Abstract: Contents of total phenolics and extractable condensed tannins in Prunus salicina Lindl. fruits were determined. Type of condensed tannins, degree of polymerization and distribution of polymer were characterized by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nuclear magnetic resonance (NMR) spectroscopy. The effects of tannins from P. salicina fruits on scavenging free radicals were determined by using 1,1-diphenyl-2-picryhydrazyl (DPPH·) free radical test. The results were showed as follows: total phenolics and extractable condensed tannins were 8.29%±1.30% and 1.43%±0.93%, respectively; Epicatechin was the basic units occurring in condensed tannins, A-type and B-type lin-kages were most common among the structural units of polymers. The average degree of polymerization was 5.3, and mean molecular weight was 1583.7u. EC₅₀ value was 57.98mg/L by DPPH· scavenging test.

Key words: Prunus salicina Lindl., polyphenolics, condensed tannins, antioxidation activity