RESUMO
Four previously undescribed steroids, identified as (3S,7S,8S,9S,10R,13S,14S,16S,17R,20S)-7α-methoxy-ergosta-5,24(28)-dien-3ß,16ß,20-triol (1), ergosta-5,24(28)-dien-3ß,7α,16ß-triol (2), ergosta-5,25-dien-3ß,7α,16ß,20-tetrol (3) and 7α,16ß,24α-trihydroxy-varninasterol (4), as well as five known analogues (5-9), were isolated from the leaves and twigs of Dysoxylum pallens Hiern (Meliaceae). Their structures were elucidated based on extensive spectroscopic analysis such as HR-ESI-MS, 1D and 2D NMR, UV, and IR. The absolute configuration of compound 1 was determined by X-ray diffraction analysis. Selected compounds were evaluated for their cytotoxic activities. Compounds 1, 2, and 8 exhibited moderate cytotoxic activity against HL-60, Hela, and HepG2 tumor cell lines with IC50 ranged from 11.09 to 17.51 µM.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Meliaceae/química , Esteroides/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , China , Células HL-60 , Células HeLa , Células Hep G2 , Humanos , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Esteroides/isolamento & purificaçãoRESUMO
Four new diterpenoids, named aspidoptoids A-D (1-4), together with two known analogues (5-6) were isolated from Aspidopterys obcordata vine. Aspidoptoids A-B (1-2) are the first examples of phenylethylene-bearing 20-nor-diterpenoids of which aspidoptoid B (2) possesses a rare 3,10-oxybridge. Their structures and absolute configuration were determined by extensive spectroscopic analyses (IR, HRESIMS, 1D and 2D NMR) and electronic circular dichroism (ECD) calculation. In addition, all the isolates were evaluated for their cytotoxic activities and inhibitory effects on the nitric oxide (NO) production.