Inmaculada Robina

Glycosidase Inhibitors as Potential HIV Entry Inhibitors

A few alpha-L-fucosidase inhibitors and alpha-D-glucosidase inhibitors have shown in vitro anti-HIV activities, that have been attributed to their ability to inhibit HIV entry. The mechanism of action of inhibitors such as 1-deoxynojirimycin (1) is not clearly established. One possible hypothesis is that the glycosidase inhibition affects the final conformation of the glycoproteins involved in the virus/cell recognition and fusion phenomena. This hypothesis is presented critically and the mechanisms of some glycoprotein biosynthesis are out-lined. Up to now, very few glycosidase inhibitors have been assayed for their potential as HIV entry inhibitors. Further assaying should be done and larger collections of glycosidase inhibitors should be prepared. To help investigations in that perspective, the inhibitory activities of alpha-glucosidase and alpha-L-fucosidase inhibitors have been summarized.

Synthesis and biological properties of monothiosaccharides

As other monosaccharide mimics such as the azasugars and the carbasugars (with nitrogen and carbon atom, respectively, instead of oxygen atom in the ring) the thiosugars (with sulfur atom instead of oxygen atom in the ring) have gained importance in glycobiology and as potential drugs. Biological properties of monothiosaccharides are presented and the methods for their synthesis are reviewed and analyzed. Since the report of the synthesis of 5-thio-alpha-D-xylopyranose, the first example of thiosugars ever described, forty years of imaginative chemistry have produced a large number of monothiosaccharides and of analogs of biological interest. The preparative chemists have at their disposal a panoply of methodologies relying on pure chemical or on biochemical means, using carbohydrate or non-carbo hydrate precursors. Because the sulfur moieties can participate more readily than the corresponding oxygen moieties in heterolytical processes, the chemistry of the thiosugars and their analogs is more subtile and sometimes more delicate than that of the corresponding aldoses and alditols.

Derivatives of (2R,3R,4S)-2-Aminomethylpyrrolidine-3,4-diol are selective α-Mannosidase inhibitors

A collection of (2R,3R,4S)-3,4-dihydroxypyrrolidin-2-yl derivatives have been tested for their inhibitory activities toward 25 glycosidases. Competitive (K-i=7.4 VM) and selective inhibition of alpha -mannosidase from jack bean has been found for (2R,3R,4S)-2-[(benzylamino)methyl]pyrrolidine-3,4-diol and other derivatives.

Synthesis of novel pyrrolidine 3,4-diol derivatives as inhibitors of α-L-fucosidases

The stereoselective synthesis of new 3,4-dihydroxypyrrolidine derivatives starting from D-mannose, D-ribose and L-fucose is presented. Two synthetic strategies employing organometallic addition to hemiacetalic sugars followed by selective nucleophilic displacement or conjugate addition of ammonia to conjugate aldonic esters as key steps, are used. The new compounds were assayed for their inhibitory activity towards 13 commercially available glycosidases. Compounds that share the absolute configuration at C(2,3,4,5) of L-fucopyranosides and incorporate aromatic moieties are potent and selective inhibitors of alpha-L-fucosidases in the nM range.

An Efficient Combinatorial Method for the Discovery of Glycosidase Inhibitors

Keywords: alpha-mannosidase inhibitor ; advanced malignancies ; swainsonine ; glycosylation ; chemistry ; libraries ; analogs Reference LGSA-ARTICLE-2002-011doi:10.1002/1439-7633(20020503)3:5 3.0.CO;2-DView record in Web of Science Record created on 2005-11-09, modified on 2017-05-12

New leads for selective inhibitors of α-l-fucosidases. Synthesis and glycosidase inhibitory activities of [(2R,3S,4R)-3,4-Dihydroxypyrrolidin-2-yl]furan derivatives

Readily derived from D-glucose, 5-[(2R,3S,4R)-3,4-dihydroxypyrrolidin-2-yl]-2-methyl-3-furoic esters and amides are selective and competitive inhibitors (K(i)> or = 3 microM) of alpha-L-fucosidase from bovine epididymis and from human placenta.

The synthesis of disaccharides, oligosaccharides and analogues containing thiosugars

Disaccharide and oligosaccharide mimics are potentially more selective glycosidases inhibitors than simple monosaccharide mimics. They represent also more selective ligands for lectins and oligosaccharide receptors and can become immunostimulating agents. The biological properties of disaccharide and oligosaccharide analogs containing thiosugars (5-thiopyranoses, 4-thiofuranoses) are revised together with the methods for their obtention.

A practical one-pot synthesis of O-unprotected glycosyl thioureas

Abstract An expeditious and high-yielding one-pot procedure to prepare different types of O -unprotected N -β- d -glycopyranosyl, N ′-substituted thioureas and di-β- d -glucopyranosyl thioureido bolaamphiphiles from β- d -glycopyranosylamines via O -unprotected glycopyranosyl isothiocyanates has been developed.

Synthesis of [(2S,3S,4R)-3,4-Dihydroxypyrrolidin-2-yl]-5-methylfuran-4-carboxylic Acid Derivatives: New Leads as Selective β-Galactosidase Inhibitors

The preparation of [(2S,3S,4R)-3,4-dihydroxypyrrolidin-2-yl]furan derivatives in a stereoselective route starting from D-glucose and ethyl acetoacetate is presented. Ethyl ester (6), N,N-diethylamide (7) and N-isopropylamide (8) have been tested towards 25 glycosidases. Ester (6) is a selective inhibitor of beta-galactosidases. The new compounds represent a new type of imino-C-nucleoside analogues.

Study of the Micellization and Micellar Growth in Pure Alkanediyl-α-ω-Bis(dodecyldimethylammonium) Bromide and MEGA10 Surfactant Solutions and Their Mixtures. Influence of the Spacer on the Enthalpy Change Accompanying Sphere-to-Rod Transitions

The micellization and micellar growth in pure aqueous alkanediyl-alpha-omega-bis(dodecyldimethylammonium) bromide, 12-s-12,2Br(-) (with s = 2,5,6,8,10,12), and N-decanoyl-N-methylglucamide MEGA10 solutions and their mixtures are investigated at 303 K. Application of different theoretical approaches to the binary mixtures shows a nonideal behavior. It also shows that the spacer length does not play an important role in the attractive interactions shown by the mixed systems. The sphere-to-rod morphological transition in the pure dimeric micellar solutions is studied at 303 K. From comparison of these results with those at 298 K the key role played by the spacer in the micellar growth is shown. The spacer length controls not only the surfactant concentration at which the morphological transition happens but also the sign of the enthalpy change accompanying the sphere-to-rod equilibrium. Spacers with an even number of methylenes show smaller C* values than those with an odd number of -CH(2)- units. An endothermic enthalpy change is found for even spacers whereas an exothermic enthalpy change is found for odd spacers. To the authors knowledge, this is the first time this experimental trend has been shown. Addition of MEGA10 diminishes the tendency of the aggregates to grow. An increment in the solution mole fraction of MEGA10 makes the formation of elongated micelles difficult. Microviscosity measurements provide additional information about the influence of the MEGA10 content on the sphere-to-rod transition.