| 摘要 |
PURPOSE:To obtain an anticarious substance, consisting of purified gymnemic acid prepared from Gymnema sylvestre, having high inhibitory effects on formation of bacterial plaques and capable of remarkably suppressing growth of cariogenic bacteria. CONSTITUTION:Dried leaves of Gymnema sylvestre are extracted with hot water and the resultant extract solution is adjusted to pH3 with 2N sulfuric acid to provide precipitates containing crude gymnemic acid. The precipitates are collected by centrifugal settling and the aggregates are washed with water and extracted with ethanol. The extract is then concentrated under reduced pressure and acetone in a volume of 2 times is added to the concentrate to carry out centrifugal settling. The supernatant liquid is subsequently concentrated to dryness under reduced pressure and extracted with diethyl carbonate as a solvent as the boiling point. Substances deposited from the above-mentioned solvent are collected and evaporated to dryness, subjected to high-speed liquid chromatography to afford the aimed purified gymnemic acid. The resultant purified gymnemic acid has action of inhibiting formation of glucan by cariogenic bacteria as well as surely preventing formation of bacterial plaques and is preferably used by containing in an amount of >=10mM. |
