Metabolism Profile of Mequindox in Sea Cucumbers In Vivo Using LC-HRMS

Abstract

In this work, the metabolism behavior of mequindox (MEQ) in sea cucumber in vivo was investigated using LC-HRMS. In total, nine metabolites were detected and identified as well as the precursor in sea cucumber tissues. The metabolic pathways of MEQ in sea cucumber mainly include hydrogenation reduction, deoxidation, carboxylation, deacetylation, and combinations thereof. The most predominant metabolites of MEQ in sea cucumber are 2-iso-BDMEQ and 2-iso-1-DMEQ, with deoxidation and carbonyl reduction as major metabolic pathways. In particular, this work first reported 3-methyl-2-quinoxalinecarboxylic acid (MQCA) as a metabolite of MEQ, and carboxylation is a major metabolic pathway of MEQ in sea cucumber. This work revealed that the metabolism of MEQ in marine animals is different from that in land animals. The metabolism results in this work could facilitate the accurate risk assessment of MEQ in sea cucumber and related marine foods.

Advances in Metabolism and Metabolic Toxicology of Quinoxaline 1,4-Di-N-oxides

“…39 Nine metabolites (M1, M2, M6, M10, M12 (M13), M14, M27, M29, and M33) were identified in a study using high-performance liquid chromatography tandem highresolution mass spectroscopy (LC-HRMS) to analyze the metabolism of MEQ in sea cucumbers. 40 Analysis of the above studies showed that a total of 33 MEQ metabolites (M1-M33) were identified in the animals. Among them, 15 metabolites were detected in rats, 31 in chickens, 12 in pigs, 2 in abalone, and 9 in sea cucumbers (Table 1; detailed information for each metabolite is provided in Table S2).…”

“…In an investigation for QdNOs analysis in abalone samples by high-performance liquid chromatography tandem positive-mode electrospray ionization mass spectrometry (HPLC-ESI-MS/MS), metabolites M1 and M6 were detected as well as the precursor MEQ . Nine metabolites (M1, M2, M6, M10, M12 (M13), M14, M27, M29, and M33) were identified in a study using high-performance liquid chromatography tandem high-resolution mass spectroscopy (LC-HRMS) to analyze the metabolism of MEQ in sea cucumbers …”