Khan S H, Jain R K, Matta K L
Department of Gynecologic Oncology, Roswell Park Memorial Institute, New York State Department of Health, Buffalo 14263.
Carbohydr Res. 1990 Oct 15;207(1):57-69. doi: 10.1016/0008-6215(90)80005-n.
Methyl 3,4,6-tri-O-benzyl-beta-D-mannopyranoside (2), methyl 2,3-O-isopropylidene-beta-D-mannopyranoside (11), and 4-nitrophenyl 2,3-O-isopropylidene-beta-D-mannopyranoside (12) were each condensed with 2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl bromide (1) in the presence of mercuric cyanide, to give after deprotection, methyl 2-(5) and 6-O-alpha-D-mannopyranosyl-beta-D-mannopyranoside (15), and 4-nitrophenyl 6-O-alpha-D-mannopyranosyl-beta-D-mannopyranoside (20), respectively. A similar condensation of 11 with 3,4,6-tri-O-acetyl-2-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-a lpha-D- mannopyranosyl bromide (21) and 2,3,4-tri-O-acetyl-6-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-a lpha D-mannopyranosyl bromide (25), followed by removal of protecting groups, afforded methyl O-alpha-D-mannopyranosyl-(1----2)-O-alpha-D-mannopyranosyl-(1----6)-beta -D- mannopyranoside (24) and methyl O-alpha-D-mannopyranosyl-(1----6)-O-alpha-D-mannopyranosyl-(1----6)-beta -D- mannopyranoside (28), respectively. Bromide 25 was also condensed with 12 to give a trisaccharide derivative which was deprotected to furnish 4-nitrophenyl O-alpha-D-mannopyranosyl-(1----6)-alpha-D-mannopyranosyl-(1----6)-beta-D - mannopyranoside (31). Phosphorylation of methyl 3,4,6-tri-O-benzyl-2-O-alpha-D-mannopyranosyl-beta-D-mannopyranoside and 15 with diphenyl phosphorochloridate in pyridine gave the 6'-phosphates 6 and 16, respectively. Hydrogenolysis of the benzyl and phenyl groups provided methyl 2-O-(disodium alpha-D-mannopyranosyl 6-phosphate)-beta-D-mannopyranoside (7) and methyl 6-O-(disodium alpha-D-mannopyranosyl 6-phosphate)-beta-D-mannopyranoside (17) after treatment with Amberlite IR-120 (Na+) cation-exchange resin. The structures of compounds 5, 7, 15, 17, 20, 24, 28, and 31 were established by 13C-n.m.r. spectroscopy.
3,4,6-三-O-苄基-β-D-甘露吡喃糖苷(2)、2,3-O-异亚丙基-β-D-甘露吡喃糖苷(11)和4-硝基苯基2,3-O-异亚丙基-β-D-甘露吡喃糖苷(12)分别在氰化汞存在下与2,3,4,6-四-O-乙酰基-α-D-甘露吡喃糖基溴(1)缩合,脱保护后分别得到2-(5)和6-O-α-D-甘露吡喃糖基-β-D-甘露吡喃糖苷(15)以及4-硝基苯基6-O-α-D-甘露吡喃糖基-β-D-甘露吡喃糖苷(20)。11与3,4,6-三-O-乙酰基-2-O-(2,3,4,6-四-O-乙酰基-α-D-甘露吡喃糖基)-α-D-甘露吡喃糖基溴(21)和2,3,4-三-O-乙酰基-6-O-(2,3,4,6-四-O-乙酰基-α-D-甘露吡喃糖基)-α-D-甘露吡喃糖基溴(25)进行类似缩合,然后除去保护基,分别得到O-α-D-甘露吡喃糖基-(1→2)-O-α-D-甘露吡喃糖基-(1→6)-β-D-甘露吡喃糖苷(24)和O-α-D-甘露吡喃糖基-(1→6)-O-α-D-甘露吡喃糖基-(1→6)-β-D-甘露吡喃糖苷(28)。溴化物25也与12缩合得到一种三糖衍生物,脱保护后得到4-硝基苯基O-α-D-甘露吡喃糖基-(1→6)-α-D-甘露吡喃糖基-(1→6)-β-D-甘露吡喃糖苷(31)。3,4,6-三-O-苄基-2-O-α-D-甘露吡喃糖基-β-D-甘露吡喃糖苷和15在吡啶中用二苯基磷酰氯进行磷酸化反应,分别得到6'-磷酸酯6和16。苄基和苯基经氢解后,用Amberlite IR-120(Na+)阳离子交换树脂处理,得到2-O-(α-D-甘露吡喃糖基6-磷酸二钠盐)-β-D-甘露吡喃糖苷(7)和6-O-(α-D-甘露吡喃糖基6-磷酸二钠盐)-β-D-甘露吡喃糖苷(17)。化合物5、7、15、17、20、24、28和31的结构通过13C核磁共振光谱确定。