RESUMO
One new compound: 3,4-dihydro-2-(hydroxymethyl)-4-methyl-2H-pyrrol-2-ol (5) was isolated from the fruits and bark of Callistemon viminalis along with the known compounds lupeol (1), octacosanol (2), ß-sitosterol (3), betulin (4), betulinic acid (6), ursolic acid (7), corosolic acid (8), ß-sitosterol-3-O-ß-D-glucoside (9), methyl gallate (10), gallic acid (11), catechin (12), ellagic acid (13) and 3-O-acetylursolic acid (14) (compound 14 was isolated from the bark and not detected in the fruits). Structures of these compounds were elucidated on the basis of their spectroscopic data (NMR, MS, IR spectra and COSY and HR-MS for 5a). The antioxidant activity of the total extracts, petroleum ether, CH2Cl2 and EtOAc fractions together with the compounds 6, 7, 9, 10, 11, 12 and 13 was comparable with that of the standard antioxidant, ascorbic acid.
Assuntos
Myrtaceae/química , Pirróis/química , Frutas/química , Estrutura Molecular , Casca de Planta/químicaRESUMO
Two new compounds: 3-ß,15-α,23,28-tetrahydroxyolean-12-en-3-O-arabinopyaranoside and 3-ß,23,28-trihydroxy-olean-12-en-3-O-ß-D-glucopyranoside were isolated from the aerial parts of Ammania auriculata along with the known compounds kaempferol, ß-sitosterol-3-O-ß- D-glucoside, 2-α,3-ß,23-trihydroxyolean-12-en-28-oic acid-28-O-ß-D-glucopyranoside, quercetin, kaempferol-3-O-α-L-arabinofuranoside, kaempferol-3-O-ß-D-xylopyranoside and ellagic acid. Structures of these compounds were elucidated on the basis of their spectroscopic data (NMR, UV, MS and IR spectra). The antioxidant activities of the total extract, the fractions CH(2)Cl(2), EtOAc and the remaining aqueous together with the compounds 1, 6 and 9 were comparable with that of the standard antioxidant, ascorbic acid.
Assuntos
Antioxidantes/química , Lythraceae/química , Ácido Oleanólico/análogos & derivados , Flavonoides/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Ácido Oleanólico/químicaRESUMO
Two new metabolites were isolated from the biotransformation reaction of parthenin by Beauveria bassiana ATCC 7159 along with the known naturally occurring sesquiterpene lactones hymenolin and dihydrocoronopilin. The new metabolites: are 3beta,4beta,6beta-trihydroxy-10alphaH,11alpha-methyl-ambrosa-1 -en-12-oic acid-gamma-lactone and 3alpha,6beta-dihydroxy-4beta-hydroperoxy-10alphaH, 11alpha-methyl-ambrosa-1-en-12-oic acid-gamma-lactone. The structure elucidation of these compounds was achieved by different spectroscopic methods.
Assuntos
Beauveria/metabolismo , Sesquiterpenos/análise , Fermentação , Radical Hidroxila/metabolismo , Espectroscopia de Ressonância Magnética , Conformação Molecular , Sesquiterpenos/metabolismo , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
The chemical investigation of the aerial parts of Haplopappus multifolius afforded the new monoterpene 2,9-epoxy-p-menth-6-en-8-ol (7, haplopappol), the new monoterpenoid ester 9-cis-p-coumaroyloxy-alpha-terpineol (8, haplofolin), the new diterpene 18-hydroxylabda-7,13Z-dien-15-oic acid (6) and its known E-isomer (5). In addition, the known dihydroflavones 3',5-dihydroxy-4',7-dimethoxydihydroflavone and 3',4',5-trihydroxy-7-methoxydihydroflavone and the known dihydroflavonols 3',5-dihydroxy-4',7-dimethoxydihydroflavonol and 3',4',5-trihydroxy-3-acetyl-7-methoxydihydroflavonol were also obtained. The structural assignments of these compounds were made possible by the different spectroscopic measurements.
Assuntos
Asteraceae/química , Flavonoides/química , Terpenos/química , Chile , Cromatografia em Camada Fina , Flavonoides/isolamento & purificação , Espectroscopia de Ressonância Magnética , Conformação Molecular , Extratos Vegetais/análise , Espectrometria de Massas por Ionização por Electrospray , Terpenos/isolamento & purificaçãoRESUMO
A mixture of beta- and gamma-eudesmols was microbiologically biotransformed by Rhizopus stolonifer ATCC 6227. Positions-2 and 3, in both substrates, proved to be accessible by hydroxylase enzyme. Four different metabolites were isolated and their structures were elucidated by different spectroscopic methods. The structures of these metabolites were established as eudesma-3-en-2 beta,11-diol; eudesma-4-en-3 beta,11-diol; eudesma-4(15)-en-2 beta,11-diol and eudesma-4(15)-en-3 beta,11-diol.
Assuntos
Antifúngicos/metabolismo , Rhizopus/metabolismo , Sesquiterpenos de Eudesmano , Terpenos/metabolismo , Antifúngicos/análise , Bactérias/metabolismo , Biotransformação , Fermentação , Fungos/metabolismo , Espectroscopia de Ressonância Magnética , Terpenos/análiseRESUMO
Two new triglycosides, kaempferol-3-O-[(4-beta-D-apiofuranosyl)-alpha-L- rhamnopyranoside]-7-O-alpha-L-rhamnopyranoside and kaempferol-3-O-[(4-beta-D-xylopyranosyl)-alpha-L-rhamnopyranoside]-7-O- alpha-L-rhamnopyranoside were isolated from the methanol extract of Chenopodium murale, together with a known diglycoside, kaempferol-3-O-beta-D-glucopyranoside-7-O-alpha-L-rhamnopyranoside. The characterization of the three compounds was achieved by various spectroscopic methods.
