DIMERIC STILBENES FROM STEM BARK OF SHOREA ROXBURGHII AND THEIR BIOLOGICAL ACTIVITIES

Abstract

Shorea roxburghii (Family Dipterocarpaceae) was found to be rich in oligostilbenes with various biological activities. However, scientific investigation into its bioactivity remains limited. In the current study, phytochemical investigation of S. roxburghii stem bark was performed to obtain three dimeric stilbenes, which were identified as (−)-ε-viniferin (1), (−)-balanocarpol (2), and (−)-ampelopsin A (3) by comparison of their spectroscopic data with those previously reported. The compounds were assayed for their effect on antioxidant, anti-inflammatory, cytotoxicity against breast cancer, anti-melanogenesis, anti-tyrosinase, and α-glucosidase inhibitory activities. Results showed that compound 2 and its C-7b epimer 3 scavenged ABTS radicals with IC₅₀ values of 12.5 and 40.1 µM, respectively, while compound 1 was inactive (IC₅₀ > 50 µM). Unfortunately, it was found that all three compounds are not active in other assays conducted.