In vitro anti-HIV activity of biflavonoids isolated from Rhus succedanea and Garcinia multiflora

Eleven biflavonoids, including amentoflavone (1), agathisflavone (2), robustaflavone (3), hinokiflavone (4), volkensiflavone (5), morelloflavone (7), rhusflavanone (9), succedaneaflavanone (10), GB-1a (11), GB-1a 7 ''-O-beta-glucoside (13), and GB-2a (14) isolated from Rhus succedanea and Garcinia multifilora, as well as their methyl ethers, volkensiflavone hexamethyl ether (6), morelloflavone heptamethyl ether (8), and GB-1a hexamethyl ether (12), were evaluated for their anti-HIV-1 RT activity. The results indicated that compounds 3 and 4 demonstrated similar activity against HIV-1 reverse transcriptase (RT), with IC50 values of 65 mu M. Compounds 1, 2, 7, 11, and 14 were moderately active against HIV-1 RT, with IC50 values of 119 mu M, 100 mu M, 116 mu M, 236 mu M, and 170 mu M, respectively. Morelloflavone (7) also demonstrated significant antiviral activity against HIV-1 (strain LAV-1) in phytohemagglutinin-stimulated primary human peripheral blood mononuclear cells at an EC50 value of 6.9 mu M and a selectivity index value of approximately 10. The other biflavonoids were either weakly active, inactive, or not selective against HIV-1 in human lymphocytes.