianum seeds are rich in fatty acids: linoleic acid (65.22%), oleic acid (27.01%), palmitic acid (12.12%). The antioxidant activity measured by two tests: DPPH and ABTS test. These two tests are complementary and confirm that the extract with the higher antioxidant effect is the extract obtained by SC-CO2 at 220 bar and 40°C. The biological activity of this extract is demonstrated with respect to a colon cancer cell line Caco-2. Silychristin, silydianin and silybin and the extract obtained by CO2-SC with co-solvent (ethanol) at 220 bar and 40°C were tested with respect to this line cancer. These experiments in vitro cytotoxic activity reflect estimable and cell death of Caco-2 flavonolignans of up to 71%
Le, Lann Klervi. „Etude de la biodiversité des Sargassaceae (Fucales, Phaeophyceae) en milieux tempéré et tropical : écologie, chimiotaxonomie et source de composés bioactifs“. Phd thesis, Université de Bretagne occidentale - Brest, 2009. http://tel.archives-ouvertes.fr/tel-00976868.
Der volle Inhalt der QuelleAchat, Sabiha. „Polyphénols de l'alimentation : extraction, pouvoir antioxydant et interactions avec des ions métalliques“. Phd thesis, Université d'Avignon, 2013. http://tel.archives-ouvertes.fr/tel-00978529.
Der volle Inhalt der QuelleHussein, Hala. „Activité anti-athérogène des lipoprotéines de haute densité dans les maladies métaboliques“. Paris 6, 2010. http://www.theses.fr/2010PA066046.
Der volle Inhalt der QuelleHmid, Ilham. „CONTRIBUTION A LA VALORISATION ALIMENTAIRE DE LA GRENADE MAROCAINE (Punica Granatum L.) : CARACTERISATION PHYSICOCHIMIQUE, BIOCHIMIQUE ET STABILITE DE LEUR JUS FRAIS“. Phd thesis, Université d'Angers, 2013. http://tel.archives-ouvertes.fr/tel-01066442.
Der volle Inhalt der QuelleOutman, Ahlam. „Production de peptides anticancéreux à partir des hydrolysats d'hémoglobine humaine et bovine, avec des propriétés additionnelles antibactériennes et antioxydantes“. Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILR082.
Der volle Inhalt der QuelleHemoglobin, the predominant protein in cruor responsible for the red colour of mammalian blood, is known to be a rich source of bioactive peptides after hydrolysis by porcine pepsin. These peptides are mainly known for their antimicrobial properties. However, these peptides stand out for their ability to specifically target cancer cells while preserving rapidly proliferating healthy cells. The aim of this thesis is to develop a strategy for adding value to human and bovine haemoglobin by producing bioactive peptides and then exploring their potential in the fight against cancer, while assessing their anti-cancer, anti-bacterial and antioxidant properties.In this work, the potential of human hemoglobin to contain bioactive peptides was first studied in silico in comparison with bovine hemoglobin using bioinformatics tools. Blast results showed high identity, 88% and 85% respectively, indicating high similarity between α and β chains. The enzymatic hydrolysis conditions (23°C, E/S = 1/11, pH 3.5) were validated on human hemoglobin and enabled efficient production of the α137-141 peptide. Indeed, more than 60% of the total α137-141 peptide production was obtained in just 30 minutes of hydrolysis, reaching a production peak at 3 h. Furthermore, the mechanism of enzymatic hydrolysis of these two types of haemoglobin follows a similar pattern, according to a zipper mechanism. Enzymatic hydrolysis was also performed at high haemoglobin concentrations (1, 2, 8 and 10%, w/v), enabling large-scale production of α137-141.Next, the results showed strong antimicrobial activity of the peptide hydrolysates against six bacterial strains, independent of the initial substrate concentration level. The hydrolysates also showed strong antioxidant activity, measured by four different tests. In addition, the antimicrobial and antioxidant activities of the human and bovine haemoglobin hydrolysates showed little or no significant difference, with only the concentration level being the determining factor in their activity.The anticancer potential of bioactive peptides derived from the enzymatic hydrolysis of haemoglobin was studied. The results obtained using two distinct approaches highlighted their promising potential as anti-cancer agents. The investigation of key parameters such as the initial concentration of haemoglobin, the degree of hydrolysis and the structural characteristics of the antimicrobial peptides highlighted the influence of these factors on the antimitotic activity of the peptides. The α137-141 peptide stood out for its strong inhibition of rootlet growth, with exceptionally low IC50 values, 10 to 15 times higher than other fractions, attributed to its strong antimicrobial potential. In vitro analyses reinforced the hypothesis that inhibition of protein synthesis plays an essential role in the anti-cancer mechanism of these peptides.Finally, the results of the mass spectrometry study showed the presence of a number of bioactive peptides, the majority of which have characteristics similar to those reported in the literature. New bioactive peptides were also identified in human hemoglobin, such as the antibacterial peptides PTTKTYFPHF (α37-46), FPTTKTYFPH (α36-45), TSKYR (α137-141) and STVLTSKYR (α133-141), as well as the antioxidant TSKYR. (α137-141) including three other opioid peptides, an ACE inhibitor, an anticancer agent. This thesis offers a new innovative approach, combining antimicrobial, antioxidant and anticancer properties, paving the way for more effective and less harmful treatments for patients
Celhay, Clément. „Fractionnement de coproduits de pin maritime (Pinus pinaster) et de peuplier (Populus tremula) pour l'obtention d'extraits polyphénoliques à activité antioxydante : procédé d'extraction aqueuse en extracteur bi- vis et étude des conditions subcritiques“. Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0015/document.
Der volle Inhalt der QuelleActual exploitation procedures can not absorb all the wood by-products (knots, barks, stumps), which are potent sources of bioactive compounds such as polyphenols, preferentially extracted by solvents such as ethanol or methanol. Aqueous fractionation has been performed with twin-screw extractors to obtain polyphenolic extracts with antioxidant activity. After having determined the extractability of polyphenols from each byproduct with subcritical water, the parameters of twin-screw extraction were optimized in order to reach temperature and pressure conditions in subcritical water area. The presence of a specific marker in the extracts supports the hypothesis that a twin-screw extractor allows to reach subcritical water conditions. The effects of the extracts on the biodegradability of horticultural pots in which the extracts have been incorporated and on the development of the plants grown in these pots have been evaluated. The valorisation of the extrudate as raw material for thermopressing particle boards has also been studied
Matou, Melissa. „Composition et propriétés biologiques d’extraits de Phyllanthus amarus Schumacher et thonning (1827) utilisés en médecine traditionnelle aux Antilles“. Thesis, Antilles, 2019. http://www.theses.fr/2019ANTI0421.
Der volle Inhalt der QuelleP. amarus, known as "Grenn anba fèy", is one of the most used plants in the treatment of diabetes by medicinal plants in Guadeloupe Island. It was introduced at the French pharmacopoeia in 2015 however healthy professionals deplore a lack of scientific data on the chemical composition of this plant.This work therefore evaluates for the first time the chemical composition and biological properties of P. amarus aqueous extracts based on the consumption habits of the population (aqueous infusion and decoction) which uses both the aerial parts and the whole plant. Our results show that the aerial parts and the roots have a very different chemical composition with only two common molecules, gallic acid and niruriflavone. In addition, Guadeloupe specimens were also distinguished from P. amarus from other countries by the presence of caffeoylhexaric acid and acalyphidin M1 in the aerial parts and prodelphinidin-A2-3'-gallate in the roots.The study of the biological properties of traditional preparations has demonstrated a strong antioxidant activity of both parts of the plant with an higher activity for the aerial parts when they are consumed freshly harvested and for the roots when they are previously dried. The results obtained for the antidiabetic activity demonstrated that the inhibition of the enzyme glucose-6-phosphatase, involved in the release of hepatic glucose during diabetes, was more important for extracts of freshly harvested aerial parts than for the dry ones. On the other hand, the antidiabetic activity was more expressed for the dried aerial parts than the fresh ones which did not show any significant effect. The purified fractions and molecules were tested for their implication in the observed activities. In addition, the study of these extracts has demonstrated, for the first time, the presence of water-soluble polysaccharides whose involvement in antioxidant and antidiabetic activities has been demonstrated.However, many identification errors have been identified between two species in the same environment : P. amarus and P. debilis. The aerial parts of P. amarus and P. debilis were compared and showed many differences. Only a few molecules are common to them. The analysis of the antioxidant properties of P. debilis showed a higher activity than that of P. amarus extracts. Only the antidiabetic activity by G6Pase inhibition was observed and was found to be higher than the activity of the aerial parts of P. amarus. This activity was mainly due to the presence of geraniin, whose activity decreases as it undergoes degradation in the extracts, initially because of its hydrolysis to other compounds and, secondly, to its degradation by the drying process.In addition, the use of simulation techniques of gastrointestinal digestion has shown that high molecular weight molecules are not directly absorbed in their intact form. Indeed, 4% of polyphenols are bioaccessibility. This work has demonstrated the interest of studying plant extracts based on the population consumption habits while considering the effects of digestion on the fate of bioactive compounds
Benabdelkader, Tarek. „Biodiversité, bioactivité et biosynthèse des composés terpéniques volatils des lavandes ailées, Lavandula stoechas sensu lato, un complexe d'espèces méditerranéennes d'intérêt pharmacologique“. Phd thesis, Université Jean Monnet - Saint-Etienne, 2012. http://tel.archives-ouvertes.fr/tel-00952695.
Der volle Inhalt der QuelleHupel, Mélanie. „Radiations UV et composés photoprotecteurs : étude comparée chez deux végétaux marins, l'algue brune Pelvetia canaliculata et l'angiosperme Salicornia ramosissima“. Brest, 2011. http://www.theses.fr/2011BRES2010.
Der volle Inhalt der QuelleHigh light irradiances, especially enhanced UV-B radiations due to present stratospheric ozone depletion, may be major stress factors for many phototrophic organisms in both aquatic and terrestrial ecosystems. The brown seaweed Pelvetia canaliculata and the coastal salt marsh angiosperm Salicornia ramosissima are two marine plants growing in the upper intertidal zone, where they are subjected to long emersion periods, to direct solar exposure and are likely to have convergent efficient photoprotective mechanisms. In this study, thanks to the development of a coculture system, their metabolic responses against various UV-B radiation levels have been compared in controlled conditions, especially the synthesis of photoprotective compounds implied in the photosynthesis maintaining by either a UV-absorbing function or a defence capacity against oxidative stress. Results show that phenols seem to be the main class of photoprotective compounds in both species, with a preferential sunscreen function of flavonoids in Salicornia ramosissima and a strong antioxidant activity of phlorotannins in Pelvetia canaliculata. However, both species could modulate the composition of their phenol pool through either 011e protective function or both depending on light conditions. The specific UV-absorbing function of these compounds has been evidenced thanks to the development of a new in vitro method for evaluating the sunscreen activity of plant extracts
Fadl, Almoulah Nahla. „Études phytochimique et biologique de cinq plantes de la famille des Solanaceae“. Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0184/document.
Der volle Inhalt der QuelleThis study aimed at the evaluation of in vitro antibacterial, antiproliferative and antioxidant activities of methanolic leaf extracts and steroidal glycoalkaloids fractions (SGAFs) of Solanum incanum L., S. schimperianum Hochst, S. nigrum L., Physalis lagascae Roem. & Schult. and Withania somnifera (L) Dunal. The sensitivity of Gram-positive and Gram-negative bacteria to each extract was variable (IC50 values in the range of 15->1000 µg/mL). The methanolic extract of S. schimperianum leaf demonstrated interesting anti-proliferative activity against the human cell lines tested with IC50 values in the range of 2.69 to 19.83 µg/mL while the highest activity from the SGAFs was obtained from W. somnifera leaf with IC50 values in the range of 1.29 to 5.00 µg/mL. The SGAFs of all species demonstrated higher scavenging activity than their respective methanolic extracts. The SGAF of S. schimperianum displayed the strongest antioxidant activity in both assays with IC50 value 3.5 ± 0.2DPPH and 3.5 ±0.3ABTS µg/mL. GC-MS analysis of methanolic and SGAFs extracts of the studied species revealed the presence of steroidal alkaloids, steroidal saponins, steroids and other compounds like terpenes, phenols and alkanes. Their distribution varied among the species and thus they could provide evidence to assess preliminary chemotaxonomic relationships. Twelve known hydroxycinnamic acid amides were tentatively identified from the methanolic extract of S. schimperianum leaf and N-caffeoyl agmatine appeared with the highest intensity. Moreover, the presence of steroid alkaloids solanopubamine and solanocapsine as well as dehydroderivatives of the 3-amino steroid alkaloids was suggested. Furthermore, three compounds quercetin, kaempferol glycoside and β-sitosterol were isolated and identified. In silico investigation of these three compounds for their potency against cancer revealed that β-sitosterol was found to be the most selective compound against human pregnane X receptor (PXR) and gave the highest binding energy (-11.2 kcal/mol). These results suggested that Solanaceae plants endogenous to Sudan could be a potential source of bioactive agents
M'Hiri, Nouha. „Étude comparative de l’effet des méthodes d’extraction sur les phénols et l’activité antioxydante des extraits des écorces de l’orange « Maltaise demi sanguine» et exploration de l’effet inhibiteur de la corrosion de l’acier au carbone“. Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0183/document.
Der volle Inhalt der QuelleThis work is a contribution to the valorization of “Maltease peel”. The objectives of this research are (i) to study the efficiency of different extraction methods in terms of total phenol contents (TPC), total flavonoid contents (TFC), individual flavonoids (FI) and antioxidant activity of extracts and (ii) to examine the corrosion inhibition of carbon steel in acidic and basic medium by orange peel extract and its main antioxidant compounds. For this, five extraction methods were used: conventional solvent extraction, CSE (ethanol (80%), m/v: 5g:50ml, 30 min, 35°C, mechanical stirring in the dark and 3 successive extractions), microwave assisted extraction, MAE (ethanol (80%), m/v: 5g:50ml, 3 successive extractions, and 180s, 67-108°C, 100-400W or at 35°C), ultrasound-assisted extraction, UAE (ethanol (80%), m/v: 5g:50ml, 30 min, 35°C, 100-200W and 3 successive extraction), high-pressure extraction, HPE (ethanol (80%), m/v: 5g:50ml, 30 min, 35°C, 0,1-100 MPa and one extraction) and supercritical CO2 extraction, SC-CO2 (ethanol (80%), m/v: 5g:50ml, 30 min, 35-80°C/10-22 MPa and 3 successive extractions). This byproduct is rich in functional ingredients such as total phenols (1.96 ±0.002 g GAE/100g DM) and vitamin C (0.10±0.003 g/100g DM). Ten individual flavonoids (FI) were identified in the extract of Maltease orange peel. Neohesperidin (0.860±0.003 g/100g orange peel powder) and hesperidin (0.551±0.001 g/100g orange peel powder) are the major compounds. The operating conditions of extraction that have achieved the highest levels of total phenol and flavonoid contents are 200 W, 76°C during 180s for MAE; 125 W during 30 min at 35°C for UAE; 80°C and 10 MPa for SC-CO2 extraction and 50 MPa,35°C during 30 min for HPE. The comparison of the different extraction methods performed at the same operating conditions (m/v: 5g/50ml, 80% ethanol, 35°C, 3 successive extractions) shows that the MAE has the highest levels of TPC and TFC, followed by UAE, CSE, HPE and SC-CO2 extraction, as well as the major individual flavonoids. However, results concerning antioxidant activity cannot be correlated to TPC, TFC or individual flavonoids and it differs depending on the test used. Orange peel extracted by HPE presents higher radical scavenging capacity compared to extracts obtained by other extraction methods. Moreover, it can be noticed a significant decrease of the antioxidant activity measured by the ABTS method in the following order: HPE, CSE, SC-CO2, MAE, UAE, whereas, it is EHP, ECS, EAM, EAU, SC-CO2 extraction for DPPH test. The study of the anti-corrosion effect of the orange extract and its antioxidant compounds (neohesperidin, naringin and ascorbic acid) showed a significant inhibition effectiveness of the corrosion steel with orange peel extract (95%) relative to that of its antioxidant compounds: ascorbic acid (92%), neohesperidin (87%) and naringin (56%). The anti-corrosion efficiency of orange peel extract is not only due to the antioxidant activity of identified compounds, but probably also to a synergic effect of molecules and to the formation of a three-dimensional surface of the film. This film can be formed due to the presence of other compounds in the extract such as pectin
Boutakiout, Amale. „Etude physico-chimique, biochimique et stabilité d’un nouveau produit : jus de cladode du figuier de Barbarie marocain (Opuntia ficus-indica et Opuntia megacantha)“. Thesis, Angers, 2015. http://www.theses.fr/2015ANGE0004/document.
Der volle Inhalt der QuelleThe orientations of the Moroccan agricultural policy concerning the Green Morocco Plan, promote the development of the arid zones and the development of crops that adapt to global warming. The prickly pear cactus is a plant which is adapted to the arid climate and still untapped in Morocco. Prickly pear cladodes contain bioactive components that have beneficial health effects. The juice extracted from cladodes of both species Opuntia ficus-indica(spineless) and Opuntia megacantha(spiny) was the subject ofthis work. The cladodes were harvested in the region of Marrakech (Ouled Dlim) in Morocco for three seasons (spring, summer and winter) between 2013 and 2014 to assess the effect of harvest time on the physico-chemical and biochemical composition and antioxidant activity. The yield of cladode juice varies within the seasons and species (63,39 –20,83 %). The physico-chemical and biochemical analyzes showed that cladode juice is rich in polyphenols (543 ± 1–456 ± 8mg GAE/mL), in ascorbic acid (17,60 ± 1,87 –22,88 ± 0,62 mg/100 mL) and in potassium (409,35 –44,23 mg/100mL) but poor in sugar (0,66 ± 0,01–1,45 ± 0,03 g/100 mL). HPLC analysis of phenolic compounds has shown that cladode juice is rich in flavonols namely isoquercetin and hyperoside (645,90 mg/mL and 164,50 mg/mL respectively). The antioxidant activity of cladode juice was measured with FRAP test (1,74 ± 0,07 –3,33 ± 0,02 μmol TE/mL) and the antiradical activity was carried out with the DPPH test (1,78 ± 0,03 –4,10 ± 0,02 μmol TE/mL ) and the ABTS test (12,78 ± 1,69 –23,10 ± 0,17 μmol TE/mL ). The correlation analysis indicated that there was a significant relationship (p<0,05) between the methods of analysis, species and seasons.Quantitative analysis of cladode juice harvested in March HPLC-DAD showed the presence of a significant quantity of flavonoids essentially isoquercetin and hyperoside. Results of these analyzes showed that cladode juice is rich in nutriments and has an antioxidant activity potential. The juice can be stored for 42 days at 4°C, after pasteurization at 95°Cfor 3 min in a water bath and lowering the pH to 3,5 with citric acid. Cladode juice can be used as nectar, iced tea or soft drink and with a valorization of its coproducts (jam, soup, powder etc.)
Chaabani, Emna. „Eco-extraction et valorisation des métabolites primaires et secondaires des différentes parties de Pistacia lentiscus“. Thesis, Avignon, 2019. http://www.theses.fr/2019AVIG0714.
Der volle Inhalt der QuelleThe development of Green chemistry, the depletion of petroleum resources and the awareness of the risks associated to the use of petroleum solvents have led to search a new alternatives to reduce the use of non-renewable petrochemical harmful solvents such as hexane. The objective of this thesis has consisted in the research of alternative solvents more respectful of health and environment for the eco-extraction of fatty acids and phenolic compounds from Pistacia lentiscus fruits and aromas from these leaves. A first in silico approach using the COSMO-RS predictions was supplemented by an experimental approach paired with chemometrics analysis. This led to selection of four alternative solvents, MeTHF for oil extraction, EtOAc for aromas extraction, EtOH/H2O (70/30) for polyphenols and flavonoids extraction and EtOH/H2O (80/20) for anthocyanins extraction. Subsequently, the anti-inflammatory activity of MeTHF lipid extract and the antioxidant activity of aromatic and phenolic extracts of P. lentiscus were evaluated in vitro. Results showed that vegetable oil exhibited a potential anti-inflammatory activity, inhibiting by 91.9% the release of (nitric oxide) NO in RAW 264.7 macrophages. In addition, results highlighted the richness of the fruits in antioxidants. In fact, EtOH/H2O (80/20) extract showed a good antiradical activity (IC50 = 2.39 μg/ml) comparable to that of the synthetic antioxidant Trolox (IC50 = 2.56 μg / ml). In addition, the aromatic extract obtained with EtOAc showed an interesting anti-radical activity against DPPH (IC50 = 5.82 μg/ml)
Mnayer, Dima. „Eco-Extraction des huiles essentielles et des arômes alimentaires en vue d'une application comme agents antioxydants et antimicrobiens“. Thesis, Avignon, 2014. http://www.theses.fr/2014AVIG0257/document.
Der volle Inhalt der QuellePlant essential oils and aromas are a real potential for the industry to substitute the synthetic compounds that might have harmful effects on the human health and the environment. In order to contribute to the green chemistry principles, this study focuses on the “eco-extraction” and valorization of natural plant extracts and the development of a new «green» technology for the extraction of aromatic compounds. The first part of this manuscript highlights the biological properties of the essential oils and aromas and the importance of their applications in various sectors especially in the food industry. In the second part, studies on the biological properties of the essential oils from plants of the Alliaceae family show their good antioxidant and antimicrobial activities. These encouraging results have allowed in the third part to evaluate the onion by-products resulting from the turbo hydrodistillation, which are normally considered as waste. The technique offers a good extraction of flavonoids and phenols using water as natural solvent. The fourth and final part of this work deals with the optimization and the development of a «green» technology using ultrasound and sunflower oil as a natural solvent for the extraction of aromatic compounds from thyme. This new ecological approach allows the extraction of absolutes free from waxes and petroleum solvent residues, having the highest content in thymol and exerting the strongest antioxidant activity
Ben, Nasr Rania. „Investigation phytochimique, évaluation des activités larvicide et anti-acétylcholinestérase de différents extraits de Mercurialis annua L“. Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0155.
Der volle Inhalt der QuelleThis work reports the link between the larvicidal activity and the chemical composition of the different extracts of the male and female feet of Mercurialis annua L. a Euphorbiaceae often used in traditional medicine. The plant material used in our study is collected in four regions of Tunisia located in different bioclimatic stages: Bizerte, Jandouba, Nabeul and Beja. This study includes a first part devoted to a bibliographic synthesis. The second part is devoted to experiments and results. Indeed, we evaluated the antioxidant activity of the different extracts using DPPH tests. The phenolic compounds were identified and quantified by liquid chromatography coupled with a UV detector and mass spectrometry (LC-UV-ESI / MS). Our results showed that methanolic extracts from male plants have higher antioxidant activity (AOA) than that detected in extracts from female plants. On the other hand, male and female plant extracts from Bizerte showed the highest AOA level. For both sexes, Beja plant extracts have the lowest AOA. Certain phenolic compounds such as: narcissin, gallocatechin, rutin, epigallocatechin and epicatechin have been identified and quantified by LC-MS. On the other hand, the larvicidal activity of the various aqueous extracts of Mercurialis annua L. against the larvae of Tribolium confusum (Du Val) showed that the mortality could reach 100% after 48 hours of exposure for certain extracts, this is confirmed. by their low LC50. Furthermore, the study of the anti-acetylcholinesterase activity of the extracts tested shows that they are more potent AChE inhibitors than galantamine used as a positive control.Our study confirmed that extracts of the leaves and seeds of both sexes of Mercurialis annua L., coming from different regions of Tunisia, can therefore be exploited for other biological activities, among which the inhibitory action of AChE. Indeed, these extracts are rich in phenolic compounds, which gives them this therapeutic property against Alzheimer's disease and scavenging free radicals
Péroumal, Armelle. „Caractérisation des fruits et de la pulpe de six accessions de Mammea americana : Aptitude à la transformation des fruits et caractérisation des composés phénoliques de la pulpe“. Thesis, Antilles-Guyane, 2014. http://www.theses.fr/2014AGUY0702/document.
Der volle Inhalt der QuelleOur work focuses on the physical and chemical properties of six mamey apple cultivars in order to select elite cultivars suitable for food processing or as table fruit. The antioxidant activity of the fruit pulp, the identification and quantification of the polyphenols responsible for it, and ultrasound assisted extraction method were also investigated.According to our results, the postharvest routes for every cultivar could be different. Pavé 11, Lézarde and Ti Jacques were found to be good for consumption, giving sweeter fruits with high total phenolic and carotenoid contents. Sonson, pavé 11 and Lézarde had suitable characteristics for the manufacturing of mamey products. The polyphenolic composition of the pulp determined by HPLC-DAD and UPLC-MS showed the presence of phenolic acids, condensed tannins, flavonols and flavanols. The results of the antioxidant test (DPPH and ORAC) point out that the most antioxidant cultivar was Ti Jacques. The design and optimization of the ultrasound assisted extraction method has done for polyphenols extraction. The results showed that the polyphenols rich extract contains the same content of phenolic acids and flavonols in comparison to the conventional method. Additionally, the dry extract obtained with a “green” solvent, had good organoleptic properties
Grigoraş, Cristina-Gabriela. „Valorisation des fruits et des sous-produits de l'industrie de transformation des fruits par extraction des composés bioactifs“. Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00772304.
Der volle Inhalt der QuelleHmid, Ilham. „Contribution a la valorisation alimentaire de la grenade marocaine (punica granatum l. ) : caracterisation physicochimique, biochimique et stabilite de leur jus frais“. Phd thesis, Angers, 2013. https://theses.hal.science/tel-01066442.
Der volle Inhalt der QuelleThe pomegranate (Punica granatum) is an important crop for the arid and semi-arid areas. For this reason, a greater interest has been observed in the last years for increasing their cultivation and diverse research has been carried out to enlarge the industrialization as much the fruit. On the other hand, the fruit possesses strong antioxidant and anti-inflammatory activities linked to the presence of anthocyanins, tannins, and ellagic acid which have an interesting therapeutic capacity to inhibit the proliferation of cancer cells. In this study, eighteen pomegranate (Punica granatum) cultivars collected at INRA in Meknes-Morocco were analyzed. The study also showed a statistically significant differences were observed between pomegranate cultivars investigated in all parameters measured. The antioxidant capacity and composition of phenolic compounds of pomegranate juices, which varied de 1385 to 9476 mg GAE/L, were influenced by the type of cultivar to a large extent. On the second part of this work, the stability of polyphenols and anthocyanins were determined as a function of temperature. The results showed that the composition of these compounds decreases after each thermal treatment due to their degradation. However, the third part analyzes the efficiency of pectinase and protease enzymes used in the clarification treatments of pomegranate juice. The pectinase treatment has a significant reduction of turbidity. The combination of both enzymes gives a good result in the term of reduction of turbidity. Finally the last part was devoted on modeling of microbial growth which consist to apply mathematical models provided by the data base ComBase on the pomegranate juice, the results showed that at the minimum values of temperature, pH and water activity ensure a long life of up to one month and the ComBase model is generally safe for this type of juice
Ben, Rhouma-Martin Ghada. „Oligomérisation enzymatique de flavonoïdes et évaluation des activités biologiques des oligomères synthétisés“. Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0017/document.
Der volle Inhalt der QuelleRutin and esculin have been polymerized by laccase. Five fractions with between 2127.42 and 8331.85 g/mol for oligorutins, and between 688.12 and 6973 g/mol for oligoesculins, were obtained. Fourier transformed infrared analysis showed that oligorutins were formed through C-C, C-O and C=O linkages, while oligoesculins were obtained through C-C linkages. Oligorutins and oligoesculins show a higher solubility in water and a lower solubility in ethanol compared to their monomers. The oligomerization of rutin decrease its antiradical capacity, while oligoesculin fractions demonstrated a high antiradical activity compared to monomeric esculin. Oligomer fractions showed a better iron chelating power, xanthine oxidase inhibition, copper reducing power (CUPRAC), antigenotoxic activity, and splenocytes stimulator activity compared to their monomers. Oligorutin and oligoesculin exhibited an important anti-inflammatory capacity through the nitric oxide inhibition. Moreover, oligorutin fractions demonstrated an immunostimulatory effect proportional to their degree of oligomerization, while oligoesculin fractions showed an immunostimulatory effect inversely proportional to their degree of oligomerization
Poole, Jessica. „Comparaison de différentes méthodes de conservation et d'extraction des composés phénoliques dans l'algue marine Ascophyllum Nodosum applicables dans les régions côtières et éloignées = Comparing the effects of different preservation and extraction methods on phenolic compounds in the sea weed Ascophyllum Nodosum applicable to remote coastal communities“. Thèse, 2019. http://depot-e.uqtr.ca/id/eprint/9736/1/eprint9736.pdf.
Der volle Inhalt der QuelleRoberts, Karla. „Mise au point d'un procédé efficace pour récupérer les polyphénols antioxydants de la camarine noire (Empetrum Nigrum) avec des extractions assistées par solvant et micro-ondes = Development of an effective process to recover antioxidant active polyphenols from crowberries (Empetrum Nigrum) with solvent and microwave-assisted extractions“. Thèse, 2019. http://depot-e.uqtr.ca/id/eprint/9738/1/eprint9738.pdf.
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