From extracts of olive (Olea europaea L., Oleaceae) leaves showing ant
i-complementary activity, the flavonoids apigenin, apigenin-4'-O-rhamn
osylglucoside, apigenin-7-O-glucoside, luteolin, luteolin-4'-O-glucosi
de, luteolin-7-O-glucoside, chrysoeriol, chrysoeriol-7-O-glucoside and
quercetin-3-O-rhamnoside were isolated. Major isolated constituents s
trongly inhibited the classical pathway of the complement system.