Synthesis and glycosidase inhibitory activity of some N-substituted 5a-carba-beta-fuco- and beta-galactopyranosylamines, and selected derivatives.

In the course of chemical modification of alpha-fucosidase inhibitors of 5a-carba-fucopyranosylamine type, an N-dodecyl derivative of the enantiomer 6-deoxy-5a-carba-beta-D-galactopyranosylamine demonstrated very strong inhibition of beta-galactosidase and beta-glucosidase. This finding led us to synthesize corresponding 6-hydroxy compounds, in order to elucidate structure-activity relationships for inhibitors of this type. Among four N-alkyl-5a-carba-beta-D-galactopyranosylamines prepared, the N-octyl derivative could be demonstrated to possess moderate activity toward alpha- and beta-galactosidases, and beta-glucosidase.

Synthesis of 5a-carba-hexopyranoses and hexopyranosylamines, as well as 5a,5a'-dicarbadisaccharides, from 3,8-dioxatricyclo[4.2.1.0(2,4)]nonan-9-ol: glycosidase inhibitory activity of N-substituted 5a-carba-beta-gluco- and beta-galactopyranosylamines, and derivatives thereof.

Since glycosidase and glycosyltransferase inhibitors, composed of carba-sugars, have recently attracted much attention, it is desirable to develop effective preparative routes for provision of new carba-sugar derivatives of potential biological interest. 1,2:3,6-Dianhydro-5a-carba-alpha-glucopyranose was here chosen for study of synthetic utility, and demonstrated to be a promising intermediate for supplying several carba-beta-glycosylamines and N-linked dicarba-oligosaccharides. An N-linked 5a,5a'-dicarbalactose derivative obtained here was found to be a strong alpha-galactosidase inhibitor (IC50 1.

Synthesis and glycosidase inhibitory activity of some N-substituted 6-deoxy-5a-carba-beta-DL- and L-galactopyranosylamines.

Chemical modification of 5a-carba-beta-DL-fucopyranosylamine (3) generated six N-substituted derivatives 9a-f, among which N-octyl 9b, decyl 9c, and phenylbutyl ones 9f were found to be very strong beta-galactosidase as well as beta-glucosidase inhibitors. The inhibitory activity appeared attributable to D-enantiomers from biological assays of prepared L-enantiomers. Therefore, 6-deoxy-5a-carba-beta-D-galactopyranosylamine (D-3) might be a promising lead compound for further design of new carba sugar-type beta-galactosidase inhibitors.

Potent and specific sialyltransferase inhibitors: imino-linked 5a'-carbadisaccharides.

Methyl 5a'-carba-beta-lactoside, imino-linked, has been shown to possess potent and specific inhibitory activity (IC50 = 185 microM) toward rat recombinant alpha2,3-sialyltransferase.