Department of Chemistry, Division of Food Chemistry and Toxicology, University of Kaiserslautern-Landau, Kaiserslautern 67663, Germany.
Chem Res Toxicol. 2024 Nov 18;37(11):1807-1820. doi: 10.1021/acs.chemrestox.4c00083. Epub 2024 Sep 6.
2-Methylfuran (2-MF) is a process-related contaminant found primarily in heat-treated foods, such as coffee or canned food. The oxidative metabolic activation of 2-MF is supposed to follow the pathway established for furan, which is known to generate the highly reactive metabolite butenedial (BDA). In the case of 2-MF, generation of the BDA homologue 3-acetylacrolein (AcA) is to be expected. 2-MF metabolism to AcA was investigated in two model systems: commercial microsomal preparations and primary rat hepatocytes (pRH). To scavenge the generated 2-MF, two model nucleophils, -acetyl-l-cysteine (AcCys) and -α-acetyl-l-lysine (AcLys), were used, and the formation of the corresponding adducts was measured in the supernatants. The metabolic activation of 2-MF to AcA was studied using human liver microsomes as well as rat liver microsomes. Incubation of 2-MF in Supersomes allowed to identify the cytochrome P450 isoenzyme primarily responsible for 2-MF. In addition, primary rat hepatocytes were incubated with 2-MF or AcA and AcLys adduct of AcA (-acetyl-l-lysine-acetylacrolein, AcLys-AcA) determined in the cell supernatants by UHPLC-MS/MS. In model experiments, AcA formed adducts with AcCys and AcLys. The structures of both adducts were characterized. For incubations in biological activating systems, CYP 2E1 was found to be a key enzyme for the conversion of 2-MF to AcA in Supersomes. When pRH were incubated with 2-MF and AcA, AcLys-AcA was detected in the cell supernatants in a time- and dose-dependent manner. The results showed that AcA was indeed formed at the cellular level. In contrast to the AcLys-AcA adduct, no -acetyl-l-cysteine-acetylacrolein (AcCys-AcA) adduct could be detected in pRH. AcA was determined as a reactive metabolite of 2-MF , and its adduct formation with nucleophilic cellular components was evaluated. The metabolites were characterized, and AcLys-AcA was identified as potential biomarker.
2-甲基呋喃（2-MF）是一种主要存在于热加工食品（如咖啡或罐头食品）中的与工艺相关的污染物。2-MF 的氧化代谢激活被认为遵循呋喃建立的途径，已知呋喃会产生高度反应性的代谢物丁烯二醛（BDA）。在 2-MF 的情况下，预计会生成 BDA 类似物 3-乙酰丙烯醛（AcA）。在两个模型系统中研究了 2-MF 代谢为 AcA：商业微粒体制剂和原代大鼠肝细胞（pRH）。为了清除生成的 2-MF，使用了两种模型亲核试剂 -乙酰-l-半胱氨酸（AcCys）和 -α-乙酰-l-赖氨酸（AcLys），并测量了上清液中相应加合物的形成。使用人肝微粒体以及大鼠肝微粒体研究了 2-MF 的代谢激活。在 Supersomes 中孵育 2-MF 允许鉴定主要负责 2-MF 的细胞色素 P450 同工酶。此外，原代大鼠肝细胞用 2-MF 或 AcA 和 AcA 的 AcLys 加合物（-乙酰-l-赖氨酸-乙酰丙烯醛，AcLys-AcA）孵育，并通过 UHPLC-MS/MS 在细胞上清液中测定。在模型实验中，AcA 与 AcCys 和 AcLys 形成加合物。表征了这两种加合物的结构。对于在生物激活系统中的孵育，发现 CYP 2E1 是在 Supersomes 中将 2-MF 转化为 AcA 的关键酶。当 pRH 用 2-MF 和 AcA 孵育时，在细胞上清液中以时间和剂量依赖的方式检测到 AcLys-AcA。结果表明，AcA 确实在细胞水平形成。与 AcLys-AcA 加合物不同，在 pRH 中未检测到 -乙酰-l-半胱氨酸-乙酰丙烯醛（AcCys-AcA）加合物。确定 AcA 是 2-MF 的反应性代谢物，并评估了其与亲核细胞成分的加合物形成。对代谢物进行了表征，并鉴定出 AcLys-AcA 为潜在的生物标志物。
