Pseudouridine 的合成研究

Abstract

自然界中，目前僅有少數C-nucleosides被分離出來，其大多為抗生素，且大多具有抗癌或抗病毒活性，這些C-nucleosides跟自然界中常見的N-nucleosides相較之下，結構有較多的相異性，因此擁有不同的物化性和生物化學特性。在此，我們感興趣的核苷為Pseudouridine (Ψ)，1957年在tRNA中被分離出來，它是Ｃ-nucleosides中最大量的核苷。相較於N-nucleosides，雖然Ｃ-nucleosides的碳-碳鍵穩定許多，建立糖苷鍵的困難度卻遠高於N-nucleosides，建立單一-組態也是一大挑戰，在此，我們將針對(1) Fredel-Craft type分子內C-glycosylation、(2) furanolactones的分子內親核性加成反應、(3) Heck的耦合反應分別做探討，希望可以開發新的方法建立糖苷鍵，合成Pseudouridine。

A handful of C-nucleosides were isolated from nature. Many of them are antibiotics and exhibit anticancer or antiviral activity. These C-nucleosides, while bearing structure resemblances to the more common naturally occurring nucleosides, are, by virtue of their unique structure feature, different in their physicochemical and biochemical properties. In this project, the C-nucleosides we were interested is pseudouridine (Ψ), which was isolated from tRNA in 1957 and the most abundant C-nucleoside. Although the C-C glycosidic bond of C-nucleosides is more stable than N-nucleosides, it is more difficult to establish. How to control the -selectivity is also a challenge to date. In this thesis, we attempted to establish C-C glycosidic bond via three different approaches: (1) Fredel-Crafts type intramolecular C-glycosylation; (2) nucleophilic addition to furanolactones; (3) Heck coupling reaction. We hope to develop the new synthetic route to form C-C glycosidic bond and then apply to the synthesis of the nature product, pseudouridine.