The flavonoids of Allium neapolitanum.

An investigation of the extracts from Allium neapolitanum has led to the isolation of 13 flavonoid glycosides, based on kaempferol, quercetin and isorhamnetin. Four of them are new compounds and have been identified as: kaempferol 3-O-[[2-O-alpha-L-rhamnopyranosyl-4-O-beta-D-glucopyranosyl]-beta-D- glucopyranoside]], isorhamnetin 3-O-[[2-O-alpha-L-rhamnopyranosyl-6-O-beta- D-glucopyranosyl]-beta-D-glucopyranoside], isorhamnetin 3-O-[[2-O-alpha-L-rhamnopyranosyl-6-O-beta-D-glycopyranosyl] beta-D-glucopyranoside]-7-O-beta-D-glucopyranoside and isorhamnetin 3-O-[[2-O-alpha-L-rhamnopyranosyl-6-O-beta-D-gentiobiosyl]- beta-D-glucopyranoside]]. The isolated compounds were evaluated for their anti-aggregation human platelet activity.