National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA.
Natural Products Utilization Research Unit, ARS. Department of Agriculture, University, MS 38677, USA.
J Pharm Biomed Anal. 2022 Oct 25;220:115012. doi: 10.1016/j.jpba.2022.115012. Epub 2022 Aug 19.
The roots and rhizomes of several Glycyrrhiza species are widely used as sweetening and flavoring agents in food, as well as important ingredients in formulations of traditional medicines. Five Glycyrrhiza species, G. uralensis, G. glabra, G. inflata, G. echinata, and G. lepidota, often share the name "licorice roots" in the botanicals' marketplace. Unfortunately, misidentification/mislabeling is very common due to their similarities in morpho-anatomical features. Significant metabolite alterations among the different Glycyrrhiza species and their hybrids have been reported, suggesting that the biological activities could vary with the licorice roots or products derived from different species. Development of simple, effective methods for species identification and differentiation is of key importance. In this study, 78 licorice samples were investigated using HPTLC and NMR as analytical tools. Significant metabolite variations were observed between the five species. The species-specific fingerprint patterns for the five Glycyrrhiza species were determined with HPTLC and NMR; then applied to the sample identification and discrimination. The results obtained from these two orthogonal analytical methods agreed with each other. Furthermore, the NMR signals and the species-specific constituents that made significant contributions to the differentiation of the five Glycyrrhiza species were confirmed based on the multivariate analysis of the NMR spectral data. Using the established OPLS-DA models, the classification of hybrids was evaluated and confirmed. The developed methods, particularly the HPTLC method with its simplicity and low cost, could be used as a rapid and reliable approach for the authentication of licorice species and quality control of licorice raw material and products.
几种甘草属植物的根和根茎被广泛用作食品中的甜味剂和调味剂，也是传统药物配方的重要成分。在植物药市场中，有五种甘草属植物，即乌拉尔甘草、光果甘草、胀果甘草、刺甘草和黄甘草，通常被称为“甘草根”。不幸的是，由于它们在形态解剖学特征上的相似性，误识别/误标记非常普遍。据报道，不同甘草属物种及其杂种之间存在显著的代谢物变化，这表明生物活性可能因甘草根或不同物种来源的产品而异。因此，开发简单、有效的物种鉴定和区分方法至关重要。本研究采用 HPTLC 和 NMR 作为分析工具，对 78 种甘草样品进行了研究。在五种植物之间观察到了显著的代谢物变化。通过 HPTLC 和 NMR 确定了五种甘草属植物的种特异性指纹图谱，并将其应用于样品的鉴定和区分。这两种正交分析方法的结果相互一致。此外，基于 NMR 光谱数据的多元分析，确定了 NMR 信号和对五种甘草属植物分化有重要贡献的种特异性成分。利用建立的 OPLS-DA 模型，对杂种的分类进行了评估和确认。所建立的方法，特别是具有简单、低成本的 HPTLC 方法，可以作为一种快速可靠的方法，用于甘草属植物的鉴定和甘草原料及产品的质量控制。
