Development of glyco-cluster materials systems to detect and neutralize pathogenic microorganisms

流感病毒和致病性大肠杆菌是流行病，有时对婴儿和老年患者至关重要。这些病原体通过细胞表面的寡糖侵入我们的身体。细胞表面的Sialo寡糖和α(l-4)-半乳糖寡糖分别是流感病毒和大肠杆菌志贺毒素（Stx-I和Stx-II）的识别信号。目前的研究旨在开发具有多价sialo和α(l-4)-Gal阵列的聚合物基生物材料，以检测、捕获和中和流感病毒和vero毒素。我们已经成功地将二氧配合物型低聚糖一锅转糖基化成α-葡萄糖功能化的三联吡啶钌配合物。所得到的糖缀合物表现出优异的凝集素亲和力，可与呈现多个唾液苷阵列的聚合物相媲美。此外，它们具有很强的发光能力，但由于病毒的加入，这种发光能力明显减弱，这可能是由于它们的糖壳结构受到破坏。我们已经发现了半乳糖-海藻糖α(l- 1)-键作为全球基α(l-4)-键的潜在替代品。虽然半乳糖海藻糖对stx - 1和stx - 2的结合能力，特别是对后者的结合能力仍然弱于天然的Gb_2和Gb_3，但半乳糖海藻糖可以通过额外引入β-糖苷片段或相关的其他单位来显著整合这种结合亲和力。

Influenza viruses and pathogenic E.coli species are epidemic and sometimes critical for infants and aged patients. These pathogens invade our bodies through cell surface oligosaccharides. Sialo oligoaccharides and α(l-4)-galactobiosyl oligosaccharides on cell surfaces are the recovnition signals respectively for influenza viruses and E.coli Shiga toxins (Stx-I and Stx-II). The present research is aimed at developing polymer-based biomaterials having multivalent sialo and α(l-4)-Gal arrays to detect, capture, and neutralize influenza-viruses and vero toxins.We have succeeded in one-pot transglycosylation of disialo complex-type oligosaccharides onto an α-glucose-functionalized tris-bipyridine ruthenium complex. The resulting glycoconjugates exhibited excellent lectin-affinities comparable to that of polymers presenting multiple sialoside arrays. Also, they have strong luminescence that is markedly depressed by addition of virus, probably due to disruption of their saccharide-shell structures.We have found the potential utility of the galacto-trehalose α(l-l)-linkage as a promising substitute for the globosyl α(l-4)-linkage. Though the binding of the galacto-trehalose to Stx-I and Stx-II, particularly to the latter, is still weaker than that of the natural Gb_2 and Gb_3 globosides, galacto-trehalose may integrate the binding affinity significantly by additionally introducing β-glucoside moiety or related other units.