基于柱前衍生化法测定糖含量并结合色度值分析熟地黄传统质量标准

Analysis of Traditional Quality Standard of Shudihuang(Rehmanniae Radix Preparata) by Color Value Combined with Determination of Carbohydrate Content Based on Pre-Column Derivatization Method

目的探究熟地黄"色黑如漆、味甘如饴"传统质量标准客观量化的可行性,并分析其外观色泽与糖含量间的相关性以阐述其炮制内涵。方法采用精密色差仪记录熟地黄色泽变化趋势;在前期糖类研究基础上筛选出与"色黑、味甘"产生机制相关联的甘露三糖、半乳糖和葡萄糖,建立柱前衍生化-HPLC同时测定3者的含量,采用SunFire?C18色谱柱以乙腈-0.1 mol·L^(-1)乙酸铵(pH 4.1)为流动相梯度洗脱,检测波长245 nm,流速0.6 mL·min-1,柱温25℃;然后基于Pearson相关系数对色度值和糖含量之间的变化趋势进行相关性分析。结果 3种糖含量分别为,甘露三糖16.95%~39.85%,半乳糖1.35%~3.18%,葡萄糖2.39%~6.61%;甘露三糖、葡萄糖与L呈极显著负相关(P<0.01),与ΔE呈极显著正相关(P<0.01),相关系数分别为-0.972、-0.646和0.960、0.643。结论熟地黄中色泽较黑较深者甘露三糖和葡萄糖含量也相对较高,在一定程度上从量化角度体现了熟地黄传统质量标准的科学内涵;采用柱前衍生化法和色度分析技术对熟地黄传统质量标准进行客观性量化的思路具备可行性,可以为其客观评价体系的建立提供研究支撑。

Objective To explore the feasibility of objective quantification of traditional quality standard of Shudihuang(Rehmanniae Radix Preparata), and analyze the correlation between its appearance color and sugar content to elaborate its processing connotation. Method The change trend of the yellow color of Shudihuang(Rehmanniae Radix Preparata) was recorded by the precise color difference meter. On the basis of previous carbohydrate studies, mannotriose, galactose and glucose associated with the production mechanism of "dark color and sweet taste" were selected. The pre-column derivatization HPLC was established to determine the contents of mannotriose, galactose and glucose simultaneously. SunFire? C18 column was used, with acetonitrile-0.1 mol·L^(-1) ammonium acetate(pH=4.1) as the mobile phase for gradient elution. The detection wavelength 245 nm. The flow rate was 0.6 mL·min-1 and the column temperature was 25 ℃. Then, based on Pearson correlation coefficient, the correlation between the color value and sugar content was analyzed. Result The content of mannose was 12.23%~39.85%. The content of galactose was 0.77%~3.18%, and the content of glucose was 2.09%~6.61%. The mannose and glucose were extremely negatively correlated with L(P<0.01). Moreover, it had very significant positive correlation with ΔE(P<0.01). The coefficients were-0.972,-0.646 and 0.960, 0.643. Conclusion The contents of mannotriose and glucose in the dark and deep color of Shudihuang(Rehmanniae Radix Preparata) are relatively high, reflecting the scientific connotation of traditional quality standard of Shudihuang(Rehmanniae Radix Preparata) to a certain extent. It is feasible to use pre-column derivatization method and colorimetric analysis technology to quantify the objectivity of traditional quality standard of Shudihuang(Rehmanniae Radix Preparata), which can provide research support for the establishment of its objective evaluation system..