Determination of phenolic content of Hypericum aucheri Jaub. and Spach by LC-HRMS and its antioxidant capacity

Abstract

The study aims to identify the secondary metabolites of Hypericum aucheri Jaub. & Spach extracts using liquid chromatography-high resolution mass spectrometry (LC-HRMS) and to evaluate the plant's antioxidant activity. Antioxidant activity was assessed using DPPH free radical scavenging and CUPRAC assays. The primary secondary metabolite detected was hyperoside, with concentrations of 1059.53 mg/L in acetone (Ac) extract and 389.73 mg/L in methanol (MeOH) extract. Syringic acid was the predominant compound in the chloroform (C) extract, with a concentration of 6646.53 mg/L. In addition, Ac extract showed the highest DPPH free radical scavenging activity (85.90±0.26 - 61.19±0.47%) of all the extracts tested. The MeOH extract exhibited the highest value in the CUPRAC assay (2.53±0.05 mmol TR g-1 ). The study highlights a numerical relationship between phenolic content and antioxidant activity, underscoring the importance of phenolics in their antioxidant functions.