Synthesis of the tetrasaccharide related to the repeating unit of the antigen from Shigella dysenteriae type 5.
Starting from L-rhamnose, D-mannose and 2-amino-2-deoxy-D-glucose hydrochloride, two disaccharide blocks, namely, ethyl 2,4-di-O-benzyl-3-O-[(R)-1-(methoxycarbonyl)ethyl]-alpha-L-rhamnopyranos yl-(1-->3)-2-O-acetyl-4,6-di-O-benzyl-1-thio-alpha-D-mannopyranoside and 2-(trimethylsilyl)ethyl 2-O-acetyl-3,6-di-O-benzyl-alpha-D-mannopyranosyl-(1-->3)-4,6-di-O-benzy l-2-deoxy-2-phthalimido-beta-D-glucopyranoside, were synthesised and then allowed to react in the presence of N-iodosuccinimide and trifluoromethane sulfonic acid to give a tetrasaccharide derivative. This compound was converted into 2-(trimethylsilyl)ethyl 2,4-di-O-benzyl-3-O-[(R)-1-(methoxycarbonyl)ethyl]-alpha-L-rhamno- pyranosyl-(1-->3)-2-O-acetyl-4,6-di-O-benzyl-alpha-D-mannopyranosyl-(1-- >4)-2-O-acetyl-3,6-di-O-benzyl-alpha-D-mannopyranosyl-(1-->3)-2-acetamid o-4,6-di-O-benzyl-2-deoxy-beta-D-glucopyranoside, which on hydrogenolysis, afforded the methyl ester 2-(trimethylsilyl)ethyl glycoside of the tetrasaccharide related to the repeating unit of the O-antigen from Shigella dysenteriae type 5.
Mukherjee
I
I
Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta.
Das
S K
SK
Mukherjee
A
A
Roy
N
N
D000942:Antigens, Bacterial / Q000737:chemistry*; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis; D008698:Mesylates / Q000737:chemistry; D008956:Models, Chemical; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry*; D011134:Polysaccharides / Q000138:chemical synthesis*; D012762:Shigella dysenteriae / Q000276:immunology*; D013388:Succinimides / Q000737:chemistry
D000942:Antigens, Bacterial; D004187:Disaccharides; D008698:Mesylates; D019081:O Antigens; D011134:Polysaccharides; D013388:Succinimides; C008155:N-iodosuccinimide; C012077:trifluoromethanesulfonic acid