Comparative analysis of quinolizidine alkaloids from different parts of Sophora alopecuroides seeds by UPLC-MS/MS

The seeds of Sophora alopecuroides L. have been utilized as a crude drug in China for thousands of years. Quinolizidine alkaloids are the main bioactive components of this plant. To determine the distribution and content of quinolizidine alkaloids in different seed organs (seed coat and cotyledon), a reliable method has been established using ultra-high-performance liquid chromatography coupled with a triple quadrupole electrospray tandem mass spectrometry (UPLC-MS/MS). Seven constituents, namely cytisine, oxymatrine, oxysophocarpine, sophoridine, sophoramine, matrine, and sophocarpine, were simultaneously determined in 10 min. The proposed method was fully validated in terms of linearity, sensitivity, precision, repeatability as well as recovery. The analysis results showed there were remarkable differences in the distribution and contents of the chemical markers between seed coat and cotyledon. The established approach could be helpful for the quality control of S. alopecuroides seeds, and also for the determination of this type class of alkaloids in other medicinal herbs. The present study can provide necessary information for the rational utilization of S. alopecuroides resources.