新穎寡糖合成技術開發及奈瑟氏菌的偵測

Abstract

於此篇論文中我們成功利用二甲基甲醯胺（DMF）做為調控子直接調控醣基化反應的α立體位向選擇性，並以此技術為基礎做延伸，配合一鍋化醣基化反應、預活化策略以及鄰基效應保護基的使用來開發新穎的連續性一鍋化醣基化反應合成策略達成各種任意不同立體位向鍵結的寡糖產物，其分別為(α,α)，(β,α)以及(α,β)天然與非天然三醣目標物。且我們開發的合成策略可以廣泛應用於絕大數去氧硫醣予體上以合成各式立體位向的寡糖鍵結，提供了未來合成天然寡糖上一個快速、實用且簡單的方法。 除了發展醣類的合成技術以外，我們也將研究延伸至生醫感測的領域。在調查出奈瑟氏菌菌毛表面一種獨有醣體後，我們利用有機合成方法合成出此bacillosamine類似醣結構，並首例將其做為噬菌體展示單鏈抗體庫的標的物成功篩選出有專一性辨識能力的單鏈抗體D7，且在經由一連串諸多的實驗證實下，確定單鏈抗體能夠辨識奈瑟氏菌（其中包含兩種知名人類致病菌株：淋病雙球菌及腦膜炎雙球菌）後再結合奈米金粒子發展成一套具有潛力且可攜帶性的生醫感測工具。

Herein, we report a simple and general α-glycosylation method in which N,N-dimethylformamide (DMF) is used as a modulating molecule to direct the stereochemical course of glycosylation. Further elaboration of this approach led to a practical α-selective procedure based on preactivation. And based on the combined use of DMF modulation and neighboring group participation, three iterative one-pot (α,α), (β,α) and (α,β)-glycosylations, were developed. These methods are applicable to a range of thioglycosyl donors, confer stereocontrol in α-/β-glycosidic bond formation, and thus provide for rapid access to natural oligosaccharides with various permutations of anomeric configurations. We not only developed the saccharide synthesis strategy, but also made an application to biological sensing. A Neissaria bacterial pilus sugar, bacillosamine, is synthesized and, for the first time, successfully used as a probe for screening a single-chain variable fragment (scFv). The recombinant scFv was prepared and unequivocally demonstrated for effectively sensing Neisseria strain, including two important pathogens, Neisseria meningitidis and Neisseria gonorrhoeae. This scFv is extremely valuable for further medical applications, such as in a convenient on-site detection kit for sexually transmitted disease caused by Neisseria infection.