112 resultados para TERPENOIDS


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Herbal medicines have been widely used around the world since ancient times. The advancement of phytochemical and phytopharmacological sciences has enabled elucidation of the composition and biological activities of several medicinal plant products. The effectiveness of many species of medicinal plants depends on the supply of active compounds. Most of the biologically active constituents of extracts, such as flavonoids, tannins, and terpenoids, are highly soluble in water, but have low absorption, because they are unable to cross the lipid membranes of the cells, have excessively high molecular size, or are poorly absorbed, resulting in loss of bioavailability and efficacy. Some extracts are not used clinically because of these obstacles. It has been widely proposed to combine herbal medicine with nanotechnology, because nano-structured systems might be able to potentiate the action of plant extracts, reducing the required dose and side effects, and improving activity. Nanosystems can deliver the active constituent at a sufficient concentration during the entire treatment period, directing it to the desired site of action. Conventional treatments do not meet these requirements. The purpose of this study is to review nanotechnology- based drug delivery systems and herbal medicines.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Agronomia (Horticultura) - FCA

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Electrophysiological responses based on electroantennographic detection (GC-EAD) and electroantennography (EAG) analysis of Naupactus bipes beetles (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) were used to test volatile oils of Piper gaudichaudianum, P. regnellii and P. hispidum. In the EAG experiments, female and male beetles showed significant EAG response to the three volatile oils of Piper species, with the females' responses slightly higher than the males'. The experiments with GC-EAD revealed that some terpenoids (namely, alpha-pinene, beta-pinene, myrcene, alpha-copaene and germacrene) present in the leaf essential oils of the Piper species are perceptible to female and male beetles.

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In this work, in vitro and in vivo antioxidant properties of the marine algae Halimeda monile were assessed and the levels of some of its compounds likely to be responsible for such properties were determined. The estimated contents of total polyphenols, chlorophylls a and b and carotenoids were 179.5, 356.3, 452.8 and 42.2 mu g/g dry weight seaweed, respectively. The presence of terpenoids and flavonoids was also observed. The antioxidant activity of two polar fractions from H. monile (lyophilized aqueous extract and free phenolic acid fraction) was evaluated using three antioxidant assays: ferric reducing antioxidant power, 1,1-diphenyl-2-picrylhydrazyl and lipid peroxidation. Treatment of CCl4-induced liver damage in rats with extracts resulted in lower serum thiobarbituric acid-reactive substances levels and higher hepatic glutathione concentrations compared to those observed in the CCl4-treated group. Also, a significant increase in catalase activity was detected after treatment with the extracts. These results suggest that the seaweed H. monile could be a potential source for natural antioxidants.

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Two new guignardones and one tricycloalternarene derivatives, named guignardone D, E (2-3) and tricycloalternarene F (4), and the known guignardone A (1) were isolated from Guignardia mangiferae, an endophytic fungus from the leaves of Viguiera arenaria (Asteraceae), after fermentation in Czapek medium. Structures were established on the basis of their spectroscopic data, including H-1 NMR, C-13 NMR, HMQC, HMBC and HRESI-MS. (C) 2012 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.

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Different species of Laurencia have proven to be a rich source of natural products yielding interesting bioactive halogenated secondary metabolites, such as terpenoids and acetogenins. It is shown that such compounds are accumulated in the spherical, reniform to claviform refractive inclusions called corps en cerise (CC), which are intensively osmiophilic and located mainly in the cortical cells of the thalli and also in trichoblast cells. Up to now, it was believed that CC were present only in these two kinds of cells. Recently, however, a species of Laurencia, L. marilzae, with CC in all cells of the thallus, i.e., cortical, medullary, including the pericentral and axial cells, as well as in the trichoblasts, was described from the Canary Islands, and subsequently also reported to Brazil and Mexico. Within the Laurencia complex, only Laurencia species produce CC. Since the species of Laurencia are targets of interest for the prospection of bioactive substances due to their potential antibacterial, antifungal, anticholinesterasic, antileishmanial, cytotoxic, and antioxidant activities, the present paper carries out a comparative analysis of the corps en cerise in several species of Laurencia from the Atlantic Ocean to obtain basic information that can support natural product bioprospection projects. Our results show that the number and size of the CC are constant within a species, independent of the geographical distribution, corroborating their use for taxonomical purposes to differentiate groups of species that present a lower number from those that have a higher number. In this regard, there was a tendency for the number of CC to be higher in some species of Laurencia from the Canary Islands. The presence of CC can also be used to distinguish species in which these organelles are present in all cells of the thallus from those in which CC are restricted to the cortical cells. Among the species analyzed, L. viridis displayed the most varied secondary metabolites composition, such as sesquiterpenes, diterpenes, triterpenes, all of which showed potent antiviral, cytotoxic, and antitumoral activities, including protein phosphatase type 2A (PP2A) inhibitory effects.

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The odor produced by a plant under herbivore attack is often used by parasitic wasps to locate hosts. Any type of surface damage commonly causes plant leaves to release so-called green leaf volatiles, whereas blends of inducible compounds are more specific for herbivore attack and can vary considerably among plant genotypes. We compared the responses of naïve and experienced parasitoids of the species Cotesia marginiventris and Microplitis rufiventris to volatiles from maize leaves with fresh damage (mainly green leaf volatiles) vs. old damage (mainly terpenoids) in a six-arm olfactometer. These braconid wasps are both solitary endoparasitoids of lepidopteran larvae, but differ in geographical origin and host range. In choice experiments with odor blends from maize plants with fresh damage vs. blends from plants with old damage, inexperienced C. marginiventris showed a preference for the volatiles from freshly damaged leaves. No such preference was observed for inexperienced M. rufiventris. After an oviposition experience in hosts feeding on maize plants, C. marginiventris females were more attracted by a mixture of volatiles from fresh and old damage. Apparently, C. marginiventris has an innate preference for the odor of freshly damaged leaves, and this preference shifts in favor of a blend containing a mixture of green leaf volatiles plus terpenoids, after experiencing the latter blend in association with hosts. M. rufiventris responded poorly after experience and preferred fresh damage odors. Possibly, after associative learning, this species uses cues that are more directly related with the host presence, such as volatiles from host feces, which were not present in the odor sources offered in the olfactometer. The results demonstrate the complexity of the use of plant volatiles by parasitoids and show that different parasitoid species have evolved different strategies to exploit these signals.

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New data are reported on the major- and trace-component compositions of acidic and weakly acidic low-concentration wetland waters and other water types. Special attention was given to dissolved organic compounds: fulvic and humic acids, bitumens, and hydrocarbons. The first comprehensive data are presented for organic trace components in the wetland waters of western Siberia: alkanes, pentacyclic terpenoids, steranes, alkylbenzenes, naphthalenes, phenanthrenes, tetraarenes, etc.

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New data on chemical and trace component compositions of acidic and low acidic swamp waters and other types of low mineralized waters are reported in the paper. Special attention is paid to dissolved organic compounds: fulvic and humic acids, bitumen, and hydrocarbons. For the first time detailed data on organic trace components (alkanes, pentacyclic terpenoids, steranes, alkylbenzenes, naphthalenes, phenanthrenes, tetraarenes, etc.) in the swamp waters of the Western Siberia: are reported.