白桑叶总黄酮含量分析

目的]为桑叶资源的合理开发和利用提供科学依据。方法]利用甲醇提取桑叶总黄酮,分光光度法测定其含量并通过稳定性、重复性、精密度和回收率试验检验了该方法的可靠性和重现性,分析了白桑不同种质资源桑叶总黄酮含量的差异。结果]标准液及供试液均在505nm处有最大吸收。重复性、精密度、回收率试验的RSD值分别为0.95%、0.67%和1.32%,平均加样回收率为100%。含量测定结果表明,白桑叶总黄酮含量较低。方差分析表明,同属白桑的不同种质资源桑叶总黄酮含量差异极显著。测定的12份种质桑叶总黄酮含量平均为44.00mg/g,其中白桑8号桑叶总黄酮含量最高,为(60.78±2.32)mg/g;桑莲桑叶总黄酮含量最低,为(34.20±0.86)mg/g。结论]以甲醇提取、硝酸铝显色、505nm测定的分光光度法适用于桑叶总黄酮含量的测定。

Analysis on the TotaI Flavonoid Content in Morus alba Linn. Leaves

Objective] The purpose of the study was to supply scientific basis for the reasonable development and utilization of mulberry leaf resources. Method] The total flavonoid was extracted from mulberry leaves with methanol and its content was determined by spectrophotometry. The reliability and repeatability of this method were tested through stability, repeatability, accuracy and recovery experiments. The difference on total flavonoid content in mulberry leaves among different germplasm resources was analyzed. Result] Both standard and tested solutions had the maximum absorbance at 505 nm. The RSD values of repeatability, accuracy and recovery experiments were 0.95%, 0.67% and 1.32% resp. and the average recovery was 100%. The results of content determination showed that the total flavonoid content was lower in Morus alba leaves. The variance analysis showed that the extremely significant difference was found on the total flavonoid content in the mulberry leaves among different germplasm resources of M. alba in the same genera. The average of total flavonoid content in mulberry leaves among the determined 12 germplasms was 44.00 mg/g, and the total flavonoid content was highest in mulberry leaves of Baisang 8, being (60.78 ± 2.32) mg/g and lowest in mulberry leaves of Sanglian, being (34.20 ± 0.86) mg/g. Conclusion] Extraction with methanol, coloring with aluminium nitrate and determination by spectrophotometry at 505 nm were suitable for the determination of total flavonoid content in mulberry leaves.