Abstract: The phenolic compounds in the fruits, stems and leaves (tender leaves and old leaves) of Rubus chingii Hu were separated and detected by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Their antioxidant activities were determined by spectrophotometry. The results showed that the contents of total phenol, total flavonoid and proanthocyanidins in the above-ground parts were significantly different, the highest contents of total phenol (69.49 mg/g), total flavonoid (87.21 mg/g) and proanthocyanidins (36.70 mg/g) being in young leaves, old leaves and fruits, respectively. The composition of phenolic compounds in young leaves was similar to that in old leaves, mainly including kaempferol derivatives as well as quercetin and its derivatives, but significantly differed from that in fruits and stems. The antioxidant activities of the three parts of R. chingii Hu followed the decreasing order of young leaves > old leaves and stems > fruits. According to correlation analysis, the total phenolics contributed to the antioxidant activity. From this study, it could be seen that the young leaves of R. chingii Hu are a potential source of natural phenolic antioxidants that is promising for the development of health foods. This study provides theoretical reference for the development and utilization of this plant’s stems and leaves to promote its comprehensive utilization.

Key words: Rubus chingii Hu; phenolic compounds; antioxidant activity