D-glucono-6-lactone

The results of inhibition studies with aldonolactones and 5-amino-5-deoxyaldonolactams may be summarized as follows y -D-glycosidases are inhibited by 1,5-lactones and the lactams some 100- to > 10,000-fold better than by the parent aldoses, with Kj values from 200 //Mto <0.1 nM. Al-dono-1,4-lactones are probably no better inhibitors than aldoses or polyols of comparable structure, with the possible exception s of 2-acetamido-2-deoxy-D-glucono-1,4-lactone. 

Reaction of D-glucono-1,4-lactone with 2,2-dimethoxypropane-tin(II) chloride yields the 5,6-0-isopropylidene derivative 13, which on periodate oxidation afforded 2,3-0-isopropylidene-D-glyceraldehyde (21). However, the acid-catalyzed isopropylidenation of D-glucono-1,5-lactone with 2,2-dimethoxypropane afforded methyl 3,4 5,6-di-0-isopropylidene-D-gluco-nate (14) as the main product (22). Reduction of the ester function gave... 

Selective silylation of aldohexono-1,4-lactones with tert-butylchlorodi-methylsilane gave the 2,6-di-O-silylated derivatives as major products (40). However, D-glucono-1,5-lactone underwent ring-contraction during silylation to give 2,6-di-O-terl-butyldimethylsilyl-D-glucono-1,4-lactone (31a) together with its 5,6-di-O-silyl isomer (31b), in 65 and 18% yields, respectively. 

Another type of amphiphUic-like structure in which an aldonolactone moiety is present was prepared by acetalization of D-glucono-1,4-lactone (24) and D-glucono-... 

Chloric acid, in conjunction with catalysts (particularly vanadium pentaoxide), is used for the oxidation of aldonic acids or lactones to the 2-glyculosonic acids. Thus, D-glucono-1,4-lactone (9) and potassium D-galactonate in methanol, in the presence of phosphoric acid and vanadium pentaoxide, are oxidized by chloric acid to methyl D-arabino-2-hexulosonate (10) and methyl D-/yxo-2-hexulosonate, respectively.38 At moderate temperatures in the absence of a catalyst, aldoses, ketoses, and sucrose are inert to the action of chlorates over a several weeks time period 39 bromates in alkaline solution also exert no oxidative action (Scheme 5). 

Isopropylidenation.1 Reaction of D-glucono-1,4-lactone (1) with 2,2-dimeth-oxypropane catalyzed by SnCl2 in DME results in the ketal in 57% yield. Periodate cleavage of 2 leads to (R)-O-isopropylidineglyceraldehyde, an attractive chiral... 

Methyl a-o-glucopyranoside, methyl 3-n-glucopyrauoside Methyl c(-D-mannopyranoside, D-xylose, D-glucono-1,5-lactone 1,4-Anhydro-n-glucitol, dipropylene glycol, pentaerythritol, 1,5 3,6-dianhydro-D-mannitol, 1,4 3,6-diarihydro-D -glucitol D-Glucono-1,4-lactone... 

A fundamental aspect of irradiated, aqueous systems is indirect action over a range of concentrations of solute. Fenton reagent provides free radicals, and it might be expected that, within certain limits, yields of products would be independent of the concentration of carbohydrate. However, for a fixed amount of iron (II) sulfate and hydrogen peroxide, yields of carbon dioxide from D-glucono-1,4-lactone indicate otherwise. In part, this result must be attributed to competition of radicals, and it is to be expected that, as the initial n-glucono-l, 4-lactone] [Fe 3 ratio is increased, reactions (19), (22), and (23) will become less important. 

Some properties of the 3-D-glucan synthetase from Saccharomyces cerevisiae have been described.UDP-D-Glucose is a competitive inhibitor and D-glucono-1,4-lactone is a non-competitive inhibitor of this enzyme. 

D-Glucono-1,4-lactone derivative 14 was converted to L-gulose by reductive opening, followed by persilylation and acetal hydrolysis to give diol 15, then primary oxidation and deprotection. Acetal hydrolysis in the presence of silyl... 

Acetamido-2-deoxy-D-galactono-l,4-Iactone 2-Acetamido-2-deoxy-D-glucono-1,4-lactone 2-Acetamido-2-deoxy-D-mannono-l,4-lactone Adenosine 5 -triphosphate (periodate-oxidized)... 

The chemical modification of hen egg-white lysozyme by AT-bromosuccinimide has been studied kinetically using the stopped-fiow method and previous results have been confirmed. One most rapidly reacting L-tryptophan residue (probably Trp-62) was clearly distinguished, by its rate of modification, from four other residues. The residue could be protected by ethylene glycol, chitin, 2-acetamido-2-deoxy-D-glucose, or chitotriose, but not by D-glucono-1,4-lactone. 

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