Anti-HIV activity of flavonoids and proanthocyanidins from Crataegus sinaica

In addition to quercetin, hyperoside, rutin, vitexin, 2 "-O-rhamnosylvitexin, (4"'-O-acetyl)-2"-O-rhamnosylvitexin, epicatechin, procyanidin B-5, proanthocyanidin A-2, procyanidin B-2 and procyanidin C-1, which were reported before in Crataegus sinaica (Rosaceae), three more flavonoids were isolated from the same plant, i.e. (+)-taxifolin, 3-O-beta-arabinopyranosyl-(+)-taxifolin and 3-O-beta-xylopyranosyl-(+)-taxifolin. The in vitro anti-HIV activity of some selected flavonoids and proanthocyanidins was evaluated. The dimeric procyanidin B2 and proanthocyanidin A2, and especially the trimeric procyanidin C1 showed some in vitro anti-HIV activity.