RESUMO
Chemical investigation of the fungal strain Microdiplodia sp. isolated from the shrub Lycium intricatum led to the isolation of four new compounds: a hexahydroxanthone (2), a 2,3-dihydrochroman-4-one (3), a 7-oxoxanthone derivative (4), and a 1,4-oxazepan-7-one (5). The relative configurations of the new compounds were determined by intensive NMR investigations, notably NOESY experiments at different temperatures. The absolute configurations of the well-known fungal metabolite diversonol (1) and of other xanthone derivatives (3, 4) were established by means of TDDFT ECD calculations. Most of the metabolites were biologically active, with antibacterial activity against Legionella pneumophila and/or antifungal activity against Microbotryum violaceum.
Assuntos
Antibacterianos/isolamento & purificação , Antifúngicos/isolamento & purificação , Ascomicetos/química , Xantonas/isolamento & purificação , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Bacillus megaterium/efeitos dos fármacos , Basidiomycota/efeitos dos fármacos , Cristalografia por Raios X , Escherichia coli/efeitos dos fármacos , Legionella pneumophila/efeitos dos fármacos , Lycium/microbiologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Espanha , Xantonas/química , Xantonas/farmacologiaRESUMO
Studies on Conyza bonariensis (L.) Cronq. led to the isolation of two new glycosides trivially named as erigeside E and F (1-2), along with two new source compounds; benzyl-beta-D-glucopyranoside (3) and 2-phenylethyl-beta-D-glucopyranoside (4). Compounds 1, 3, and 4 are aromatic glycosides, while compound 2 is an alkyl glycoside. Their structures were elucidated through mass spectrometric, and 1D- and 2D-NMR spectroscopic techniques, including 1H NMR, 13C NMR, HMQC, HSQC and HMBC.
Assuntos
Conyza/química , Glicosídeos/química , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
Two new glycosides, 2-O-methylglucopyranosyl-carthamoside (1) and beta-D-fructofuranosyl carthamoside (2), along with the known compound 3',4',5,7-tetrahydroxyflavanone (3) have been isolated from Carthamus oxyacantha, using recycling preparative HPLC. The structures of these compounds were established by mass spectrometric and extensive spectroscopic analysis.