Anti-HIV-1 activities of extracts and phenolics from Smilax china L.

Four extracts (EtOH, CHCl3, EtOAc, and BuOH) and five phenolics (dihydrokaempferol (1), resveratrol (2), kaempferol-7-O-β-D-glucoside (3), dihydrokaempferol-3-O-α-L-rhamnoside (4), oxyresveratrol (5)) from Smilax china L. was evaluated for anti-HIV-1 activities and cytotoxicity activities in vitro. All these extracts and phenolics showed lower or no cytotoxicity at a concentration ranged from 0.8 μg/mL to 100 μg/mL, but some showed potential anti-HIV-1 activities, that is, BuOH extract and compound 2 showed higher anti-HIV-1 activities than other extracts and compounds in the tested concentrations. EtOAc extract and compound 1 and 3 showed moderate anti-HIV-1 activities at a concentration higher than 4 μg/mL. In the end, the structure-activity relationship of four extracts and five phenolics was discussed.