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Atividade antimicrobiana de extratos vegetais e toxicidade em modelos alternativos / Antimicrobial activity of plant extracts and toxicity in alternative modelsGiordani, Claudia 22 February 2017 (has links)
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Previous issue date: 2017-02-22 / Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul - FAPERGS / As plantas medicinais têm sido utilizadas desde épocas remotas, e atualmente são alvos da pesquisa para obtenção de novos compostos bioativos, para combater, principalmente, patógenos resistentes. Nessa realidade, existe a preocupação do uso das plantas sem a avaliação química e toxicológica. Assim, este trabalho teve por objetivo avaliar a suscetibilidade dos isolados clínicos resistentes aos fármacos convencionais frente a extratos hidroalcoólicos de Schinus terebinthifolius (ST), Eugenia uniflora (EU), Polygonum hydropiperoides (PH), Baccharis trimera (BT), Equisetum hyemale (EH) e Solidago chilensis (SC), e determinar a composição química, atividade antioxidante e toxicidade in vitro e in vivo dos extratos. Para avaliação da suscetibilidade in vitro das bactérias (n=58) e fungos (n=30) realizou-se o teste de microdiluição em caldo (CLSI, M07-09, M38-A2 e M27-A3). Os níveis de atividade antioxidante foram identificados pelos testes com DPPH e ATBS, e os compostos químicos identificados através de cromatografia líquida e gasosa. A determinação da toxicidade dos extratos in vitro foi avaliada em células Vero (teste do MTT), em células espermáticas (parâmetros de motilidade = CASA, e de estrutura = citometria de fluxo), e em eritrócitos caninos (capacidade hemaglutinante e hemolítica). A toxicidade in vivo foi avaliada em ovos de codorna embrionados. Os extratos de ST, PH e EU apresentaram ação fungiostática e fungicida sobre Sporothrix brasiliensis, Malassezia pachydermatis e dermatófitos (0,19-100 mg.mL-1), bacteriostática e bactericida em Gram-positivas e Gram-negativas (0,03-7,5 mg.mL-1), além de níveis antioxidantes superiores, com presença de compostos fenólicos e flavonoides. Em relação a toxicidade in vitro, houve alterações nas concentrações mais altas, principalmente nos EU e ST. No ensaio de toxicidade espermática observou-se redução na viabilidade celular e motilidade espermática, reação no acrossoma, aumento de fluidez da membrana, diminuição do potencial de membrana mitocondrial, sendo observadas alterações a partir da concentração 1,5 mg.mL-1 para ST, ao contrário de PH, onde só se observam alterações na motilidade a partir de 6,2 mg.mL-1. Em concentrações ≤0,08 mg.mL-1 (ST, EU e PH) não foram observadas reações de hemaglutinação e hemólise, sendo PH o menos tóxico. Na avaliação in vivo, nenhum destes extratos demonstrou efeitos tóxicos nos embriões (0,94-7,5 mg.mL-1). Os extratos de ST, EU e PH, apresentam-se promissores, com possibilidade de isolamento de substâncias antimicrobianas e antioxidantes. / Medicinal plants have been used since remote times, and are currently the target of the research to obtain new bioactive compounds, to combat, mainly, resistant pathogens. In this reality, there is concern about the use of plants without chemical and toxicological evaluation. The objective of this study was to evaluate the susceptibility of the clinical isolates resistant to conventional drugs against hydroalcoholic extracts of Schinus terebinthifolius (ST), Eugenia uniflora (EU), Polygonum hydropiperoides (PH), Baccharis trimera (BT), Equisetum hyemale (EH) and Solidago chilensis (SC), and to determine the chemical composition, antioxidant activity and in vitro and in vivo toxicity of the extracts. The broth microdilution test (CLSI, M07-09, M38-A2 and M27-A3) was used to evaluate the in vitro susceptibility of bacteria (n = 58) and fungi (n = 30). The levels of antioxidant activity were identified by the DPPH and ATBS tests, and the chemical compounds identified by liquid and gas chromatography. In vitro toxicity determination of extracts was evaluated in Vero cells (MTT test), sperm cells (motility parameters = CASA, and structure = flow cytometry), and in canine erythrocytes (haemagglutination and haemolytic capacity). In vivo toxicity was evaluated in embryonated quail eggs. The extracts of ST, PH and US presented fungiostatic and fungicidal action on Sporothrix brasiliensis, Malassezia pachydermatis and dermatophytes (0,19-100 mg.mL-1), bacteriostatic and bactericidal on Gram-positive and Gram-negative (0.03- 7.5 mg.mL-1), in addition to superior antioxidant levels, with presence of phenolic compounds and flavonoids. In relation to in vitro toxicity, there were changes in the highest concentrations, mainly in the US and ST. In the sperm toxicity assay, a reduction in cell viability and sperm motility was observed, acrosome reaction, increased membrane fluidity, decreased mitochondrial membrane potential, and changes from 1.5 mg.mL-1 to ST, unlike PH, where there are only changes in motility from 6.2 mg.mL-1. At concentrations ≤0.08 mg.mL-1 (ST, EU and PH) no haemagglutination and haemolysis reactions were observed, PH being the least toxic. In the in vivo evaluation, none of these extracts showed toxic effects on the embryos (0.94-7.5 mg.mL-1). The extracts of ST, EU and PH, are promising, with the possibility of isolation of antimicrobial substances and antioxidants.
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Phytochemistry and biological activities of selected Lebanese plant species (Crataegus azarolus L. and Ephedra campylopoda) / Phytochimie et activités biologiques de plantes libanaises sélectionnées (Crataegus azarolus L. et Ephedra campylopoda)Kallassy, Hany 22 September 2017 (has links)
Les plantes ont longtemps été connues pour leur arsenal naturel, servant d'une source importante de substances nutritives et de composants thérapeutiques. Depuis il y a environ 600 000 ans, les hommes ont utilisé des plantes comme médicaments. Aujourd'hui, les médicaments issus des plantes sont largement présents dans le monde entier où environ 80 % de la population mondiale utilisent des plantes comme médicaments primaires. Cette valeur médicinale est principalement attribuée au fait que les plantes sont riches en composés phytochimiques bioactifs. Le Liban, en raison de son emplacement géographique et des caractéristiques environnementales importantes, est doté d'une flore riche. Des centaines de plantes libanaises ont été définies en termes de composition chimique et de valeur médicinale. Dans cette étude, nous avons caractérisé le contenu phytochimique de deux espèce de plantes libanaises, Crataegus azarolus L et Ephedra campylopoda. Des feuilles fraîches tirées de chaque espèce de plante, ont été dissoutes dans trois solvants différents : eau, éthanol et méthanol. La composition phytochimique des extraits a été examinée en utilisant la chromatographie liquide à haute performance (HPLC) et le contenu d'huile essentielle a été déterminé par la chromatographie gazeuse (GC) couplée avec la spectrométrie de masse (MS). Le radical DPPH a été utilisé pour évaluer le potentiel antioxydant. Le potentiel anti-inflammatoire a été évalué en mesurant les quantités sécrétées de la prostaglandine E2 (PGE2) en utilisant la technique ELISA, aussi bien qu'en déterminant les niveaux d’expression d’ARNm de cytokines pro-inflammatoires (IL-, IL-ß et IL-6), de chimiokines (CCL3 et CCL4) et de COX-2 et iNOS par RT-PCR quantitative (qRT-PCR). Un essai de viabilité cellulaire par le test XTT a été effectué pour déterminer l'effet antiprolifératif de chaque extrait. Nous avons observé un contenu phytochimique important à partir des extraits alcooliques. En parallèle, nous avons mis en évidence des activités biologiques significatives avec ces extraits alcooliques exerçant in vitro des effets antioxydants, anti-inflammatoires et antiprolifératifs.En résumé, nos observations suggèrent un potentiel prometteur pour Crataegus azarolus L et Ephedra campylopoda pour le traitement de maladies associées au stress oxydatif, à un processus inflammatoire ou à une prolifération cellulaire non contrôlée. Cependant, in vivo, la caractérisation de ces effets est indispensable. / Plants have long been known for their natural arsenal, serving as an important source of nutrients and therapeutic components. Since about 600,000 years ago, humans used plants as medicines. Plant medicines correspond to the preparations issued from those plants. Today, plant medicines are widely worldwide where about 80% of the world's population uses herbs as primary medicines. This medicinal value is mainly attributed to the fact that plants are rich inbioactive phytochemicals. Lebanon, due to its geographical location and important environmental characteristics, is endowed with a rich flora. Hundreds of Lebanese plants have been defined in terms of their chemical composition and medicinal value where many other species are yet to be characterized.In this study, we aimed at characterizing the phytochemical content and therapeutic value of two Lebanese plant species, Crataegus azarolus L and Ephedra campylopoda. Fresh leaves, derived from each plant species, were dissolved in three different solvents distilled water, ethanol, and methanol. The phytochemical composition of different extracts issued from the two plant species was examined using high performance liquid chromatography (HPLC) and the essential oil content was determined by gas chromatography (GC) coupled with mass spectrometry (MS). DPPH radical scavenging and Fe2+ chelating activity assays were used to assess the antioxidant potential. Anti-inflammatory potential was evaluated by measuring the secreted amounts of the pro-inflammatory mediator PGE2 using ELISA technique, as well as by assaying the mRNA levels of the pro-inflammatory cytokines (IL-α, IL-β and IL-6), chemokines (CCL3 and CCL4) and inflammation-sensitive COX-2 and iNOS using quantitative RT-PCR (qRT-PCR). XTT viability assay was carried out to determine the anti-proliferative effect of each extract. For both plant species, we observed an important phytochemical content with thealcoholic (methanol and ethanol) extracts being more rich in bioactive molecules. In parallel, the two plant species exhibited significant biological activities with the alcoholic extracts exerting important, in vitro, antioxidant, anti-inflammatory and anti-proliferative effects.Collectively, our observations suggest a promising potential for Crataegus azarolus L and Ephedra campylopoda during treatment of diseases associated with oxidative stress, aberrant inflammatory responses or uncontrolled cell proliferation. However, further in vivo characterization of these effects is indispensable.
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Chemical and biological investigation into some selected African indigenous medicinal plantsBabajide, Jelili Olalekan January 2009 (has links)
Philosophiae Doctor - PhD / African medicinal plants are commonly used throughout Africa to treat a variety of ailments including wounds and ulcers, cough and chest complaints, gingivitis, fever and gonorrhoea, indication all related to infection and inflammation. In screening several plant species from an inventory of common medicinal plants from both South and West Africa for diverse medicinal purposes, 6 plants were selected because of their interesting and useful ethnomedicinal values. / South Africa
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An Investigation of Pulp Mill Effluents and Their Wood Feedstocks as Potential Neuroendocrine Disruptors of the Fish Reproductive AxisWaye, Andrew January 2015 (has links)
Common observations of reduced gonad size and spawning inhibition in wild and laboratory raised fish exposed to pulp mill effluents indicate that reproductive neuroendocrine signalling pathways may be upset. This thesis supported the neuroendocrine disruption of reproduction hypothesis by identifying potential disruptors and targets where these impacts may occur. A mechanistic study of the in vivo fathead minnow (FHM) spawning assay used by industry to assess effluent quality showed that ovulation, but not milt production, was impaired. This finding supported the hypothesis that the neuroendocrine cascade that triggers ovulation may be disrupted. I hypothesized that neuroactive constituents previously described in effluents were originating in wood feedstocks and neuroactive extracts of hardwood and conifer feedstocks were identified. Phytochemicals associated with effluents were neuroactive. Structurally similar phenolic phytochemicals showed monoamine oxidase (MAO) inhibition, and resin acid diterpenes displayed glutamic acid decarboxylase (GAD) inhibition. Inhibitors of these enzymes may have impacts on the control of reproduction since MAO metabolizes dopamine, an inhibitor of the neuroendocrine reproductive axis, while GAD synthesizes -aminobutyric acid (GABA), a stimulator of this axis. Bioassay-guided fractionations of effluents and wood feedstocks identified that medium polar extracts of primary- and secondary-treated effluents and balsam fir feedstock contained high GAD inhibitory activity. This activity was associated with chemically complex fractions rather than single active principles. Advanced metabolomic comparison of medium polar extracts of feedstock and treated effluent identified 15 common plant metabolites, demonstrating that phytochemicals entering the mill in wood are surviving pulp production and effluent treatment processes and may be responsible for observed GAD inhibition. Discriminant metabolomics analysis identified 4-acetylpyridine, a novel compound to be described in effluents, as well as two other tentatively identified compounds, as chemical markers of GAD inhibitory effluent fractions. Five tentatively identified chemical markers and (+)-lariciresinol were found in inhibitory balsam fir feedstock fractions. Neuroendocrine pathways that control reproduction in fish, such as dopamine and GABA pathways, are also important drug targets for the treatment of neurological disorders in mammals; therefore these results also have implications for the development of natural health products from phytochemicals and tree extracts common to Canadian forests. By using an interdisciplinary approach (phytochemistry, neuroendocrinology, ecotoxicology), I was able to explore the various implications of my research on the fields of natural health products chemistry and aquatic toxicology.
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Systematics of Hypoxis (Hypoxidaceae) in southern AfricaSingh, Yashica 17 July 2009 (has links)
Hypoxis is a diverse group of perennial geophytic herbs characterised by hairy leaves and yellow (seldom white) star-shaped flowers. The genus comprises about 70 species with a distribution in the warmer parts of all continents except Europe. With one third of the taxa, the Flora of southern Africa region (South Africa, Swaziland, Lesotho, Namibia and Botswana) is the most species rich for the genus world-wide. A taxonomic revision of the genus in southern Africa was undertaken; 28 species are recognised, one, H. nivea having been newly described. Morphological data were gathered through field observations and specimens kept in cultivation as well as herbarium specimens. Habit, leaf dimensions, inflorescence type and distribution of hairs on leaves were found to provide reliable diagnostic characters for species separation. These characters in combination with geographical distribution patterns were applied in drawing up a key to species in the Flora of southern Africa region. The treatment also includes brief notes on diagnostic characters and relationships, distribution and ecology, etymology, red data status and common names for each taxon. Nine species are data deficient due to insufficient collections or type specimens still to be located, and remain unresolved. Evidence from vegetative anatomy, seed micromorphology and preliminary phytochemistry were used to test possible phylogenetic relationships among species inferred from macromorphology. A few members of the southern African Hypoxis are of medicinal importance as their rhizomes are a rich source of hypoxoside which in its hydrolysed form has been shown to inhibit the growth of some cancer cells. Based largely on a literature survey, a review of the ethnobotany of the Hypoxidaceae, denoting the food, medicinal and magical value of members of the family is also offered. / Thesis (PhD)--University of Pretoria, 2009. / Plant Science / unrestricted
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Perfil metabolômico e farmacológico da Mansoa hirsuta D.C. (Bignoniaceae) / Metabolomic and pharmacological profile of Mansoa hirsuta D.C. (Bignoniaceae)Silva, Daniel de Melo 06 August 2010 (has links)
Mansoa hirsute (Bignoniaceae), popularly known as Cipo d'álho, is chemically little known, although it is popularly used in the treatment of many disesases. The present studiy aimed to study the biological potential of the extracts and fractions obtained from leaves of M. hirsuta, to isolate and purify the active principles and to study the metabolomics of the plant. Plant materials were collected in five different regions from Semi-Arid in northeastern Brazil and were submitted to classic phytochemistry and analysis of the metabolomics. For that, the brute extract of the plants of Gentio do Ouro was obtained by extraction with ethanol 96% and was submitted to partitioning with different solvents, while the volatile were extracted by Clavenger apparatus. The isolated compounds were identified by GC-MS and NMR. Extract and subfractions were submitted to biological tests to clarify their possible biological
activities. The brute extracts of the plants provenientes of the five regions was submitted to NMR analysis RMN to adquire 1D 1H and 2D COSY and J-resolved spectra. NMR data were submitted to chemiometry (HCA, PC and PSL-of the) to classify the species according to their metabolome. Pentacyclic triterpenes ursólico and oleanolic acids, and the steroids stigmasterol, ß-stitosterol and lupeol were isolated, together with dialyl sulfide and trialyl sulfide. The ethyl acetate fraction was
able to inhibit the production of NO (57.92%) and proliferation of linfocites (99.92%), while the acid ursólico and oleanolic presented inhibition values greater than 99%. Metabolic analysis allowed to establish that plants of Gentio do Ouro are rich in pentacyclic triterpens, while plants from Boninal contains mostly flavonoids in its chemical composition. The results also suggest that protoantocianidinas are the main constituents of the plants from Caetité, while saponinas are found in the plants from Campo Alegre de Lourdes. Plants of Morro do Chapéu were distinguished form the
other regions for being rich in oligosaccharides and aminoacids. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A espécie Mansoa hirsuta (Bignoniaceae), popularmente conhecida como Cipó d'alho, é quimicamente pouco conhecida, embora seja popularmente utilizada no tratamento de muitas infecções. O presente trabalho objetivou estudar o potencial biológico dos extratos e frações obtidos das folhas de M. hirsuta, isolar e purificar os possíveis princípios ativos e estudar o perfil metabolômico da planta. O material
vegetal foi coletado em cinco regiões diferentes do Semi-Árido nordestino e foi submetido à fitoquímica clássica e análise metabolômica. Para tanto, o extrato bruto das plantas de Gentio de Ouro foi obtido pela extração com etanol 96% e submetido a fracionamento com diferentes solventes, enquanto os voláteis foram extraídos por Clavenger. Os compostos isolados foram identificados por GC-MS e dados de RMN. O extrato e as subfrações foram submetidos a testes biológicos para esclarecer suas
possíveis atividades biológicas. Os extratos brutos das plantas provenientes das cinco regiões foi submetido a análise por RMN para obtenção de espectros 1D 1H e 2D COSY e J-resolvido. Os dados provenientes do RMN foram então submetidos à métodos quimiométricos (HCA, PCA e PSL-DA) com vistas a classificar as espécies de acordo com seu metaboloma. Os triterpenos pentacíclicos ácidos ursólico e oleanólico e os esteróides estigmasterol, β-stitosterol e lupeol foram isolados, juntamente com o dissulfeto de dialila e trissulfeto de dialila. A fração acetato de etila inbiu a produção de NO (57,92%) e a linfoproliferação (99.92%), enquanto os ácidos ursólico e oleanólico apresentaram valores de inibição maiores que 99%. A análise metabólica permitiu estabelecer que as plantas oriundas de Gentio de Ouro são ricas em triterpernos pentacíclicos, enquanto as plantas de Boninal contêm principalmente flavonóides em sua composição química. Os resultados também sugerem que as
protoantocianidinas são os principais constituintes das plantas oriundas de Caetité, enquanto saponinas são encontradas na plantas de Campo Alegre de Lourdes. As plantas de Morro do Chapéu diferem daquelas das demais regiões por serem ricas em oligossacarídeos e aminoácidos.
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Isolation, characterisation and antimalarial activity of four selected South African plantsAdebayo, Oluwakemi Monisola 20 September 2019 (has links)
MSc (Chemistry) / Department of Chemistry / Malaria, an infectious disease affecting both human beings and other animals, is transmitted by parasitic protozoans belonging to the Plasmodium genus. Malaria is commonly treated with drugs such as quinine, chloroquine, and artesunate. However, the incidence of treatment failure due to drug-drug interactions and parasite resistance is increasing. Therefore, the rich medicinal potential of plants found in nature in Africa is increasingly being explored.
The traditional use of Lippia javanica, Sclerocarya birrea, Melia azedarach and Capparis tomentosa for the treatment of malaria is well-known, but the phytochemistry of these four plants is not fully known. Parts of these plants were extracted and column chromatography was used to fractionate the extracts. The antioxidant activities of the fractions were determined using free radical scavenging and reducing power assays, while the cytotoxic, antiplasmodial and antitrypanosomal activities were determined using cell toxicity assay, parasite lactate dehydrogenase (pLDH) and trypanosome assay.
The methanol stem bark extract of Melia azedarach (Fraction 2) had the highest phenolic content (59.39 mg GAE/g), while the methanol leaf extract of Melia azedarach had the highest flavonoid content of 188.65 mg QE/g. In the reducing power tests and DPPH free radical scavenging activity, the methanol stem bark extract of Melia azedarach had the lowest IC50 value of 0.1074 μg/mL and an IC0.5 value of 0.5296 μg/mL, respectively. Furthermore, the methanol stem bark extract of Melia azedarach at a concentration of 50 μg/mL showed significant cytotoxicity against HeLa cells (-1.22±0.07 %). The methanol stem bark extract of Melia azedarach at the tested concentration (250 μg/mL) decreased the viability of Plasmodium falciparum to 36.38±11.96 % with an IC50 value of 6.5 μg/mL. Concerning the antitrypanosomal activity, the methanol stem bark extract of Melia azedarach affected the viability of the trypanosomes at the tested concentration (250 μg/mL), giving a viability of 14.05 ± 0.59 %, with an IC50 value of 0.4 μg/mL. The presence of epicatechin (29) and catechin (31) in this extract was confirmed using several spectroscopic techniques (IR, NMR, UPLC-MS and HRMS). / NRF
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Isolation and Characterization of a Suspected Phytoalexin from Wilted Red Maple LeavesBaisden, Jared T. January 2013 (has links)
No description available.
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A Review of the Toxicity and Phytochemistry of Medicinal Plant Species Used by Herbalists in Treating People Living With HIV/AIDS in UgandaAnywar, G., Kakudidi, E., Byamukama, R., Mukonzo, J., Schubert, A., Oryem-Origa, H., Jassoy, C. 30 March 2023 (has links)
Introduction: Despite concerns about toxicity, potentially harmful effects and herb-drug
interactions, the use of herbal medicines remains widely practiced by people living with
HIV/AIDS (PLHIV) in Uganda.
Objective: The objective of the paper was to comprehensively review the literature on the
toxicity and chemical composition of commonly used medicinal plant species in treating
PLHIV in Uganda.
Methods: We reviewed relevant articles and books published over the last sixty years on
ethnobotany, antiviral/anti-HIV activity, toxicity, phytochemistry of Vachellia hockii, Albizia
coriaria, Bridelia micrantha, Cryptolepis sanguinolenta, Erythrina abyssinica, Gardenia
ternifolia, Gymnosporia senegalensis, Psorospermum febrifugium, Securidaca
longipendunculata, Warburgia ugandensis and Zanthoxylum chalybeum and their
synonyms. We searched PubMed, Web of Science, Scopus, Science Direct and
Google Scholar.
Discussion: Most of the plant species reviewed apart from P. febrifugium, S.
longipedunculata and C. sanguinolenta lacked detailed phytochemical analyses as well
as the quantification and characterization of their constituents. Crude plant extracts were
the most commonly used. However, purified/single component extracts from different
plant parts were also used in some studies. The U87 human glioblastoma was the most
commonly used cell line. Water, ethanol, methanol and DMSO were the commonest
solvents used. In some instances, isolated purified compounds/extracts such as
Cryptolepine and Psorospermin were used.
Conclusion: Cytotoxicity varied with cell type, solvent and extract type used making it
difficult for direct comparison of the plant species. Five of the eleven plant species namely,
A. coriaria, C. sanguinolenta, G. ternifolia, P. febrifugium and Z. chalybeum had no
cytotoxicity studies in animal models. For the remaining six plant species, the crude
aqueous and ethanol extracts were mainly used in acute oral toxicity studies in mice.
Herbalists reported only A. coriaria and W. ugandensis to cause toxic side effects in
humans. However, selective cytotoxic plant extracts can potentially be beneficial as
anticancer or anti-tumour drugs.
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Flavonolignóides de Iryanthera grandis / Flavonolignoids Iryanthera grandisSilva, Dulce Helena Siqueira 25 June 1993 (has links)
Este trabalho estabelece uma comparação entre amêndoas de Iryanthera Grandis Ducke (Myristicaceae) atacadas por insetos e amêndoas inteiras através do isolamento, identificação e determinação estrutural de alguns de seus constituintes químicos. Os extratos hexânicos foram fracionados por técnicas cromatográficas e forneceram a neolignana (8R,7\'S,8\'S)-2,3-dimetil-4-(p-hidroxifenil)-6-hidroxitetralina e a lactona (2S,3S,4S)-2-(heptadecil-17\'-fenil)-3-hidroxi-4-metilbutanolido, além de dois tocotrienóis: 2,8-dimetil-2-(4,8,12-trimetil-3,7,11-tridecatrienil)-6-cromanol e 2,8-dimetil-2-(4,12-dimetil-8-carbóxi-3,7,11-tridecatrienil)-6-cromanol, sendo o primeiro encontrado apenas nas amêndoas atacadas por insetos e o segundo, apenas nas amêndoas inteiras. Estas 4 substâncias já haviam sido isoladas de I. grandis em trabalho anterior. Um estudo quantitativo revelou a presença de 25% em massa a mais de metabólitos especiais nas amêndoas atacadas por insetos, quando comparadas às amêndoas inteiras, (provavelmente devido a uma maior concentração de triglicerídeos nas amêndoas inteiras). A investigação fitoquímica dos extratos etanólicos forneceu, após partição com solventes e fracionamentos cromatográficos, incluindo o uso de cromatografia líquida de alta eficiência, 4 flavonolignóides inéditos designados de iryantherinas G, H, I e J. A biossíntese de flavonolignóides envolve provavelmente o ataque eletrofilico de álcool cinamílico ao anel floroglucinólico de uma diidrochalcona. No caso destas iryantherinas, o álcool cinamílico é representado pela unidade 1,4-diaril-2,3-dimetilbutílica. As propostas estruturais das substâncias isoladas foram baseadas no exame de espectros dos produtos naturais e/ou dos derivados acetilados. As técnicas espectrométricas utilizadas foram EM, RMN de 1H e de 13C, RMN bidimensional HOMOCOSY 1H-1H, experimentos de DEPT 135° e para a observação do Efeito Nuclear Overhauser. / This work describes the comparison between unspoiled fruits of Iryanthera Grandis (Ducke) and fruits which had been attacked by insects by means of isolation, identification and structural elucidation of some of its chemical constituents. Hexanic extracts submitted to chromatographic techniques afforded neolignan (8R,7\'S,8\'S)-2,3-dimethyl-4-(p-hydroxyphenil)-6-hydroxytetraline and lactone (2S,3S,4R)-2-(heptadecyl-17\'-phenyl)-3-hydroxy-4-methyl\'butanolide, besides two tocotrienols: 2,8-dimethyl-2-(4,8,12-trimethyl-3,7,11-tridecatrienyl)-6-cromanol and 2,8-dimethyl-2-(4,12-dimethyl-8-carboxyl-3,7,11-tridecatrienyl)-6-cromanol. Ethanolic extracts submitted to partition and chromatografic analysis including HPLC techmques afforded 4 new flavonolignoids, iryantherins G, H, I and J. Biosynthesis of flavonolignoids results from eletrophyllic attack of cinnamyl alcohol to the phloroglucinolic ring of a dihydrochalcone. In this work, the cinnamyl alcohol is represented by the 1,4-diaryl-2,3-dimethyl unit. Structural proposals of isolated compounds were based on MS, 1H and 13C NMR, bidimensional HOMOCOSY 1H-1H, DEPT 135° and NOE experiments.
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