基于高光谱分析的淫羊藿药用成分快速检测研究

中药材淫羊藿富含朝霍定和淫羊藿苷等黄酮类化合物，具有滋阴补肾、提高免疫力等功效，有较大的药用价值。当前，面对生产及育种过程中批量样品快速、无损检测需求的增加，传统的化学分析方法难以满足需要，而高效、廉价的现代高光谱分析技术备受青睐。但受制于光谱数据谱峰重叠及噪声的干扰，全波段光谱分析建模存在模型精度不高和运行效率低的问题。利用便携式地物光谱仪器获取淫羊藿可见-近红外光谱数据，借助遗传算法（GA）特征波段选择方法剔除无关波段，并与偏最小二乘回归（PLSR）分析建模技术结合，构建淫羊藿药用组分（朝霍定A、朝霍定B、朝霍定C和淫羊藿苷）高光谱GA-PLSR校正模型，探讨淫羊藿药用组分含量高效分析预测的可行性，并挖掘获取淫羊藿品质鉴定的重要光谱响应波段。结果表明：高光谱分析结合化学计量学在淫羊藿有效药用组分的快速无损检测方面具有相当大的潜力。与全波段PLSR校正模型相比，通过GA迭代优化，参与建模的有效光谱数据得到简化，GA-PLSR模型的测量精度和稳定性得到明显提升。主要表现在交叉验证的决定系数（R2_CV）得到明显提高，交叉验证的均方根误差（RMSE_CV）普遍降低。其中，四种药用组分校正模型的R2_CV分别从0.645，0.720，0.718和0.642提升为0.671，0.835，0.782和0.796；同时，其对应的RMSE_CV值分别由2.102，2.896，21.069和1.221降为2.071，2.230，18.656和0.912。此外，明确了红边波段690～740 nm以及420 nm附近波段为淫羊藿药用组分朝霍定A、朝霍定B、朝霍定C和淫羊藿苷光谱鉴别分析的重要响应波段。该研究为高光谱技术淫羊藿品质准确高效鉴定和光谱传感器的波段设计提供一定的理论依据。

Rapid Measurement of the Pharmacological Active Constituents in Herba Epimedii Using Hyperspectral Analysis Technology

Herba Epimedii contains high amounts of flavonoids, such as epimedin and icariin, which are efficient in tonifying kidney and improving immunity. Nowadays, various chemical analysis methods have been applied to measure the flavonoid content of Herba Epimedii. However, these traditional methods are destructive, time-consuming, and costly and cannot meet the requirements of massive samples analysis in pharmaceutical production and plant breeding. As a rapid and effective tool for quantitative determination and process monitoring, modern hyperspectral analysis technology has earned more and more concerns. However, for the full-range spectra, the existence of insignificant and irrelevant spectral variables can weaken the calibration models’ accuracy and efficiency. Therefore, the spectral variables selection is essential to improve the performance of the final models by eliminating the uninformative bands. In this study, the partial least squares regression (PLSR) coupled with the genetic algorithm (GA) variables selection procedure, namely GA-PLSR, was used to estimate epimedin A, epimedin B, epimedin C, and icariin content in Herba Epimedii. This paper aims to explore the feasibility of hyperspectral analysis technology in the measurement of the pharmacologically active constituents in Herba Epimedii and further explore their important spectral response bands. The results show thatthe hyperspectral analysis technology combined with chemometrics exhibited considerable potential for rapid and nondestructive assessment of Herba Epimedii. When compared with full-spectrum PLSR models, GA-PLSR models could improve the accuracies and robustness of epimedin A, epimedin B, epimedin C, and icariin content measurements (with R2_CV values increased from 0.645, 0.720, 0.718, and 0.642 to 0.671, 0.835, 0.782, and 0.796, and with RMSE_CV values declined from 2.102, 2.896, 21.069, and 1.221 to 2.071, 2.230, 18.656, and 0.912, respectively). Besides, we found some feature wavelengths, mainly around 690~740 and 420 nm, which play important roles in detecting pharmacologically active constituents in Herba Epimedii. Given these desirable findings, this study can provide a valuable reference for the rapid and accurate measurement of epimedin A, epimedin B, epimedin C, and icariin contents by hyperspectral technology, can provide a theoretical basis for the design of spectral sensors in qualifying Herba Epimedii.