Two pairs of rare benzofuran glucoside epimers, indicuses A and B and indicuses C and D, three biogenetically related compounds indicuses E–G, and one coumarin indicus H, as well as 11 known compounds, were isolated from the bark of Streblus indicus (Bur.) Corner. The structures of indicuses A–H were elucidated by NMR and MS data, as well as by CD. (S)-Marmesinin exhibited moderate antimicrobial activity in vitro against Bacillus subtilis and Saccharomyces cerevisiae. 7,8-Dihydroxy-3-(3-methyl-2-butenyl) coumarin, umbelliferone, and scopoletin displayed strong cytotoxic activity in vitro against human bladder carcinoma cell line EJ. The structure-activity relationships indicate that hydroxylation at C-7 in the cytotoxic compounds is crucial to their activities.
