977 resultados para Piper of Hameln.
Geranylation of benzoic acid derivatives by enzymatic extracts from Piper crassinervium (Piperaceae)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study investigated the composition and antifungal activity against Cladosporium sphaerospermum and Cladosporium cladosporioides of essential oils of leaves of Piper cernuum, Piper diospyrifolium, Piper crassinervium, Piper solmsianum and Piper umbelata and fruits of P. cernuum and P. diospyrifolium. The essentials oils were analyzed by GC-MS and submitted of the antifungal activity tests. The essential oils of fruits from P. cernuum and leaves of P. crassinervium and P. solmsianum showed potential antifungal activity against C. sphaerospermum and C. cladosporioides. In addition, this is the first report of the composition of essential oils of fruits of P. cernuum and P. diospyrifolium.
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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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The biosynthesis of (2S)-2-methyl-2-(4'-methyl-3-pentenyl)-8-(3-methyl-2-butenyl)-2H-1-benzopyran-6-carboxylic acid (gaudichaudianic acid), the major metabolite in leaves and roots of Piper gaudichaudianum Kunth (Piperaceae), has been investigated employing [1(-13) C]-D-glucose as precursor. The labelling pattern in the isolated gaudichaudianic acid was determined by quantitative 13 C NMR spectroscopy analysis and was consistent with involvement of both mevalonic acid and 2-C-methyl-D-erythritol-4-phosphate pathways in the formation of the dimethylallyl- and geranyl-derived moieties. The results confirmed that both plastidic and cytoplasmic pathways are able to provide isopentenyl diphosphate units for prenylation of p-hydroxybenzoic acid. (c) 2007 Elsevier Ltd. All rights reserved.
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A rapid, sensitive and reliable reverse-phase HPLC method was used for the quantitative determination of the anti-fungal and insecticide amides, dihydropiplartine (1), piplartine (2), Delta(alpha,beta)-dihydropiperine (3) and pellitorine (4) in plants in natura, in plantlets in vitro and ex vitro, and in callus of Piper tuberculatum. Well-resolved peaks were obtained with good detection response and linearity in the range of 15.0-3000 mug/mL. The plants in natura contained compounds 1-4, the plantlets ex vitro and in vitro accumulated compounds 1-2 and 1-4, respectively, while only amide 4 was found in callus. Copyright (C) 2003 John Wiley Sons, Ltd.
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Leaves of Piper aduncum accumulate the anti-fungal chromenes methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (1) and methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate (2). The enzymatic formation of 2 from dimethylallyl diphosphate and I was investigated using cell-free extracts of the title plant. An HPLC assay for the prenylation reaction was developed and the enzyme activity measured in the protein extracts. The prenyltransferase that catalyses the transfer of the dimethylallyl group to C-2' of 1 was soluble and required dimethylallyl diphosphate as the prenyl donor. In the leaves, the biosynthesis of the prenylated chromene 2 was time-regulated and prenyltransferase activity depended upon circadian variation. Preliminary characterisation and purification experiments on the prenyltransferase from P. aduncum have been performed. Copyright (C) 2005 John Wiley & Sons, Ltd.
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We performed field tests using mimetic Piper fruits with and without essential oil extracted through hydrodistillation from Piper gaudichaudianum ripe fruits in order to evaluate the role of odor in Carollia perspicillata attraction and capture in mist-nets. During the field tests, 26 C. perspicillata were captured, 21 (80.7%) in nets with the essential oil of P. gaudichaudianum and five (19.3%) in nets without oil. Other bat species, Artibeus spp. ( 67), which is specialized on fruits of Moraceae, and Sturnira lilium ( 10), specialized on those of Solanaceae, were also captured, but they exhibited no significant preference for nets with or without oil. We conclude that odor is pre-eminent over visual cues in food location by C. perspicillata in a field situation. Based on the result, we propose the extraction and use of essential oils of chiropterochoric fruits as a useful approach to improve autoecological studies on fruit-eating bats and to promote tropical forest restoration through the attraction of frugivorous bats to degraded areas.
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The composition of essential oils from leaves, stems and fruits of Piper aduncum, P arboreum and P. tuberculatum was examined by means of GC-MS and alltifungal assay. There was a predominance of monoterpenes in P aduncum and P tuberculatum and of sesquiterpenes in P arboreum. P aduncum showed the richest essential oil composition, including linalool. The essential oils from fruits of P. aduncum and R tuberculatum showed the highest antifungal activity with the MIC of 10 mu g as determined against Cladosporium cladosponoides and C. sphaerospermum, respectively. This is the first report of the composition of essential oils from P. tuberculatum.
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The isobutyl amides pellitorine (compound 1) and 4,5-dihydropiperlonguminine (compound 2) were extracted from the seeds of Piper tuberculatum Jacq. (Piperaceae) in yields of 6.10 and 4.45% respectively. The acute toxicities to the velvetbean caterpillar, Anticarsia gemmatalis (Hubner) (Lepidoptera: Noctuidae), of extracts of seeds, leaves and stems of P. tuberculatum, and of compounds 1 and 2, were evaluated by means of contact bioassays. The extracts caused 80% mortality when doses higher than 800.00 mu g insect(-1) of extract of seeds, leaves and stems were administered to the velvetbean caterpillars. Compounds I and 2 showed 100% mortality at doses of 200 and 700 mu g insect(-1) respectively. The LD50 and LD90 values were respectively 31.3 and 104.5 mu g insect(-1) for compound 1, and 122.3 and 381.0 mu g insect(-1) for compound 2. The potential value of extracts and amides derived from P. tuberculatum as efficient insecticides against velvetbean caterpillars is discussed. (c) 2007 Society of Chemical Industry.
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Piper cernuum is a native plant of the Brazilian Atlantic rain forest. This work studies the distribution of allozyme diversity in P. cernuum natural populations in order to establish a strategy for sustainable management and conservation. Leaf samples were collected in two Brazilian states. High divergences among populations (F-SR = 0.380) and low divergences among regions (F-RT = -0.069) and among gaps of the same population (F-GT = 0.062) were found. No association between the geographical variation and the genetic distance was detected. An excess of heterozygotes was detected in the populations (F-IS = -0.170), suggesting selection in favor of heterozygotes. The results, and the fact that the species depends on constant gap formation for maintenance of its dynamism, suggest that the founder effect is largely responsible for the structuring of populations. For sustainable management, the maintenance of plants/reproductive branches in the gaps is of major importance. The genotypes produced in these gaps are responsible for the establishment of new gaps and are the foundation for new populations, maintaining the dynamics of allele movement.
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Bioactivity-guided fractionation of a CH2Cl2 extract from leaves of Piper hispidum (Piperaceae) yielded a new pyrrolidine amide, N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl] pyrrolidine 1, in addition to two known amides N-[5-(3',4'-methylenedioxyphenyl)-2(E)-pentadienoyl]pyrrolidine and N-[2-(3',4'-methylenedioxy-6'-methoxyphenyl)-2(Z)-propenoyl]pyrrolidine. The structure of compound 1 was elucidated by interpretation of spectral data, including ES-MS. Compound 1 showed antifungal activity against Cladosporium sphaerospermum.