龙爪槐叶中黄酮醇苷元成分的研究

Study on the constituents of flavonoid aglycones in the leaves of Sophora japonica f. pendula.

目的建立高效液相色谱法，同时测定龙爪槐叶中主要黄酮醇苷元成分槲皮素、山柰酚和异鼠李素的含量，考察其含量在不同生长期的变化规律。方法选取不同时间点采摘龙爪槐叶，甲醇连续提取，水解后用高效液相色谱法测定槲皮素、山柰酚和异鼠李素的含量。结果龙爪槐叶中含有与银杏叶相似的黄酮醇苷元成分，含量高于银杏叶；其中槲皮素含量最高、山柰酚次之、异鼠李素含量最低。三者含量都表现出随不同生长期变化的规律，以4．5月份最高，以后逐渐降低。结论龙爪槐叶含有丰富的黄酮醇类化合物，不同生长期其含量有所变化，最佳槐叶采摘时间为4、5月份。

Objective To develop a method of RP-HPLC for determination of three kinds of flavnoid aglycones, quercitin, kaempferol, and isorhamnetin simultanenoasly and to discover changes of them in the/eaves of Sophorajaponica f. pendula, in different growth periods. Methods The leaves of Sophora japonica f. pendula, were collected at different time point. Flavonoids in the leaves were extracted by successive extraction with methanol. The extracts were acid-hydrolyzed before being tested with RP-HPLC. Results The constituent of flavnoid aglycones in the leaves of Sophora japonica f. pendula, was quite similar to that in ginkgo leaves,but the content of them in the former was much higher than that in the latter. Among three flavonoid aglycones determined, the content of quercitin was the highest and that of isorhamnetin was the lowest. The contents of these flavonoid aglycones reached maximum in the months of April and May and declined gradually later. Conclusion The leaf of Sophora japonica f. pendula, has aboundant of flavonoids in the leaves of Sophorn japonica f. pendula. The contents of them change along with the growth periods. April and May should be the optimal collecting time of leaves of Sophora japonica f. pendula, for extraction of flavonoids.