Potent inhibition of chitin synthase by an azasugar--investigation of synergistic effect with UDP

Iminosugars as glycosyltransferase inhibitors

Iminosugars are naturally occurring carbohydrate analogues known since 1967. These natural compounds and hundreds of their synthetic derivatives prepared over five decades have been mainly exploited to inhibit the glycosidases, the enzymes catalysing the glycosidic bond cleavage, in order to find new drugs for the treatment of type 2 diabetes and other diseases. However, iminosugars are also inhibitors of glycosyltransferases, the enzymes responsible for the synthesis of oligosaccharides and glycoconjugates. The selective inhibition of specific glycosyltransferases involved in cancer or bacterial infections could lead to innovative therapeutic agents. The synthesis and biological properties of all the iminosugars assayed to date as glycosyltransferase inhibitors are reviewed in the present article.

Regiospecific formation of sugar-derived ketonitrone towards unconventional C-branched pyrrolizidines and indolizidines

The synthesis of unprecedented branched pyrrolizidines and indolizidines was accomplished via nitrone chemistry.

Gem-difluoromethylated and trifluoromethylated derivatives of DMDP-related iminosugars: synthesis and glycosidase inhibition

Gem-difluoromethylated and trifluoromethylated derivatives of DMDP-related iminosugars have been synthesized from cyclic nitrones and assayed against various glycosidases.

Inhibition of chitin synthase by a series of 7-deoxycasuarine stereoisomers designed as constrained analogues of the potent inhibitor 6-deoxyhomoDMDP

A series of polyhydroxy-pyrrolizidines were designed as constrained analogues of 6-deoxy-homoDMDP, a potent naturally occurring inhibitor of chitin synthase. Enzymatic evaluation revealed that 7-deoxycasuarine was the best inhibitor of the series (IC50 = 820 microM) displaying a noncompetitive inhibition pattern, whereas the other tested compounds had IC50 in the range 4.3-18.9 mM. This is the first report of pyrrolizidine-type iminosugars inhibiting a glycosyltransferase. In addition, the inhibitory potencies towards glycosidases of these synthetic casuarine analogues is also disclosed.

Inhibition of chitin synthase by a series of 7-deoxycasuarine stereoisomers designed as constrained analogues of the potent inhibitor 6-deoxyhomoDMDP

A series of polyhydroxy-pyrrolizidines were designed as constrained analogues of 6-deoxyhomoDMDP, a potent naturally occurring inhibitor of chitin synthase. Enzymatic evaluation revealed that 7-deoxycasuarine was the best inhibitor of the series (IC50 = 820 microM) displaying a non-competitive inhibition pattern, whereas the other tested compounds had IC50 in the range 4.3-18.9 mM. This is the first report of pyrrolizidine-type iminosugars inhibiting a glycosyltransferase. In addition, the biological evaluation towards glycosidases of these synthetic casuarine analogues is also disclosed.

Iminosugars as glycosyltransferase inhibitors: synthesis of polyhydroxypyrrolidines and their evaluation on chitin synthase activity

Chitin synthase is an enzyme involved in the biosynthesis of chitin, a major structural component of the cell wall of many fungi. Since chitin is absent in vertebrates, chitin synthase has been envisaged as a valuable target in the search for new antifungal agents. In this report, a series of C-2 substituted polyhydroxypyrrolidines were designed and synthesized with the aim of mimicking the glycosylation involved at the transition state of the enzymatic reaction governed by chitin synthase. Some of these models displayed chitin synthase inhibition in the millimolar range. However, no significant antifungal activity was noted on a panel of fungal strains.