Activity of triterpenoid glycosides from the root bark of Mussaenda macrophylla against two oral pathogens

Four new triterpenoid glycosides were isolated from the root bark of Mussae nda macrophylla. Their structures were determined as 3-O-beta-D-glucopyrano syl-28-O-alpha-L-rhamnopyranosyl- protobassic acid (1), 28-O-beta-D-glucopy ranosyl-16 alpha-hydroxy-23-deoxyprotobassic acid (2), 3-O-beta-D-glucopyra nosyl-28-O-alpha-L-rhamnopyranosyl- 16 alpha-hydroxyprotobassic acid (3), a nd 3-O-([beta-D-glucopyranosyl- (1-->6)1-O-alpha-L-rhamnopyranosyl-(1-->2)- O-beta-D-glucopyranosyl-(1-->2))-O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-g lucopyranosyl-cycloarta-22,24-dien-27-oic acid (mussaendoside W, 4). Four k nown triterpenoids [3-O-acetyloleanolic acid (5), 3-O-acetyldaturadiol (6), rotundic acid (7), and 16 alpha-hydroxyprotobassic acid (8)] were also iso lated. The structures of 1-4 were determined by several spectroscopic techn iques including 2D NMR methods. Compounds 1-6 showed inhibitory activity ag ainst a periodontopathic bacterium, Porphyromonas gingivalis, but were inac tive against the cariogenic organism, Streptococcus mutans.