The fate of the Amadori compound N-(1-deoxy-D-fructos-1-yl)-glycine (DFG) was studied in aqueous model systems as a function of pH and temperature. The samples were heated at 100 and 120 degrees C with initial reaction pH of 5.5 and 6.8. Special attention was paid to the formation of the free amino acid, glycine; parent sugars, glucose and mannose; organic acids, formic and acetic acid and alpha-dicarbonyls, 1- and 3-deoxyosone together with methylglyoxal. For the studied conditions decreasing the initial reaction pH with 1.3 units or increasing the temperature with 20 degrees C has the same effect on the DFG degradation as well as on glycine formation. An increase in pH seems to favour the formation of 1-deoxyosone. The lower amount found comparatively to 3-deoxyosone, in all studied systems, seems to be related with the higher reactivity of 1-deoxyosone. Independently of the taken pathway, enolization or retro-aldolization, DFG degradation is accompanied by amino acid release. Together with glycine, acetic acid was the main end product formed. Values of 83 and 55 mol% were obtained, respectively. The rate of parent sugars formation increased with pH, but the type of sugar formed also changed with pH. Mannose was preferably formed at pH 5.5 whereas at pH 6.8 the opposite was observed, that is, glucose was formed in higher amounts than mannose. Also, independently of the temperature, at higher pH fructose was also detected. pH, more than temperature, had an influence on the reaction products formed. The initial steps for a complete multiresponse kinetic analysis have been discussed. Based on the established reaction network a kinetic model will be proposed and evaluated by multiresponse kinetic modelling in a subsequent paper.

中文翻译：

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Amadori N-（1-脱氧-D-果糖-1-基）-甘氨酸降解途径的动力学模型。第一部分-反应机制。

在水性模型系统中，研究了Amadori化合物N-（1-脱氧-D-果糖-1-基）-甘氨酸（DFG）的命运与pH和温度的关系。将样品在100和120℃下加热，初始反应pH为5.5和6.8。特别注意游离氨基酸甘氨酸的形成。母糖，葡萄糖和甘露糖；有机酸，甲酸和乙酸以及α-二羰基，1-和3-脱氧松酮以及甲基乙二醛。对于所研究的条件，将初始反应pH降低1.3个单位或将温度升高20℃对DFG降解以及甘氨酸形成具有相同的效果。pH值的升高似乎有利于1-脱氧肌松的形成。在所有研究的系统中，与3-deoxyosone相比，其含量较低，似乎与1-脱氧肌松的较高反应性有关。DFG降解与所采取的途径（烯醇化或逆醛缩醛化）无关，其降解伴随着氨基酸的释放。乙酸与甘氨酸一起是形成的主要最终产物。分别获得83和55mol％的值。母糖形成的速率随pH的增加而增加，但是形成糖的类型也随pH的变化而变化。优选在pH 5.5下形成甘露糖，而在pH 6.8下观察到相反，即形成的葡萄糖量高于甘露糖。另外，与温度无关，在较高pH下也检测到果糖。pH值大于温度对形成的反应产物有影响。讨论了完整的多响应动力学分析的初始步骤。