Histochemical evaluation of alkaloids in rhizome of Coptis chinensis using laser microdissection and liquid chromatography/mass spectrometry

Traditional macroscopic and microscopic identification methods of medicinal materials are economical and practical, but usually experience-based due to few chemical supports. Here histochemical evaluation on bioactive components of Coptidis Rhizoma (CR) in anatomic sections using laser microdissection and liquid chromatography-mass spectrometry (LMD-LC-MS) was developed to correlate the inner quality and outer features of materials from different growing areas. Results of a total 33 peaks representing potential different alkaloids were detected and 8 common peaks were identified as the major alkaloids, namely magnoflorine, thalifendine, columbamine, epiberberine, jatrorrhizine, coptisine, palmatine, and berberine. Six major alkaloids were quantified in the top and middle sections of raw materials and in their tissues and cells at the same time. Histochemical analyses showed consistent results with direct determination in raw materials and explained the reason why top sections of all samples contained higher contents of alkaloids by giving out attributions of each alkaloid in different anatomic sections. Besides, results manifested the distribution and accumulation rules of alkaloids in diverse tissues and cells of CR. This study demonstrates an effective and scientific way to correlate bioactive components and morphological features of medicinal materials, which is beneficial to future research, agriculture and application.