Kaufmann Martin, Krüger Sophie, Mügge Clemens, Kroh Lothar W
Berlin Institute of Technology, Department of Food Chemistry and Food Analysis, Gustav-Meyer-Allee 25, TIB 4/3-1, D-13355 Berlin, Germany.
Humboldt University of Berlin, Department of Chemistry, NMR Facility, Brook-Taylor-Straße 2, D-12489 Berlin, Germany.
Carbohydr Res. 2018 Mar 22;458-459:44-51. doi: 10.1016/j.carres.2018.01.006. Epub 2018 Feb 12.
Analyzing classical model reaction systems of Amadori rearrangement products (ARP) it became apparent that the formation of 3-deoxy-d-threo-hexo-2-ulose (3-deoxygalactosone, 3-DGal) during the degradation of ARPs is highly dependent on pH and the amino acid residue of the respective ARP. Based on a detailed analysis of the NMR chemical shifts of the sugar moieties of different ARPs, it could be derived that the formation of 3-DGal is sensitive to the stability of a co-operative hydrogen bond network which involves HO-C3, the deprotonated carboxyl functionality and the protonated amino nitrogen of the amino acid substituent. Participating in this bond network, HO-C3 is partially protonated which facilitates the elimination of water at C3. Based on that, a new mechanism of 3-deoxyglycosone formation is proposed.
通过分析阿玛多里重排产物（ARP）的经典模型反应体系，很明显ARP降解过程中3-脱氧-D-苏式-己-2-酮糖（3-脱氧半乳糖酮，3-DGal）的形成高度依赖于pH值和相应ARP的氨基酸残基。基于对不同ARP糖部分的NMR化学位移的详细分析，可以得出3-DGal的形成对协同氢键网络的稳定性敏感，该网络涉及HO-C3、去质子化的羧基官能团和氨基酸取代基的质子化氨基氮。参与该键网络时，HO-C3部分质子化，这有利于C3处的水消除。基于此，提出了一种新的3-脱氧糖苷酮形成机制。
