9 新規エンド-α-マンノシダーゼ阻害剤のデザイン及び合成(口頭発表の部)

抄録

Glycosidases are enzymes that are involved in several important biological processes such as digestion, biosynthesis of glycoproteins and catabolism of glycoconjugates. Glycosidase inhibitors have a potential to produce a number of beneficial therapeutic effects and are of biotechnological relevance. Thus carbohydrate heteroanalogues are potential inhibitors of carbohydrate-processing enzymes, which are useful tools in the study of N-linked glycoprotein biosynthesis, in that they can act as substrate analogues. Spohr and Spiro previously reported that the azadisaccharide 1-deoxy-3-O-(α-D-glucopyranosyl)-mannojirimycin (1) effectively inhibited glycoprotein-processing hydrolase endo-α-D-mannosidase (IC_<50>=1.7×10^<-6>M) in vitro, which was the enzyme responsible for the cleavage of α-D-Glc-(1→3)-D-Man from the GlcMan_9GlcNAc_2 oligosaccharide present inmmature N-linked glycoproteins. However, this disaccharide can be cleaved by intracellular glucosidases, therefore has a very short half-life. Then we developed the disaccharides 5-thio-glucosyl-α(1→3)-DMJ(2), 5-thio-glucosyl-α(1→3)-5-thio-mannoside (3), and 5-thio-glucosyl-α(1→3)-α-mannoside (4), the glycosyl unit in 1 was replaced with 5-thioglucose, for more metabolically-stable inhibitors for endo-α-D-mannosidase. Furthermore, we planned to synthesize new disaccharide (5), deoxymannojirimycin linked to pseudosugar such as validamine, which has amino-linkage in the molecule. The validamine, a glycosyl doner to construct the amino linkage of the disaccharide, is known as an excellent α-glucosidase inhibitor. Our designed analogues can be expected as a potent endo-α-D-mannosidase inhibitor in account of the resistance to hydrolysis in the metabolic system as well as the different inhibitory mechanism.