Two new coumarins 7-O-(6-O-(5-O-3,4,5-tri-methoxycinnamate-β-d-apiofuranosyl-β-d-glucopyranosyl)-6-methoxy coumarin (1) and 7-O-(6-O-(4-(2-hydroxy-1-hydroxymethyl-ethoxy)-3-methoxy-cinnamyl)-β-d-glucopyranosyl)-6-methoxy coumarin (2), along with 10 known metabolites, were isolated from the bark of Streblus indicus, their structures were identified by comparison of experimental and published spectroscopic data. (S)-marmesinin (6) and scoparone (7) exhibited moderate antimicrobial activity in vitro against Staphylococcus aureus strain with the MIC values of 62.5 and 125.0 μg/mL, respectively. Betulinic acid showed inhibitory activity in vitro against MCF-7 cell with IC50 value of 9.5 ± 0.1 μM.
Keywords: Streblus; Streblus indicus (Bur.) Corner; antimicrobial activity; coumarins; cytotoxicity.