High-resolution monophenolase/diphenolase/radical scavenging profiling for rapid screening of natural whitening candidates from Rosa rugosa cv. 'Plena'.

Antioxidants and tyrosinase inhibitory components were successfully screened and separated from Rosa rugosa cv. 'Plena' by HPLC microfractionation bioactive screening combined with several separation and purification methods. Ethyl acetate extract of Rosa rugosa cv. 'Plena' showed high antioxidant activity and tyrosinase inhibitory activity. High speed countercurrent chromatography, silica gel column chromatography and semi-preparative high performance liquid chromatography were used for preparative separation of four bioactive components from ethyl acetate extract. Two tyrosinase-inhibiting active substances, flavogallonic acid and N 1 -N 5 -N 10 -tri-4-p-coumaroylspermidine, were isolated from Rosa rugosa cv. 'Plena', and they showed great monophenolase inhibition activity (half maximal inhibitory concentration: 664.60 μg/mL and 23.77 μg/mL, respectively) and excellent diphenolase inhibition activity (half maximal inhibitory concentration: 23614.61 μg/mL and 16.80 μg/mL, respectively). Meanwhile, gallic acid, flavogallonic acid and ellagic acid were shown to have excellent 1,1-diphenyl-2-picryl-hydrazyl antioxidant activity (half maximal inhibitory concentration: 6.66 μg/mL, 20.17 μg/mL and 13.45 μg/mL), and 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant activity (half maximal inhibitory concentration: 3.53 μg/mL, 3.83 μg/mL and 2.78 μg/mL). Molecular docking revealed that flavogallonic acid and N 1 -N 5 -N 10 -tri-4-p-coumaroylspermidine had strong binding affinity (-9.3 kcal/mol and -10 kcal/mol, respectively) to tyrosinase through hydrogen bonding and hydrophobic interactions. This article is protected by copyright. All rights reserved.