Four new steroids from the leaves and twigs of Dysoxylum pallens and their cytotoxic activities

Abstract

Four previously undescribed steroids, identified as (3S,7S,8S,9S,10R,13S,14S,16S,17R,20S)-7α-methoxy-ergosta-5,24(28)-dien-3β,16β,20-triol (1), ergosta-5,24(28)-dien-3β,7α,16β-triol (2), ergosta-5,25-dien-3β,7α,16β,20-tetrol (3) and 7α,16β,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.