Arbutin is an inhibitor of tyrosinase in human melanocytes. Arbutin can effectively inhibit the biological tyrosinase activity in the skin and block the formation of melanin. Arbutin directly combines itself with tyrosinase to accelerate the decomposition and excretion of melanin, thereby reducing skin pigmentation and removing spots and freckles. Because arbutin has a good whitening effect and minimal side effects, it is widely added to whitening cosmetics.
However, due to the lack of sources of natural extracts of arbutin, complex extraction steps, and low yields, most commercially available arbutin is converted from hydroquinone. Hydroquinone has great toxicity and side effects. Long-term use can cause skin exogenous chloasma and leukoplakia, and it can also cause skin toxicity, carcinogenicity, and genotoxicity after entering the blood. The residual hydroquinone contained in arbutin or the hydroquinone decomposed from arbutin will cause harm to the human body, so the safety issue is also worthy of attention.
Currently, known arbutin includes α-arbutin, β-arbutin, and deoxyarbutin. α-arbutin and deoxyarbutin are generally obtained through synthetic methods, while β-arbutin can be isolated from various plants. α-arbutin is an epimer of β-arbutin. Deoxyarbutin CAS NO. 53936-56-4 was first mentioned in Hamd's doctoral dissertation in 2004. In recent years, they have been widely concerned by the international medical beauty industry because of their good whitening effect.
Among these ingredients, deoxyarbutin has a significant blocking effect on the formation of melanin in the skin by reversibly inhibiting the activity of tyrosinase. According to the test results of human skin melanocytes, in the case of ensuring 95% cell survival, the safe concentration of deoxyarbutin is more than 4 times that of hydroquinone. From this point of view, deoxyarbutin actually has the strongest whitening ability.