Boc Solid-Phase Synthesis of Conjugable Cyclic Depsipeptides for Use as Biological Probes

Boc 固相合成用作生物探针的可缀合环状缩肽

• 批准号: 2117468
• 金额: --
• 依托单位: University of Surrey
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2117468
• 关键词: Boc; Solid; Phase; Synthesis; Conjugable

Research into the mechanism of action of bioactive chemicals, such as drugs, natural products and toxins, can be greatly informed by the application of synthetic chemical probes to biological systems, usually cells. Probes are often conjugates of the active molecule with a 'tracer' in the form of a fluorescent group that allows its location in a cell to be visualised but, more importantly, assays to be developed that show when it is binding to its target (usually a protein) in the cell (e.g. a bioluminescence resonance energy transfer (BRET) assay). In order to convert bioactive molecules into conjugates, they must have a reactive 'handle' incorporated. The aim of this project is to develop methods to rapidly synthesise bioactive cyclic depsipeptides (peptides containing an ester bond) bearing such a handle in the form of the amino group of a lysine (or lysine-like) residue. The synthesis of peptides is most rapidly performed on solid-phase: the first residue is attached, by its carboxylic acid, to an insoluble polymer resin and subsequent iterative deprotection and coupling reactions build up the rest of the peptide without the need to purify after each step - only wash off excess reagents from the resin. In this project, we will take advantage of the older "Boc"-method as it does not involve an alkaline step (Fmoc deprotection by piperidine) which leads to problems in depsipeptide synthesis (hydrolysis of the ester bond). However, the Boc-method is usually avoided due to it requiring dangerous hydrofluoric acid for the final removal of the product from the resin. We will develop alternative linkages to the resin to circumvent the use of this reagent as well as carry out a full investigation of protecting groups to be used as the depsipeptide is built that will allow on-resin cyclisation prior to removal from resin and purification, followed by conversion into chemical probes.

对生物活性化学品（如药物、天然产物和毒素）的作用机制的研究，可以通过将合成化学探针应用于生物系统（通常是细胞）而得到很大的启发。探针通常是活性分子与荧光基团形式的“示踪剂”的缀合物，其允许其在细胞中的位置被可视化，但更重要的是，待开发的测定显示何时与细胞中的靶（通常是蛋白质）结合（例如生物发光共振能量转移（BRET）测定）。为了将生物活性分子转化为缀合物，它们必须具有并入的反应性“柄”。该项目的目的是开发快速合成生物活性环状缩肽（含有酯键的肽）的方法，所述环状缩肽以赖氨酸（或赖氨酸样）残基的氨基的形式带有这种手柄。肽的合成在固相上进行得最快：第一个残基通过其羧酸连接到不溶性聚合物树脂上，随后的迭代脱保护和偶联反应构建肽的其余部分，而无需在每个步骤后纯化-仅从树脂上洗掉过量的试剂。在本项目中，我们将利用较旧的“Boc”方法，因为它不涉及碱性步骤（通过哌啶进行Fmoc脱保护），该步骤会导致缩肽合成中的问题（酯键水解）。然而，通常避免Boc方法，因为它需要危险的氢氟酸用于从树脂中最终去除产物。我们将开发树脂的替代连接，以避免使用该试剂，并对待使用的保护基团进行全面研究，因为缩肽构建将允许在从树脂中去除和纯化之前在树脂上环化，然后转化为化学探针。