Extraction and Characterization of Anthocyanidins from Loropetalum chinense var.rubrum Yieh Leaves

The anthocyanidinsins in Loropetalum chinense var.rubrum Yieh leaves were extracted by solvent extraction method and analyzed for their physico-chemical properties.The best extraction conditions were found as follows: 99.5% methanol as extraction solvent at a solid-to-liquid ratio of 1:5(g/mL) for 2 h extraction at 60 ℃.The pigments were unstable to light and heating but stable to strongly acidic environments and had a different color in slightly acidic and nearly neutral environments.Their tolerance to H2O2 and Na2SO3 was poor and their sensitivity to EDTA and sodium benzoate was high.Glucose and sucrose had little effect on the pigments.Salt,citric acid and some metal ions such as A13+,Ca2+ and Co2+ had hyperchromic effect on them and vitamin C and other metal ions such as Cu2+,Mg2+,Zn2+,Mn2+,K+ and Sn2+ had hypochromic effect.Moreover,Fe2+,Fe3+ and Pb2+ affected the stability of the pigments.