|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1991 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1990 : ¥1,400,000 (Direct Cost : ¥1,400,000)
The glycosphingolipids isolated from spermatozoa of a fresh water bivalve, Hyriopsis schlegelii, have a unique structure. The biological function, especially the recognition mechanism of fertilization, of these glycosphingolipias in fresh water bivalves remains to be elucidated, but studies should be facilitated by the availability of synthetic samples. We have previously reported the synthesis of the nonreducing end trisaccharide and the reducing end pentasaccharide corresponding to the partial structure derived from lipid IV.
The disaccharide, trisaccharide, and tetrasaccharide reducing ends of lipid Iv were the targets for the synthetic studies described here as part of our investigations on the synthesis of oligosaccharides of biological interest. The disaccharide derivative was obtained by condensation of 2, 3-di-O-acetyl-1, 6-anhydro-beta-D-glucopyranose with 4, 6-di-O-acetyl-2, 3-di-O-benzyl-alpha-D-mannopyranosyl bromide.
An attempted debenzylation of disaccharide derivative gave the disaccharide acceptor for the synthesis of trisaccharide. The glycosylation of this acceptor with 3, 4, 6-tri-O-acetyl-2-chloroacetyl-alpha-D-mannopyranosyl bromide afforded a trisaccharide. To achieve a synthesis of a tetrasaccharide, the trisaccharide was condensed with 2, 3, 4-tri-O-acetyl-alpha-D-xylopyranosyl bromide. Each oligosaccharide was transformed into the corresponding deblocked compound. 4-OH Free glucosamine of the pentasaccharide, which was derivatized by deblocking and selectively blocking, was condensed with the bromide compound of the nonreducing end trisaccharide.
Biological tests of these synthetic oligosaccharides are now undertaken.