目的 对不同商品等级单枝味连Coptis chinensis的皮部/木部生物碱类成分进行比较分析，阐明生物碱类成分在不同组织部位中的分布规律。方法 以不同商品等级的单枝味连为研究对象，使用游标卡尺对其皮部和木部的占比进行量化，色差仪测定根茎及其2个组织部位的色差值，紫外分光光度计测定三者的总生物碱含量。使用一测多评法和外标法对木兰花碱、格兰地新、非洲防己碱、药根碱、表小檗碱、黄连碱、巴马汀及小檗碱8种有效成分的含量进行测定，结合方差分析、相关性分析、主成分分析、正交偏最小二乘判别分析方法对皮部/木部化学成分进行比较，寻找皮部木部差异的标志性成分。结果 不同商品等级的单枝味连，直径越大，皮部/木部比值越大，其中三等占比0.63、二等占比0.78、一等占比0.87、特等占比1.01。根茎及其皮部色差值L^*、a^*、b^*均小于木部。总生物碱在根茎及其皮部和木部的含量分别为15.96%、16.68%和13.53%，皮部显著高于木部（P＜0.001），不同商品等级之间没有显著性差异。所测定的8种成分中，大部分生物碱含量随商品等级的升高呈现降低趋势，外标法和一测多评法结果基本一致。不同商品等级单枝味连根茎生物碱含量与质量、长度和皮部/木部占比没有显著相关性，黄连碱含量与直径呈显著负相关（P＜0.05）；色差值L^*与盐酸药根碱和黄连碱含量呈显著负相关（P＜0.05），与盐酸巴马汀和小檗碱含量呈极显著负相关（P＜0.01），色差值a^*与木兰花碱含量呈极显著正相关（P＜0.01），色差值b^*与盐酸巴马汀含量呈显著负相关（P＜0.05）。不同组织部位颜色测定值L^*、a^*、b^*与生物碱含量呈极显著负相关（P＜0.01）。主成分分析筛选出累计贡献率达到81.59%的3个主成分，偏最小二乘法找出皮部木部差异的4个标志性成分，分别为黄连碱、小檗碱、非洲防己碱和巴马汀。结论 通过色差分析、紫外分光光度法、高效液相色谱法和化学计量学方法揭示了不同商品等级单枝味连不同组织部位的生物碱类成分分布规律，为黄连“辨状论质”提供了科学依据。

Objective To analyze and compare the alkaloids in phloem and xylem of Coptis chinensis with different grades, and clarify the distribution rules of the components in different tissues of C. chinensis. Methods Taking the different commodity grades of C. chinensis as the research object, vernier caliper was used to measure proportion of phloem and xylem accurately, colorimeter was used to determine L^*, a^* and b^* values of powder, and ultraviolet spectrophotometry was used to detecte the content of total alkaloids in rhizome, phloem and xylem. The content of magnoflorine, groenlandicine, columbamine, jatrorrhizine, epiberberine, coptisine, palmatine and berberine were analyzed by external standard method and multi-components single-marker method. Combined with analysis of variance, correlation analysis, principal component analysis and partial least squares discriminant analysis to compare the chemical compounds in phloem and xylem, and find the signature components. Results The larger diameter of the medicinal material had a relatively larger proportion of phloem and xylem. Among them, the proportion of third grade was 0.63, second grade was 0.78, first grade was 0.87 and special grade was 1.01. The color difference values L^*, a^* and b^*of the rhizome and phloem were smaller than those of the xylem. The content of total alkaloids was 15.96% in rhizome, 16.68% in the phloem and 13.53% in the xylem, the alkaloid content in the phloem was significantly higher than that of the xylem (P < 0.001), and there was no significant difference in the total alkaloid content of different grades of C. chinensis. The contents of most compounds showed a decreasing trend with the increase of the commercial grade of C. chinensis, and there was no significant difference between the quantitative results of external standard method and multi-components by single-marker method. There was no significant correlation betweenthe alkaloid content of rhizome and weight, length and ratio of phloem to xylem, but there was a significant negative correlation between the coptisine content and diameter (P < 0.05). The color difference value L^* was significantly negatively correlated with jatrorrhizine hydrochloride and coptisine (P < 0.05), extremely significantly negatively correlated with palmatine hydrochloride and berberine (P < 0.01). The color difference value a^* was significantly positively correlated with magnoflorine (P < 0.01), and the color difference value b^* was significantly negatively correlated with palmatine hydrochloride (P < 0.05). The color measurement values L^*, a^*, b^* were negatively correlated with the content of alkaloids (P < 0.01). Principal component analysis indicated that the cumulative variance contribution rate of three principal components were 81.59%. According to the orthogonal partial least squares-discriminant analysis, four different index compounds were found, namely coptisine, berberine, columbamine and palmatine. Conclusion The distribution of alkaloids in different tissues of C. chinensis was clarified by means of colorimeter, ultraviolet spectrophotometry, high performance liquid chromatography and chemometrics analysis, with view to providing the scientific basis for the “quality evaluation through morphological identification” of C. chinensis.

R286.2

科技部国家重点研发计划（2021YD1601005-2）；农业部国家中药材产业技术体系重庆站（CARS-21）；重庆市农业农村委员会重庆市中药材产业技术体系2022（10）；四川省中医药管理局（2021MS448）；成都中医药大学“杏林学者”项目（CCYB2022007）