糖与氨基酸反应产物结构的EPR和^(13)C NMR研究(英文)

EPR AND ^(13)C NMR STUDIES ON THE STRUCTURE OF THE FREE RADICAL PRODUCTS FORMED BY THE REACTION OF SUGAR WITH AMINO ACIDS

应用EPR和^(13)C NMR技术系统地研究了糖与氨基酸反应的产物。EPR波谱分析表明,反应产物的结构主要取决于氨基酸的结构。^(13)C NMR波谱的化学位移表明、反应产物的结构应该是2,5-哌嗪二酮,糖是作为1,4位取代的配位基。本文还提出了一种可能的反应机制。

EPR and 13C-NMR techniques were used to study systematically tbe new free radical products formed by the reaction cf D-gluoose with amino acids. The hyperfine structure and splitting line numbers of EPR spectra of the free radical products depended mainly upon the structure of amino compounds, and could be assigned to the contributions of one set with two equivalent nitrogens and of three sets of equivalent protons. The chemical shifts of 13C-NMR spectra of the free radical products showed that ihe principal structure would be. According to the analyses of EPR ,13C-NMR spe- ctra and the reaction processes,, We propose the assumption of the identity of the radical product as 1,2-1, 5 tetrasubstituted piperazine biradical. The assumed structure and EPR spectral analyses mechanism were strongly supported by the close agreement between, the observed Spectra and those simulated on aspect 2000 computer. The proposed mechanism of the free radical formation in the reaction of sugar with amino acids is presented in this paper.