Short synthesis of new salacinol analogues and their evaluation as glycosidase inhibitors

Versatile synthesis of some analogues of the naturally-occurring α-glucosidase inhibitor salacinol (1), involving thioanhydro alditol moieties with erythro, d,l-threo, xylo, ribo, d-arabino and d-manno configurations is described. Nucleophilic attack at the least-hindered carbon atom of an l- or d-protected erythritol cyclic sulfate by the thioanhydro alditol sulfur atom yielded the desired zwitterionic compounds. In addition, the preparation of the cyclic sulfates of 2,4-O-benzylidene-d-erythritol and 2,4-O-isopropylidene-l-erythritol was improved. Enzyme inhibition tests showed that most of the new compounds were weak but specific inhibitors, while good inhibitory activity was found for a six-membered ring analogue (β-glucosidase: Ki=16 μM

A straightforward synthesis of an aminocyclitol based on an enzymatic aldol reaction and a highly stereoselective intramolecular Henry reaction

The reactions of 4-nitroaldehydes 9 and 10 with dihydroxyacetonephosphate (DHAP) catalyzed by fructose-1,6-diphosphate aldolase from rabbit muscle were studied. Starting from 9 or 10, only one main stereomer of nitrocyclitol 8 was isolated. A highly stereoselective intramolecular cyclization (Henry reaction or nitroaldol reaction) took place under acidic conditions during the aldolase catalyzed condensation and phytase catalyzed phosphate hydrolysis coupled step. The catalytic hydrogenation of nitrocyclitol 8 yielded aminocyclitol 7, a valiolamine analogue. Its inhibition properties were evaluated towards five glycosidase

Nitrile biotransformationby aspergillus niger

A nitrile-converting enzyme activity was induced in Aspergillus niger K10 by 3-cyanopyridine. The whole cell biocatalyst was active at pH 3–11 and hydrolyzed the cyano group into acid and/or amide functions in benzonitrile as well as in its meta- and para-substituted derivatives, cyanopyridines, 2-phenylacetonitrile and thiophen-2-acetonitrile. Amides constituted a significant part of the total biotransformation products of 2- and 4-cyanopyridine, 4-chlorobenzonitrile, 4-tolunitrile and 1,4-dicyanobenzene, while α-substituted acrylonitriles gave amides as the sole product

Biotransformation of nitriles to amides using soluble and immobilized nitrile hydratase from Rhodococcus erythropolis A4

A semi-purified nitrile hydratase from Rhodococcus erythropolis A4 was applied to biotransformations of 3-oxonitriles 1a–4a, 3-hydroxy-2-methylenenitriles 5a–7a, 4-hydroxy-2-methylenenitriles 8a–9a, 3-hydroxynitriles 10a–12a and 3-acyloxynitrile 13a into amides 1b–13b. Cross-linked enzyme aggregates (CLEAs) with nitrile hydratase and amidase activities (88% and 77% of the initial activities, respectively) were prepared from cell-free extract of this microorganism and used for nitrile hydration in presence of ammonium sulfate, which selectively inhibited amidase activity. The genes nha1 and nha2 coding for α and β subunits of nitrile hydratase were cloned and sequenced

Synthèse et évaluation d'inhibiteurs potentiels de glycosidases, analogues du salacinol

The synthesis of potent and selective inhibitors of glycosidases, enzymes which are crucial in many biological process, give access to potential therapeutic agents. The aim of this work was to synthetise new analogues of salacinol, a natural potent glucosidase inhibitorwith an original zwitterionic structure, and to evaluate the inhibition properties of the prepared compounds towards six commercially available glucosidases. Therefore, we synthesized several iminosugars, deoxynojirimycin and pipecolic acid analogues, using an original method based on isoxazolines. The coupling reaction of these iminosugars or different thiosugars with two cyclic sulfates led to six new nitrogen and nine new sulfur salacinol analogues. One of these sulfur analogues showed very good inhibition of almonds β-glucosidase.La synthèse d'inhibiteurs puissants et selectifs de glycosidases, enzymes impliquées dans de nombreux processus biologiques, permet d'accéder à des agents thérapeutiques potentiels. L'objectif de ce travail était de synthétiser de nouveaux analogues du salacinol, un puissant inhibiteur naturel d'alpha - glucosidases possédant une stucture originale zwitterionique, et d'évaluer les propriétés inhibitrices des composes obtenus sur six glycosidases commerciales. Nous avons donc préparé plusieurs iminosucres, analogues de la désoxynojirimycine et de l'acide pipécolique, par une méthode originale basée sur l'utilisation d'isoxazolines. par couplage de ces iminosucres ou de différents thiosucres avec deux sulfares cycliques, nous avons synthétisé six nouveaux analogues azotés et neuf nouveaux analogues soufrés du salacinol. L'un de ces analogues soufrés s'est révélé être un très bon inhibiteur de la béta - glucosidase d'amandes

Synthèse et évaluation d'inhibiteurs potentiels de glycosidases

Poste

Synthesis of new nitrogen analogues of salacinol and deoxynojirimycin and their evaluation as glycosidase inhibitors.

The synthesis of two enantiomerically pure iminosugars, analogues of 1-L-deoxynojirimycin (L-DNJ) and 1-D-deoxymannojirimycin (DMJ), was achieved using cyclic sulfate substituted isoxazoline derivatives. The piperidine ring was formed via the reduction of an isoxazoline into an amine which underwent a spontaneous intramolecular cyclization by reaction with the cyclic sulfate moiety. The nucleophilic attack of these two trisubstituted piperidines and morpholine on L- and D-erythritol-1,3-cyclic sulfates gave six new nitrogen analogues of salacinol. The inhibitory properties of the synthesized salacinol analogues were evaluated on several commercial glycosidases

Intramolecular Palladium-Catalyzed Carboamination for the Stereoselective Synthesis of Five-Membered Iminosugar C-Glycosides

International audienc

Stereoselective synthesis of 1-C-alkyl iminogalactitol derivatives, potential chaperones for galactosidase-linked LSDs: a real challenge

International audienc

Synthèse chimioenzymatique et évaluation d'inhibiteurs potentiels de glycosidases.

Communication oral