Rare flavonoids and sesquiterpenoids isolated from the leaves of Goniothalamus gracilipes.

Abstract Three previously undescribed benzopyranyl sesquiterpenes gracilipins B D (1–3) and two flavonoids 5,4′-dihydroxy-6-(2-hydroxybenzyl)-3,7,3′-trimethoxyflavone (4), and 5,4′-dihydroxy-8-(2-hydroxybenzyl)-3,7-dimethoxyflavone (5) were isolated from the leaves of Goniothalamus gracilipes (Annonaceae). Their structures were determined by analyses of MS and 2D NMR data. The absolute configurations of 1 were established by analysis of X-ray diffraction data. Cytotoxic evaluation of the compounds 1–5 against four cancer cell lines (KB, LU-1, HepG-2 and MCF-7) indicated that compound 5 had inhibitory activity against HepG-2 cell line with IC50 value of 16.7 μM. All new compounds (1–5) were evaluated for their antimicrobial activity against a panel of clinically significant microorganisms. Compound 2 showed significant antimicrobial effect on Staphylococus aureus with MIC value of 32 μg/mL.