POLYMERIZATION MECHANISMS OF MELANOIDlN AND ITS EFECTS ON THE SUPPRESSION OF IMMUNE STSEM

为了阐明木糖和甘氨酸反应形成的类黑素的聚合机理和化学结构，我们观察到黄色色素与蓝色色素（蓝- m1，马拉诺素的中间体）的形成有关。木糖酮（XLO）和3-脱氧木糖酮（3DX）在木糖-甘氨酸反应体系中被鉴定为二羰基化合物。n -羧基甲基吡咯醛（CMPA）也被鉴定为Blue-M1的有效中间体。推测XLO和3DX分别缩合成甘氨酸形成两种黄色颜料中间体，再缩合成CMPA形成黄色化合物。蓝- m1被认为是由两种黄色色素的脱羧作用形成的。Blue-M1很容易与黄色化合物反应，具有聚合活性，表明它是通过形成类黑素的重要美拉德反应中间体。蓝- m2被认为是由黄色颜料与蓝- m1的加成反应形成的。在美拉德反应的高级阶段，可以形成这样的聚合反应。研究了类黑素对过敏反应的抑制作用。以Th1型细胞因子IFN-γ mRNA的表达比例作为过敏反应的标志。以卵清蛋白为抗原，小鼠免疫（BALB/c）。脾细胞在RPMI-1640培养基中孵育。结果表明，在抗原免疫过程中，IFN-γ mRNA随着类黑素的存在而增加，而在没有类黑素的情况下则不增加。malanidins对Th2型细胞因子il - 4mrna的表达无影响。这些结果提示了类黑素对过敏反应的抑制作用。

In order to elucidate the polymerization mechanisms and chemical strucure of melanoidins formed by the reaction of xylose and glycine, we observed that yellow pigments are related the formation of blue pigment (Blue-M1, the intermediate of malanodins) . Xylosone (XLO) and 3-deoxyxylosone (3DX) were identified as dicarbonyl compounds in xylose-glycine reaction systems. N-Carboxymethylpyrrole aldehyde (CMPA) was also identified as a potent intermediate of Blue-M1. It is speculated that XLO and 3DX condensate to glycine, respectively, to form two types of intermediate of yellow pigments, then they condensate to CMPA to form yellow compounds. Blue-M1 is considered to be formed by the decarboxylation of two types of yellow pigments. Blue-M1 thet reacts readily to yellow compounds has polymerizing activity, suggesting it is an important Maillard reaction intermidiate through the formation of melanoidins. Blue-M2 is thought to be formed by the addition reaction of yellow pigment to Blue-M1. In an advanced stage of the Maillard reaction, mealnoidins may be formed such a polymerization reaction.The effects on the suppression of allergy reaction by melanoidins were investigated. The marker of allergy reaction was used the expression ratio of the IFN-γ mRNA being cytokine of Th1 type. Ovalbumin was used as an antigen and immunidized by mice (BALB/c). The spleen cell was incubated in the medium of RPMI-1640. The results indicated that IFN-γ mRNA was increased with the presence of melanoidins on the immunization of the antigen, but not without the melanoidins. Malanoidins had no effect of the expression of IL-4 mRNA being cytokine of Th2 type. These results indicate the suppression effects of melanoidins on allergy reaction.