|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1992 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1991 : ¥1,400,000 (Direct Cost : ¥1,400,000)
The facile regio- and stereocontrolled alpha-glycosylation of sialic acids with several sugar residues are now well studied and high yields of desired products are possible either by DMTST or NIS/TfOH in acetonitrile under kinetically controlled conditions. By using this procedure, a variety of gangliosides, such as GM4, GM3, GM2, GM1, GM1b, GD1a, lacto and neolacto-tetraosyl ceramides, sialyl Le^x, and their positional isomers, have systematically been synthesized. Sialyl Le^x and its related compounds are very attractive molecules related to cancer methastasis, inflammation and other biological activities. We have also synthesized various analogs of gangliosides, containing thioglycosidic linkages, modified sialic acids, and pseudo-ceramides. Some of the thioglycosides analogs showed potential inhibition of the influenza A viruses. We hope that the evaluation of these compounds along with the native gangliosides for their biological properties will not only elucidate unknown aspects of structural relations of native gangliosides but also contribute to the development of novel medicinal therapeutic strategies.