Studies on Dental Caries Prevention by Traditional Medicines. VIII. : Inhibitory Effect of Various Tannins on Glucan Synthesis by Glucosyltransferase from Streptococcus mutans

Hydrolyzable tannins from crude drugs were examined for inhibitory activity against glucosyltransferase from a cariogenic bacterium, Streptococcus mutans. Pentagalloylglucose showed a strong inhibitory effect, whereas ellagitannins stimulated the glucan synthesis in 10% ethanol. All the gallotannins were more potent than chlorhexidine gluconate in an aqueous reaction mixture. Among them, penta- and hexagalloylglucose were the most potent, being inhibitory at a concentration of 10-3M. The inhibitory character of gallotannins depended on the number of galloyl residues.