EUROPEAN FOOD RESEARCH AND TECHNOLOGY, cilt.248, sa.4, ss.1059-1067, 2022 (SCI-Expanded)
In this study, we tested tyrosinase and oc-glucosidase effects of different extracts of Ziziphus jujuba fruits. The n-BuOH sub-extract inhibited both tyrosinase and oc-glucosidase (IC50 =18.82 +/- 1.13 and 25.03 +/- 0.77 mu g/mL, respectively) better than the positive controls kojic acid and acarbose (IC50 =58.26 +/- 0.25 and 46.10 +/- 2.3 mu g/mL, respectively). Thus, the n-BuOH extract was selected for further phytochemical studies. Indole-3-lactic acid methylester, catechin, magnoflorine, kaempferol 3-O-alpha-rhamnopyranosyl-(1 -> 6)-beta-galactopyranoside, quercetin 3-O-alpha-rhamnopyranosyl-(1 -> 6)-beta-galactopyranoside, and procyanidin B4 were isolated from the extract. We tested alpha-glucosidase and tyrosinase inhibitory effects, as well as DNA nuclease effects of the isolated compounds. Procyanidin B4 exhibited the best activity against both tyrosinase and alpha-glucosidase (IC50 =60.25 +/- 0.88 and 170.18 +/- 5.60 mu g/mL, respectively). The isolates did not show any nuclease effect at increasing concentrations. Molecular docking studies provided insights into inhibition mechanisms of the isolates against tyrosinase and alpha-glucosidase at the molecular level.