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The synthesis of 2-azidoacetyl-2-deoxy-5-fluoro-[beta]-D-gluopyranosyl fluoride is described as an activity-based proteomics probe for profiling these exo-glycosidases. The general strategy involving 5-fluoro inactivators can be used for profiling proteomes and also identifying glycoside hydrolases of medical importance or having desirable properties for biotechnology.

A synergistic method was reported for analysis of inhibitors with a single enzyme 'model system', the Thermotoga martima family 1 [Beta]-glucosidase, TmGH1. The findings revealed that the ensemble of inhibitors showed strong enthalpy-entropy compensation.

The binding of 1-deoxynojirimycin and (+)-isofagomine to the 'family GH-1' beta-glucosidase of Thermotoga maritima is investigated by kinetic analysis, isothermal titration calorimetry and X-ray crystallography. A resolution reveal that additional ordering of bound solvent may present an entropic penalty to 1-deoxynojirimycin binding that does not penalize isofagomine.

The treatment of benzyl 2,3-O-isopropylidene-[beta]-L-xylopyranoside with N-hydroxyphthalimide under Mitsunobu conditions, followed by protecting-group interchange, gave benzyl 4-O-[(tert-butoxycarbonyl)amino]-2, 3-isopropylidene-[alpha]-D-arabinoside. Mild acid hydrolysis and catalytic hydrogenolysis afforded 4-O-[(tert-butoxycarbonyl)amino]-D-arabinose that, upon heating in water, gave the dihydrooxazine [(4R,5S,6R)-5,6-dihydro-4,5-dihydroxy-6-hydroxymethyl-4H-1, 2-oxazine] as a crystalline solid. A single-crystal structure determination of this solid showed it to exist in the [sup.5][H.sub.6] conformation. Reduction of the dihydrooxazine gave the tetrahydrooxazine [(4R,5S,6R)-4,5-dihydroxy-6-hydroxymethyl-3,4,5,6-tetrahydro-2H-1,2-oxazine]. The dihydrooxazine was an effective inhibitor of two [beta]-glucosidases ([K.sub.i] = 27 and 35 [micro]M). Benzyl 2,3-O-isopropylidene-[beta]-L-xylopyranoside, via the derived imidazylate, was convened into a nitrile that, upon reduction and protecting-group manipulations, gave benzyl 4-C-aminomethyl-4-deoxy-[alpha]-D-arabinoside. Treatment of this amine with hydrogen and palladium-on-carbon gave isofagomine. Key words: dihydrooxazine, tetrahydrooxazine, isofagomine, iminosugars, glycosidase inhibitors.

A detailed analysis of the inhibition of the endocellulase Ce15A from Bacillus agaradhaerens by a series of oligosaccharide glycosydase inhibitors (2-4)(super 3), derived from the parent isofagomine (1) is presented. Assignment of the prolongation state of the catalytic apparatus in conjunction with the pH dependence of Ki and K(sub cat)/K(sub m) suggests that both the enzymatic nucleophile and the acid/base are unprotonated.

A visually exciting chemistry demonstration for high school and undergraduate students involves the addition of diazonium salt solutions to various phenols in alkaline solutions. The phenols produce different colors including red, purple and blue. This demonstration helps introduce acid-base reactions, diazotization, equilibria and other chemical concepts. Experiment procedures are included.