To investigate the role of the Maillard reaction in the pathogenesis of diabetic complications, we produced several clones of monoclonal antibodies against advanced glycation end products (AGEs) by immunizing mice with AGE-modified keyhole limpet hemocyanin, and found that one clone (AG-1) of the anti-AGE antibodies reacted specifically with imidazolones A and B, novel AGEs. Thus, the imidazolo...

Photosensitized oxidation of guanine provides various oxidation products, including 8-oxoguanine (8-oxoG) and imidazolone. Ribo‰avin (vitamin B2) is known as an eŠective photosensitizer for oxidation of guanine. Here, we show the user-friendly synthesis and photoreaction of a ‰avin-linked oligonucleotide; the practical synthesis of a hydroxyethyl-‰avin (2) from commercially available ribo‰avin;...

Intermediates formed during the microbial degradation of imidazole, namely 4(5)-imidazolone, formiminoglycine, and possibly glycine, are similar to those formed during metabolism of imidazole derivatives.

The major pathway of histidine metabolism in animals and bacteria other than incorporation into protein involves first deamination to urocanic acid, then the anaerobic addition of water to form an intermediate generally considered to be 4(5)imidazolone-5(4)-propionic acid (1, 2). Finally, the ring is split enzymatically to ~formiminoglutamic acid (3) which is converted to free cglutamic acid by...

A novel series of 7,7-diphenyl-1,2-dihydroimidazo[2,1-c][1,2,4]triazin-6(7H)-one 6a-h, were easily prepared via reactions of novel 2-hydrazinyl-4,4-diphenyl-1H-imidazol-5(4H)-one (2) with hydrazonoyl halides 3a-h. In addition, we also examined the reaction of compound 2 with commercially available active methylene compounds to afford new pyrazoles containing an imidazolone moiety, expected to b...

Imidazolonepropionase (HutI) (imidazolone-5-propanote hydrolase, EC 3.5.2.7) is a member of the amidohydrolase superfamily and catalyzes the conversion of imidazolone-5-propanoate to N-formimino-L-glutamate in the histidine degradation pathway. We have determined the three-dimensional crystal structures of HutI from Agrobacterium tumefaciens (At-HutI) and an environmental sample from the Sargas...

The physiological a-oxoaldehyde methylglyoxal binds and modifies arginine, lysine, and cysteine residues in proteins. The kinetics and mechanism of these reactions were investigated with Na-acetylamino acids and bovine serum albumin at pH 7.4 and 37 “C. The reaction of methylglyoxal with Na-acetylarginine involved the initial reversible formation of glycosylamine and 4,5-dihydroxy5-methylimidaz...

A green fluorescent protein chromophore inspired chemosenor for Zn(2+) was designed and synthesized. A Zn(2+) specific fluorescence enhancement was observed due to restricted rotation between the 1,10-phenanthroline and imidazolone moieties.

The lithiation and electrophilic substitution of dimethyl triazones is described. Directed lithiation or tin-lithium exchange of dimethyl triazones afforded the corresponding dipole stabilized nucleophiles that were trapped with various electrophiles. Keto-triazone derivatives accessed by acylation of such nucleophiles were readily converted to the corresponding imidazolone heterocycles.