Abstract:
Objective: To establish the polyphenol fingerprints of
Lycium barbarum leaves from different origins in Ningxia, and to clarify the differences in nutritional quality of
Lycium barbarum leaves across distinct geographical origins. Methods: Using UPLC-Q-TOF-MS to establish the polyphenol fingerprints of 95 batches of
Lycium barbarum leaves from 3 origins (Zhongning, Yinchuan and Guyuan) in Ningxia. The similarity was evaluated and the common peaks were confirmed, and combined with hierarchical cluster analysis, principal component analysis, orthogonal partial least squares and other chemometric methods for comprehensive analysis. The common peaks were analyzed qualitatively and quantitatively, and the contents of 7 polyphenols were determined. Results: The polyphenol fingerprints of 95 batches of
Lycium barbarum leaves of different origins were established, with similarities of 0.488~0.839. 7 common peaks were identified, namely rutin, chlorogenic acid, p-coumaric acid, naringenin, neochlorogenic acid, quercetin-3-O-rutinose-(1→2)-O-rhamnoside, and kaempferol-3-O-glucorhamnoside. Hierarchical cluster analysis clustered the 95 batches of
Lycium barbarum leaves into 4 categories: Class I consisted of samples from Zhongning-1 Goji cultivation base (ZN1), Class II from Zhongning-2 Goji cultivation base (ZN2), Class III from Guyuan Goji cultivation base (GY), and Class IV from Yinchuan-1&2 Goji cultivation base (YC1 and YC2). Principal component analysis screened 3 principal components with a cumulative contribution of 88.841%. Orthogonal partial least squares-discriminant analysis indicated that rutin, chlorogenic acid and naringenin were the main landmark substances distinguishing
Lycium barbarum leaves among the 3 origins. Qualitative and quantitative analysis of polyphenols indicated that samples from Zhongning were characterized by the enrichment of rutin and kaempferol-3-O-glucorhamnoside, samples from Guyuan by the high content of chlorogenic acid, neochlorogenic acid, and quercetin-3-O-rutinose-(1→2)-O-rhamnoside, while samples from Yinchuan showed a significant advantage of naringenin. Conclusion: This study establishes a research foundational for the nutritional quality assessment of
Lycium barbarum leaves in Ningxia.