基于“辨状论质”理论研究黄柏饮片外观性状与内在质量相关性

Exploring correlation between appearance characters and internal quality of Phellodendri Chinensis Cortex slice based on the theory of“quality evaluation through morphological identification”

黄柏传统评价以“肉厚色黄者”为佳,但该性状特征的科学内涵尚未被阐释。本研究基于“辨状论质”理论,首先采用游标卡尺和全自动测色色差仪对黄柏饮片厚度和粉末颜色进行量化,同时采用高效液相色谱(HPLC)法建立黄柏饮片特征图谱,共表征12个特征峰,将外观性状指标与水分、醇溶性浸出物以及特征成分进行Pearson相关性分析、主成分分析(PCA)、正交偏最小二乘判别分析(OPLS-DA)和方差分析(ANOVA),探讨黄柏饮片外观性状(包括厚度和粉末三色空间值L^(*)亮度、a^(*)红绿、b^(*)黄蓝)与内在成分及相对含量之间的相关性。结果表明黄柏的外观性状特征(厚度和颜色)与黄柏中的化学成分(生物碱和酚酸)的含量呈显著相关性。基于分析结果,对5种代表性成分进行含量测定,5种成分含量总和在厚度≥4 mm(13.15%±2.25%)和鲜黄色样品(12.14%±2.00%)中的含量显著高于厚度<4 mm(10.89%±1.41%)和暗黄色黄柏样品(10.32%±2.41%),将外观性状与成分含量建立“性状-质量-含量”对应关系。研究结果证实黄柏饮片厚度和颜色2个主要外观性状指标可作为判断其品质的依据,一定程度上诠释了黄柏传统评价“肉厚色黄者为佳”的科学内涵,同时为黄柏饮片商品等级标准的建立积累了数据和基础。

Phellodendri Chinensis Cortex(PCC)featured with thick cortex and bright-yellow is considered to be of high quality according to traditional appearance traits evaluation mode.However,the correlation between appearance traits and internal quality of PCC has not been scientifically revealed.Here,based on the theory of"Quality Evaluation Through Morphological Identification",the correlation of both sides was studied systematically.Firstly,the thickness of PCC slices was measured by vernier calipers for classification,and the colour of PCC slice was estimated by naked eyes and automatic colorimeter and classified.Secondly,high performance liquid chromatography(HPLC)was used to establish fingerprint chromatogram containing 12 characteristic peaks,and the contents of moisture and ethanolic extractive were determined as well.The correlation among the appearance traits of PCC slice(including the thickness and the spatial values of colour of PCC slice powder:L^(*)Lightness,a^(*)Red-Green,b^(*)Yellow-Blue)and peak areas of 12 characteristic peaks,contents of moisture and extractive were explored through multivariate statistical analysis tools,including Pearson's correlation analysis,principal component analysis(PCA),orthogonal partial least squares-discriminant analysis(PLS-DA)and analysis of variance(ANOVA).Association analysis results showed the morphological parameters(thickness and color)are significantly correlated with 2 kinds of principle chemical constituents(alkaloids and phenolic acids),among them,5 major constituents including 2 isoquinoline alkaloids and 3 feruloylquinic acids were simultaneously quantitatively analyzed under the same chromatographic condition for establishing a correspondence between appearance traits and content of internal substances,and the sum of the contents of the five components was significantly higher in the thickness≥4 mm(13.15%±2.25%)and bright yellow samples(12.14%±2.00%)than that in the thickness<4 mm(10.89%±1.41%)and dark yellow samples(10.32%±2.41%).The research results confirm that thickness and colour,two main appearance parameters of PCC slice,can be used as the indicators for evaluating the quality PCC slice,which to some extent interprets the scientific connotation of traditional evaluation theory of"thick and yellow are better".At the same time,the results provided substantial data and foundation for the establishment of commodity grade standards of PCC slice.