Structural elucidation and antioxidant activities of proanthocyanidins from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves.

• Main Authors: Yu Fu, Liping Qiao, Yuming Cao, Xiaozhou Zhou, Yu Liu, Xingqian Ye
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2014-01-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC4013063?pdf=render

Proanthocyanidins in Chinese bayberry leaves (PCBLs) were qualitatively analyzed. NMR data suggest that PCBLs are mostly composed of (epi)gallocatechin gallate units. Matrix-assisted laser desorption time-of-flight MS data indicate 95 possible prodelphinidin structures, ranging from dimers to tridecamers. Preparative normal-phase HPLC and further analysis by reverse-phase HPLC together with electrospray ionization MS enabled detection of 20 compounds, including seven newly identified compounds in Chinese bayberry leaves. The antioxidant capacity of PCBLs was evaluated by (1,1-diphenyl-2-picryl-hydrazyl), ferric-reducing antioxidant power, and oxygen radical absorption capacity assays. The EC50 of DPPH radical scavenging activities (as 50% decrease in the initial DPPH concentration) were 7.60 µg. The FRAP and ORAC values were 8859.33 ± 978.39 and 12991.61 ± 1553.34 µmol Trolox equivalents per gram, respectively. The results indicate the high antioxidant potency of PCBLs.