Synthesis and characterization of hydroquinone fructoside using Leuconostoc mesenteroides levansucrase

Hydroquinone (HQ) functions as a skin-whitening agent, but it has the potential to cause dermatitis. We synthesized a HQ fructoside (HQ-Fru) as a potential skin-whitening agent by reacting levansucrase from Leuconostoc mesenteroides with HQ as an acceptor and sucrose as a fructofuranose donor. The product was purified using 1-butanol partition and silica-gel column chromatography. The structure of the purified HQ-Fru was determined by 1H and 13C nuclear magnetic resonance, and the molecular ion of the product was observed at m/z 295 (C12 H16 O7 Na)+. The HQ-Fru was identified as 4-hydroxyphenyl-β-d-fructofuranoside. The optimum condition for HQ-Fru synthesis was determined using a response surface method (RSM), and the final optimum condition was 350 mM HQ, 115 mM sucrose, and 0.70 U/ml levansucrase, and the final HQ-Fru produced was 1.09 g/l. HQ-Fru showed anti-oxidation activities and inhibition against tyrosinase. The median inhibition concentration (IC50) of 1,1-diphenyl-2-picrylhydrazyl scavenging activity was 5.83 mM, showing higher antioxidant activity compared to β-arbutin (IC50 = 6.04 mM). The Ki value of HQ-Fru (1.53 mM) against tyrosinase was smaller than that of β-arbutin (Ki = 2.8 mM), indicating that it was 1.8-times better as an inhibitor. The inhibition of lipid peroxidation by HQ-Fru was 105.3% that of HQ (100%) and 118.9 times higher than that of β-arbutin (0.89% of HQ).