OBJECTIVE  To estimate the quality markers of antioxidant activity for standard decoction of Schisandrae Chinensis Fructus.

  METHODS  15 batches of Schisandrae Chinensis Fructus standard decoctions were subjected to quality evaluation by ultra high-performance liquid chromatography (UPLC) based on single-marker (QAMS) method, before being summarized by chemometrics analysis. The antioxidant abilities of 15 batches of samples were determined by DPPH and ABTS methods, while gray correlation analysis (GRA) and the partial least squares regression (PLSR) methods were subsequently applied to investigating the relationship between the contents of 8 components and the antioxidant activity. Ultimately, molecule docking was utilized to explore the binding properties between candidate quality markers and the core targets of anti-oxidation, with the experimental verification being executed on the individual compound by in vitro anti-oxidation.

  RESULTS  There was no remarkable difference between the results of QAMS and external standard method (ESM), with P valued greater than 0.05. And it was speculated that protocatechuic acid, gomisin A, schizantherin B and schisandrin B were the constituents of quality difference. Moreover, the 4 quality variation components were reckoned to be the alternative markers on antioxidant according to the results of GRA and PLSR. The molecule docking result also showed that 4 candidate quality markers presented good binding affinity with the antioxidant core targets. The antioxidant capacity was presumably originated from the collaborated effects by multi-components in the standard decoction of Schisandrae Chinensis Fructus. In the interim, protocatechuic acid exhibited noteworthy antioxidant efficacy with dosage-depended manner in the results of single-compound verification, which was best conformed to the characteristics of quality markers and supposed to be the antioxidant quality marker for Schisandrae Chinensis Fructus standard decoction.

  CONCLUSION  This research predicts the potential antioxidant substances on the basis of content determination by UPLC and in vitro antioxidant assay, but also provides rational foundation for quality assessment on other preparations of Schisandrae Chinensis Fructus.