Wesche D L, Black J
Faculty of Medicine, University of Papua New Guinea, Boroko, NCD.
J Trop Med Hyg. 1990 Jun;93(3):153-9.
The effects of four major cinchona alkaloids: (-) quinine, (+) quinidine, (-)cinchonidine, and (+)cinchonine against Plasmodium falciparum FCQ-27/PNG were studied. The alkaloids were tested in vitro as either single alkaloids, racemic mixtures of stereoisomers, or as an equimolar combination of all four alkaloids. Results indicate (+)quinidine to be most effective and both (+)stereoisomers were more potent than the (-)stereoisomers. Inhibitory concentrations 50% (Ki) of racemic mixtures of stereoisomers were similar to those of the (+)stereoisomers alone. The Ki of four alkaloids in equimolar combination were similar to that of the (-) cinchonidine/(+)cinchonine racemic mixture. A total alkaloidal extract of Cinchona sp. was tested and compared with the pure alkaloids. HPLC analysis indicated that (+)cinchonine, (-)cinchonidine and (-)quinine were present in a ratio of approximately 1:1:2, respectively. The total alkaloid extract, with (-)stereoisomers predominating, was less effective than the four alkaloids in combination. The nature of the interaction between stereoisomers was investigated and appears to be one of addition.
（-）奎宁、（+）奎尼丁、（-）辛可宁和（+）辛可宁对恶性疟原虫FCQ-27/PNG的作用。这些生物碱在体外分别作为单一生物碱、立体异构体的外消旋混合物或四种生物碱的等摩尔组合进行测试。结果表明（+）奎尼丁最有效，且两种（+）立体异构体比（-）立体异构体更有效。立体异构体的外消旋混合物的50%抑制浓度（Ki）与单独的（+）立体异构体相似。四种生物碱等摩尔组合的Ki与（-）辛可宁/（+）辛可宁外消旋混合物的Ki相似。对金鸡纳属植物的总生物碱提取物进行了测试，并与纯生物碱进行了比较。高效液相色谱分析表明，（+）辛可宁、（-）辛可宁和（-）奎宁的含量比例约为1:1:2。以（-）立体异构体为主的总生物碱提取物比四种生物碱组合的效果差。研究了立体异构体之间相互作用的性质，似乎是加成作用之一。
