The Analytical Chemistry of Anti-AIDS Agents

毛细管电泳（CE）检测和分析方法的发展 表征合成核苷酸混合物以及细胞内核苷酸代谢物 继续。我们以前的工作表明，定量在线样品堆积产生了 超过100倍的信号增强用于核苷酸的CE分析。这些方法具有 已应用于表征和研究水解和酶的稳定性的混合物， 合成核苷酸衍生物。然而，生物衍生的核苷酸混合物显示， 样品堆积和CE分析时信号和分辨率明显恶化， 这些样品的高离子强度样品制备方法和分析 已经探索了克服这种效应的策略并且已经取得了一些成功， 导致生物样本的信号增强20至30倍。这次调查 继续。我们也在评估微制备CE的全柱样品堆积 分离痕量核苷酸代谢物用于通过MALDI质谱法进行结构分析。 这将应用于测定和测量细胞内的活性物质， 所使用的基于核苷的逆转录酶抑制剂的核苷酸代谢物 艾滋病治疗核苷类逆转录酶抑制剂包括一类重要的 治疗艾滋病的药物。药物化学实验室有一个 长期研究构象锁定核苷作为潜在抗艾滋病药物的项目， 抗癌剂。在这些研究过程中，人们逐渐认识到， 核苷糖的构象对其化学和生物学性质有着深刻的影响。 我们已经通过实验证实，在两个构象锁定的 双脱氧腺苷（ddA）类似物，其中糖氧的取向是孤对轨道 被冻结以增强或削弱异头效应的强度。其中异头的 作用增强，糖苷键延长，核苷变得更多， 易水解。在pH 2时，构象锁定的ddA类似物具有增强的 异头效应的脱嘌呤速率比其结构异头效应的脱嘌呤速率高6倍以上。 异构体。然而，两种ddA类似物都比ddA本身更稳定，ddA本身的半衰期为 在pH 2时仅为2.67分钟。

The development of methods using capillary electrophoresis (CE) to measure and characterize synthetic nucleotide mixtures as well as intracellular nucleotide metabolites continues. Our previous work has shown that quantitative on-line sample-stacking produces a more than 100-fold signal enhancement for the CE analysis of nucleotides. These methods have been applied to characterize and study the hydrolytic and enzymatic stability of mixtures of synthetic nucleotide derivatives. Biologically derived mixtures of nucleotides, however, show a marked deterioration in signal and resolution upon sample-stacking and CE analysis because of the high ionic strength of these samples. Sample preparation methods and analysis strategies to overcome this effect have been explored and have provided some success, resulting in a 20- to 30-fold signal enhancement for biological samples. This investigation continues. We are also evaluating whole-column sample stacking for the micropreparative CE isolation of trace nucleotide metabolites for structural analysis by MALDI mass spectrometry. This will have application for the determination and measurement of the active intracellular nucleotide metabolites of the nucleoside-based reverse transcriptase inhibitors that are used in AIDS therapy. Nucleoside-based reverse transcriptase inhibitors comprise an important class of therapeutically useful drugs for AIDS. The Laboratory of Medicinal Chemistry has had a long-standing program studying conformationally locked nucleosides as potential anti-AIDS and anticancer agents. During the course of these studies it has come to be recognized that the conformation of nucleoside sugar can profoundly affect its chemical and biological properties. We have experimentally confirmed that this is indeed the case in two conformationally locked dideoxyadenosine (ddA) analogues where the orientation of the sugar oxygens lone pair orbitals are frozen to either enhance or impair the strength of the anomeric effect. Where the anomeric effect is enhanced, the glycosidic bond is lengthened and the nucleoside becomes more susceptible to hydrolysis. At pH 2, the conformationally locked ddA analogue with an enhanced anomeric effect has a depurination rate more than 6-fold greater than that of its structural isomer. Both ddA analogues, however, are more stable than ddA itself which has a half-life of only 2.67 min at pH 2.