Rapid and Comprehensive Identification of Vincosamide Metabolites in vitro and in vivo in Rats by Ultra-High Performance Liquid Chromatography-Quadrupole- Exactive Orbitrap-High Resolution Mass Spectrometry

Background: Vincosamide, an indole alkaloid extracted from Nauclea officinalis, exhibits a range of pharmacological activities, such as anti-tumor, antibacterial, and anti-inflammatory properties. However, despite its promising therapeutic applications, there is a notable gap in research focused on the metabolic pathways of vincosamide. Objective: This study aims to investigate the metabolism of vincosamide both in vitro and in vivo in rats, and to elucidate its metabolic pathways. Methods: Samples of liver microsomal incubation, plasma, bile, urine, and feces following vincosamide ad-ministration were analyzed by ultra-high performance liquid chromatography-quadrupole-Exactive Orbitrap-high resolution mass spectrometry (UHPLC-Q-Exactive Orbitrap HRMS). The collected data were analyzed using Compound Discovery 3.2 software and the molecular network method. The metabolites identified through these methodologies were subsequently validated using Xcalibur 4.1 software, which provided infor-mation on retention times, parent ions, and characteristic fragment ions. Results: A total of 37 metabolites were identified, including 8 in vitro and 32 in vivo (3 in plasma, 7 in bile, 22 in urine, and 17 in feces). While the metabolism of vincosamide differs in vitro and in vivo in rats, the type of metabolic reaction that occurs is well-defined. The predominant metabolic pathways are oxidation, reduc-tion, deglycosylation, hydration, glucuronidation, methylation, sulfation, glycine conjugation, cysteine conju-gation, taurine conjugation, and complex reactions. Conclusion: This study elucidates the metabolism of vincosamide in vitro and in vivo in rats, thereby expand-ing the metabolite profile of vincosamide. These findings provide a foundation for the potential development of new drugs based on vincosamide.