Fructoside

Abstract: 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).

Abstract: Evidence is presented which indicates that the initiating reaction in the thermal decomposition of sucrose is a first-order intramolecular displacement yielding D-glucose and a fructose derivative(F*) (anhydride?). The latter product has not yet been identified, but is postulated as reacting rapidly with sucrose to yield trisaccharides of the type F2G. When another alcohol (erythritol) is present in the melt, F* reacts with it to produce fructoside(s).