Minor sesquiterpenes from the volatile oil from leaves of Guarea guidonia Sleumer (Meliaceae).

The essential oil from leaves of Guarea guidonia was subjected to chromatographic separation procedures to afford nine sesquiterpenes; two of them are new eudesmane derivatives. The chemical structures of the obtained compounds were characterised by spectrometric analysis, mainly mass spectrometry and NMR.

New (9betaH)-lanostanes and lanostanes from Mikania aff. jeffreyi (Asteraceae).

Four new (9betaH)-lanostanes, i.e., (9betaH)-3beta-acetoxylanosta-7,24-diene, (9betaH)-3-oxolanosta-7,24-diene, (9betaH,24R)-3beta-acetoxy-24-hydroxylanosta-7,25-diene, and (9betaH,24S)-3beta-acetoxy-24-hydroxylanosta-7,25-diene, two new lanostanes, i.e., (24R)-3beta-acetoxy-24-hydroxylanosta-8,25-diene and (24S)-3beta-acetoxy-24-hydroxylanosta-8,25-diene, and two known lanostanes, i.e., 3beta-acetoxylanosta-8,24-diene and 3-oxolanosta-8,24-diene, were obtained from a new Mikania species (Asteraceae) besides pentacyclic triterpenes, steroids, and diterpenes. The structures of the compounds were determined by spectroscopic methods. This is the second study about acetyl-lanosterols from higher plants. Moreover, (9betaH)-lanostanes are very rare metabolites from dicotyledone angiosperms. The occurrence of these terpenes together in the same plant makes the species a good source for lanostane- and (9betaH)-lanostane-biosynthesis studies.

Preliminary studies on the volatile constitution of Mikania species / Estudos preliminares dos constituintes voláteis de espécies de Mikania

Volatile oils obtained from the aerial parts of three Mikania species plants were analyzed by GC-MS and NMR. Forty-six terpenes among monoterpenes, sesquiterpenes and diterpenes were identified by this methodology. The analysis classified Mikania hookriana as diterpene producer as the majority Mikania species occurring in Brazil.

Óleos voláteis obtidos das partes aéreas de plantas de três espécies de Mikania foram analisados por CG-EM e RMN. Quarenta e seis terpenos, entre monoterpenos, sesquiterpenos e diterpenos, foram identificados. A análise classificou Mikania hookeriana como produtora de diterpenos, de acordo com a maioria das espécies de Mikania que ocorrem no Brasil.

Sesquiterpenos e hidrocarbonetos dos frutos de Xylopia emarginata (Annonaceae) / Sesquiterpenes and hydrocarbons from Xylopia emarginata (Annonaceae) fruits

O extrato hexânico dos frutos de Xylopia emarginata foi particionado entre hexano e MeOH/H2O. A fase hidroalcoólica foi submetida à separação cromatográfica fornecendo quatro sesquiterpenos: óxido de cariofileno, espatulenol, 1beta,6alfa-diidroxi-4(15)-eudesmeno e 4-hidroxi-1,15-peróxieudesmano. A fase hexânica foi fracionada através de cromatografia em coluna fornecendo dois hidrocarbonetos (nonadecano e 1-nonadeceno) e uma cetona alifática (hentriacontan-16-ona). As estruturas dos compostos isolados foram estabelecidas através de análise espectroscópica, principalmente RMN e EM.

The hexane extract from Xylopia emarginata fruits was partitioned between hexane and MeOH/H2O. The hydro-alcoholic phase was submitted to chromatographic separation to afford four sesquiterpenes: caryophyllene oxide, spathulenol, 1beta,6alpha-dihydroxy-4(15)-eudesmene and 4-hydroxy-1,15-peroxy-eudesmane. The hexane phase was fractioned in column chromatography to afford two hydrocarbons (nonadecane and 1-nonadecene) and one aliphatic ketone (hentriacontan-16-one). The structures of the isolated compounds were established by spectral data analysis, mainly NMR and MS.

Aldingenin derivatives from the red alga Laurencia aldingensis.

Three brominated bisabolene-type sesquiterpene derivatives, aldingenin B, C and D, together with cholesterol and palmitic acid, have been isolated from the red alga Laurencia aldingensis (Ceramiales, Rodophyta) and their structures elucidated by spectroscopic methods including NMR analysis.

Volatile oil from Guarea macrophylla ssp. tuberculata: seasonal variation and electroantennographic detection by Hypsipyla grandella.

GC and GC-MS analyses of the volatile oils from Guarea macrophylla (Meliaceae) collected during three different periods in one year (February, June and October) indicated a seasonal variation in chemical composition. Whilst sesquiterpenes were the predominant class of components present in the leaf oil, a seasonal dependent variation in the degree of oxygenation of these compounds was detected, which seemed to be associated with phenological factors. The leaf oil, and fractions thereof, were subjected to GC coupled with electroantennographic detection employing antennae of females of Hypsipyla grandella, an insect pest that attacks several meliaceous species. Five compounds elicited significant responses and these were identified as ledol, 1-cubenol, guai-6-en-10beta-ol, 1-epi-cubenol, and tau-muurolol. The results suggest that these components could be responsible for the attraction of H. grandella to G. macrophylla.

Terpenoids from Guarea guidonia.

The volatile oil and the methanol extract from the leaves of Guarea guidonia, Meliaceae, were individually submitted to chromatographic separation. A sesquiterpene (2S*)-eudesma-5,7-dien-2-ol, together with six known ones, were isolated from the volatile oil. The methanolic extract afforded two known and two new triterpenes (23S*)-cycloart-24-ene-3 beta,23-diol and (23R*)-cycloart-24-ene-3 beta,23-diol, besides three known sesquiterpenes, one known diterpene and two steroids. Their structures were established on the basis of spectrocopic data, mainly by 1H and 13C NMR spectroscopic analyses.

Cycloartane triterpenoids from Guarea macrophylla.

Nine cycloartane triterpenoids, including two new derivatives 22,25-dihydroxy-cycloart-23E-en-3-one and 24-methylenecycloartane-3 beta,22-diol have been isolated from leaves of Guarea macrophylla. The structures were elucidated by interpretation of spectral data, mainly 1H and 13C NMR, including bidimensional analysis (HOMOCOSY, HMQC and HMBC).

Analgesic activity of a triterpene isolated from Scoparia dulcis L. (vassourinha)

Analgesic and anti-inflammatory activities of water (WE) and ethanolic (EE) extracts of Scoparia dulcis L. were investigated in rats and mice, and compared to the effects induced by Glutinol, a triterpene isolated by purification of EE. Oral adminsitration (p.o.) of either WE or EE (up to 2 g/Kg) did not alter the normal spontaneous activity of mice and rats. The sleeping time induced by sodium pentobarbital (50 mg/Kg, i.p.) was prolonged by 2 fold in mice pretreated with 0.5 g/Kg EE, p.o. Neither extract altered the tail flick response of mice in immersion test, but previous administration of EE (0.5 g/Kg, p.o.) reduced writhings induced by 0.8% acetic acid (0.1 ml/10 g, i.p.) in mice by 47% EE (0.5 and 1 g/Kg, p.o.) inhibited the paw edema induced by carrageenan in rats by respectively 46% and 58% after 2 h, being ineffective on the paw edema induced by dextran. No significant analgesic or anti-edema effects were detected in animals pretreated with WE (1 g/Kg, p.o.). Administration of Glutinol (30 mg/Kg, p.o.) reduced writhing induced by acetic acid in mice by 40% and the carrageenan induced paw edema in rats by 73%. The results indicate that the analgesic activity of S dulcis L. may be explained by explained by an anti-inflammatory activity probably related to the triterpene Glutinol.