Ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry analysis of the impact of processing on toxic components of Kansui Radix.

BACKGROUND Kansui Radix (Gansui in Chinese), the dried tuber of Euphorbia kansui, is a Chinese medicinal herb commonly used for the treatment of oedema and ascites with dyspnea. Because of its toxic nature, the herb is usually processed with vinegar to reduce the toxicity. A report has shown that the contents of toxic terpenoids in Gansui decreased after processing with vinegar. However, comprehensive comparison of the chemical profiles between vinegar-processed and raw Gansui has not yet been conducted. METHODS An ultra-high-performance liquid chromatography in conjunction with ultra-high resolution quadrupole time-of-flight mass spectrometry (UHPLC UHD Q-TOF MS/MS) method was developed for the analysis of chemical profiles of vinegar-processed and raw Gansui in this study. RESULTS Results showed that processing with vinegar caused conspicuous chemical changes. Among the altered components, 11 toxic terpenoids, 3-O-benzoyl-13-O- dodecanoylingenol/20-O-benzoyl-13-O-dodecanoylingenol, kansuinine D, kansuinine A, 3-O-benzoyl-13-O-dodecanoylingenol/20-O-benzoyl-13-O-dodecanoylingenol, 3-O- benzoylingenol/20-O-benzoylingenol, 20-O-(2'E,4'Z-decadienoyl)ingenol/20-O-(2'E,4'E- decadienoyl)ingenol/3-O-(2'E,4'Z-decadienoyl)ingenol/3-O-(2'E,4'E-decadienoyl)ingenol, 3-O-(2'E,4'Z-decadienoyl)-20-deoxyingenol,3-O-(2'E,4'Z-,ecadienoyl)-5-O-acetylingenol,3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol,3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoylingenol, were tentatively identified. The contents of most of these terpenoids were obviously decreased after processing with reductions of 6.66-95.25%. CONCLUSION Our findings could help us understand the chemical basis for the toxicity reduction of Gansui afforded by processing with vinegar. Further investigations are warranted to establish the relationship between processing-induced chemical changes and the reduction of toxicity of Gansui.