Chemical constituents from the leaves of Styrax argentifolius H.L. Li and their biological activities

Abstract Searching for bioactive agents from Vietnamese plants, nine compounds, including five nor-lignan-type benzofurans 1–5, two lignans 6 and 7, one sterol 8 and one triterpenoid 9 were separated from Styrax argentifolius for the first time. 5-((E)-2-Carboxyvinyl)-7-methoxy-2-(3′,4′-methylenedioxyphenyl)benzofuran (1) and 5-carboxy-7-methoxy-2-(3′,4′-methylenedioxyphenyl)benzofuran (2) were new benzofurans in nature. Sterol (20R)-24-ethylcholest-5,22-dien-7-one (8) and triterpenoid 2α,3α,24-trihydroxy-urs-12-en-28-oic acid (9) were isolated from the genus Styrax for the first time. Egonol (3) showed potential IC50 values of 18.15–22.11 μg/mL against three cancer cell lines KB, HepG2 and Lu, while the IC50 values of new compound 1, (–)-machicendiol (4), and triterpenoid 9 were comparable with that of the positive control acarbose (IC50 118.43 ± 2.44 μg/mL) in α-glucosidase inhibitory assays. Styrax benzofurans and triterpenoids show cytotoxic and α-glucosidase inhibitory activities. The activities of benzofurans 1 and 3–5 were due to the effect of propyl side chains at carbon C-5.