Quinoxaline 1,4-di-N-Oxides (QdNOs) have been used as synthetic antimicrobial agents in animal husbandry and aquaculture. The metabolism and potential toxicity have been also concerns in recently years. The metabolism investigations showed that there were 8 metabolites of Carbadox (CBX), 34 metabolites of Cyadox (CYA), 33 metabolites of Mequindox (MEQ), 35 metabolites of Olaquindox (OLA), and 56 metabolites of Quinocetone (QCT) in different animals. Among them, Cb3 and Cb8, M6, and O9 are metabolic residual markers of CBX, MEQ and OLA, which are associated with N → O reduction. Toxicity studies revealed that QdNOs exhibited severe tumorigenicity, cytotoxicity, and adrenal toxicity. Metabolic toxicology showed that toxicity of QdNOs metabolites might be related to the N → O group reduction, and some metabolites exhibited higher toxic effects than the precursor, which could provide guidance for further research on the metabolic toxicology of QdNOs and provide a wealth of information for food safety evaluation.

中文翻译：

---

1,4-二氮氧化物喹喔啉的代谢及代谢毒理学研究进展

喹喔啉 1,4-二-N-氧化物 (QdNOs) 已在畜牧业和水产养殖业中用作合成抗菌剂。近年来，代谢和潜在毒性也受到关注。代谢研究表明，不同动物体内存在卡巴氧(CBX) 8 种代谢物、Cyadox (CYA) 34 种代谢物、甲喹乙醇(MEQ) 33 种代谢物、喹乙醇(OLA) 35 种代谢物和喹烯酮(QCT) 56 种代谢物。其中，Cb3和Cb8、M6和O9是CBX、MEQ和OLA的代谢残留标记物，与N→O还原相关。毒性研究表明，QdNOs 表现出严重的致瘤性、细胞毒性和肾上腺毒性。代谢毒理学表明，QdNOs代谢物的毒性可能与N→O基团的还原有关，并且部分代谢物表现出比前体更高的毒性作用，这可以为QdNOs代谢毒理学的进一步研究提供指导，并为QdNOs的代谢毒理学研究提供丰富的信息。食品安全评价。