Flavonoid glycosides from Adina racemosa and their inhibitory activities on eukaryotic protein synthesis

From the dried leaves, flowers, and twigs of Adina racemosa, five new flavonoid glycosides, quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-(3-O-trans-p-coumaroyl)-beta-d-galactopyranoside (1), quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-(4-O-trans-p-coumaroyl)-alpha-l-rhamnopyranosyl(1-->2)]-(4-O-trans-p-coumaroyl)-beta-d-galactopyranoside (2), kaempferol 3-O-alpha-l-rhamnopyranosyl(1-->6)-(4-O-trans-p-coumaroyl)-alpha-l-rhamnopyranosyl(1--> 2)]-(4-O-trans-p-coumaroyl)-beta-d-galactopyranoside (3), quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-(4-O-trans-p-coumaroyl)-alpha-l-rhamnopyranosyl(1-->2)]-(3-O-trans-p-coumaroyl)-beta-d-galactopyranoside (4), and quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-(4-O-trans-caffeoyl)-alpha-l-rhamnopyranosyl(1-->2)]-(3-O-trans-p-coumaroyl)-beta-d-galactopyranoside (5), and eight known compounds were isolated. The structures of the new compounds were determined by spectroscopic and chemical means. Their inhibitory activities on protein synthesis were assessed. The new glycosides were found to be inhibitors of eukayrotic, but not prokaryotic, protein synthesis.