Alfalfa (Medicago sativa L.) flavonoids. 2. Tricin and chrysoeriol glycosides from aerial parts

Ten flavone glycosides have been isolated and identified in aerial parts of alfalfa. These included six tricin, one 3 ' -O-methyltricetin, and three c hrysoeriol glycosides. Most of these compounds were acylated with ferulic, coumaric, or sinapic acids, and acylation occurred on the terminal glucuron ic acid. Eight of these compounds,. including 7-O-beta -D-glucuronopyranosy l-3 ' -O-methyltricetin, 7-O-beta -D-glucuronopyranosyl-4 ' -O-beta -D-gluc uronopyranosidechrysoeriol, 7-O-[2 ' -O-feruloyl-beta -D-glucuronopyranosyl (1 -->2)-O-beta -D-glucuronopyranoside]chrysoeriol, 7-O-[2 ' -O-feruloyl-be ta -D-glucuronopyranosyl(1 -->3)]-O-beta -D-glucuronopyranosyl(1 -->2)-O-be ta -D-glucuronopyranoside]chrysoeriol, 7-O-[2 ' -O-sinapoyl-beta -D-glucuro nopyranosyl(1 -->2)-O-beta -D-glucuronopyranoside]tricin, 7-O-[2 ' -O- feru loyl-beta -D-glucuronopyranosyl(1 -->2)-O-beta -D-glucuronopyranoside]trici n, 7-O-[2 ' -O-p-coumaroyl-beta -D-glucuronopyranosyl(1 -->2)-O-beta -D-glu curonopyrpLnosideltricin, and 7-O-{2 ' -O-feruloyl-[beta -D-glucuronopyrano syl(1 -->3)]-O-beta -D-glucuronopyranosyl(1 -->2)-O-beta -D-glucuronopyrano side}tricin, have not been reported previously in the plant kingdom. Two pr eviously identified alfalfa flavones, 7-O-beta -D-glucuronopyranosidetricin and 7-O-[beta -D-glucuronopyranosyl(1 -->2)-O-beta -D-glucuronopyranoside] tricin, were also isolated.