Boronated L-nucleotides targeted against HIV

描述(由申请人提供)：本提案的目的是创建 一类新的抗病毒核苷酸前药，它结合了效力和 L核苷抑制剂对逆转录酶的选择性 硼磷酸盐替代的优点(在这种情况下， A-磷酸被取代为硼基(BH3))。我们假设这些 前药将具有良好的细胞膜通透性，并在水解后， 细胞内的亲脂载体会产生(α-P-硼烷) 相应核苷类似物的单磷酸、二磷酸和三磷酸。这个 建议的硼化类似物对磷酸二酯酶和 磷酸酶，是核苷酸酶的良好底物，对 病毒RTS。此外，(α-P-硼氧基)三磷酸盐被提出为 HIV-RT-ATP依赖和焦磷分解的有效抑制剂 核酸链终止子；以及结合的硼磷酸键 病毒DNA被认为对修复表现出更高的稳定性 导致抗药性的机制。我们的具体目标包括1) 强效病毒α-P-硼氧基类似物的合成与表征 复制抑制剂，包括D-和L对映体 2‘，3’-二脱氧核苷(2‘，3’-DDN)，2‘，3’-二脱氧-2‘，3’-二脱氢胸苷 (D4T)，2‘-脱氧-3’-硫代胞苷三磷酸(3TC)和2‘，3’-双脱氧-2‘- 氟阿拉伯核苷(2‘-FddAraN)。2)将这些含硼类似物作为 病毒核苷一磷酸和二磷酸核苷酶的底物和抑制剂 逆转录酶和哺乳动物聚合酶；测定 结构-功能关系；选择最有力和最有选择性的 用于未来药理学研究的聚合酶链终止物；以及研究 硼磷酸盐对病毒DNA修复的阻断作用及其机制 堵塞。3)通过选择偶联设计新的核苷酸前药 具有适当官能团的α-P-硼类似物以促进 它们的细胞穿透和对目标分子的化学灭活；以及 研究细菌的化学、生化和生物物理性质 对生化和治疗应用最重要的类似物； 4)研究细胞对磷酸二酯酶的摄取和稳定性 以及与其他实验室合作研究该酶的活性 在细胞培养中对抗人类病毒疾病的新前体药物。我们期待着 这些研究将使我们更好地理解 核苷激活、病毒复制和耐药性，并提供 合理设计高效低毒抗病毒药物的基础 探员们。

DESCRIPTION (Provided by the applicant): The aim of this proposal is to create a new class of antiviral nucleotide prodrugs, which combine the potency and selectivity of L-nucleoside inhibitors for reverse transcriptase (RT) with advantages of boranophosphate substitution (in which an oxygen of the a-phosphate is replaced with a borano (BH3) group). We hypothesize that these prodrugs will have good cellular membrane permeability and, after hydrolysis of the lipophilic carriers inside the cell, would generate the (alpha-P-borano) mono-, di- and triphosphates of the corresponding nucleoside analogs. The boronated analogs are proposed to be stable to phosphodiesterases and phosphatases, yet good substrates for nucleotide kinases and selective for viral RTs. Moreover, the (alpha-P- borano) triphosphates are proposed to be effective inhibitors of the HIV-RT ATP-dependent and pyrophosphorolytic removal of nucleotide chain terminators; and a boranophosphate linkage incorporated into viral DNA is proposed to exhibit increased stability toward repair mechanisms that contribute to drug resistance. Our Specific Aims include 1) To synthesize and characterize (alpha-P-borano) analogs of potent viral replication inhibitors, including D- and L-enantiomers of 2',3'-dideoxynucleosides (2',3'-ddN), 2',3'-dideoxy- 2',3'-didehydrothymidine (d4T), 2'-deoxy-3'-thiacytidine triphosphate (3TC), and 2',3'-dideoxy-2'- fluoroarabinonucleosides (2'-FddAraN). 2) To study these boronated analogs as substrates and inhibitors of nucleoside mono- and diphosphate kinases, viral reverse transcriptases, and mammalian polymerases; to determine structure-function relationships; to select the most potent and selective polymerase chain terminators for future pharmacological studies; and to study how well boranophosphates block the repair of viral DNA and their mechanism of blockage. 3) To design new nucleotide prodrugs by conjugating selected alpha-P-boronated analogues with appropriate functional groups to facilitate their cell penetration and chemical inactivation of target molecules; and to investigate the chemical, biochemical, and biophysical properties of the analogs that are most essential for biochemical and therapeutic applications; 4) To investigate cell uptake and stability to phosphodiesterases and phosphatases; and to collaborate with other laboratories to study the activity of the new prodrugs against human viral diseases in cell culture. We anticipate that these studies will lead to better understanding of the mechanisms of nucleoside activation, viral replication, and drug resistance, and provide a basis for the rational design of more efficient and less toxic antiviral agents.