Study on Antibacterial Activity in Vitro and Stability of Chinese Medicine Compound Gongyanjing's Different Solvent Extracts

The Gong Yanjing compound was extracted by petroleum ether,70 % ethanol and distilled water with agar punch method. The antimicrobial activities of different solvent extracts were determined by comparing the size of inhibition zone,and the minimum inhibitory concentrations of compound alcohol extract and water extract for staphylococcus aureus and escherichia coli were tested,meanwhile the effects of culture medium p H,sugar,temperature and ultraviolet on the bacteriostatic activity of alcohol extract and water extract were also investigated. The results showed that: The alcohol extract and water extract had a good antibacterial effect. The minimum inhibitory concentrations of the compound alcohol extract for Staphylococcus aureus was 0. 00625 g / m L and E. coli and B. subtilis were 0. 125 g / m L; The minimum inhibitory concentrations of water extract for S. Aureus and Escherichia coli were 0. 125 g / m L. The temperature and ultraviolet rays treatment on compound ethanol extract,water extract did not affect their inhibitory effect; When medium p H values increased the antibacterial activities of two solvent extracts weakened,and when the sugar content in culture medium increased,the antibacterial activities of two extracts enhanced.