Qualitative and quantitative analysis of the component variations of Raphani Semen during the stir-frying process and elucidation of transformation pathways of multiple components

Abstract

Raphani Semen (RS) encompasses two distinct application forms in Chinese clinical practice: raw RS (RRS) and stir-fried RS (SRS). They exhibit divergent drug properties and effects, as described in traditional Chinese medicine theory known as “Sheng shu yi zhi, sheng sheng shu jiang”. The dissimilarity in RS's drug properties is intrinsically linked to alterations in its internal components during the stir-frying process. Previous studies have demonstrated that stir-frying renders myrosinase inactive, thereby preventing the enzymatic hydrolysis of glucosinolates in RS. However, the precise enzymatic hydrolysis pathway and products of glucosinolates remain unclear. Furthermore, it remains uncertain whether other components undergo changes influenced by endogenous enzymes. The objective of this study is to systematically analyze the chemical components disparities between RRS and SRS using high-performance liquid chromatography coupled with time-of-flight mass spectrometry (HPLC-TOF-MS). Additionally, it seeks to elucidate the potential transformation pathways of multiple components from an enzymatic hydrolysis perspective. We have developed a sensitive and efficient high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC-QQQ-MS) method for quantifying the content of 5 characteristic components, including glucoraphenin, sinapine thiocyanate, sulforaphene, sinapic acid, and 3′,6-disinapoylsucrose. Based on retention time and MS spectra, we have identified 19 characteristic components in both SRS and RRS, encompassing glucosinolates and sulfur-containing derivatives, oligosaccharide esters, and small-molecule phenolic acids. Notably, 18 of these components undergo changes during the enzymatic hydrolysis process, leading to the identification of 4 transformation pathways: glucoraphenin, 6-sinapoylglucoraphenin, 3′,6-disinapoylsucrose and β-D-(3,4-disinapoyl) furanofructosyl-α-D-(6-sinapisoyl) glucoside, along with 3′-O-sinapoyl-6-O-feruloylsucrose. Quantitative analysis reveals significant differences, including lower levels of glucoraphenin in RRS compared to SRS, higher sulforaphene and sinapic acid levels in RRS, while sinapine thiocyanate and 3′,6-disinapoylsucrose remain unchanged before and after stir-frying. The results of this study highlight distinct chemical compositions between RRS and SRS. Additionally, the method of characterization and content determination constructed in this paper has strong practical value and provides a useful approach for comprehensively evaluating the chemical composition and quality of RS.