Comprehensive Investigation of Sweroside Metabolism in Rats Using a De Novo Strategy Based on Ultra-High-Performance Liquid Chromatography/Quadrupole-Exactive Mass Spectrometry

Sweroside, a natural secoiridoid glycoside derived from various medicinal plants, is known for its anti-tumor, anti-inflammatory, and hepatoprotective properties. However, its pharmacological significance is not fully supported by its low systemic exposure. In this study, a de novo strategy was proposed to investigate the metabolism of sweroside in rats, including drug administration, sample pretreatment, ultra-high-performance liquid chromatography/Quadrupole-Exactive mass spectrometry data acquisition, data processing, and semi-quantitative analysis. First, following oral administration of sweroside to rats, plasma, urine, and feces were collected, and respectively mixed using the area-under-the-curve pooling method. Secondly, data-dependent, dynamic exclusion, and parallel reaction monitoring scan modes were employed to build a tandem mass spectra database. Using a neutral loss fragment-based method, target metabolites were effectively filtered. As a result, sweroside was demonstrated to be extensively metabolized, while 18 metabolites were identified and nine of them were newly reported. Sweroside predominantly underwent phase II metabolism, including glycosylation, sulfonation, glucuronidation, and deglycosylation, and were primarily excreted via the kidney. Notably, N-heterocyclization (M7 and M10) was likely catalyzed by intestinal bacteria. This study not only elucidates the in vivo drug elimination of sweroside but also offers an efficient approach for profiling the metabolism of specific molecules.