Spectrum-effect relationship of antibacterial extracts from Isatidis Radix / 中草药

ABSTRACT

Objective: To study the active components with anti-bacterial effect in Isatidis Radix. Methods: Using cylinder-plate method with bacteriostatic coefficient as the index, the anti-Escherichia coli AG100A effects of five extracts (total extract, tatal organic acid extract, total alkaloids extract, tatal nudeoside extract, and total anthraquinone extract) from Isatidis Radix were studied. After the determination of the most active extract, HPLC fingerprints on 10 batches of Isatidis Radix from different habitats were established. The correlations between areas of common peaks and bacteriostatic coefficients were analyzed by principal component analysis (PCA). Results: The total organic acid extract showed the best anti-bacterial effect, with 21 common peaks in HPLC fingerprint. The results of the PCA demonstrated that the common peaks 2, 10, 16, 18, 20, and 21 were connected closely with the antibacterial activity, among which the common peaks 10 and 18 were proved to be salicylic acid and benzoic acid, respectively. Conclusion: The total organic acid extract from Isatidis Radix shows the significant antibacterial effect, in which salicylic acid and benzoic acid are the active chemical constituents with the antibacterial activity.