Objective: To extract the effective ingredient (crystal I) from effective section (saponin) of Ligustrum Lucidum Ait, identify the chemical structure of crystal I, study the effect of crystal I on P. gingivalis, B. forsythus and P. intermedia.
Methods: Isolated crystal I from saponin using the silica gel column chromatograph. Identified crystal I with IR spectra, (1)H-NMR and (13)C-NMR. Measured the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) through micro-liquid dilution. Studied the killing curve of ursolic acid on B. forsythus and P. intermedia.
Results: The crystal I was identified as ursolic acid; its MIC and MBC to P. gingivalis, B. forsythus and P. intermedia were 0.740 and 0.295 microg/L respectively. The killing curve indicated that 0.800 microg/L ursolic acid could kill P. intermedia and B. forsythus in 3 and 6 hours respectively.
Conclusion: Ursolic acid has obvious effect to inhibit periodontal pathogen.