Precision Synthesis of Glycopeptide-Type Sugar Balls and Development of Their Molecular Catalyst and Molecular Recognition

1.糖肽型糖球的精确合成：通过伯胺封端的树枝状大分子与糖衍生物α-氨基酸N-羧酸酐反应，建立了一种合成结构明确的糖肽型糖球的有效方法。以葡萄糖、半乳糖和N-乙酰氨基葡萄糖衍生物取代的L-丝氨酸为原料，与8代以下的聚氨基胺树枝状大分子反应，合成了多种糖肽型糖球。径向生长聚合(RGP)中的传播速率加速分析：通过电导率测量的方法，研究了以伯胺封端的树枝状大分子为引发剂的NCA的开环聚合反应。根据溶剂、取代基、温度和添加氰基封端的树枝状大分子对传播速率常数的影响，可以得出结论，观察到的加速是由于树枝状大分子表面附近单体浓度的增加以及从表面径向生长引起的碰撞几率增加所致。糖肽型糖球作为生物功能材料的评价：以8-苯胺基-1-萘磺酸钠(ANS)为探针，研究了低分子化合物在糖肽型糖球中的包封性。第八代聚酰胺胺树枝状大分子与N-乙酰氨基葡萄糖衍生物取代的NCA在二甲基亚砜中反应时，包裹的ANS分子的数量明显增加。凝集素诱导的血凝抑制实验证明，糖肽型糖球比相应的单糖或寡糖具有更强的分子识别能力。

1. Precision Synthesis of Glycopeptide-Type Sugar Balls :An efficient synthetic method via a reaction of primary amine-terminated dendrimer with sugar derivative-substituted α-amino acid N-carboxyanhydride (NCA) was established for glycopeptide-type sugar balls of well-defined structure. A variety of glycopeptide type-sugar balls were synthesized by the reactions of poly(amido amine) dendrimers of up to the eighth generation with glucose, galactose, and N-acetylglucosamine derivative-substituted L-serine NCAs.2. Analysis of Propagation Rate Acceleration in Radial-Growth Polymerization (RGP) :Ring-opening polymerization of NCAs with primary anime-terminated dendrimer as an initiator was kinetically investigated by means of conductivity measurement. On the basis of the effects of solvents, substituents, temperature, and added cyano-terminated dendrimer on the propagation rate constant, it was concluded that the observed acceleration was due to the increased monomer concentration near the dendrimer surface and the enhanced collision probability arising from the radial-growth from the surface as well.3. Evaluation of Glycopeptide-Type Sugar Balls as Biofunctional Materials :Encapsulation of low molecular weight compounds inside glycopeptide-type sugar balls was investigated using sodium 8-anilino-1-naphthalenesulfonate (ANS) as a probe. The number of the encapsulated ANS molecules appreciably increased when poly(amido amine) dendrimer of the eighth generation was allowed to react with N-acetylglucosamine derivative-substituted NCA in dimethyl sulfoxide. Inhibition experiments of lectin-induced hemagglutination proved that the glycopeptide-type sugar balls possessed much higher molecular recognition ability than the corresponding mono- or oligosaccharides.