The Analytical Chemistry of Anti-AIDS Agents

使用毛细管电泳法(CE)测量和表征细胞内核苷酸代谢物和内源核苷酸池的方法的发展仍在继续。我们以前的工作表明，通过在线定量样品堆积，核苷酸的CE分析可以获得100多倍的信号增强。这些方法已被用于表征和研究合成核苷酸衍生物的混合物。然而，生物衍生的核苷酸混合物在样品堆积和CE分析中显示出信号和分辨率的显著恶化。已经探索了克服这种影响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了20至30倍。这项调查仍在继续。我们还评估了用于微制备毛细管电泳法分离微量核苷酸代谢物的全柱样品堆积，以用于MALDI质谱仪的结构分析。这将在艾滋病治疗中使用的核苷类逆转录酶抑制剂的活性细胞内核苷酸代谢物的测定和测量中得到应用。国家癌症研究所(NCI)化学数据库包含50多万个在过去50年中获得的独特结构，是生物测试、药物开发和化学信息应用的宝贵资源。许多研究人员使用这个数据库来识别新的先导化合物，用于抗癌和抗病毒药物的开发。这种方法的有效性取决于所选择的具有所述结构的化合物。我们最近在开放的NCI化学数据库中完成了对化合物结构完整性和纯度的有针对性的分析评估，结果显示，对于上述目的，很大一部分(30%)化合物可能是不可接受的。这些化合物没有光谱证据证明所需结构的存在，或者污染物超过样品的50%。正因为如此，我们继续逐一分析和评估从NCI数据库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.