gamma-modified triphosphates of nucleoside analogues as potential antivirals and lipophilic prodrugs therof

作为潜在抗病毒药的核苷类似物的γ-修饰三磷酸酯及其亲脂性前药

基本信息

批准号：
329712853
负责人：
Professor Dr. Chris Meier
金额：
--
依托单位：
Institut für Organische Chemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/329712853?language=en
关键词：
gamma modified triphosphates nucleoside analogues

项目摘要

Nucleoside analogues have significant impact as antiviral agents in chemotherapy. However, there are also two major drawbacks associated with the use of these compounds. First, they require an intracellular metabolism to form the nucleoside triphosphate which is the ultimately active metabolite. Second, they can not only interact with viral polymerases but can also act as substrates of human polymerases which might result in severe toxic side effects. With the project presented here we aim not only to bypass the often rate-limiting metabolism in the triphosphate formation but also to develop a entirely new approach resulting potentially in an improvement in the substrate selectivity between viral and human polymerases by using gamma-modified nucleoside analogue triphosphates as putative antiviral agents. Here we would like to work on three different aspects:1. We will synthesize and study gamma-modified nucleoside analogue triphosphates as potential substrates of viral polymerases in comparison with the human polymerases. The gamma modification should be constructed as such, that this modifcation is a non-cleavable moiety, which is covalently attached to the triphosphate unit. By that, this moiety prevents also the enzymatic degradation of the triphosphate unit of the nucleoside triphosphate. In recent studies we showed that the gamma-acyloxybenzyl-modified triphosphate of the known antiviral 3-deoxy-2,3-didehydrothymidine (d4T) was acting as a substrate of HIVs reverse transcriptase which led to the incorporation of d4TMP into DNA-strands. In contrast, this gamma-modified triphosphate was not a substrate of human polymerase beta. Interestingly, the parent compound d4TTP was also a substrate of DNA-polymerase beta. Due to this difference in selectivity this offers now a completely new option for the use of gamma-modified triphosphate analogues. This is of tremendous importance in the context of possible toxic side effects which are caused by the interaction of the triphosphate with the cellular polymerases. As gamma-modifications we propose on the one hand non-cleavable acylbenzyl-(ketone) moieties which resemble closely the previously used bioreversible acyloxybenzyl-groups and on the other hand lipophilic alkyl-residues.2. It is expected that the gamma-modified triphosphates will not be up-taken by cells due to the negative charges at the triphosphate-moiety. Therefore, lipophilic prodrugs of these gamma-modified triphosphate analogues will be developed. We aim to introduce enzyme-cleavable masking groups, e.g acyloxybenzyl-groups. Studies to elucidate the hydrolysis mechanism, stability studies in biological media such as cell extracts and antiviral tests will guide us to optimized prodrug molecules.3. The cellular up-take of the new prodrugs of the gamma-modified nucleoside triphosphates will be studied by incorporating the fluorescent bicyclic nucleoside analogue (BCNA) and cell incubation assays.

核苷类似物作为化学疗法中的抗病毒剂具有显着影响。但是，与这些化合物的使用有关，还有两个主要缺点。首先，它们需要细胞内代谢形成三磷酸核苷，这是最终活跃的代谢产物。其次，它们不仅可以与病毒聚合酶相互作用，而且还可以充当人类聚合酶的底物，这可能会导致严重的毒性副作用。在此处提出的项目中，我们不仅旨在绕过三磷酸盐形成中经常限制的代谢，而且还旨在开发一种全新的方法，从而有可能通过使用γ-修饰的核苷类模拟三磷酸磷酸盐作为推测抗病毒剂来提高病毒和人类聚合酶之间的底物选择性。在这里，我们想在三个不同的方面工作：1。与人类聚合酶相比，我们将合成和研究伽马修饰的核苷类似物三磷酸作为病毒聚合酶的潜在底物。应当构建伽马修饰，使该修饰是一个不可裂解的部分，该部分是共价附着在三磷酸单元上的。这样，该部分也可以防止三磷酸核苷的三磷酸单元的酶促降解。在最近的研究中，我们表明，已知的抗病毒3-脱氧-2,3-二羟基氨基氨基氨酸（D4T）的γ-乙酰苯基修饰的三磷酸三磷酸是HIVS逆转录酶的底物，从而导致D4TMP掺入DNA链接中。相比之下，这种伽玛修饰的三磷酸不是人类聚合酶β的底物。有趣的是，母体化合物D4TTP也是DNA聚合酶β的底物。由于选择性的这种差异，因此现在为使用伽马修饰的三磷酸类似物提供了一个全新的选择。在可能的有毒副作用的背景下，这是由于三磷酸与细胞聚合酶的相互作用引起的。作为伽马修饰，我们一方面提出了不可裂解的酰基苯基（酮）部分，它们与先前使用的生物可烘烤的丙氧甲苯基团以及另一方面的亲纤维烷基硫磺非常相似。2。预计，由于三磷酸酯裂解的负电荷，伽玛修饰的三磷酸盐不会被细胞抬高。因此，将开发这些伽玛改性三磷酸类似物的亲脂性前药。我们旨在引入可裂解酶的掩蔽基团，例如丙氧苄基组。为了阐明水解机制的研究，生物学培养基（例如细胞提取物和抗病毒测试）的稳定性研究将指导我们进行优化的前药分子。3。通过结合荧光双环核苷类似物（BCNA）和细胞孵化测定法，研究了伽马修饰核苷三磷酸的新前药的细胞上升。