Colored compounds formed by the Maillard reaction of carnosine with xylose or glucose were investigated in this study. Yellow pigments showing an absorption maximum at 450 nm were found in a heated solution of carnosine with xylose at pH 5.0. These pigments were then isolated and identified as dicarnosyl-dipyrrolones A and B. The generation of dipyrrolones in the absence of lysine suggests that dipyrrolone pigments can be formed by pentose as well as every amino compound such as amino acids, peptides and proteins possessing a free amino group. Analysis of α-dicarbonyls using LC-MS/MS showed that pentosone, 1-deoxypentosone, 3-deoxypentosone (3-DP), and methylglyoxal were predominantly generated via degradation of Amadori compounds. Also, a potential formation pathway of dypyrrolones was established, indicating that an Amadori compound that could form 3-DP is likely to play a role as a main precursor for dipyrrolones.

中文翻译：

---

在弱酸性条件下肌肽和戊糖的美拉德反应中形成的双吡咯酮色素及其前体的鉴定。

本研究研究了由肌肽与木糖或葡萄糖的美拉德反应形成的有色化合物。在 pH 5.0 的肌肽与木糖的加热溶液中发现了在 450 nm 处显示最大吸收的黄色颜料。然后将这些色素分离并鉴定为二肉桂基-二吡咯酮 A 和 B。在没有赖氨酸的情况下二吡咯酮的产生表明二吡咯酮色素可以由戊糖以及具有游离氨基酸、肽和蛋白质的每种氨基化合物形成。氨基。使用 LC-MS/MS 分析 α-二羰基化合物表明戊酮、1-脱氧戊酮、3-脱氧戊酮 (3-DP) 和甲基乙二醛主要通过 Amadori 化合物的降解产生。此外，建立了地吡咯酮的潜在形成途径，