Comparative analysis of four active compounds of Baikal skullcap and its classical TCM prescriptions according to different clinical curative effects

Objective: A sensitive HPLC-DAD detection method was established for the comparative analysis of the four active compounds (including baicalin, baicalein, wogonoside and wogonin) of Baikal Skullcap and its classical TCM prescriptions according to different clinical curative effects. And analyze the relationship between compatibility of medicines, content and clinical curative effect. Methods: Water extracts were analyzed by high-performance liquid chromatography-diode array detection (HPLC-DAD), using an Agilent extend-C18 (4.6mm×250mm,5μm) column by using solvent A (0.2% phosphoric acid water) and solvent B (methanol) in the ratio of 52:48 (v/v) at a flow rate of 1 ml/min. The column temperature was maintained at 25°C and the detection wavelength was set at 280 nm. Results: In quantitative analysis, the four selected markers showed good regression (R>0.999) within test ranges. The average recoveries were between 99.75~100.60% and their RSD values were between 0.97%~1.71%. The proportions of the four chemical compounds for different efficacy were 33.51~35.76: 6.78~6.87: 3.45~3.64: 1; 18.6~23.64: 3.63~4.27: 1.36~1.53: 1; 29.94~31.78: 5.14~5.23: 3.28~3.56: 1; 33.99~41.91: 5.83~7.42: 2.83~3.39: 1. Conclusion: Clinical practice of thousands of years have proved that the curative effect of Traditional Chinese Medicine depends on the compatibility of different kinds of medicine material crude slices. According to this study we found that different compatibility of medicines leads to different proportions of the chemical compounds. We assume that there is a certain correlation between therapeutical effect of TCM and compatibility of medicines.