Reaction of 3-deoxypentosulose with N-methyl- and N,N-dimethylguanidine as model reagents for protein-bound arginine and for creatine.
Deoxyosones are established key-intermediates in Maillard processes. Due to their dicarbonyl structure, they undergo condensation to form heterocyclic compounds with guanidine derivatives. In biological systems, guanidino functions are present in protein-bound arginine moieties as well as in creatine. The reactivity of such structures towards 3-deoxypentosulose is investigated with N-methyl- and N,N-dimethylguanidine as model substrates. Two diastereoisomers each are isolated from both reactions; they have been characterized unequivocally, respectively, as 4-(2,3-dihydroxypropyl)-2-N-methylamino-2-imidazoline-5-one and 4-hydroxy-5-(2,3-dihydroxypropyl)-2-(N,N-dimethylamino)-5H-imidazole. In aqueous medium as well as in the crystalline state, both diastereoisomer pairs exist in different tautomeric forms.
Sopio
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Institut für Lebensmittelchemie und Analytische Chemie, Universität Stuttgart, Germany.
Lederer
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D001120:Arginine / Q000032:analysis*; D003401:Creatine / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D007661:Ketoses; D009682:Magnetic Resonance Spectroscopy; D008760:Methylguanidine / Q000031:analogs & derivatives* / Q000737:chemistry*; D015394:Molecular Structure; D011506:Proteins / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013237:Stereoisomerism
D007202:Indicators and Reagents; D007661:Ketoses; D011506:Proteins; D008760:Methylguanidine; C042632:N,N-dimethylguanidine; C048054:3-deoxy-glycero-pentos-2-ulose; D001120:Arginine; D003401:Creatine