栘[木衣]属植物多酚的含量测定与比较

Determination of Polyphenol Contents in Docynia Dcne

以根皮苷为标样,研究Folin-Ciocalteu(FC)比色法测定栘[木衣]属3个种的多酚含量适宜条件,进一步用此改良法测定和比较多酚含量在栘[木衣]属的3个种的叶以及在长爪栘[木衣]的不同器官中的差异性。结果表明,FC比色法最佳测定条件为:加质量分数10%的Na2CO3溶液2.5 m L和FC显色剂0.5 m L,在55℃条件下反应7 min。在1.252~15.024 μg/m L范围内,根皮苷的吸光度与其质量浓度呈良好的线性关系(R2=0.999 1),平均加样回收率为(100.08±2.43)%;测定结果还表明,3个物种的叶片多酚含量的差异显著,云南栘[木衣]最低12.55 g/100 g,长爪栘[木衣]最高25.35 g/100 g;长爪栘[木衣]的不同器官均含有多酚类化合物,含量差异显著(3.75~25.35 g/100 g)(P<0.05),由低到高为:果核<根<果肉<根皮<果皮<茎<叶。结论:改良后的FC比色法,用于测定栘[木衣]的多酚含量,具有快速、准确、重复性好的特点。栘[木衣]属植物的多酚含量较高,且多酚含量有明显的种间差异性及部位的差异性,栘[木衣]属的植物具有较大的开发和应用价值。

Using phlorizin as reference substance, Folin-Ciocalteu colorimetric assay for polyphenols extracted from Docynia Dcne. was systematically investigated for developing an optimal colorimetric method. The contents of polyphenols in three species of Docynia Dcne. were determined and compared as well as in different parts of Docynia longiunguis. The optimum colorimetric conditions were determined as follows: 0.5 m L of FC reagent and 2.5 m L of 10% Na2CO3, 7 min of reaction time, and 55 ℃ of reaction temperature. The absorbance of phlorizin was in good linear relationship with concentration in the range of 1.252–15.024 μg/m L, R2 = 0.999 1, and the average recovery for the analysis of spiked samples was 100.08%, with RSD of 2.43%. The contents of polyphenols in leaves of three species were significantly different, with the lowest and highest levels detected in Docynia delavayi(12.55 g/100 g) and Docynia longiunguis(25.35 g/100 g), respectively. Moreover, there was a significant difference in polyphenol contents among different organs of Docynia longiunguis, which showed the increasing order: pyrene < root < pulp < root bark < peel < stem < leaf. Conclusion: The established method was simple, stable, accurate, and suitable for the analysis of polyphenols and quality control of Docynia Dcne.. Docynia Dcne. is widespread and abundant with polyphenols, but there is a significant difference among species and organs. Accordingly, the plants of this genus have a high value for development and application.