School of Pharmacy, Henan University, Kaifeng, China.
School of Health Sciences Faculty of Health & Medicine, The University Newcastle, Newcastle, Australia.
Phytochem Anal. 2022 Apr;33(3):490-501. doi: 10.1002/pca.3104. Epub 2022 Feb 22.
Forsythia suspensa (Thunb.) Vahl (FS), the fruit of Oleaceae plants, as a large part of traditional Chinese medicine, is classified as "Qingqiao (Q)" and "Laoqiao (L)" based on the harvest time. Because the maturation of FS is a gradual process, its accurate identification based on different maturity levels is an important issue.
We suggest colorimetric, electronic tongue, and high-performance liquid chromatography (HPLC) characteristic fingerprints to discriminate FS in different harvest periods.
First, FS fruits from different harvest times were collected, and then, their colour parameters, E-tongue sensory properties, HPLC characteristic fingerprints, and contents of nominal ingredients were determined. Finally, multivariate statistical analyses, including three-dimensional scatter plots, hierarchical cluster, principal component, linear discriminant, similarity, and partial least squares discriminant analyses were performed.
The results demonstrated that the three experimental techniques could effectively discriminate FS based on different harvest times with 100% accuracy. Under the qualitative conditions, nine common peaks were identified in the HPLC fingerprints of 60 samples, among which, six peaks [variable importance in projection (VIP) > 1] could be used as index peaks for qualitative identification. In fact, the contents of quality marker components, including forsythin, phillygenin, rutin and forsythoside A, were significant different (P < 0.001) at different harvest times. Interestingly, the quality markers not only accurately reflected the maturity of FS but also showed close correlations with the colour parameters and sensory E-tongue responses.
In our present investigation, bionic technologies, including a colorimeter, E-tongue analysis, and HPLC characteristic fingerprints, combined with chemometrics, were employed to develop a novel and accurate method for discriminating FS based on different harvest times.
连翘（FS），木樨科植物的果实，作为中药的重要组成部分，根据收获时间分为“青翘（Q）”和“老翘（L）”。由于 FS 的成熟是一个渐进的过程，因此根据不同的成熟度准确识别是一个重要问题。
我们建议使用比色法、电子舌和高效液相色谱（HPLC）特征指纹图谱来区分不同收获期的 FS。
首先，收集不同收获时间的 FS 果实，然后测定其颜色参数、电子舌感官特性、HPLC 特征指纹图谱和标称成分含量。最后，采用多元统计分析，包括三维散点图、层次聚类、主成分、线性判别、相似度和偏最小二乘判别分析。
结果表明，三种实验技术可以有效地根据不同的收获时间准确区分 FS，准确率为 100%。在定性条件下，从 60 个样品的 HPLC 指纹图谱中鉴定出 9 个共有峰，其中 6 个峰（VIP>1）可作为定性鉴定的指标峰。事实上，质量标志物成分（包括连翘苷、连翘脂素、芦丁和连翘苷 A）的含量在不同收获时间显著不同（P<0.001）。有趣的是，质量标志物不仅准确反映了 FS 的成熟度，而且与颜色参数和感官电子舌响应密切相关。
在本研究中，仿生技术（包括比色计、电子舌分析和 HPLC 特征指纹图谱）与化学计量学相结合，开发了一种新颖而准确的方法，可根据不同的收获时间来区分 FS。
