Studies of Phytochemical Constituents by UPLC-QTOF-MS/MS of Black Hulless Barley Bran and Its Antioxidation and Α-Glucosidase Inhibition Effect

Anthocyanidins and flavonoids are important components in plant. In present study, the anthocyanidins and flavonoids in black hulless barley bran were identified by operating UPLC-QTOF-MS/MS. Among them, chrysoeriol-7-O-glucouronid, luteolin-7-O-glucouronid, chrysoeriol, and luteolin were quantified by using UPLC. Additionally, the total phenolic content (TPC), total flavonoids content (TFC) and total anthocyanin content (TAC) were determined. Furthermore, the antioxidant activity (via ferric reducing, DPPH and ABTS method) and α-glucosidase inhibition effect were estimated. From the results, fifty-one constituents comprised 19 anthocyanidins and 32 flavonoids were detected in hulless barley bran fractions. Wherein compounds 1 and 9-19 (belong to anthocyanidins), and 21, 25-32, 35-42, 44-50 (belong to flavonoids) were first identified in hulless barley. The contents of chrysoeriol-7-O-glucouronid luteolin-7-O-glucouronid, chrysoeriol and luteolin were higher in E80% than that of in E40%, but were not detected in E20%. Another, the TAC exhibited the trend of E40% > E80% > E20%, and the TPC and TFC showed same trend of E40% > E20% > E80%. The higher TPC and TFC showed stronger antioxidant activity. However, no significant correlation between TAC, TPC, TFC and α-glucosidase inhibitory activity was observed. These results provided the anthocyanidins and flavonoids information, antioxidant value and α-glucosidase inhibition potential, which could provide reference in the development of black hulless barley bran.