微量量热法研究两种生物碱与DNA的嵌插作用

A Study of Intercalation Binding of Harmaline and Harmine to DNA by Microcalorimetry

我国西北地区人们很早就发现了当地所产骆驼蓬草的药用价值,近年来,我国科学工作者从中提取出了两种有效成份——二氢骆驼蓬碱(harmaline)和骆驼蓬碱(harmine)。两种纯的化合物在国外也已由人工合成。它们的分子式、分子量及结构式为两种生物碱的抗单胺氧化酶活性早有报导。最近,我国一些医学部门又将它们作为新型抗癌药物用于临床实验。由于很多药物(包括很多抗菌、抗生素及抗癌药物)治疗疾病是通过进入到人体细胞中DNA的双螺旋里发生嵌插作用来实现的。因此。

The enthalpy changes for the binding of two alkaloids with the bioactivity to inhibit monoamine oxidase, harmaline(HL) and harmine(HM) to calf thymus DNA have been determined calorimetrically in a 0.01 mol.L^(-1) piperazine-N、N'-bis(2-ethanesulfonic acid) buffer(pH=7.0) at 298.15 K by a MS-80 standard Calvet microcalorimeter. The results are △H_(298)(HL)=-10.7 kJ·mol^(-1), △H_(298)(HM)=-29.6 kJ·mol^(-1) respectively. According to the binding energy and thermokinetic curves from the experiments, the mechanism of intercalationm binding of two alkaloids to DNA has been discussed.