Flavonols and Antioxidant Activity of Ammi visnaga L. (Apiaceae)

Eleven flavonols have been isolated from the aerial parts of Ammi visnaga L. from which four aglycones, four monoglycosides, two diglycosides and one triglycoside. The flavonoid aglycones were distributed into one hydroxylated, quercetin (1) and three methoxylated, namely, rhamnetin (2), isorhamnetin (3) and rhamnazin (4). Among the monoglycosides, we found three 3-O-glucosides respectively linked to rhamnetin (5), isorhamnetin (6) and rhamnazin (7) and one 7-O-glucoside of isorhamnetin (8). The two diglycosides were 3-O-rutin of quercetin (9) and isorhamnetin (10) while the single trioside was quercetin 7,3,3’-O-triglucoside (11). These flavonols are reported for the first time from A. visnaga L . Free radical DPPH scavenging potential of the butanolic extract was investigated.