Betulin, a naturally occurring abundant triterpene is converted in four steps to 3,28-di-O-acetyllupa-12,18-diene. When various 4-substituted urazoles were oxidized to the corresponding urazines with iodobenzene diacetate in the presence of 3,28-di-O-acetyllupa-12,18-diene, new heterocyclic betulin derivatives were produced. These betulin derivatives were examined in a microplate assay at 50 μM for
桦木素,一种天然存在的丰富的三萜,可通过四个步骤转化为3,28-二-O-乙酰基acetyl- 12,18-二烯。在3,28-二-O-乙酰基lu- 12,18-二烯的存在下,用
碘代苯二
乙酸酯将各种4-取代的
脲唑氧化为相应的
脲嗪时,会生成新的杂环桦木衍
生物。在微孔板分析中以50μM的浓度检测了这些betulin衍
生物对抑制致死性内脏利什曼病的物种Leishmania donovani axenic amastigotes的生长的能力。胃肠道50测定最有效化合物的浓度(50%生长抑制的浓度),并评估其对人巨噬细胞THP-1的细胞毒性。还检查了对在巨噬细胞中生长的杜氏
乳酸杆菌的抗利什曼活性。3,28-二-O-乙酰基lupa- 12,18-二烯和4-甲基尿
嘧啶之间的杂环加合物是最有效的衍
生物,其 对杜氏
乳酸链球菌的GI 50 = 8.9μM。