School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica, State Administration of Traditional Chinese Medicine (TCM), Engineering Technology Research Center for Chinese Materia Medica Quality of Universities in Guangdong Province, Guangzhou, 510006, Guangdong, China.
College of Pharmacy, Jinan University, Guangzhou, 510632, China.
J Pharm Biomed Anal. 2021 Feb 20;195:113837. doi: 10.1016/j.jpba.2020.113837. Epub 2020 Dec 10.
Curcumae Rhizoma (CR) and vinegar processed Curcumae Rhizoma (PCR) are common medicinal materials widely used in clinical practice in China. There are sliced CR (SCR) and two kinds of PCR products which are processed by different methods: WPCR-prepared with the whole CR root boiled in vinegar and then sliced, and SPCR-prepared with the whole CR root steamed and sliced before boiled with vinegar. In this study, the feasibility of Fourier transform near infrared spectrum (FT-NIR) used to determine the main discrepant components of SCR, WPCR and SPCR were investigated. High performance liquid chromatography (HPLC) was used to identified five discrepant compounds in the three kinds of CR products-curzerene, curcumenol, curdione, furanodienone and demethoxycurin. Pretreatment of NIR qualitative data by different methods revealed that the second derivative in combination with 9 points of Savitzky-Golay smooth (2D9S) could accurately distinguish SCR, SPCR and WPCR from each other, and the discrimination ability was improved significantly by wavebands selection. Then a model with great accuracy was established by combining with wavebands selection and partial least squares regression (PLSR). Compared with the competitive adaptive reweighted sampling (CARS) selection method, 2D9S- variable combination population analysis (VCPA)-Genetic algorithm (GA)-PLSR model was evidently more accurate in prediction of the content of curzerene, curcumenol, curdione and furanodienone, with an R2p of 0.9558, 0.9129, 0.9098 and 0.9350, as well as a ratio of performance to deviation (RPD) of 4.8454, 3.4640, 3.3020 and 4.0082, respectively. Whereas, the content of demethoxycurin failed to be well predicted. The correlation analysis revealed that the results of wavebands selection were consistent with the trend of changes in the content of these target compounds and the findings of NIR absorption analysis, and the characteristic chemical bonds of these compounds corresponded to the areas with significant correlation in the heat map. It can be concluded that the NIR system, combined with appropriate variable selection and linear regression method, can precisely distinguish SCR, SPCR and WPCR from each other, and can accurately and rapidly determine the four discrepant compounds in the three CR products, suggesting a potential of being routinely used for a more diversified analysis in medicinal herbs study.
莪术和醋制莪术是中国临床常用的两种药用材料，莪术通常有两种炮制方法，分别是醋莪术（PCR）和醋制莪术（PCR）。醋制莪术又分为醋莪术（PCR）和醋制莪术（PCR）两种，其中一种是将莪术的整个根茎煮熟后切成薄片，另一种是将莪术的整个根茎蒸制后切成薄片，然后用醋煮。在本研究中，探讨了傅里叶变换近红外光谱（FT-NIR）用于测定莪术、醋莪术和醋制莪术主要差异成分的可行性。采用高效液相色谱法（HPLC）鉴定了三种莪术药材中的五种差异化合物——莪术烯、莪术醇、莪术二酮、呋喃二烯酮和去甲氧基莪术。通过不同方法对近红外定性数据进行预处理，发现二阶导数与 9 点 Savitzky-Golay 平滑（2D9S）相结合，能准确地区分莪术、醋制莪术和醋制莪术，且通过波段选择，其区分能力显著提高。然后，结合波段选择和偏最小二乘回归（PLSR）建立了一个精度很高的模型。与竞争自适应重加权抽样（CARS）选择方法相比，二阶导数与变量组合种群分析（VCPA）-遗传算法（GA）-PLSR 模型在预测莪术烯、莪术醇、莪术二酮和呋喃二烯酮的含量方面明显更准确，其相关系数分别为 0.9558、0.9129、0.9098 和 0.9350，偏最小二乘回归的性能偏差比分别为 4.8454、3.4640、3.3020 和 4.0082。然而，去甲氧基莪术的含量则无法得到很好的预测。相关性分析表明，波段选择的结果与这些目标化合物含量的变化趋势一致，与近红外吸收分析的结果一致，这些化合物的特征化学键与热图中显著相关的区域相对应。综上所述，NIR 系统结合适当的变量选择和线性回归方法，能准确区分莪术、醋制莪术和醋制莪术，能快速、准确地测定三种莪术药材中的四种差异化合物，有望在草药研究中常规应用于更多样化的分析。
