Acetylated triterpenoids betulin, oleanolic acid, ursolic acid, and glycyrrhetinic acid were converted into their succinyl-spacered acetazolamide conjugates. These conjugates were screened for their inhibitory activity onto carbonic anhydrase II and their cytotoxicity employing several human tumor cell lines and non-malignant fibroblasts. As a result, the best inhibitors were derived from betulin and glycyrrhetinic acid while those derived from ursolic or oleanolic acid were significantly weaker inhibitors but also of diminished cytotoxicity. A betulin-derived conjugate held a Ki = 0.129 μM and an EC50 = 8.5 μM for human A375 melanoma cells.
乙酰化三萜类化合物白桦脂素、齐墩果酸、熊果酸和甘草次酸被转化为琥珀酰-空位乙酰唑胺共轭物。利用几种人类肿瘤细胞系和非恶性成纤维细胞筛选了这些共轭物对碳酸酐酶 II 的抑制活性及其细胞毒性。结果表明,白桦脂酸和甘草次酸的抑制效果最好,而熊果酸和齐墩果酸的抑制效果明显较弱,但细胞毒性也较低。对人类 A375 黑色素瘤细胞而言,从白桦脂提取的共轭物的 Ki = 0.129 μM,EC50 = 8.5 μM。