THE ANALYTICAL CHEMISTRY OF NEW ANTICANCER DRUGS

该项目的目标是开发和应用生物分析方法，以：(1)确定新抗癌药物的物理、化学和生化性质；(2)测量新药物、其代谢物和生物样品中潜在的生物调节剂；(3)阐明体外和体内药理学和药代动力学；(4)确定有助于发现新药物先导的独特分子特征。高效液相色谱法、荧光法和紫外可见光谱分析是主要的分析手段。腺苷脱氨酶(ADA)是一种普遍存在的人类酶，也是腺嘌呤类化疗药物的生物调节剂，它的催化结合部位正在通过构象偏向的合成腺嘌呤核苷获得新的见解。酶动力学、核磁共振和分子模拟研究表明，北方构型的呋喃核糖类似物具有优先催化作用。这些结果反映在结合常数的改善(K<SUB>M</SUB>)和北部构型类似物的更高的水解率上，无论是在限制的还是非限制的糖构象中。这为设计作为嘌呤代谢调节剂的新型化疗药物提供了一条新的合理途径。成功地应用荧光化学衍生法测定了外周血淋巴细胞中腺嘌呤核苷酸的三磷酸水平，结果表明，接受抗艾滋病新药洛地诺辛治疗的患者淋巴细胞中的三磷酸浓度处于低分子水平。虽然这种方法最初是为了测量一种新的抗艾滋病毒药物的细胞浓度，但在生物样本有限且无法使用放射性同位素的情况下，这种方法将有助于测量其他抗癌和抗病毒的腺嘌呤核苷酸。毛细管电泳法(CE)是一种筛选丙型肝炎病毒潜在抑制剂的高通量方法。纳升样品的要求使得这种方法对于常规分析和当可用于测试的药物数量有限时非常有吸引力。在一项针对恶性黑色素瘤的临床基因治疗试验中，正在确定更昔洛韦递增剂量的人体药代动力学。该试验使用表达单纯疱疹病毒胸苷激酶的腺病毒进行药物激活。药物的亲脂性仍然是生物系统中药物吸收的一个重要的物理化学描述。辛醇-水分配系数(logP<SUB>O/W</SUB>)是这一参数的最直接量度，已用我们新的微摇瓶技术测定了132多个核苷类似物的分配系数。这些数据的汇编导致了核苷衍生物的预测结构-对数P模型，该模型直观且优于目前使用的许多计算机算法。-腺苷脱氨酶，荧光衍生，亲脂性，毛细管电泳法，丙型肝炎病毒，分配系数，

The goal of this project is the development and application of bioanalytical methods to: (1) determine physical, chemical and biochemical properties of new anticancer drugs, (2) measure novel drugs, their metabolites, and potential biomodulators in biological samples, (3) elucidate in vitro and in vivo pharmacology and pharmacokinetics and (4) define unique molecular features which facilitate discovery of new drug leads. High-performance liquid chromatography (HPLC), fluorimetry and ultraviolet-visible spectroscopy are the principle analytical tools. New insight into the catalytic binding site of adenosine deaminase (ADA), a ubiquitous human enzyme and biomodulator of adenine-based chemotherapeutic agents, is being obtained using conformationally biased synthetic adenine nucleosides. Enzyme kinetics, nuclear magnetic resonance, and molecular modeling studies show preferential catalysis of northern configured ribofuranosyl analogues. These results are reflected in improved binding constants (K_M) and enhanced rates of hydrolysis for northern configured analogues whether in constrained or unconstrained sugar conformations. This affords a new rational approach for the design of novel chemotherapeutics as modulators of purine metabolism. Successful application of fluorogenic chemical derivatization to measure triphosphate levels of an adenine nucleotide in peripheral blood lymphocytes has demonstrated concentrations at low pmole levels in lymphocytic cells of patients receiving lodenosine, a new anti-AIDS drug. Although originally designed to measure cellular concentrations of a new anti-HIV drug, this method will be conducive for the measurement of other anti-cancer and antiviral adenine nucleotides where limited biological sample is available and where utilization of radioisotopes is not feasible. Capillary electrophoresis (CE) is being explored as a high through-put method for screening potential inhibitors of hepatitis C virus. Nanoliter sample requirements make this method quite attractive for routine assay and when limited amounts of drug are available for testing. Human pharmacokinetics of escalating doses of ganciclovir are being determined in a clinical gene therapy trial targeting malignant melanoma with a herpes simplex-thymidine kinase expressing adenovirus for drug activation. Drug lipophilicity remains an important physicochemical descriptor of drug absorption in biological systems. Octanol-water partition coefficients (log P_o/w), being the most direct measure of this parameter, have been determined for more than 132 nucleoside analogues using our novel micro shake-flask technique. The compilation of this data has led to a predictive structure-log P model for nucleoside derivatives which is intuitive and superior to many computer algorithm currently in use. - adenosine deaminase, fluorogenic derivatization, lipophilicity, capillary electrophoresis, hepatitis C virus, partition coefficient,