Quality Evaluation of Lycium Barbarum 

(Wolfberry) From Different Regions in China Based on Polysaccharide Structure, Yield and Bioactivities

2019 Nov 8 Abstract

Background: Lycium barbarum (wolfberry) has been widely cultivated in China, particularly in northwest regions. However, the fruit size and taste of L. barbarum from different habitats are quite different. Traditionally, only the fruit of L. barbarum produced in Ningxia province is recorded as an authentic herb, although the detailed mechanism responsible for this remains obscure. Polysaccharides are considered major active ingredients in L. barbarum which is crucial for its quality evaluation.

Methods: In this study, we assessed the yield, monosaccharide composition, molecular weight, and conformation of L. barbarum polysaccharides (LBPs) collected from different regions of China. The antioxidant and immune activities of LBPs were also determined as its quality indicator.

Results: Our results showed that the similarity values of monosaccharide composition were larger than 0.926, and the Mw of the two fractions (peaks 1-2) in LBPs were ranging from 1.36 × 10⁶ to 2.01 × 10⁶ (peak 1), and 6.85 × 10⁴ to 10.30 × 10⁴ (peak 2) which indicated that the structure of LBPs were similar. In addition, results showed that there was no significant difference in antioxidant and immune activities of nine LBPs from different regions. However, the yield of LBPs from Qinghai Province (low atmospheric temperature, high altitude) was significantly lower (p < 0.05) than those collected from Xinjiang and Ningxia province.

Conclusions: These data suggested that the L. barbarum produced in Ningxia and Xinjiang maybe more suitable as materials for medicines and functional foods. This study also provides a reference for improving the quality control standard of LBPs.

https://pubmed.ncbi.nlm.nih.gov/31719838/

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

2016 May 6 Abstract

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.

https://pubmed.ncbi.nlm.nih.gov/27155221/