[Separation and identification of the flavonoids from Buddleia officinalis Maxim]

The flowers of Buddleia officinalis Maxim have been used to cure eye inflammation in China. Eight flavonoid compounds were isolated from them. Their structures were characterized as acacetin (1), apigenin (2), luteolin (3), neobudofficide (4), linarin (acaciin 5), luteolin-7-O-rutinoside (6), luteolin-7-O-glucoside (7) and cosmosiin (8), on the basis of chemical and spectral evidences. The new compound 4 was identified as 5,7-dihydroxy-4'-O-methoxyflavone-7-O-alpha-L-rhamnopyranosyl (1-->2)-[alpha-L-rhamnopyranosyl (1-->6)]-beta-D-glucopyranoside and named neobudofficide. All the compounds were isolated from B. officinalis for the first time, except linarin and acacetin.