Hase J, Kobashi K, Mitsui K, Namba T, Yoshizaki M, Tomimori T
J Pharmacobiodyn. 1981 Nov;4(11):833-7. doi: 10.1248/bpb1978.4.833.
Chikusetsusaponin IV and V, whose genin is oleanolic acid, exhibited weak hemolytic activities. Removal of glucose residue at position 29 of chikusetsusaponin V by partial hydrolysis increased the activity more than 30-fold. Methylation of the carboxyl group at position 28 increased the activity furthermore by about 10-fold, showing HD50 value of 3.77 microM. On the other hand, removal of the sugar chain at position 3 of chickusetsusaponin V by partial hydrolysis completely lost the activity. These facts suggest that the sugar chain at position 3 of oleanolic acid is essential but that at position 29 is pernicious for the activity. The cytolytic agents, whose target has been regarded as membrane cholesterol, were inactivated not only by cholesterol but also by sapogenins such as oleanolic acid, gitogenin and hederagenin. Among saponins tested, akebia saponin B and C were inactivated by cholesterol, but not by the genins, probably because their affinities for the genins are too low to form complexes.
以齐墩果酸为苷元的竹节人参皂苷IV和V表现出较弱的溶血活性。通过部分水解去除竹节人参皂苷V第29位的葡萄糖残基，活性增加了30多倍。第28位羧基的甲基化使活性进一步增加约10倍，HD50值为3.77 microM。另一方面，通过部分水解去除竹节人参皂苷V第3位的糖链则完全丧失活性。这些事实表明，齐墩果酸第3位的糖链对活性至关重要，而第29位的糖链则对活性有害。被认为作用靶点为膜胆固醇的细胞溶解剂不仅会被胆固醇灭活，也会被齐墩果酸、吉托皂苷元和常春藤皂苷元等皂苷元灭活。在所测试的皂苷中，木通皂苷B和C被胆固醇灭活，但不被苷元灭活，可能是因为它们对苷元的亲和力太低，无法形成复合物。
