香菇多糖核心片段六糖的合成研究

以已知的2,3,4,6-四-O-苯甲酰基-?-D-葡萄吡喃糖-(1?3)-2,3,4,6-四-O-苯甲酰基-β-D-葡萄吡喃糖-(1?6)]-2,4- 二-O-乙酰基-β-D-葡萄吡喃糖-(1?3)-2,4,6-三-O-乙酰基-α-D-葡萄吡喃糖三氯乙酰亚胺酯(2)为供体, 以2-O-苯甲酰 基-4,6-O-苄叉基-α-D-葡萄吡喃糖烯丙基苷(4)作为受体, 立体专一性地偶联得到β-1,3连接的五糖5. 五糖5酸解脱去4,6-苯亚甲基基后与2,3,4,6-四-O-苯甲酰基-α-D-葡萄吡喃糖三氯乙酰亚胺酯(7)偶联, 区域和立体专一性地得到全保护的β-1,3主链β-1,6支链的六糖8. 六糖8脱保护后得到目标化合物香菇多糖核心片段六糖9. 发展了合成该类化合物的一种新方法.

Synthesis of Core Gluco-hexasaccharide of Lentinan

Abstract The known 2,3,4,6-tetra-O-benzoyl-β-D-glucopyranosyl-(1?3)-2,3,4,6-tetra-O-benzoyl-β-D- glucopyrano-syl-(1?6)]-2,4-di-O-acetyl-β-D-glucopyranosyl-(1?3)-2,4,6-tri-O-acetyl-α-D-glucopyranosyl- trichloroacetimidate (2) was chosen as glycosyl donor to couple with allyl 4,6-O-benzylidene-2-O-benzoyl- α-D-glucopyran-oside (4) to afford β-(1→3) linked pentasaccharide 5 in a stereo-specific manner. After removal of 4,6-O-benzylidene of 5, followed by coupling with 2,3,4,6-tetra-O-benzoyl-α-D-glucopyranosyl trichloroacetimidate (7), the blocked gluco-hexasaccharide (8) was regio- and stereo-specifically obtained. Deprotection of 8 provided the target sugar 9. Thus, a new method for the preparation of this kind of compounds was developed.