Enzyme Inhibitors as Potential Anticancer and Antiviral

使用毛细管电泳（CE）测量和表征细胞内核苷酸池和代谢物的方法的开发仍在继续。我们以前的工作已经证明，一个100至160倍的信号增强，可以获得的CE分析的混合物的合成核苷酸与样品堆积，但一个显着恶化的信号和分辨率是注意到生物样品。样品制备方法和分析策略，以克服这种影响，如使用固相萃取和控制离子强度，提供了一些成功和20- 30倍的信号增强生物样品。我们还使用CE方法表征了细胞基质如培养的Molt-4和Hela细胞中的核苷酸药物代谢物。我们正在评估全柱样品堆积的微量核苷酸代谢物的微制备CE分离的MALDI质谱结构分析。这将应用于测定和测量用于AIDS治疗的基于核苷的逆转录酶抑制剂的活性细胞内核苷酸代谢物。国家癌症研究所（NCI）化学数据库包含在过去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。我们已经完成并验证了开放的NCI化学数据库中化合物结构完整性和纯度的目标分析评价。这是通过将所有结构随机化并进行聚类分析以识别298个簇来实现的，这些簇代表数据库的85.8%。获得代表每个簇的化合物用于分析。在这些化合物中，59.3%被评为良好，10.4%为可疑，30.3%为不可接受。指定为良好表示结构与光谱数据一致，表观纯度为80%或更高。评级为可疑表示似乎存在所需结构，但样品含有明显的（>20%）污染物或分解产物。分类为不可接受表示没有光谱证据表明存在超过样品50%的所需化合物或污染物。一个很好的相关性，观察到质谱和NMR数据的结构完整性和样品的均匀性，虽然这两种技术都不适用于所有的化合物。化合物排序与分子量、结构复杂性或NSC编号（数据库登录顺序）之间无明显相关性。根据本研究获得的结果，应确认从药物可获得的化合物获得的任何化合物的结构和纯度，特别是如果这些化合物具有生物活性。

The development of methods using capillary electrophoresis (CE) to measure and characterize intracellular nucleotide pools and metabolites continues. Our previous work has demonstrated that a 100- to 160-fold signal enhancement can be obtained for the CE analysis of mixtures of synthetic nucleotides with sample stacking, but that a marked deterioration in signal and resolution is noted for biological samples. Sample preparation methods and analysis strategies to overcome this effect, such as using solid phase extraction and controlling ionic strength, have provided some success and a 20- to 30-fold signal enhancement for biological samples. We have also characterized nucleotide drug metabolites in cellular matrices such as cultured Molt-4 and Hela cells using CE methods. We are 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 for 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. We have completed and validated a targeted analytical evaluation of the structural integrity and purity of compounds in the open NCI Chemical Database. This was accomplished by randomizing all structures and conducting a clustering analysis to identify 298 clusters which represented 85.8% of the database. A compound representative of each cluster was obtained for analysis. Of these compounds, 59.3% are ranked as good, 10.4% as questionable, and 30.3% as unacceptable. Designation as good indicates the structure is consistent with spectral data and the apparent purity is 80% or better. Ranking as questionable signifies the desired structure appears to be present but that the sample contains appreciable (>20%) contaminants or decomposition products. Classification as unacceptable denotes there is no spectral evidence for the presence of the desired compound or contaminants exceed 50% of the sample. A good correlation was observed between mass spectral and NMR data for structural integrity and sample homogeneity, although neither technique is applicable to all compounds. No obvious correlation between compound ranking and molecular weight, structural complexity or NSC number (database accession order) was observed. On the basis of the results obtained in this study, the structures and purity of any compounds obtained from a publically available compound should be confirmed, especially if those compounds have biological activity.