Comparison of Volatile Oils and Primary Metabolites of Raw and Honey-Processed Ephedrae Herba by GC–MS and Chemometrics

BackgroundEphedrae Herba (EH) is the terrestrial stem of Ephedra sinica Stapf, E. intermedia Schrenk et C. A. Mey., or E. equisetina Bge, which has been used as a diaphoretic, antiasthmatic, and diuretic. Honey-processed EH (HEH) is a widely used traditional Chinese medicine, and has a better effect of dispersing lung qi and relieving asthma and a lower effect of dispelling cold than raw EH (REH).ObjectiveTo understand the differences in volatile oils and primary metabolites between REH and honey-processed HEH, and to provide a reference for elucidating the mechanism behind the effect of this processing.MethodsA system data acquisition and mining strategy was designed to investigate the differences in volatiles and primary metabolites between the REH and HEH, based on GC–MS coupled with multivariate statistical analysis, including principal component analysis and orthogonal partial least squares discriminant analysis.ResultsOverall, 15 volatile oils and 14 primary metabolites were shown to be potential characteristic markers differentiating REH and HEH.ConclusionThe results may provide a scientific foundation for comprehensively revealing the honey-processing mechanism of EH.HighlightVolatile oils and primary metabolites were used to distinguish REH and HEH and elucidate the processing mechanism of EH for the first time.