银杏外种皮提取银杏酸工艺的优化试验

Optimization of the extraction process in Ginkgo biloba exocarp

试验主要探讨了从银杏外种皮中提取分离银杏酸的工艺条件及银杏酸含量的测定方法。考虑到不同条件对提取效果的影响,选取溶剂浓度、温度、提取时间和料液比4个因素,进行4因素3水平的正交设计试验,用紫外分光光度法测定提取样品的含量。测定含量时,对样品进行预净化处理,使在波长310 nm处测定银杏酸含量时没有其他杂质的干扰。样品的预净化方法是用正己烷萃取样品,将萃取的样品挥干,挥干后用甲醇溶解进行含量测定。研究结果表明:以75%乙醇为提取溶剂,采用1∶4(g/ml)的料液比,在45℃条件下振荡提取2次,每次4 h为最优提取条件;相关因素方差分析,溶剂浓度对提取效果有显著影响。

Technological conditions of extracting ginkgolic acids from testa of Ginkgo biloba and analytic method of ginkgolic acids content were studied in this paper. As different conditions in solvent concentration, temperature, time and solid-liquid ratio may influence extraction result, so orthogonal experiments of four factors and three levels were adopted. UV spectrophotometry was used to assay the content of the sample. The samples need pre-purification by n-hexane extracting and volatilizing to dryness to ensure the determination of ginkgolic acids content in the wavelength of 310 nm with no other material interfere. The result showed that using 1：4 of 75% ethanol as solid-liquid ratio, extracting by reflusing at 45℃ for 2 times and 4 h each time were the best extracting conditions; analysis of variance for four factors showed that the solvent concentration could affect extraction efficiency significantly.