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Artykuły w czasopismach na temat "Natural Products - Carbocyclic compounds"
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Banwell, MG. "New Methods for the Synthesis of Troponoid Compounds". Australian Journal of Chemistry 44, nr 1 (1991): 1. http://dx.doi.org/10.1071/ch9910001.
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The ring expansion of 7-halogenobicyclo[4.1.0] heptenones and related compounds provides a useful new method for the preparation of the seven-membered conjugated carbocyclic compounds known as tropones and tropolones. This methodology has been exploited in the synthesis of various biologically active troponoid natural products including nezukone, the thujaplicins, thujaplicinol, MY3-469 and colchicine.
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Schmiedel, Volker Martin, i Hans-Ulrich Reissig. "Alkoxyallenes as Starting Materials for the Syntheses of Natural Products". Current Organic Chemistry 23, nr 27 (15.01.2020): 2976–3003. http://dx.doi.org/10.2174/1385272824666191218115731.
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Alkoxyallenes are easily available and versatile building blocks for the preparation of a variety of natural products (terpenes, polyketides, alkaloids, amino acids, carbohydrates etc.) originating from different classes. The synthetic use of the three allene carbon atoms frequently follows the “normal” reactivity pattern showing that alkoxyallenes can be regarded as special enol ethers. Additions of alcohols or amines to alkoxyallenes form vinyl-substituted O,O- or N,O-acetals that are frequently used in ring-closing metathesis reactions. This methodology delivers crucial heterocyclic units of the target compounds. Enantioselective additions provide products with high enantiopurity. Alternatively, an “Umpolung” of reactivity of alkoxyallenes is achieved by lithiation at C-1 and subsequent reaction with electrophiles, such as alkyl halides, carbonyl compounds, imines or nitrones. High stereoselectivity of the addition step can be achieved by substrate control or auxiliary control. The high diastereo- or enantioselectivity is transferred to the subsequent acyclic or cyclic products. The cyclization of primary addition products occurs efficiently under mild conditions and provides functionalized dihydrofuran, dihydropyrrole or 1,2-oxazine derivatives. These are valuable intermediates for the synthesis of a variety of heterocyclic natural products. Nazarov cyclizations or gold catalyzed rearrangements allow the synthesis of five- and six-membered carbocyclic compounds that are also used for natural product synthesis. Dedicated to Dr. Reinhold Zimmer, a pioneer of alkoxyallene chemistry, on the occasion of his 60th birthday.
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Mandal, Sumana, Raju D. Chaudhari i Goutam Biswas. "Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds". Beilstein Journal of Organic Chemistry 17 (9.09.2021): 2348–76. http://dx.doi.org/10.3762/bjoc.17.153.
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The synthesis of complex cyclic compounds is extremely challenging for organic chemists. Many transition-metal-salt-mediated cyclizations are reported in literature. Hg(II) salts have been successfully employed in cyclizations to form complex heterocyclic and carbocyclic structures that are impossible to synthesize with other transition metal salts. In this review, we have summarized cyclization reactions that are performed with Hg(II) salts. These salts are also successfully applied in stoichiometric or catalytic amounts to form complex cyclic structures and natural products.
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Yan, Ning, Yongmei Du, Xinmin Liu, Hongbo Zhang, Yanhua Liu i Zhongfeng Zhang. "A Review on Bioactivities of Tobacco Cembranoid Diterpenes". Biomolecules 9, nr 1 (16.01.2019): 30. http://dx.doi.org/10.3390/biom9010030.
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Cembranoids are carbocyclic diterpenes comprising four isoprene units and are natural products with a parent skeleton consisting of a 14-membered ring. They have gained wide interest in recent years and are a major hotspot in the research of natural product chemistry. Since 1962, various tobacco cembranoid diterpenes have been identified. This review systematically discusses and summarises the excellent antimicrobial, insecticidal, cytotoxic and neuroprotective activities of tobacco cembranoid diterpenes. These compounds show potential to be developed as botanical fungicides, cytotoxic drugs and drugs for the treatment of human immunodeficiency virus, Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative diseases. However, there are relatively few studies on the structure–activity relationship (SAR) of tobacco cembranoid diterpenes. Therefore, future studies should focus on their structural modification, SAR and biogenic relationships.
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Mhaske, Santosh, i Ranjeet Dhokale. "Transition-Metal-Catalyzed Reactions Involving Arynes". Synthesis 50, nr 01 (22.11.2017): 1–16. http://dx.doi.org/10.1055/s-0036-1589517.
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The plethora of transformations attainable by the transition-metal-catalyzed reactions of arynes has found immense contemporary interest in the scientific community. This review highlights the scope and importance of transition-metal-catalyzed aryne reactions in the field of synthetic organic chemistry reported to date. It covers transformations achieved by the combination of arynes and various transition metals, which provide a facile access to a biaryl motif, fused polycyclic aromatic compounds, different novel carbocycles, various heterocycles, and complex natural products.1 Introduction2 Insertion of Arynes3 Annulation of Arynes4 Cycloaddition of Arynes5 Multicomponent Reactions of Arynes6 Miscellaneous Reactions of Arynes7 Total Synthesis of Natural Products Using Arynes8 Conclusion
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Chen, Xuefei, Min Xu, Jin Lü, Jianguo Xu, Yemin Wang, Shuangjun Lin, Zixin Deng i Meifeng Tao. "Biosynthesis of Tropolones inStreptomycesspp.: Interweaving Biosynthesis and Degradation of Phenylacetic Acid and Hydroxylations on the Tropone Ring". Applied and Environmental Microbiology 84, nr 12 (13.04.2018): e00349-18. http://dx.doi.org/10.1128/aem.00349-18.
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ABSTRACTTropolonoids are important natural products that contain a unique seven-membered aromatic tropolone core and exhibit remarkable biological activities. 3,7-Dihydroxytropolone (DHT) isolated fromStreptomycesspecies is a multiply hydroxylated tropolone exhibiting antimicrobial, anticancer, and antiviral activities. In this study, we determined the DHT biosynthetic pathway by heterologous expression, gene deletion, and biotransformation. Ninetrlgenes and some of the aerobic phenylacetic acid degradation pathway genes (paa) located outside thetrlbiosynthetic gene cluster are required for the heterologous production of DHT. ThetrlAgene encodes a single-domain protein homologous to the C-terminal enoyl coenzyme A (enoyl-CoA) hydratase domain of PaaZ. TrlA truncates the phenylacetic acid catabolic pathway and redirects it toward the formation of heptacyclic intermediates. TrlB is a 3-deoxy-d-arabino-heptulosonic acid-7-phosphate (DAHP) synthase homolog. TrlH is an unusual bifunctional protein bearing an N-terminal prephenate dehydratase domain and a C-terminal chorismate mutase domain. TrlB and TrlH enhancedde novobiosynthesis of phenylpyruvate, thereby providing abundant precursor for the prolific production of DHT inStreptomycesspp. Six seven-membered carbocyclic compounds were identified from thetrlC,trlD,trlE, andtrlFdeletion mutants. Four of these chemicals, including 1,4,6-cycloheptatriene-1-carboxylic acid, tropone, tropolone, and 7-hydroxytropolone, were verified as key biosynthetic intermediates. TrlF is required for the conversion of 1,4,6-cycloheptatriene-1-carboxylic acid into tropone. The monooxygenases TrlE and TrlCD catalyze the regioselective hydroxylations of tropone to produce DHT. This study reveals a natural association of anabolism of chorismate and phenylpyruvate, catabolism of phenylacetic acid, and biosynthesis of tropolones inStreptomycesspp.IMPORTANCETropolonoids are promising drug lead compounds because of the versatile bioactivities attributed to their highly oxidized seven-membered aromatic ring scaffolds. Our present study provides clear insight into the biosynthesis of 3,7-dihydroxytropolone (DHT) through the identification of key genes responsible for the formation and modification of the seven-membered aromatic core. We also reveal the intrinsic mechanism of elevated production of DHT and related tropolonoids inStreptomycesspp. The study on DHT biosynthesis inStreptomycesexhibits a good example of antibiotic production in which both anabolic and catabolic pathways of primary metabolism are interwoven into the biosynthesis of secondary metabolites. Furthermore, our study sets the stage for metabolic engineering of the biosynthetic pathway for natural tropolonoid products and provides alternative synthetic biology tools for engineering novel tropolonoids.
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Okumura, Mikiko, i David Sarlah. "Arenophile-Mediated Photochemical Dearomatization of Nonactivated Arenes". CHIMIA International Journal for Chemistry 74, nr 7 (12.08.2020): 577–83. http://dx.doi.org/10.2533/chimia.2020.577.
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Aromatic compounds are one of the most abundant classes of organic molecules and find utility as precursors for alicyclic hydrocarbon building blocks. While many established dearomatization reactions are exceptionally powerful, dearomatization with concurrent introduction of functionality, i.e. dearomative functionalization, is still a largely underdeveloped field. This review aims to provide an overview of our recent efforts and progress in the development of dearomative functionalization of simple and nonactivated arenes using arenophile-arene cycloaddition platform. These cycloadducts, formed via a visible-light-mediated [4+2]-photocycloaddition, can be elaborated in situ through olefin chemistry or transition-metal-catalyzed ring-opening with carbon-, nitrogen-, and oxygen-based nucleophiles, providing access to diverse structures with functional and stereochemical complexity. Moreover, the dearomatized products are amenable to further elaborations, which effectively install other functionalities onto the resulting alicyclic carbocycles. The utility of the arenophile-mediated dearomatization methods are also highlighted by the facile syntheses of natural products and bioactive compounds through novel disconnections.
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Smyrniotopoulos, Vangelis, Anna Cláudia de Andrade Tomaz, Maria de Fátima Vanderlei de Souza, Emídio Vasconcelos Leitão da Cunha, Robert Kiss, Véronique Mathieu, Efstathia Ioannou i Vassilios Roussis. "Halogenated Diterpenes with In Vitro Antitumor Activity from the Red Alga Sphaerococcus coronopifolius". Marine Drugs 18, nr 1 (29.12.2019): 29. http://dx.doi.org/10.3390/md18010029.
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Eight new (1–8) structurally diverse diterpenes featuring five different carbocycles were isolated from the organic extracts of the red alga Sphaerococcus coronopifolius collected from the coastline of the Ionian Sea in Greece. The structures of the new natural products, seven of which were halogenated, and the relative configuration of their stereocenters were determined on the basis of comprehensive spectroscopic analyses, including NMR and HRMS data. Compounds 5 and 8 were found to possess in vitro antitumor activity against one murine and five human cancer cell lines with mean IC50 values 15 and 16 μM, respectively.
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Tammam, Mohamed A., Lucie Rárová, Marie Kvasnicová, Gabriel Gonzalez, Ahmed M. Emam, Aldoushy Mahdy, Miroslav Strnad, Efstathia Ioannou i Vassilios Roussis. "Bioactive Steroids from the Red Sea Soft Coral Sinularia polydactyla". Marine Drugs 18, nr 12 (10.12.2020): 632. http://dx.doi.org/10.3390/md18120632.
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Six new (1, 2, 6, 8, 13, and 20) and twenty previously isolated (3–5, 7, 9–12, 14–19, and 21–26) steroids featuring thirteen different carbocycle motifs were isolated from the organic extract of the soft coral Sinularia polydactyla collected from the Hurghada reef in the Red Sea. The structures and the relative configurations of the isolated natural products have been determined based on extensive analysis of their NMR and MS data. The cytotoxic, anti-inflammatory, anti-angiogenic, and neuroprotective activity of compounds 3–7, 9–12, 14–20, and 22–26, as well as their effect on androgen receptor-regulated transcription was evaluated in vitro in human tumor and non-cancerous cells. Steroids 22 and 23 showed significant cytotoxicity in the low micromolar range against the HeLa and MCF7 cancer cell lines, while migration of endothelial cells was inhibited by compounds 11, 12, 22, and 23 at 20 µM. The results of the androgen receptor (AR) reporter assay showed that compound 11 exhibited the strongest inhibition of AR at 10 µM, while it is noteworthy that steroids 10, 16, and 20 displayed increased inhibition of AR with decreasing concentrations. Additionally, compounds 11 and 23 showed neuroprotective activity on neuron-like SH-SY5Y cells.
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Yang, Ji-Min, Yu-Kun Lin, Tao Sheng, Liang Hu, Xin-Pei Cai i Jin-Quan Yu. "Regio-controllable [2+2] benzannulation with two adjacent C(sp 3 )–H bonds". Science 380, nr 6645 (12.05.2023): 639–44. http://dx.doi.org/10.1126/science.adg5282.
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Regiocontrol in traditional cycloaddition reactions between unsaturated carbon compounds is often challenging. The increasing focus in modern medicinal chemistry on benzocyclobutene (BCB) scaffolds indicates the need for alternative, more selective routes to diverse rigid carbocycles rich in C(sp 3 ) character. Here, we report a palladium-catalyzed double C–H activation of two adjacent methylene units in carboxylic acids, enabled by bidentate amide-pyridone ligands, to achieve a regio-controllable synthesis of BCBs through a formal [2+2] cycloaddition involving σ bonds only (two C–H bonds and two aryl–halogen bonds). A wide range of cyclic and acyclic aliphatic acids, as well as dihaloheteroarenes, are compatible, generating diversely functionalized BCBs and hetero-BCBs present in drug molecules and bioactive natural products.
Rozprawy doktorskie na temat "Natural Products - Carbocyclic compounds"
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Wong, Wan Yee. "Solvothermal crystallization of organic compounds and natural products /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202006%20WONG.
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Cowe, H. J. de L. "Molecular studies of natural products and related compounds". Thesis, Robert Gordon University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370758.
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Atkinson, A. M. "Structures of some natural products and metallo-organic compounds". Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/46946.
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Hussain, Amjad. "The synthesis of heterocyclic compounds related to natural products". Thesis, Swansea University, 2001. https://cronfa.swan.ac.uk/Record/cronfa43039.
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The thesis relates to the synthesis of heterocyclic compounds related to Natural Products. Chapter 1 deals with an introduction to hypervalent iodine reagents and their uses as phenolic oxidation reagents. The mechanism is also discussed. Chapter 2 concentrates on the production of 3-substituted phenols and the subsequent hypervalent iodine oxidation to see if a variety of chromenone compounds can be formed via intramolecular attack. Whilst not successful in generating the desired compounds, a number of oxidised products were isolated. Chapter 3 deals with making the 3-nucleophilic side chain on various phenols more rigid in the hope of aiding cyclisation. One reaction of note from this chapter was that an epoxide ring utilised, to give rigidity in the side chain, withstood the hypervalent iodine oxidation. Chapter 4 utilises the epoxide to bring rigidity to the 3-substituted side chain. All products bar one proved successful in generating their appropriate epoxychromenes, and that which didn't provided an alternative cyclised product. The final chapter deals with possible future work now that some success has been achieved.
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Dengada, Amrapali Harishkumar. "Isolation and Structural Elucidation of Compounds from Natural Products". Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64303.
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Isolation and Structural Elucidation of Compounds from Natural Products
Amrapali H. Dengada
In continuation of the Kingston group's work to identify new compounds from natural products as a part of the International Cooperative Biodiversity Group (ICBG) program and in collaboration with the Institute for Hepatitis and Virus Research (IHVR), the two plants Neoharmsia baronii and Lopholaena cneorifolia were studied to identify their chemical components. Structural elucidation and characterization of the compounds were done using mass spectrometry, 1D and 2D NMR spectroscopy techniques.
A systematic study of the ethanol extract of the plant Neoharmsia baronii Drake from the Madagascar forest led to the isolation of seven compounds, characterized as isoflavones and pterocarpans. The structures of the compounds were characterized by using 1D NMR and 2D NMR spectra, mass spectroscopy and in one case, x-ray crystallography. The HSQC and HMBC data along with comparison of these data with reported literature values confirmed the structures. The aforementioned isoflavones and pterocarpans showed varying cytotoxicity to ovarian cancer cell lines, with the isoflavone vogelin E being the most active compound.
The extract of Lopholaena cneorifolia was studied as a part of a cooperative project with the IHVR to identify its chemical composition. Fractionation of this extract led to the isolation of three compounds which were characterized as stilbenes. Their structures were elucidated by using 1D NMR and 2D NMR spectra and mass spectroscopic data.Master of Science
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Fabiano, E. "Synthesis and reactions of amino compounds relating to natural products". Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373890.
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Reddy, P. S. "Synthesis of some biologically active compounds and some natural products". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1986. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3261.
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Heltzel, Carl E. "Structural and synthetic studies of bioactive natural products". Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40067.
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Bioassay directed fractionation of the methyl ethyl ketone extract of Crescentia cujete resulted in the isolation of nine bioactive compounds, and detailed spectroscopic interpretation led to the assignment of their structures as (2S,3S)-3-hydroxy-5,6-dimethoxy dehydroiso-α-Iapachone [2.10], (2R)-5,6- dimethoxydehydroiso-α-Iapachone [2.11], (2R)-5-methoxy dehydroiso-alapachone [2.12], 5-hydroxy-2-(1'-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.13], 2-(1 '-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.14]' 2-isopropenylnaphtho[ 2,3-b ]furan-4,9-dione [2.15], 5-hydroxydehydro-iso-a-Iapachone [2.16], 3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.17], and 9- hydroxy-3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.18]. Compounds 2.10-2.12 are new, showing selective activity towards DNA repair-deficient yeast mutants. The selective DNA damaging activity of known compounds 2.13-2.16 is reported herein for the first time. Compounds 2.17 and 2.18 also show DNA damaging activity, and possess a novel fused ring system.
The bioactive sterols ergosta-5-24(28)-diene-3β,7α-diol [3.1] and 24,28- epoxyergost-5-ene-3β,7α-diol [3.2], originally isolated from Pseudobersama mossambicensis, have been synthesized from stigmasterol. In addition to these sterols, some of their analogs were prepared, and the bioactivity of all compounds were assessed.Ph. D.
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Marucci, C. "NATURAL PRODUCTS AS BUILDING BLOCKS AND LEAD COMPOUNDS FOR API PRODUCTION". Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/480029.
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This dissertetion describes the relevance of natural products as building blocks for production of active pharmaceutical ingredients (API) and as lead compounds.
Chapter 1 offers an introduction on the use of natural products as an effective therapeutic and its role on inspiring the discovery of new drugs.
Chapter 2 focuses on the importance of natural products as lead compounds for active pharmaceutical ingredients (API) production. In the first part of this chapter the synthesis of vincamine, the major indole alkaloid presents in Vinca minor L., will be discussed. In particular the design of experiment (DOE) applied to the synthesis of vincamine starting from vincadifformine will be described. In the second part of this chapter the semi-synthesis of two lignan derivatives, oxomatairesinol and (-)-7-(R)-hydroxymatairesinol, will be reported.
Chapter 3 will focus on the isolation and structural characterization of natural products. The first part describes the isolation and structural characterization of ten indole alkaloids from Voacanga africana (Apocynaceae) seeds. Then the semisynthesis of two cytisine derivatives, N-formyl and N-methyl cytisine, will be described.
Chapter 4 describes the role of natural products as lead compounds. The first section illustrate a project that was performed in the laboratory of Prof. Karl-Heinz Altmann (ETH-Zurich, Switzerland) in the frame of COST Action CM1407 (Challenging Organic Synthesis Inspired By Nature: From Natural Product Chemistry To Drug Discovery). It is related to the synthesis of an analogue of the natural product doliculide, a 16-membered depsipeptide, that has been isolated in 1994 from the Japanese sea hare Dolabella auricularia. The second section will focus on the design and synthesis of hybrid compounds. Particularly it will describe the synthesis of pironetin-dumetorine hybrid compounds whose structures are representative of an optimizable lead scaffold for the discovery of new tubulin binders. Another topic here discussed will be the production of bivalent compounds linking two different units, a pironetin-dumetorine hybrid compound and a drug able to bind beta-tubulin, in order to have a duble action with the aim to limit the the protein-protein interaction between alfa and beta tubulin.
Chapter 5 offers an overview on the role of natural products in drug discovery, in particular related to cancer stem cells (CSCs). In a recent review we summarized the natural products that demonstrate activity against CSCs. Forty-nine different natural products grouped into several structural classes (such as flavonoids, polyketides, terpenes, alkaloids and many others) will be described. Their structure diversity could suggest the synthesis of libraries of new compounds for a huge exploration of the chemical space of CSCs inhibitors.
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Sun, Lin. "Application of New Technologies for the Rapid Identification of Compounds from Natural Sources". Thesis, University of Canterbury. Chemistry, 2009. http://hdl.handle.net/10092/4188.
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This thesis represents a continuation of the work on the isolation and
structure elucidation of potential drug leads from terrestrial fungal sources
that the natural products group at the University of Canterbury has been
engaged in.
Capillary NMR spectroscopy was involved in the research as the main tool
for dereplication and elucidating the structures of novel bioactive
compounds as well as for biosynthetic studies.
Eleven new compounds including five cyclic peptides, four related pyrones
and two diketopiperazines were isolated from the extract of Aspergillus sp.
of endophyte collected from Malaysia. The five peptides F8268-A-1 to
F8268-A-5 showed excellent P388 (HCT116 (ATCC CCL-247) and human
breast cancer, MCF7 (ATCC HTB-22)) activities. Two of the peptides
F8268-A-3 and F8268-A-5 were 4,000 times more active when compared
with commercial drugs (fluorouracil, cisplatin and tamoxifen). The partial
stereochemistries of F8268-A-2 and F8268-A-3 were established by
Marfey’s method.
Four related pyrones isolated from the same extract were also shown to have
good P388 activities. They are related to the known compound NF00659A3.
The relative stereochemistries were established from NOSEY experiments
and the energy-minimised (MM2) model created using CHEM 3D software.
Two new diketopiperazines, F7474-D3 and F7474-D11, also isolated from
the Aspergillus extract did not show activity in the P388 assay. F7474-D11
contained the amino acid Me-kynurenine which is the first report of this
from a natural source. The absolute stereochemistry of F7474-D11 was
elucidated by Marfey’s method. The other diketopiperazine F7474-D3 was similar to the known compound lumpidin, and combined use of ROESY
NMR and Marfey’s method established that the constituent amino acids had
the unusual R configuration.
Dereplication has been greatly improved by the application of capillary
NMR. For example, the HPLC analysis and UV library searching of
compounds from extracts F8095 and F7855 suggested they contained related
compounds belonging to the lasiodiplodin family. However, CapNMR
spectroscopic analysis and AntiMarin database searching revealed that the
compounds from F8095 were all known polyesters while the compounds
from F7855 did belong to the lasiodiplodin family. Two new lasiodiplodins
were found in the F7855 extract,
(3R,4R)-4-hydroxy-de-O-methyl-lasiodiplodin (F7855-4) and
(E)-9-etheno-de-O-methyl-lasiodiplodin (F7855-6). The relative
stereochemistries were elucidated from NMR coupling constant analyses.
Two new dimers (F7090-A and F7090-B) were elucidated from a New
Zealand fungal endophyte. The differences between these two dimers was
their stereochemistries. F7090-A had the same stereochemistries for the
three stereocentres in both parts, while the stereochemistry of F7090-B was
different in the two parts of the dimer.
Biosynthetic studies were also carried out using CapNMR methodology. A
known compound tetrahydrofuran A and a new compound tetrahydrofuran B
from an unidentified New Zealand fungus were used for this study. For the
first time an INADEQUATE NMR experiment was successfully carried out
using CapNMR spectroscopy, thus demonstrating the capability for carrying
out biosynthetic studies on a very small scale (<200 μg of ¹³C-labelled
compound). The implementation of efficient dereplication procedures with CapNMR
methodology is paramount for those working in the field of natural products.
The recent advances that have been made in the dereplication process in the
natural products group at the University of Canterbury are given using
examples from this research and where necessary from other group
members.
Książki na temat "Natural Products - Carbocyclic compounds"
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Mahendra, Rai, i Carpinella Maria Cecilia, red. Naturally occurring bioactive compounds. Amsterdam: Elsevier, 2006.
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Bioactive compounds from natural sources: Natural products as lead compounds in drug discovery. Wyd. 2. Boca Raton: CRC Press, 2011.
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1944-, Mulzer J., red. Natural product synthesis. Berlin: Springer-Verlag, 2005.
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Shahidi, Fereidoon, i Chi-Tang Ho, red. Phenolic Compounds in Foods and Natural Health Products. Washington, DC: American Chemical Society, 2005. http://dx.doi.org/10.1021/bk-2005-0909.
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1951-, Shahidi Fereidoon, Ho Chi-Tang 1944- i American Chemical Society. Division of Agricultural and Food Chemistry, red. Phenolic compounds in foods and natural health products. Washington, DC: American Chemical Society, 2005.
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Pavel, Kočovský, Tureček František i Hájíček Josef, red. Synthesis of natural products: Problems of stereoselectivity. Boca Raton, Fla: CRC Press, 1986.
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Nag, Ahindra. Greener Synthesis of Organic Compounds, Drugs and Natural Products. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003089162.
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Natural products and their active compounds on disease prevention. Hauppauge, N.Y: Nova Science Publishers, 2011.
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From biosynthesis to total synthesis: Strategies and tactics for natural products. Hoboken, New Jersey: John Wiley & Sons, Inc., 2016.
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Formulating, packaging, and marketing of natural cosmetic products. Hoboken, N.J: Wiley, 2011.
Znajdź pełny tekst źródłaCzęści książek na temat "Natural Products - Carbocyclic compounds"
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Lattanzio, Vincenzo. "Phenolic Compounds: Introduction". W Natural Products, 1543–80. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-22144-6_57.
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Sadeghi-aliabadi, Hojjat, i Afsaneh Yegdaneh. "Taxol and Related Compounds". W Natural Products, 3159–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-22144-6_143.
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Ignat, Ioana, Irina Volf i Valentin I. Popa. "Analytical Methods of Phenolic Compounds". W Natural Products, 2061–92. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-22144-6_56.
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Li, Wende, i Trust Beta. "Food Sources of Phenolics Compounds". W Natural Products, 2527–58. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-22144-6_68.
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Pereira, David M., Patrícia Valentão, Mariana Sottomayor, Federico Ferreres i Paula B. Andrade. "Phenolic Compounds in Catharanthus roseus". W Natural Products, 2093–106. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-22144-6_96.
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Routray, Winny, i Valérie Orsat. "Preparative Extraction and Separation of Phenolic Compounds". W Natural Products, 2013–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-22144-6_55.
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Sirikantaramas, Supaart, Mami Yamazaki i Kazuki Saito. "How Plants Avoid the Toxicity of Self-Produced Defense Bioactive Compounds". W Natural Products, 67–82. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781118794623.ch4.
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Dinan, Laurence. "Dereplication and Partial Identification of Compounds". W Natural Products Isolation, 297–321. Totowa, NJ: Humana Press, 2006. http://dx.doi.org/10.1385/1-59259-955-9:297.
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Gill, M. "Aromatic Compounds". W The Chemistry of Natural Products, 60–105. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-2144-6_2.
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Kelly, D. R. "Aliphatic compounds". W The Chemistry of Natural Products, 382–441. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-2144-6_9.
Pełny tekst źródłaStreszczenia konferencji na temat "Natural Products - Carbocyclic compounds"
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Sahidin, I., Syefira Salsabila, W. Wahyuni, M. Hajrul Malaka, Imran i Marianti A. Manggau. "Antibacterial Activity of Methanol Extracts and Compounds of Wualae (Etlingera elatior) Fruits from Southeast Sulawesi-Indonesia". W Bromo Conference, Symposium on Natural Products and Biodiversity. SCITEPRESS - Science and Technology Publications, 2018. http://dx.doi.org/10.5220/0008358901510154.
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Shin, Moonshik, Sungyoung Yoo, Suhyun Ha, Kyungrin Noh i Doheon Lee. "Identifying Potential Bioactive Compounds of Natural Products by Combining ADMET Prediction Methods". W CIKM'15: 24th ACM International Conference on Information and Knowledge Management. New York, NY, USA: ACM, 2015. http://dx.doi.org/10.1145/2811163.2811168.
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van Beelen, ESE, i J. Runco. "Purification & isolation of compounds from natural products using an SFE-SFC workflow". W 67th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA) in cooperation with the French Society of Pharmacognosy AFERP. © Georg Thieme Verlag KG, 2019. http://dx.doi.org/10.1055/s-0039-3399689.
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Ferreira Queiroz, E., R. Huber, L. Marcourt, A. Luscher, A. Koval, N. Hanna, J. Nitschke i in. "Short Lecture “Enzymatically engineered natural products as a source of invaluable bioactive compounds”". W GA – 70th Annual Meeting 2022. Georg Thieme Verlag KG, 2022. http://dx.doi.org/10.1055/s-0042-1758937.
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Azkia, Adinda, Sumi Hudiyono i Sri Handayani. "Study of Enzymatic Synthesis of Glycol – Castor Oil Fatty Acid and Glycol – Palmitic Acid Esters as Emulsifier and Antimicrobial Compounds Using Candida rugosa Lipase EC. 3.1.1.3". W Bromo Conference, Symposium on Natural Products and Biodiversity. SCITEPRESS - Science and Technology Publications, 2018. http://dx.doi.org/10.5220/0008356800050011.
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Blagojević, Julijana, Olga Govedarica, Kojić Predrag, Oskar Bera, Mirjana Jovičić, Sonja Stojanov, Jelena Pavličević i Dragan Govedarica. "INVESTIGATION OF HEMPSEED PROCESS OIL AS THE ALTERNATIVE IN NATURAL RUBBER COMPOUNDING PROCESS". W 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac, 2021. http://dx.doi.org/10.46793/iccbi21.121b.
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Good selection of natural rubber compounds is substantial in rubber industry. Behavior of products based on natural rubber is determined by rubber blending components, especially nature of process oil and concentration of reinforcing fillers. Rubber process oil main purpose is to improve dispersibility of fillers and reduce the viscosity of the rubber compound, therefore enable better processing. Mineral oils are mostly used process oils in natural rubber compounding, but, due to their toxicity and new requirements for preservation of the environment, more and more well-known manufacturers have turned to the use of environmentally friendly process oils. In this study, influence of the hempseed oil as process oil on the products properties in natural rubber compounding was investigated. Properties of hempseed oil as process oil were experimentally determined or calculated. Blending of natural rubber was performed in a laboratory by internal batch mixer, at the constant temperature of 90°C and a rotor speed of 60 rpm. Main rubber properties such as hardness, tensile strength, elongation at break, modulus at 100 and 300% elongation, and rheological properties were determined. Also, voltage and amperage were experimentally measured for calculating power consumption during effective mixing phase in rubber blending.
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Wickramanayake, Kokila Kumudu, Talaat Abdel-Fattah Ahmed i Mohammed Hussain S. A. Al safran. "Effect of Plant Growth Regulators on Callus Induction from Leaf and Petiole explants of Hummeid (Rumex Vesicarius)". W Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2021. http://dx.doi.org/10.29117/quarfe.2021.0059.
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Advancement in plant cell culture technology has permitted the increasing interest in harvesting plant metabolites from cell cultures. This technique is based on in vitro propagation of plant callus which contains many beneficial compounds under sterile conditions as the plant source or raw material for natural product extraction. In vitro production of plant sources acknowledges; conservation of plant species in natural habitats which has been a global issue due to over harvesting of medicinal plants for the natural products manufacturing and production of phytochemicals, independent from seasonal and environmental limitations. Establishment of cell cultures is challenging. The main aim is to establish cell cultures as the starting material for the phytochemical analysis in Rumex Vesicarius.
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Brito, Jordana T., Lucas H. Martorano, Ana Carolina F. de Albuquerque, Carlos Magno Rocha Ribeiro, Rodolfo Goetze Fiorot, José Walkimar de Mesquita Carneiro, Alessandra L. Valverde i Fernando Martins dos Santos Junior. "ESPECTROSCOPIA COMPUTACIONAL APLICADA AO REASSINALAMENTO ESTRUTURAL DE MOLÉCULAS QUIRAIS: HELIANNUOL L". W VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202025.
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In the past, structure determination of natural products was an arduous process depending almost entirely on chemical synthesis, mainly by derivatization and degradation processes, taking years of effort. Recently, structural elucidation of natural products has undergone a revolution. Nowadays, with the combined use of different advanced spectroscopic methods, it became possible to completely assign the structure of natural products using small amounts of sample. However, despite the extraordinary ongoing advances in spectroscopy, the mischaracterization of natural products has been and remains a recurrent problem, especially in the presence of several chiral centers. The misinterpretation of NMR data has resulted in frequent reports addressing the issue of structural reassignment. In this context, a great effort has been devoted to the development of quantum chemical calculations to predict NMR parameters, and thus achieve a more accurate spectral interpretation. In this work, we applied a protocol for theoretical calculations of 1H NMR chemical shifts in order to establish the correct and unequivocal structure of Helianuol L, a member of the Heliannuol’s class, isolated from Helianthus annus. These secondary metabolites present a broad spectrum of biological activities, including the allelochemical activity, making them promising candidates as natural agrochemicals. It is worth mentioning, however, that the process of elucidating the structure of Heliannuol L was based on structural correlations with molecules already known in the literature, where few stereochemical analyses were performed. In this way, based on the fact that other compounds of the Heliannuol’s class had their structure previously reassigned, the verification of the proposed structure of Heliannuol L becomes of great importance.
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Albuquerque, Ana Carolina Ferreira de, José Walkimar de Mesquita Carneiro i Fernando Martins dos Santos Junior. "Estudo do tautomerismo ceto-enólico da 7-epi-clusianona através de cálculos teóricos de deslocamentos químicos de RMN". W VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202063.
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The properties of natural products, including their biological and pharmacological activities, are directly correlated with their chemical structures. Thus, a correct structural characterization of these compounds is a crucial step to the understanding of their biological activities. However, despite the recent advances in spectroscopic techniques, structural studies of natural products can be challenging. This way, theoretical calculations of Nuclear Magnetic Resonance (NMR) parameters (such as chemical shifts and coupling constants) have proven to be a powerful and low-cost tool for the aid to experimental techniques traditionally used for the structural characterization of natural products. One of the several applications of quantum-mechanical calculations of NMR parameters is the study of tautomerism. Since chemical shifts are sensitive to the tautomeric equilibrium, this technique can provide crucial informations. In this work, it was applied a protocol for theoretical calculations of ¹³C chemical shifts in order to study the tautomerism of the natural product 7-epi-clusianone, isolated from Rheedia gardneriana. This protocol consists in a Monte Carlo conformational search, followed by geometry optimization and shielding tensors calculations, both using a density functional level of theory. After comparison of theoretical and experimental data, it was possible to confirm the two tautomers present in equilibrium in the experimental solution. Furthermore, this study highlights how this theoretical protocol can be an effective method in identifying the preferred tautomeric form in solution.
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Alexander, Elinor. "Natural hydrogen exploration in South Australia". W PESA Symposium Qld 2022. PESA, 2022. http://dx.doi.org/10.36404/putz2691.
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South Australia has taken the lead nationally in enabling exploration licences for natural hydrogen. On 11 February 2021 the Petroleum and Geothermal Energy Regulations 2013 were amended to declare hydrogen, hydrogen compounds and by-products from hydrogen production regulated substances under the Petroleum and Geothermal Energy Act 2000 (PGE Act). Companies are now able to apply to explore for natural hydrogen via a Petroleum Exploration Licence (PEL) and the transmission of hydrogen or compounds of hydrogen are now permissible under the transmission pipeline licencing provisions of the PGE Act. The maximum area of a PEL is 10,000 square kilometres so they provide a large acreage position for explorers. PEL applicants need to provide evidence of their technical and financial capacity as well as a 5-year work program which could include field sampling, geophysical surveys (e.g., aeromagnetics, gravity, seismic and MT) and exploration drilling to evaluate the prospectivity of the licence for natural hydrogen. Since February 2021, seven companies have lodged 35 applications for petroleum exploration licences (PELs), targeting natural hydrogen. The first of these licences (PEL 687) over Kangaroo Island and southern Yorke Peninsula was granted to Gold Hydrogen Pty Ltd on 22 July 2021. As well as issuing exploration licences, a key role of the South Australian Department for Energy and Mining is to provide easy access to comprehensive geoscientific data submitted by mineral and petroleum explorers and departmental geoscientists since the State was founded in 1836. Access to old 1920s and 1930s reports, together with modern geophysical and well data has underpinned the current interest in hydrogen exploration. Why the interest? 50-80% hydrogen content was measured in 1931 by the Mines Department in gas samples from wells on Kangaroo Island, Yorke Peninsula and the Otway Basin, potential evidence that the natural formation of hydrogen has occurred. Iron-rich cratons and uranium-rich basement (also a target for geothermal energy explorers) occur in the Archaean-Mesoproterozoic Gawler Craton, Curnamona and Musgrave provinces which are in places fractured and seismically active with deep-seated faults. Sedimentary cover ranges from Neoproterozoic-Recent in age, with thick clastic, carbonate and coal measure successions in hydrocarbon prospective basins and, in places, occurrences of mafic intrusives and extrusives, iron stones, salt and anhydrite which could also be potential sources of natural hydrogen.
Raporty organizacyjne na temat "Natural Products - Carbocyclic compounds"
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Phillips, Donald A., Yitzhak Spiegel i Howard Ferris. Optimizing nematode management by defining natural chemical bases of behavior. United States Department of Agriculture, listopad 2006. http://dx.doi.org/10.32747/2006.7587234.bard.
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This project was based on the hypothesis that nematodes interacting with plants as either parasites or beneficial saprophytes are attracted to their host by natural products. This concept was supported by numerous observations that parasitic nematodes are attracted to root exudates. Our overall goal was to identify nematode sensory compounds from root exudates and to use that information for reducing nematicide applications. We applied skills of the investigators to achieve three specific objectives: 1) Identify nematode behavioral cues (e.g., attractants or repellents) in root exudates; 2) Identify new natural nematicidal compounds; and 3) Combine a natural attractant and a nematicide into a nematode trap. Because saprophytic nematodes benefit plants by mineralizing organic matter, we sought compounds attractive primarily to parasitic nematodes. The project was constructed on several complementary foundations. First, data from Dr. Spiegel’s lab showed that under aseptic conditions Ditylenchus dipsaci, a parasite on onion, is attracted to certain fractions of onion root exudates. Second, PI Phillips had a sizeable collection of natural plant products he had identified from previous work on Rhizobium-legume interactions, which could be tested “off the shelf”. Third, Dr. Ferris had access to aseptic and natural populations of various saprophytic and parasitic nematodes. The project focused on five nematode species: D.dipsaci, Heterodera avenae, and Tylenchulussemipenetransat ARO, and Meloidogyne javanicand Caenorhabditis elegans at UCD. Ten pure plant compounds, mostly flavonoids, were tested on the various nematode species using six different assay systems. Results obtained with assorted test systems and by various scientists in the same test systems were essentially irreproducible. Many convincing, Many convincing, i.e. statistically significant, results in one system or with one investigator could not be repeated with other assays or different people. A recent report from others found that these compounds, plus another 30, were inactive as attractants in three additional parasitic nematode species (Wuyts et al. Nematology 8:89- 101, 2006). Assays designed to test the hypothesis that several compounds together are required to attract nematodes have thus far failed to find a reproducibly active combination. In contrast to results using pure plant compounds, complex unfractionated exudates from aseptic onion root reproducibly attracted D. dipsaci in both the ARO and UCD labs. Onion root exudate collection, separation into HPLC fractions, assays using D. dipsaci and MS-MS experiments proceeded collaboratively between ARO and UCD without any definitive identification of an active compound. The final active fraction contained two major molecules and traces of several other compounds. In the end, analytical studies were limited by the amount of onion root exudate and the complexity of the purification process. These tests showed that aseptic plant roots release attractant molecules, but whether nematodes influence that release, as insects trigger release of attractants from plants, is unknown. Related experiments showed that the saprophyte C. elegans stimulates its prey, Pseudomonas bacteria, to increase production of 2, 4-diacetylphloroglucinol (DAPG) a compound that promotes amino acid exudation by plant roots. It is thus possible that saprophytic nematodes are attracted primarily to their bacterial or fungal prey and secondarily to effects of those microorganisms on root exudation. These observations offer promising avenues for understanding root-zone interactions, but no direct routes to controlling nematodes in agriculture were evident. Extracts from two plant sources, Chrysanthemum coronarium and Sequoia sempervirens, showed nematicidal activity at ARO and UCD, respectively. Attempts to purify an active compound from S. sempervirens failed, but preliminary results from C. coronarium are judged to form a potential basis for further work at ARO. These results highlight the problems of studying complex movement patterns in sentient organisms like nematodes and the issues associated with natural product isolation from complex mixtures. Those two difficulties combined with complications now associated with obtaining US visas, slowed and ultimately limited progress on this project. As a result, US investigators expended only 65% of the $207,400 originally planned for this project. The Israeli side of the project advanced more directly toward its scientific goals and lists its expenditures in the customary financial report.
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Jander, Georg, i Daniel Chamovitz. Investigation of growth regulation by maize benzoxazinoid breakdown products. United States Department of Agriculture, styczeń 2015. http://dx.doi.org/10.32747/2015.7600031.bard.
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Introduction Previous research had suggested that benzoxazinoids, a class of defensive metabolites found in maize, wheat, rye, and wild barley, are not only direct insect deterrents, but also influence other areas of plant metabolism. In particular, the benzoxazinoid 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxa- zin-3(4H)- one (DIMBOA) was implicated in: (i) altering plant growth by interfering with auxin signaling, and (ii) leading to the induction of gene expression changes and secondary plant defense responses. The overall goal of this proposal was to identify mechanisms by which benzoxazinoids influence other aspects of plant growth and defense. Specifically, the following hypotheses were proposed to be tested as part of an approved BARD proposal: Benzoxazinoid breakdown products directly interfere with auxin perception Global changes in maize and barley gene expression are induced by benzoxazinoid activation. There is natural variation in the maize photomorphogenic response to benzoxazinoids. Although the initial proposal included experiments with both maize and barley, there were some technical difficulties with the proposed transgenic barley experiments and most of the experimental results were generated with maize. Summary of major findings Previous research by other labs, involving both maize and other plant species, had suggested that DIMBOA alters plant growth by interfering with auxin signaling. However, experiments conducted in both the Chamovitz and the Jander labs using Arabidopsis and maize, respectively, were unable to confirm previously published reports of exogenously added DIMBOA effects on auxin signaling. Nevertheless, analysis of bx1 and bx2 maize mutant lines, which have almost no detectable benzoxazinoids, showed altered responses to blue light signaling. Transcriptomic analysis of maize mutant lines, variation in inbred lines, and responses to exogenously added DIMBOA showed alteration in the transcription of a blue light receptor, which is required for plant growth responses. This finding provides a novel mechanistic explanation of the trade-off between growth and defense that is often observed in plants. Experiments by the Jander lab and others had demonstrated that DIMBOA not only has direct toxicity against insect pests and microbial pathogens, but also induces the formation of callose in both maize and wheat. In the current project, non-targeted metabolomic assays of wildtype maize and mutants with defects in benzoxazinoid biosynthesis were used to identify unrelated metabolites that are regulated in a benzoxazinoid-dependent manner. Further investigation identified a subset of these DIMBOA-responsive compounds as catechol, as well as its glycosylated and acetylated derivatives. Analysis of co-expression data identified indole-3-glycerol phosphate synthase (IGPS) as a possible regulator of benzoxazinoid biosynthesis in maize. In the current project, enzymatic activity of three predicted maize IGPS genes was confirmed by heterologous expression. Transposon knockout mutations confirmed the function of the maize genes in benzoxazinoid biosynthesis. Sub-cellular localization studies showed that the three maize IGPS proteins are co-localized in the plastids, together with BX1 and BX2, two previously known enzymes of the benzoxazinoid biosynthesis pathway. Implications Benzoxazinoids are among the most abundant and effective defensive metabolites in maize, wheat, and rye. Although there is considerable with-in species variation in benzoxazinoid content, very little is known about the regulation of this variation and the specific effects on plant growth and defense. The results of this research provide further insight into the complex functions of maize benzoxazinoids, which are not only toxic to pests and pathogens, but also regulate plant growth and other defense responses. Knowledge gained through the current project will make it possible to engineer benzoxazinoid biosynthesis in a more targeted manner to produce pest-tolerant crops without negative effects on growth and yield.
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Naim, Michael, Andrew Spielman, Shlomo Nir i Ann Noble. Bitter Taste Transduction: Cellular Pathways, Inhibition and Implications for Human Acceptance of Agricultural Food Products. United States Department of Agriculture, luty 2000. http://dx.doi.org/10.32747/2000.7695839.bard.
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Historically, the aversive response of humans and other mammals to bitter-taste substances has been useful for survival, since many toxic constituents taste bitter. Today, the range of foods available is more diverse. Many bitter foods are not only safe for consumption but contain bitter constituents that provide nutritional benefits. Despite this, these foods are often eliminated from our current diets because of their unacceptable bitterness. Extensive technology has been developed to remove or mask bitterness in foods, but a lack of understanding of the mechanisms of bitterness perception at the taste receptor level has prevented the development of inhibitors or efficient methods for reducing bitterness. In our original application we proposed to: (a) investigate the time course and effect of selected bitter tastants relevant to agricultural products on the formation of intracellular signal molecules (cAMP, IP3, Ca2+) in intact taste cells, in model cells and in membranes derived therefrom; (b) study the effect of specific bitter taste inhibitors on messenger formation and identify G-proteins that may be involved in tastant-induced bitter sensation; (c) investigate interactions and self-aggregation of bitter tastants within membranes; (d) study human sensory responses over time to these bitter-taste stimuli and inhibitors in order to validate the biochemical data. Quench-flow module (QFM) and fast pipetting system (FPS) allowed us to monitor fast release of the aforementioned signal molecules (cGMP, as a putative initial signal was substituted for Ca2+ ions) - using taste membranes and intact taste cells in a time range below 500 ms (real time of taste sensation) - in response to bitter-taste stimulation. Limonin (citrus) and catechin (wine) were found to reduce cellular cAMP and increase IP3 contents. Naringin (citrus) stimulated an IP3 increase whereas the cheese-derived bitter peptide cyclo(leu-Trp) reduced IP3 but significantly increased cAMP levels. Thus, specific transduction pathways were identified, the results support the notion of multiple transduction pathways for bitter taste and cross-talk between a few of those transduction pathways. Furthermore, amphipathic tastants permeate rapidly (within seconds) into liposomes and taste cells suggesting their availability for direct activation of signal transduction components by means of receptor-independent mechanisms within the time course of taste sensation. The activation of pigment movement and transduction pathways in frog melanophores by these tastants supports such mechanisms. Some bitter tastants, due to their amphipathic properties, permeated (or interacted with) into a bitter tastant inhibitor (specific phospholipid mixture) which apparently forms micelles. Thus, a mechanism via which this bitter taste inhibitor acts is proposed. Human sensory evaluation experiments humans performed according to their 6-n-propyl thiouracil (PROP) status (non-tasters, tasters, super-tasters), indicated differential perception of bitterness threshold and intensity of these bitter compounds by different individuals independent of PROP status. This suggests that natural products containing bitter compounds (e.g., naringin and limonin in citrus), are perceived very differently, and are in line with multiple transduction pathways suggested in the biochemical experiments. This project provides the first comprehensive effort to explore the molecular basis of bitter taste at the taste-cell level induced by economically important and agriculturally relevant food products. The findings, proposing a mechanism for bitter-taste inhibition by a bitter taste inhibitor (made up of food components) pave the way for the development of new, and perhaps more potent bitter-taste inhibitors which may eventually become economically relevant.
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Paterek, J. Robert. L51963 Environmental Benign Mitigation of Microbiologically Influenced Corrosion (MIC). Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), wrzesień 2002. http://dx.doi.org/10.55274/r0011299.
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The objective is to develop and evaluate environmental benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) on the internal surfaces of metallic natural gas pipelines. The goal is one or more products that can be applied to maintain the structure and dependability of the natural gas infrastructure. The technical approach for this year has been to evaluate a number of methods to fractionate and concentrate the components found in the pepper extracts. The separation methods considered include size exclusion chromatography, hygroscopic and hydrophobic extraction with HPLC fractionation and analysis; preparative HPLC; and other methods based on the chemical class of compounds to be evaluated. The first classes to be studied are: terpenoids; phenolics; fatty metabolites; alkaloids; and other products of secondary metabolism in plants. Other methods to be reviewed as needed include: planar chromatography; supercritical water and CO2 extraction; and ion-exchange methods. A review of the patent literature and scientific databases found no evidence that any of the potential products have been patented, indicating potential for establishment of a strong intellectual property position. The work plan for the continuation of specific tasks of this project for two additional years was completed and accepted for funding. Laboratory testing protocols for control of biofilm formation and/or biocidal activities for both aerobic and anaerobic microorganisms known to support MIC were codified.
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Annunziato, Dominick. HPLC Sample Prep and Extraction SOP v1.3 for Fungi. MagicMyco, sierpień 2023. http://dx.doi.org/10.61073/sopv1.3.08.11.2023.
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medicine, industry, and biotechnology. Fungi produce a wide range of bioactive compounds, such as alkaloids, antibiotics, antifungals, immunomodulators, anticancer agents, enzymes, and vitamins. However, these compounds are often locked inside the fungal cell wall, which is composed of chitin, a tough substance that is dif�icult to digest by humans1. Therefore, it is essential to have a good extraction technique that can break down the chitin and release the valuable compounds from the fungi, this is especially essential in the laboratory for accurate lab assays and potency determination during routine HPLC chromatography analysis. During licensure and/ or certi�ication any given lab will be required to take a pro�iciency test which gauges the lab’s pro�iciency at measuring a given matrices for accurate evaluation. They evaluate our abilities to run the gear and accurately measure the potency of what was extracted; however, at the time of this writing none existed for extraction of the fungal material itself, so this remains a variable between testing labs. It is important that we openly share our extraction techniques for evaluating fungi materials speci�ically for the clean extraction of active alkaloids for which potency can be measure via chromatography and/or spectrometry devices. In this way hopefully creating less variables between testing lab and more concise results. In this paper, we present a novel sample prep and extraction technique for fungi that uses speci�ic solvent composition in conjunction with M.A.E (microwave assisted extraction) in 75% methanol , 25% water which helps break the cell wall to release the compounds. Also used is an ultrasonication unit and vortex mixer. Our technique quickly releases all the available alkaloids for accurate chromatography measurements in just two hours, forty-�ive minutes with minimal handling. We demonstrate the effectiveness and ef�iciency of our technique by applying it to magic mushroom fruit bodies for the extraction of tryptamines namely psilocybin and its active derivative psilocin; however, this technique can be used for other species of fungi and compounds like Cordyceps/ cordycepin or Lions’ mane/ erinacines, etc.. We also compare our technique with other popular methods in terms of extraction techniques, digestion times and solvent compositions. Our results show that our technique is superior to the others in terms of time and effectiveness while pulling all the active compounds and not degrading them. Our extraction technique for fungi chromatography analysis offers a new and improved way to access the natural products of fungi and explore their potential for various biotechnological applications. We hope that our technique will inspire further research and innovation in the field of fungal extraction and natural product.
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Phillips, Donald, i Yoram Kapulnik. Using Flavonoids to Control in vitro Development of Vesicular Arbuscular Mycorrhizal Fungi. United States Department of Agriculture, styczeń 1995. http://dx.doi.org/10.32747/1995.7613012.bard.
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Vesicular-arbuscular mycorrhizal (VAM) fungi and other beneficial rhizosphere microorganisms, such as Rhizobium bacteria, must locate and infect a host plant before either symbiont profits. Although benefits of the VAM association for increased phosphorous uptake have been widely documented, attempts to improve the fungus and to produce agronomically useful amounts of inoculum have failed due to a lack of in vitro production methods. This project was designed to extend our prior observation that the alfalfa flavonoid quercetin promoted spore germination and hyphal growth of VAM fungi in the absence of a host plant. On the Israeli side of the project, a detailed examination of changes in flavonoids and flavonoid-biosynthetic enzymes during the early stages of VAM development in alfalfa found that VAM fungi elicited and then suppressed transcription of a plant gene coding for chalcone isomerase, which normally is associated with pathogenic infections. US workers collaborated in the identification of flavonoid compounds that appeared during VAM development. On the US side, an in vitro system for testing the effects of plant compounds on fungal spore germination and hyphal growth was developed for use, and intensive analyses of natural products released from alfalfa seedlings grown in the presence and absence of microorganisms were conducted. Two betaines, trigonelline and stachydrine, were identified as being released from alfalfa seeds in much higher concentrations than flavonoids, and these compounds functioned as transcriptional signals to another alfalfa microsymbiont, Rhizobium meliloti. However, these betaines had no effect on VAM spore germination or hyphal growth i vitro. Experiments showed that symbiotic bacteria elicited exudation of the isoflavonoids medicarpin and coumestrol from legume roots, but neither compound promoted growth or germination of VAM fungi in vitro. Attempts to look directly in alfalfa rhizosphere soil for microbiologically active plant products measured a gradient of nod-gene-inducing activity in R. meliloti, but no novel compounds were identified for testing in the VAM fungal system in vitro. Israeli field experiments on agricultural applications of VAM were very successful and developed methods for using VAM to overcome stunting in peanuts and garlic grown in Israel. In addition, deleterious effects of soil solarization on growth of onion, carrot and wheat were linked to effects on VAM fungi. A collaborative combination of basic and applied approaches toward enhancing the agronomic benefits of VAM asociations produced new knowledge on symbiotic biology and successful methods for using VAM inocula under field conditions
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Brydie, Dr James, Dr Alireza Jafari i Stephanie Trottier. PR-487-143727-R01 Modelling and Simulation of Subsurface Fluid Migration from Small Pipeline Leaks. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), maj 2017. http://dx.doi.org/10.55274/r0011025.
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The dispersion and migration behavior of hydrocarbon products leaking at low rates (i.e. 1bbl/day and 10 bbl/day) from a pipeline have been studied using a combination of experimental leakage tests and numerical simulations. The focus of this study was to determine the influence of subsurface engineered boundaries associated with the trench walls, and the presence of a water table, upon the leakage behavior of a range of hydrocarbon products. The project numerically modelled three products including diesel, diluted bitumen (dilbit) and gasoline; which were chosen to span a range of fluid types and viscosities. Laboratory simulations of leakage were carried out for the most viscous product (i.e. dilbit) in order to capture plume dispersion in semi-real time, and to allow numerical predictions to be assessed against experimental data. Direct comparisons between observed plume dimensions over time and numerically predicted behavior suggested a good match under low moisture conditions, providing confidence that the numerical simulation was sufficiently reliable to model field-scale applications. Following a simulated two year initialization period, the leakage of products, their associated gas phase migration, thermal and geomechanical effects were simulated for a period of 365 days. Comparisons between product leakage rate, product type and soil moisture content were made and the spatial impacts of leakage were summarized. Variably compacted backfill within the trench, surrounded by undisturbed and more compacted natural soils, results porosity and permeability differences which control the migration of liquids, gases, thermal effects and surface heave. Dilbit migration is influenced heavily by the trench, and also its increasing viscosity as it cools and degases after leakage. Diesel and gasoline liquid plumes are also affected by the trench structure, but to a lesser extent, resulting in wider and longer plumes in the subsurface. In all cases, the migration of liquids and gases is facilitated by higher permeability zones at the base of the pipe. Volatile Organic Compounds (VOCs) migrate along the trench and break through at the surface within days of the leak. Temperature changes within the trench may increase due liquid migration, however the change in predicted temperature at the surface above the leak is less than 0.5�C above background. For gasoline, the large amount of degassing and diffusion through the soil results in cooling of the soil by up to 1�C. Induced surface displacement was predicted for dilbit and for one case of diesel, but only in the order of 0.2cm above baseline. Based upon the information gathered, recommendations are provided for the use and placement of generic leak detection sensor types (e.g liquid, gas, thermal, displacement) within the trench and / or above the ground surface. The monitoring locations suggested take into account requirements to detect pipeline leakage as early as possible in order to facilitate notification of the operator and to predict the potential extent of site characterization required during spill response and longer term remediation activities.
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Borch, Thomas, Yitzhak Hadar i Tamara Polubesova. Environmental fate of antiepileptic drugs and their metabolites: Biodegradation, complexation, and photodegradation. United States Department of Agriculture, styczeń 2012. http://dx.doi.org/10.32747/2012.7597927.bard.
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Many pharmaceutical compounds are active at very low doses, and a portion of them regularly enters municipal sewage systems and wastewater-treatment plants following use, where they often do not fully degrade. Two such compounds, CBZ and LTG, have been detected in wastewater effluents, surface waters, drinking water, and irrigation water, where they pose a risk to the environment and the food supply. These compounds are expected to interact with organic matter in the environment, but little is known about the effect of such interactions on their environmental fate and transport. The original objectives of our research, as defined in the approved proposal, were to: Determine the rates, mechanisms and products of photodegradation of LTG, CBZ and selected metabolites in waters exposed to near UV light, and the influence of DOM type and binding processes on photodegradation. Determine the potential and pathways for biodegradation of LTG, CBZ and selected metabolites using a white rot fungus (Pleurotusostreatus) and ADP, and reveal the effect of DOM complexation on these processes. Reveal the major mechanisms of binding of LTG, CBZ and selected metabolites to DOM and soil in the presence of DOM, and evaluate the effect of this binding on their photodegradation and/or biodegradation. We determined that LTG undergoes relatively slow photodegradation when exposed to UV light, and that pH affects each of LTG’s ability to absorb UV light, the efficiency of the resulting reaction, and the identities of LTG’sphotoproducts (t½ = 230 to 500 h during summer at latitude 40 °N). We observed that LTG’sphotodegradation is enhanced in the presence of DOM, and hypothesized that LTG undergoes direct reactions with DOM components through nucleophilic substitution reactions. In combination, these data suggest that LTG’s fate and transport in surface waters are controlled by environmental conditions that vary with time and location, potentially affecting the environment and irrigation waters. We determined that P. ostreatusgrows faster in a rich liquid medium (glucose peptone) than on a natural lignocellulosic substrate (cotton stalks) under SSF conditions, but that the overall CBZ removal rate was similar in both media. Different and more varied transformation products formed in the solid state culture, and we hypothesized that CBZ degradation would proceed further when P. ostreatusand the ᵉⁿᶻʸᵐᵃᵗⁱᶜ ᵖʳᵒᶠⁱˡᵉ ʷᵉʳᵉ ᵗᵘⁿᵉᵈ ᵗᵒ ˡⁱᵍⁿⁱⁿ ᵈᵉᵍʳᵃᵈᵃᵗⁱᵒⁿ. ᵂᵉ ᵒᵇˢᵉʳᵛᵉᵈ ¹⁴C⁻Cᴼ2 ʳᵉˡᵉᵃˢᵉ ʷʰᵉⁿ ¹⁴C⁻ᶜᵃʳᵇᵒⁿʸˡ⁻ labeled CBZ was used as the substrate in the solid state culture (17.4% of the initial radioactivity after 63 days of incubation), but could not conclude that mineralization had occurred. In comparison, we determined that LTG does not degrade in agricultural soils irrigated with treated wastewater, but that P. ostreatusremoves up to 70% of LTG in a glucose peptone medium. We detected various metabolites, including N-oxides and glycosides, but are still working to determine the degradation pathway. In combination, these data suggest that P. ostreatuscould be an innovative and effective tool for CBZ and LTG remediation in the environment and in wastewater used for irrigation. In batch experiments, we determined that the sorption of LTG, CBZ and selected metabolites to agricultural soils was governed mainly by SOM levels. In lysimeter experiments, we also observed LTG and CBZ accumulation in top soil layers enriched with organic matter. However, we detected CBZ and one of its metabolites in rain-fed wheat previously irrigated with treated wastewater, suggesting that their sorption was reversible, and indicating the potential for plant uptake and leaching. Finally, we used macroscale analyses (including adsorption/desorption trials and resin-based separations) with molecular- level characterization by FT-ICR MS to demonstrate the adsorptive fractionation of DOM from composted biosolids by mineral soil. This suggests that changes in soil and organic matter types will influence the extent of LTG and CBZ sorption to agricultural soils, as well as the potential for plant uptake and leaching.
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Hefetz, Abraham, i Justin O. Schmidt. Use of Bee-Borne Attractants for Pollination of Nonrewarding Flowers: Model System of Male-Sterile Tomato Flowers. United States Department of Agriculture, październik 2003. http://dx.doi.org/10.32747/2003.7586462.bard.
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The use of bee natural product for enhancing pollination is especially valuable in problematic crops that are generally avoided by bees. In the present research we attempted to enhance bee visitation to Male Sterile (M-S) tomato flowers generally used in the production of hybrid seeds. These flowers that lack both pollen and nectar are unattractive to bees that learn rapidly to avoid them. The specific objects were to elucidate the chemical composition of the exocrine products of two bumble bee species the North American Bombus impatiens and the Israeli B. terrestris. Of these, to isolate and identify a bee attractant which when sprayed on M-S tomato flowers will enhance bee visitation, and to provide a procedure of the pheromone application regime. During the research we realized that our knowledge of B. impatiens is too little and we narrowed the objective to learning the basic social behavior of the bees and the pattern of foraging in a flight chamber and how it is affected by biogenic amines. Colonies of B. impatiens are characterized by a high number of workers and a relatively small number of queens. Size differences between queens and workers are pronounced and the queen seems to have full control over egg laying. Only about 9% of the workers in mature colonies had mature oocytes, and there were no signs of a "competition phase" as we know in B. terrestris. Queens and workers differ in their exocrine bouquet. Queen's Dufour's gland possesses a series of linear, saturated and unsaturated hydrocarbons whereas that of workers contains in addition a series of wax-type esters. Bees were trained to either visit or avoid artificially scented electronic flowers in a flight chamber. Since bee also learned to avoid scented non-rewarding flowers we attempted to interfere with this learning. We tested the effect of octopamine, a biogenic amine affecting bee behavior, on the choice behavior of free-flying bumblebees. Our results show that octopamine had no significant effect on the bees' equilibrium choice or on the overall rate of the behavioral change in response to the change in reward. Rather, octopamine significantly affected the time interval between the change in reward status and the initiation of behavioral change in the bee. In B. terrestris we studied the foraging pattern of the bees on tomato flowers in a semi commercial greenhouse in Yad Mordechai. Bee learned very quickly to avoid the non- rewarding M-S flowers, irrespective of their arrangement in the plot, i.e., their mixing with normal, pollen bearing flowers. However, bees seem to "forget" this information during the night since the foraging pattern repeats itself the next morning. Several exocrine products were tested as visitation enhancers. Among these, tarsal gland extracts are the most attractive. The compounds identified in the tarsal gland extract are mostly linear saturated hydrocarbons with small amounts of unsaturated ones. Application was performed every second day on leaves in selected inflorescences. Bee visitation increased significantly in the treated inflorescences as compared to the control, solvent treated. Treatment of the anthers cone was more effective than on the flower petals or the surrounding leaves. Methanol proved to be a non-flower-destructive solvent. We have shown that bumble bees (B. terrestris) can be manipulated by bee-borne attractants to visit non-rewarding flowers. We have further demonstrated that the bees learning ability can be manipulated by applying exogenously octopamine. Both methods can be additively applied in enhancing pollination of desired crops. Such manipulation will be especially useful in tomato cultivation for hybrid seed production.