Amino-reductones. Formation mechanisms and structural characteristics.
Various types of amino-reductones are known to be involved in process-induced chemical changes in foods. Since most amino-reductones, especially enaminol compounds are unstable reaction intermediates and are difficult to isolate, their structural characteristics are still unclear. In order to obtain more precise structural information about amino-reductones, the structures of the enaminol form of fructoseglysine (D-fructoseglycine = FG) and scorbamic acid (L-scorbamic acid = SCA), a relatively stable cyclic enaminol compound were examined by the use of a semi-empirical molecular orbital method. Optimized structures, heat of formations and charge distributions of various enol forms of FG were obtained. Heat of formations of the non-dissociated, mono-anion, and di-anion forms of FG were estimated to be about -302, -347 and -308 kcal/mol, respectively. Optimized structures of non-dissociated, anion, and dipolar ion forms of SCA were also obtained and their heat of formations were estimated to be about -197, -204 and -248 kcal/mol, respectively. The nitrogen atom of the enaminol group in the SCA molecule was found to be positively charged.
Kurata
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Institute of Environmental Science for Human Life, Ochanomizu University, Tokyo, Japan.
Otsuka
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Y
D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D004563:Electrochemistry; D005504:Food Analysis; D005511:Food Handling; D005998:Glycine / Q000031:analogs & derivatives / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D013816:Thermodynamics
C017945:scorbamic acid; C033188:fructosyl-glycine; D001205:Ascorbic Acid; D005998:Glycine