Current Application of Chemometrics Analysis in Authentication of Natural Products: A Review.

BACKGROUND: The efficiency of herbal medicinal products depends on the quantity of active ingredients in them, which can vary considerably in different contents. Hence, the quality control of herbal medicines is a critical concern. OBJECTIVE: This paper aims to provide a succinct review of recent chemometrics applications in solving the uncertainty of the authentication of herbal medicines over the last two decades. METHODS: Studies involving chemometrics applications in conjunction with various analytical methods have been categorized according to the type of research used in the quality evaluation of different samples, including chromatographic (HPLC, GC-MS) and spectroscopic analysis (UVVis, FTIR, NMR, and MS). RESULTS: This review consists of over 90 studies illustrating the relevance of chemometrics methods in the discrimination based on the key bioactive components and phytochemical diversity of several herbs from closely related species. In addition to the prediction of the active components, the distinction between varieties and hybrids was accomplished through quantitative analysis techniques. CONCLUSION: Methods of chemometrics have provided an important and potent tool for the quality control and authentication of various herbs.

ATR-FTIR Spectroscopy, HPLC Chromatography, and Multivariate Analysis for Controlling Bee Pollen Quality in Some Algerian Regions.

Bee pollen collected by honeybees (Apis mellifera) is one of the bee products, and it is as valuable as honey, propolis, royal jelly, or beebread. Its quality varies according to its geographic location or plant sources. This study aimed to apply rapid, simple, and accurate analytical methods such as attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and high-performance liquid chromatography (HPLC) along with chemometrics analysis to construct a model aimed at discriminating between different pollen samples. In total, 33 samples were collected and analyzed using principal component analysis (PCA), hierarchical clustering analysis (HCA), and partial least squares regression (PLS) to assess the differences and similarities between them. The PCA score plot based on both HPLC and ATR-FTIR revealed the same discriminatory pattern, and the samples were divided into four major classes depending on their total content of polyphenols. The results revealed that spectral data obtained from ATR-FTIR acquired in the region (4000-500 cm-1) were further subjected to a standard normal variable (SNV) method that removes scattering effects from spectra. However, PCA, HCA, and PLS showed that the best PLS model was obtained with a regression coefficient (R 2) of 0.9001, root-mean-square estimation error (RMSEE) of 0.0304, and root-mean-squared error cross-validation (RMSEcv) of 0.036. Discrimination between the three species has also been possible by combining the pre-processed ATR-FTIR spectra with PCA and PLS. Additionally, the HPLC chromatograms after pre-treatment (SNV) were subjected to unsupervised analysis (PCA-HCA) and supervised analysis (PLS). The PLS model confers good results by factors (R 2 = 0.98, RMSEE = 8.22, and RMSEcv = 27.86). Prospects for devising bee pollen quality assessment methods include utilizing ATR-FTIR and HPLC in combination with multivariate methods for rapid authentication of the geographic location or plant sources of bee pollen.