Chemical profiling and histochemical analysis of Bupleurum marginatum roots from different growing areas of Hubei province

Bupleuri Radix has been widely used in traditional Chinese medicine. In the current herbal market, the species Bupleurum marginatum Wall. ex DC. is the main source of Bupleuri Radix. Although Bupleuri Radix from the roots of B. marginatum grown wild in the North West of Hubei province has higher quality compared with those from other regions according to the previous investigations, the exhaustive exploitation driven by increasing demand has drastically reduced the wild resource. As a result, germplasm evaluation and quality resource exploration are important for the sustainable utilization and cultivation of B. marginatum. A preliminary study indicated differences in the tissue structure of B. marginatum grown in different areas of North Western Hubei province. In the current study, various tissues of the roots of B. marginatum grown in different areas of North Western Hubei were subjected to laser microdissection and analyzed by microscopy and ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC–Q-TOF-MS). The results show that wild plants from Maqiao Town, Baokang County contain the most saikosaponins distributed mainly in cork, cortex and phloem. This study provides key chemical information for evaluating the quality of B. marginatum roots.