Determination of the Thermodegradation of deoxyArbutin in Aqueous Solution by High Performance Liquid Chromatography

Abstract

Tyrosinase is the key and rate-limiting enzyme responsible for the conversion of tyrosine into melanin. Competitive inhibition of tyrosinase enzymatic activity results in decreased or absent melanin synthesis by melanocytes in human skin. DeoxyArbutin (4-[(tetrahydro-2H-pyran-2-yl)oxy]phenol), a novel skin whitening agent, was synthesized through the removal of hydroxyl groups from the glucose side-chain of arbutin. DeoxyArbutin not only shows greater inhibition of tyrosinase activity but is also safer than hydroquinone and arbutin. Hence, deoxyArbutin is a potential skin whitening agent for cosmetics and depigmenting drugs; however, stability of this compound under some conditions remains a problem. The lack of stability poses developmental and practical difficulties for the use of deoxyArbutin in cosmetics and medicines. Improving the thermostability of deoxyArbutin is an important issue for its development. In this research, we established an analytical procedure to verify the amount of deoxyArbutin in solutions using a high performance liquid chromatographic (HPLC) method. The results indicate that this novel skin whitening agent is a thermolabile compound in aqueous solutions. Additionally, the rate constant for thermodegradation (k) and the half-life (t1/2) of deoxyArbutin were determined and can be used to understand the thermodegradation kinetics of deoxyArbutin. This information can aid in the application of deoxyArbutin for many future uses.

Formulation, Characterisation, and in Vitro Skin Diffusion of Nanostructured Lipid Carriers for Deoxyarbutin Compared to a Nanoemulsion and Conventional Cream

“…dArb is a hydrophobic substance and is insoluble in water, but it easily degrades in aqueous conditions, as previously shown [3]. The chemical structures are shown in Figure 1.…”

Comparative Study on the Photostability of Arbutin and Deoxy Arbutin: Sensitivity to Ultraviolet Radiation and Enhanced Photostability by the Water-Soluble Sunscreen, Benzophenone-4

“…Consequently, deoxy arbutin may be degraded to hydroquinone and such other molecules as tetrahydro-2H-pyran-2-ol. 18) Although it is not surprising that UV-irradiated deoxy arbutin may release hydroquinone, our study is the first to confirm this decomposition process and also to compare the photostability of these two hydroquinone derivatives.…”

“…The concentrations of UV-irradiated arbutin and deoxy arbutin were analyzed by an HPLC method, 18) the results being shown in Fig. 2.…”

“…17) We have also established in our previous study that deoxy arbutin was thermolabile in an aqueous solution and decomposed to hydroquinone under such conditions. 18) To our knowledge, there have been no studies describing the photostability of deoxy arbutin or demonstrating hydroquinone to be the decomposition product of ultraviolet (UV)-irradiated deoxy arbutin. Further investigation of the photostability of arbutin and deoxy arbutin may also enhance the applications of arbutin and deoxy arbutin by the cosmetic industry in the future.…”

Tyrosinase Inhibitory Activity and Thermostability of the Flavonoid Complex from <i>Sophora japonica</i> L (Fabaceae)

“…Some potent anti-tyrosinase agents, such as kojic acid, arbutin and deoxyarbutin, are unstable in aqueous environments [25][26][27]. Thus, we compared the stability of SJ-FC with the stabilities of two well-known and frequently used tyrosinase inhibitors, ascorbic acid and arbutin, using a tyrosinase inhibitory activity-based method in PG and H 2 …”