Davyson de Lima Moreira

Essential oil analysis of 10 Piperaceae species from the Brazilian Atlantic forest

The volatile composition of ten Piperaceae species, comprising three genera (Ottonia, Piper and Peperomia) has been studied. The species were collected in a typical fragment of the Brazilian Atlantic forest, constantly being damaged by human action. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus and their analyses were performed by GC and GC/MS. Identification of the substances was made by comparison of mass spectra and retention indices with literature records. A great number of non-oxygenated monoterpenes and sesquiterpenes were identified. Most of these sesquiterpenes are derived from E,E-farnesyl-PP, suggesting a preference of these species to synthesize metabolites from this pathway. Arylpropanoids, although being common compounds produced by Piperaceae species, were not found in these oils.

A Chromene from Piper Aduncum

A new chromene, methyl 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-chromene-6-carboxylate, present in a mixture of eupatoriochromene, and mono- and sesquiterpenes from Piper aduncum was identified by spectroscopic analysis. In addition, seven known flavonoids and a mixture of sitosterol and stigmasterol were also isolated and identified.

A C-glucosylflavone from leaves of Piper lhotzkyanum

The dichloromethane fraction obtained from the methanolic extract of leaves of P. lhotzkyanum afforded a C-glucosylflavone (kaplanin) together with sakuranetin, methyl 4-methoxydihydroferulate and a mixture of methyl ferulate and dihydroferulate derivatives. Spectrometric methods were used to elucidate the structures of these compounds.

Non-polar constituents from leaves of piper lhotzkyanum

Abstract The hexane extract from leaves of P. lhotzkyanum yielded lhotzchromene (2-methyl-2-[4′-methyl-3′-pentenyl]-2H-1-benzopyran-6-carboxylic acid) together with the known ( E ) and ( Z ) isomers of 4-hydroxy-3-(3′,7′-dimethyl-1′-oxo)-2′,6′-octadienylbenzoic acid and a mixture of six hydroxylated sesquiterpenes along with phytol. Spectroscopic methods were used to identify these compounds.

Effect of leaf essential oil from Piper solmsianum C.DC. in mice behaviour.

The essential oil from Piper solmsianum leaves and its major compound (sarisan) were tested to verify their influences upon mice behaviour. The essential oil was obtained by hydrodistillation in a modified Clevenger extractor and analysed by GC/ MS. This analysis revealed in the oil the presence of monoterpenes, sesquiterpenes and of arylpropanoids. The compound sarisan, a myristicin analogue, was isolated from the oil to perform the pharmacological tests. Emulsions of the oil and of sarisan (5.0 and 10.0% v/v) were used in the tests. Pentobarbital (30 mg/ kg s.c.) or diazepam (2.5 mg/ kg s.c.) were tested as standard drugs to verify depressant or anxiolytic effects, respectively. Both essential oil and sarisan showed to have exciting and depressant effects in the tested animals.

1-Butyl-3,4-Methylenedioxybenzene as the Major Constituent of Essential Oil from Ottonia anisum Sprengel (Piperaceae)

Abstract Leaves from Ottonia anisum submitted to steam distillation yielded an oil which contains 1-butyl-3,4-methylenedioxybenzene as the major component (about 95%). GC/MS analysis of this oil showed the presence of monoterpenes and Sesquiterpenes. Spectroscopic and GC characterization of these components has been performed by comparison with literature records. They were identified as α-pinene, β-pinene, myrcene, limonene, δ-cadinene, germacrene D and γ-muurolene.

Substâncias fenólicas com atividade antioxidante de Pseudopiptadenia contorta (Leguminosae-Mimosoideae)

O extrato bruto em acetona/ agua das folhas de Pseudopiptadenia contorta foi purificado rendendo fracoes e substâncias puras. A atividade antioxidante foi avaliada para o extrato e fracoes, empregando-se o teste quimico do DPPH. As fracoes contendo taninos condensados e substâncias fenolicas de baixo peso molecular mostraram ser as responsaveis pela atividade antioxidante do extrato bruto das folhas de P. contorta.

Anatomia de folha e caule e quantificação espectrofotométrica de fenóis totais e taninos da erva-de-bicho (Polygonum acre Kunth var. aquatile Meisn.)

Polygonum acre Kunth var. aquatile Meisn., a medicinal plant, was studied with the purpose of selecting useful characteristics for fragmented plant identification as well as to contribute to the botanical study of the species. Usual anatomical analysis was used and total phenolics, condensed and galic tannins were quantified. The comparison with bibliographic data allowed to select some characteristics to help the identification of P. acre: 1) absence of well defined endodermis with Casparian strips on the stem in accordance with others species of the Polygonum genus; 2) numerous multicellular trichomes on the ocrea and secretory cavities only in abaxial epidermis; 3) fibers on the interior of the xylem from the stem; 4) inverted bundle in midrib and 5) lignified protuberances in the edge of the leaf. The quantification of total phenolics and tannins from P. acre shows remarkable amounts of condensed tannins, but no hydrolysable tannins were detected.