As chemical drugs, separation and quantification of the specific enantiomer from the chiral compounds in herbal medicines are becoming more important. To clarify the chemical characterization of chiral glucosinolates-the antiviral active ingredients of Radix Isatidis, an optimized efficient method of HPLC-UV-CD was developed to simultaneously separate and quantify the four main chiral glucosinolates: progoitrin, epiprogoitrin, and R,S-goitrin. The first step was to determine progoitrin, epiprogoitrin, and R,S-goitrin using HPLC-UV, and then determine the R-goitrin and S-goitrin by coupling with CD detection. Subsequently, through the linear relations between anisotropy factor (g factor) and the percent optical purity of R-goitrin, the contents of R-goitrin and S-goitrin from the R,S-goitrin mixture were calculated separately. Furthermore, the chemical composition features of the four chiral glucosinolates in 37 samples from crude drugs, decoction pieces, and granules of R. Isatidis were conducted. The total content of the four glucosinolates was obviously higher in crude drugs, and the variance character of each glucosinolate contents was different. In summary, the accurate measurement method reported here allows for better control of the internal quality of R. Isatidis and its granules and provides a powerful approach for the analysis of other chiral components in traditional Chinese medicines.
Keywords: HPLC-UV-CD; Radix Isatidis; chiral analysis; glucosinolates; quantification.