关键词: 枣花蜜；抗氧化活性；高效液相色谱-电喷雾-四极杆-飞行时间串联质谱；酚类化合物；DNA损伤

Abstract: In this study, the physicochemical properties, phenolic content, and antioxidant activity in vitro of jujube honeys collected from four regions of Shaanxi province: Jiaxian, Fugu, Dali and Weinan were investigated as well as their effect in protecting plasmid pBR322 against hydroxyl radical-induced oxidative DNA damage and protecting mouse lymphocytes against oxidative DNA damage induced by hydrogen peroxide (H2O2). The results showed that the jujube honeys contained 196.55–454.95 mg/kg of total phenolics, and 22.03–39.40 mg/kg of total flavonoids. By high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC/ESI-Q-TOF-MS), a total of 15 phenolic compounds were detected in the samples, including four phenolic acids and 11 flavonoids. In vitro antioxidant test indicated that the jujube honeys had strong 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical scavenging capacity with a half maximal inhibitory concentration (IC50) of 38.03–122.81 mg/mL, ferrous ion chelating activity (110.93–158.45 mg/kg), and ferric reducing power (166.68–365.06 mg/kg). Furthermore, the jujube honeys had a protective effect against oxidative DNA damage in plasmid pBR322 induced by hydroxyl radical and could significantly reduce oxidative DNA damage induced by H2O2 in mouse lymphocytes. The present study provides a theoretical basis for the development and utilization of jujube honey resources.

Key words: jujube honey; antioxidant activity; high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry; phenolics; DNA damage