APHIDICOLIN: METABOLISM/SYNTHESIS OF ANTITUMOR AGENTS

这项拟议研究的目标是通过研究其 代谢在人类疾病中的应用Aphidicolin，一种特定的DNA 聚合酶α抑制剂和可能的抗肿瘤和抗病毒剂，和 开发新的化学治疗剂， 蚜虫菌素 Aphidicolin已经见证了相当多的应用， 鉴定真核生物DNA聚合酶的功能作用及其 具体和独特作用模式鼓励了临床试验。 然而，在抑制DNA合成的活性水平下，阿非迪霉素 通过大鼠、小鼠和小鼠的肝酶（S-9组分）快速"灭活"， 大概是人类 由于失活的速度和巨大的 参与异生物质代谢的许多肝酶水平的变异性 代谢（由于性别，年龄和诱导），代谢的aphidicolin 可能会严重限制其在某些疾病状态下的使用。 我们提出 一套完整的调查，通过这些调查， 将获得蚜虫菌素代谢产物，并应用于开发 合理定义的阿非迪霉素类似物和特异性酶抑制剂。 这些研究包括蚜虫菌素的代谢研究， 确定产生的代谢物的化学结构， 负责其在微粒体（和胞质溶胶）中代谢的特定酶 从大鼠肝脏中分离，并诱导的负责酶， 化学药剂包括蚜虫菌素。 所有分离出的新化合物将 测定DNA聚合酶α抑制活性。 通过知识 代谢物的结构及其DNA聚合酶抑制 活动，大大改善了结构-活动关系， 将得到独特的化合物。 此外，"活性"代谢物与 官能化位点（例如，在饱和位置的羟基化）可以有助于 在这种亲脂性化合物的药物制剂中。 特异性抑制剂 参与代谢的酶将被追踪（例如，抑制剂 特定细胞色素P-450同工酶），如果此类抑制剂不能证明 致命的 一个对映选择性的，直接的和多功能的合成进入 将开发一种能够合成 蚜虫菌素和产生具有特定位点的蚜虫菌素类似物 修饰（旨在抑制酶促生物转化）。

The goal of this proposed research is to promote through studies of its metabolism the utility in human disease of aphidicolin, a specific DNA polymerase Alpha inhibitor and possible antitumor and antiviral agent, and to develop new chemotherapeutic agents structurally related to aphidicolin. Aphidicolin has witnessed considerable application in identifying the functional roles of eukaryotic DNA polymerases and its specific and unique mode of action have encouraged clinical trials. However, aphidicolin, at levels active in inhibiting DNA synthesis, is rapidly "inactivated" by hepatic enzymes (S-9 fraction) of rats, mice and presumably humans. Due to the rate of inactivation and to the great variability in the levels of many liver enzymes involved in xenobiotic metabolism (due to sex, age and induction), the metabolism of aphidicolin could severely limit its employment in certain disease states. We propose an integrated set of investigations through which a detailed knowledge of aphidicolin metabolism will be obtained and applied to the development of rationally defined aphidicolin analogs and specific enzyme inhibitors. These investigations include metabolic studies of aphidicolin which will determine the chemical structures of the metabolites generated, the specific enzymes responsible for its metabolism in microsomes (and cytosol) isolated from rat liver, and the inducibility of the responsible enzymes by chemical agents including aphidicolin. All new compounds isolated will be assayed for DNA polymerase Alpha inhibitory activity. Through a knowledge of the structures of the metabolites and their DNA polymerase inhibition activities, vastly improved structure-activity relationships for this unique compund will be obtained. In addition, "active" metabolites with functionalized sites (eg. hydroxylation at saturated positions) may assist in the drug formulation of this lipophilic compound. Specific inhibitors of the enzymes involved in the metabolism will be pursued (eg. inhibitors of specific cytochrome P-450 isozymes), if such inhibitors would not prove lethal. An enantioselective, direct and versatile synthetic entry into the aphidicolin framework will be developed which is capable of synthesizing aphidicolin and generating aphidicolin analogs with specific site modifications (which are designed to inhibit enzymatic biotransformation).