Chemical constituents from Citrus grandis Linn. and their biological activities

This research aimed to study the chemical constituents and their biological activity of the peels of Citrus grandis Linn. (Tubtim Siam Pomelo). The peels of C. grandis Linn. were immersed in acetone at room temperature. After evaporation, the acetone extract was purified with column chromatography (CC) to give a flavonoid (1). The structure of pure compound (1) was elucidated by analyses of spectroscopic data and comparing their spectroscopic data with the previously published data. Crude acetone and 1 have been evaluated for antioxidant, anti-tyrosinase, and antimicrobial. Compound 1 has DPPH radicals and tyrosinase with IC₅₀ 0.123 ± 0.004 and 0.357 ± 0.117 mg/mL, respectively.