HPLC-UV profiles of Cynanchum auricutalaum, Cynanchum bungei and Cynanchum wilfordii and relationships of their antioxidant activities

The method for simultaneous determination of the two types of principal components, C21- steroids and acetophenones, in Cynanchum bungei, C. auriculatum and C. wilfordii by high-performance liquid chromatography-ultraviolet (HPLC-UV) was developed for the first time. Under the optimized conditions, good linearities (R2≥0.999) were obtained for all analytes, and relative standard deviations (RSDs) of HPLC-UV method validation ranged from 0.01-1.62%. The results of DPPH (1,1-diphenyl 2-picryl hydrazyl) and ABTS (2,2-azobis-3ethylbenzthiazoline-6-sulfonic acid) free radical scavenging assays indicated that the three species had a significant antioxidant activity, with the half maximal effective concentration (EC50) range of 64.56-593.38 μg/mL. Combined with bivariate analysis, the fingerprint-activity relationship of the offline antioxidant activity of the three species with their fingerprints peak was studied, and the results revealed a dose-effect relationship between acetophenones and antioxidant activity. This study provides a theoretical basis for the correct identification and application of the antioxidant activities of C. auriculatum, C. wilfordii and C. bungei.