Preparation Methods of Harpagide from Scrophularia Ningpoensis

OBJECTIVE To optimize the preparation methods of harpagide of Scrophularia ningpoensis. METHODS Orthogonal test was adopted to optimize extraction technology of harpagide with extraction capacity as the index. The macroporous resin was employed to enrich the harpagide. Taking the adsorption and desorption rates as the indexes, the best type of macroporous adsorption resin was screened and the enrichment technology was optimized. The purification technology of harpagide was optimized using column chromatography by investigating the stationary phase, eluting solvents, loading amount of sample, the diameter height ratio of chromatographic column and eluting volumns. RESULTS The optimized extraction technology of harpagide was that Scrophularia ningpoensis was extracted with water for 3 times, 1.5 h for each time. The optimized enrichment technology was that the SP825 type of macroporous adsorption resin was employed to enrich the harpagide with the following parameters:the sample concentration at 0.07 g·mL^-1, l:6 of the ratio of diameter and height, the absorptive flow rate at 1.0 mL·min^-1, and 0.40 g·mL^-1 of the maximum adsorption capacity. The optimized purification process using silica gel and C₁₈ column chrimatography was as follows:1:70 of the ratio of loading sample amount and silica gel, l:15 of the ratio of diameter and height, the eluant solvent of a mixture solvent system of chloroform and methanol, eluting with 2 BV of chloroform/methanol (4:1),then eluting with 1 BV of chloroform/methanol (2:1); the final purification using C₁₈ column chrimatography (the ratio of diameter and height was l:9). CONCLUSION The established preparation method of harpagide is convenient and good repeatability with a better effect. The purity of prepared harpagide is over 98%, and the yield is high. And the preparetion methods can be used for bulk production. It provides a reference for the further application and product development of Scrophularia ningpoensis.