比较不同溶剂提取银杏(Ginkgo biloba L.)叶黄酮类化合物的提取效率, 从成本效益角度考虑, 以 70%乙醇作为提取溶剂更为有利。 在分级沉淀中 , 黄酮含量与蛋白质含量呈正相关, 在乙醇提取液中黄酮和蛋白质含量最高;蛋白质的存在有助于提高黄酮的溶解度。 乙醇提取液用饱和(NH4)2SO4浓缩两次, 可使醇相中的黄酮沉淀析出。 根据试验结果, 提出了银杏叶黄酮的优化提取
方法。
 

The contents of flavonoid of Ginkgo biloba L .leaves from different extract solution with different solvents were compared , and 70 %ethanol w as suggested for the better solvent according to the consideration of lower cost and better beneficial result .When 3 %(NH4)2 SO4 , 6 %(NH4)2 SO4 and 75 % ethanol was used in turn to extract the same sample , the flavonoid was largely found in the ethanol ex tract solution , and the flavonoid content was positive relevent to the protein content among different extract solutions.Existence of protein may help the flavonoid to dissolve in the solution .The ethanol ex tract solution was concentrated twice with the similar volume of (NH4)2SO4 saturated solution , and the flavonoid sediment was separated out in 0～4 ℃. According to the experimental result , the authors put fo rw ard a suggestion about better extracting technical process of the flavonoid from Ginkgo biloba leaves .