Abstract：
Amadori rearrangement products (ARPs) are gaining more attention for their potential usage in the food flavor industry. Peptide-ARPs have been studied, but pyrazinones that were theoretically found in the Maillard reaction (MR) have not been reported to be formed from small peptide-ARPs. This study found four pyrazinones: 1-methyl-, 1,5-dimethyl-, 1,6-dimethyl-, and 1,5,6-trimethyl-2(1H)-pyrazinones in both MR and ARP systems. It was the first time 1-methyl-2(1H)-pyrazinone was reported, along with 1,5-dimethyl- and 1,5,6-trimethyl-2(1H)-pyrazinones being purified and analyzed by nuclear magnetic resonance for the first time. The primary formation routes of the pyrazinones were also proven as the reaction between diglycine and α-dicarbonyls, including glyoxal, methylglyoxal, and diacetyl. The pyrazinones, especially 1,5-dimethyl-2(1H)-pyrazinone, have strong fluorescence intensity, which may be the reason for the increase of fluorescence intensity in MR besides α-dicarbonyls. Cytotoxicity analysis showed that both Gly-/Digly-/Trigly-ARP and the three pyrazinones [1-methyl-, 1,5-dimethyl-, and 1,5,6-trimethyl-2(1H)-pyrazinones] showed no prominent cytotoxicity in the HepG2 cell line below 100 μg/mL, further suggesting that ARPs or pyrazinones could be used as flavor additives in the future. Further research should be conducted to investigate pyrazinones in various systems, especially the peptide-ARPs, which are ubiquitous in real food systems.
摘要：
Amadori重排产品（ARPs）因其在食品风味行业的潜在用途而受到越来越多的关注。已经研究了肽-ARPs，但是在美拉德反应（MR）中理论上发现的吡嗪酮尚未报道是由小肽-ARPs形成的。这项研究发现了四种吡嗪酮：1-甲基-，1,5-二甲基-,1,6-二甲基-,MR和ARP系统中的1,5,6-三甲基-2(1H)-吡嗪酮。首次报道1-甲基-2(1H)-吡嗪酮,以及1,5-二甲基-和1,5,6-三甲基-2（1H）-吡嗪酮首次通过核磁共振进行了纯化和分析。吡嗪酮的主要形成途径也被证明是二甘氨酸和α-二羰基之间的反应，包括乙二醛,甲基乙二醛，和二乙酰.吡嗪酮,特别是1,5-二甲基-2(1H)-吡嗪酮，有很强的荧光强度，除α-二羰基外，这可能是MR荧光强度增加的原因。细胞毒性分析表明，Gly-/Digly-/Trigly-ARP和三种吡嗪酮[1-甲基-，1,5-二甲基-,和1,5,6-三甲基-2（1H）-吡嗪酮]在低于100μg/mL的HepG2细胞系中没有明显的细胞毒性，进一步表明，ARPs或吡嗪酮可以在未来用作风味添加剂。应进行进一步的研究，以调查各种系统中的吡嗪酮，尤其是肽-ARPs，在真实的食物系统中无处不在。
