Deoxyarbutin is a tyrosinase inhibitor (IC50 = 17.5 μM for mushroom tyrosinase). It reduces melanin content in isolated dark human melanocytes when used at a concentration of 1.56 μM. Topical administration of deoxyarbutin (5%) induces skin lightening in human skin mouse xenograft models. Deoxyarbutin also inhibits proliferation of B16/F10 murine melanoma cells (EC50 = 39.56 μM). It induces apoptosis and halts the cell cycle at the S phase in B16/F10 cells when used at a concentration of 50 μM. Deoxyarbutin (50 mg/kg) reduces tumor growth in a B16/F10 murine melanoma model.
Under nitrogen protection, 3,4-dihydro-2H-pyran (19.1 g, 227.0 mmol) was dissolved in a solution of dichloromethane (200 ml) containing pyridinium p-toluenesulfonate (PPTS) (5.7 g, 22.7 mmol). After cooling the reaction system to 10°C, a solution of hydroquinone (25.0 g, 227.0 mmol) in dichloromethane (100 ml) was added slowly and dropwise. Subsequently, the reaction mixture was gradually warmed to 25°C and stirred continuously for 16 hours. After completion of the reaction, the mixture was poured into water (500 ml) and the aqueous layer was extracted with dichloromethane. The organic layers were combined and washed sequentially with saturated aqueous sodium chloride solution and saturated aqueous sodium bicarbonate solution, then dried with anhydrous magnesium sulfate. The organic phase was concentrated under reduced pressure and the residue was purified by silica gel column chromatography (eluent: toluene/ethyl acetate=5:1, v/v) to afford 4-((tetrahydro-2H-pyran-2-yl)oxy)phenol (23.2 g, 119.7 mmol, 52.7% yield).
[1] Canadian Journal of Chemistry, 2006, vol. 84, # 9, p. 1174 - 1179
[2] Patent: JP5978938, 2016, B2. Location in patent: Paragraph 0149; 0154
[3] Journal of Materials Chemistry, 2012, vol. 22, # 48, p. 25011 - 25018
[4] Patent: US2009/326186, 2009, A1. Location in patent: Page/Page column 64
[5] Angewandte Chemie - International Edition, 2013, vol. 52, # 16, p. 4356 - 4360
