Comparison and Characterization of Compounds with Antioxidant Activity in Lycium barbarum Using High-Performance Thin Layer Chromatography Coupled with DPPH Bioautography and Tandem Mass Spectrometry.

Methanol extracts from 50 batches of Lycium barbarum (L. barbarum, wolfberry) in China were compared and characterized using high-performance thin-layer chromatography coupled with 2,2-diphenyl-1-picrylhydrazyl (DPPH) bioautography (HPTLC-DPPH) and electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF-MS/MS), respectively. Results showed that similar components occupying the major antioxidant activity existed in L. barbarum collected from different origins. However, the average antioxidant capacities of methanol extracts of L. barbarum collected in Ningxia were significantly higher than those of Qinghai, Xinjiang, Inner Mongolia, and Gansu, which may contribute to rational use of L. barbarum in China. Furthermore, the chemical structure of compound with the highest antioxidant capacity was tentatively identified as 2-O-β-d-glucopyranosyl-l-ascorbic acid using ESI-Q-TOF-MS/MS analysis, which possessed high potentials to be used as an antioxidant biomarker for the quality control of L. barbarum. Results are helpful for the bioactivity-based quality control of L. barbarum, and beneficial for the improvement of their performance in functional/health foods area, suggesting that HPTLC-DPPH bioautography with ESI-Q-TOF-MS/MS could be used as a routine approach for quality control of antioxidant components in L. barbarum.