The Analytical Chemistry of Anti-AIDS Agents

使用毛细管电泳（CE）来测量和表征细胞内核苷酸代谢物和内源性核苷酸库的方法的开发仍在继续。我们以前的工作已经表明，超过100倍的信号增强，可以获得用于CE分析的核苷酸，通过使用定量在线样品堆积。这些方法已被应用于表征和研究合成的核苷酸衍生物的混合物。然而，生物衍生的核苷酸的混合物，在样品堆叠和CE分析时显示出信号和分辨率的显著恶化。已经探索了克服这种效应的样品制备方法和分析策略，并取得了一些成功，导致生物样品的信号增强20至30倍。调查仍在继续。我们还评估了全柱样品堆积，用于微量核苷酸代谢物的微制备CE分离，用于MALDI质谱法的结构分析。这将应用于测定和测量用于艾滋病治疗的核苷类逆转录酶抑制剂的活性细胞内核苷酸代谢物。美国国家癌症研究所（NCI）化学数据库包含了过去50年中获得的50多万个独特结构，是生物测试、药物开发和化学信息应用的宝贵资源。许多研究人员使用该数据库来识别用于抗癌和抗病毒药物开发的新的先导化合物。该方法的有效性取决于所选的具有所述结构的化合物。我们最近完成了对开放的NCI化学数据库中化合物的结构完整性和纯度的目标分析评价，结果显示，其中相当大一部分（30%）可能无法用于上述目的。这些化合物没有光谱证据表明存在所需结构，或污染物超过样品的50%。正因为如此，我们继续分析和评估从NCI数据库中获得的任何化合物的结构和纯度。

The development of methods using capillary electrophoresis (CE) to measure and characterize intracellular nucleotide metabolites and endogenous nucleotide pools continues. Our previous work has shown that a more than 100-fold signal enhancement can be obtained for the CE analysis of nucleotides by using quantitative on-line sample-stacking. These methods have been applied to characterize and study 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. 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 transciptase inhibitors that used in AIDS therapy. The National Cancer Institute (NCI) Chemical Database, which contains over half a million unique structures acquired over the past 50 years, is a valuable resource for biological testing, for drug development and for chemical information applications. Many investigators use this database to identify new lead compounds for anticancer and antiviral drug development. The validity of this approach depends on the selected compounds possessing the stated structures. Our recently completed targeted analytical evaluation of the structural integrity and purity of compounds in the open NCI Chemical Database revealed that a substantial fraction (30%) of them may be unacceptable for the above purposes. These compounds have no spectral evidence for the presence of the desired structure, or contaminants exceed 50% of the sample. Because of this, we continue to analyze and evaluate the structures and purities of any compounds obtained from NCI Database on a case-by-case basis.