单糖的类型对模拟体系中晚期糖基化终末产物生成的影响

为了研究单糖-赖氨酸模拟体系中单糖类型对晚期糖基化终末产物(AGEs)生成的影响。探讨了葡萄糖、半乳糖、果糖、山梨糖在120 ℃加热0~120 min期间pH、反应颜色、底物消耗、AGEs中间体包括3种二羰基化合物乙二醛(GO)、丙酮醛(MGO)和三脱氧葡萄糖醛酮(3-DG)以及果糖基赖氨酸(FL),以及最终三种AGEs包括羧甲基赖氨酸(CML)、羧乙基赖氨酸(CEL)、吡咯素(Pyr)的变化。结果显示随着反应进行,醛糖体系的pH下降程度以及颜色增加程度高于酮糖体系。反应结束时,葡萄糖-赖氨酸(Glu-Lys)、半乳糖-赖氨酸(Gla-Lys)、果糖-赖氨酸(Fru-Lys)和山梨糖-赖氨酸(Glu-Lys)体系中赖氨酸的损失分别为26.65%、28.95%、11.47%、14.90%;而所有体系中单糖在反应结束时的损失均达到了75.00%以上,要远高于赖氨酸。模拟体系中单糖会出现醛酮转换,但比例低于10%。所有体系中GO和3-DG的含量随着时间的延长而下降,这表明体系中GO和3-DG在反应前20 min内就已大量生成。α-二羰基化合物的生成量远高于FL的生成量。反应结束时,酮糖体系的CML和CEL含量要高于醛糖体系。所有体系中,三种AGEs生成量均为CEL > CML > Pyr。本文表明将来研究食品中AGEs的生成和抑制途径,需重点从中间体途径着手,尤其是α-二羰基化合物。

Effect of Monosaccharide on the Formation of Advanced Glycation Endproducts in Model Systems

In this study,the effects of monosaccharide types on the formation of advanced glycation endproducts(AGEs)in the monosaccharide-lysine model systems were investigated. The pH,reaction color,substrate consumption,AGEs intermediates(glyoxal,GO;methylglyoxal,MGO;3-deoxyglucosone,3-DG;fructoselysine,FL),and AGEs(Nε-(Carboxymethyl)lysine,CML;Nε-(Carboxyethyl)lysine,CEL;pyrraline,Pyr)in glucose-,galactose-,fructose-and sorbose-lysine heated at 120 ℃ for 0~120 min were discussed. The results showed that the pH decrease and the color increase degree in aldose systems were higher than that in ketose systems as the reaction progressed. At the end of reaction,the loss of lysine in the glucose-lysine(Glu-Lys),galactose-lysine(Gla-Lys),fructose-lysine(Fru-Lys)and sorbose-lysine(Glu-Lys)systems were 26.65%,28.95%,11.47% and 14.90%,respectively;The loss of monosaccharides in all model systems was more than 75.00%,which was much higher than that of lysine. In the simulated system,aldehyde-ketone conversion occured in monosaccharides,but the ratio was less than 10%. The contents of GO and 3-DG in all model systems were decreased with the increase of heating time,which indicated that GO and 3-DG were abundantly formed within 20 min.The formation of α-dicarbonyl compounds was much higher than that of FL. When the reaction was end,the content of CML and CEL in ketose systems was higher than that in ketose systems. The AGEs level was in the order of CEL>CML>Pyr. This paper indicates that it is necessary to focus on the intermediate pathways,especially α-dicarbonyl compounds,for study the formation and inhibition of AGEs in the future research.