Arabian Journal of Chemistry (Aug 2023)
Dynamic variations in the chemical constituents of Tiebangchui stir-fried with Zanba by integrating UPLC-Q-TOF-MS based metabolomics and DESI-MSI
Abstract
Tiebangchui, which mainly originates from the dried root of Aconitum pendulum Busch, is an important traditional Tibetan medicine and has long been used for the treatment of various types of cold and pain. However, the excellent pharmacological activities of Tiebangchui are accompanied by high toxicity caused by Aconitum alkaloids. To ensure clinical medication safety, Tiebangchui is only used after processing. Stir-frying with Zanba is an effective and unique processing method in traditional Tibetan medicine, but chemical variations in raw and processed Tiebangchui are rarely reported. In this study, an integrated method combining ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was applied to explore chemical constituent variations, transformation mechanisms, and in situ spatial distributions of metabolites in raw Tiebangchui and its series of processed products. Three important diterpenoid alkaloids were quantified by HPLC. Results revealed visible differences between raw Tiebangchui and its Zanba stir-fried products, and 60 min was demonstrated to be the proper processing time. A total of 64 components were detected, and 32 of them were considered as metabolic markers to distinguish raw Tiebangchui and its processed products stir-fried for different time. Chemical changes were also visualized by DESI-MSI: the contents of aconitine and 3-deoxyaconitine significantly decreased, and those of benzoylaconine, benzoyldeoxyaconine, 16-epi-pyrodeoxyaconitine, and 16-epi-pyroaconitine markedly increased. Transformations from diester-diterpenoid alkaloids to monoester-diterpenoid alkaloids through hydrolysis and pyrolysis were found to be the major detoxication processes during Zanba stir-frying. In summary, UPLC-Q-TOF-MS based metabolomics, DESI-MSI, and quantitative combined approach could be an efficient method to characterize chemical variations in Tiebangchui and its Zanba processed products with different stir-frying time. The wide application of this method would contribute to the process monitoring and safe control of Tiebangchui and other toxic Aconitum medicine.
