Thin Layer Chromatography and Chemometric Studies of Selected <i>Potentilla</i> Species

Abstract

Herbal medicinal products have a long-standing therapeutic record. To ensure the quality of herbal products specific identification tests which allow experts to discriminate related species and/or potential adulterants/substitutes are required. The purpose of the research was to recommend an original and simple method for the separation of closely related five triterpenic acids (ursolic, oleanolic, tormentic, euscaphic, pomolic acid) and its application to chemotaxonomy studies. 17 standard samples of Potentilla species and 3 test samples were chromatographed (with or without prechromatographic derivatization) on silica gel plates using the mobile phase: chloroform-diethyl ether-methanol-formic acid (30:10:1:0.2 v/v/v/v); they were subsequently derivatized, and visualized in UV 366 nm light. After images received pre-treatment (montaging stack, removal of noise, background subtract, horizontal equalization, two types of warping) exploratory analysis of the investigated Potentilla species fingerprints was processed. The method without prechromatographic derivatization was used to create differential fingerprints. Good results were obtained by the application of r-project iterative algorithm for subtract background and our simple algorithm for warping to image processing of TLC chromatograms for the first time.

Comparison of Analytical Methods in Chemometric Fingerprinting of Metallicolous and Non-metallicolous Populations of Echium vulgare L.

“…Plant extracts (30 μL) were applied on 20 cm × 10 cm silica gel plates (TLC Silica gel 60, F254, Merck, Darmstadt, Germany) as a band by an automatic TLC sampler (ATS4, CAMAG, Muttenz, Switzerland) and developed in horizontal Teflon DS‐Chambers (Chromdes, Lublin, Poland) (Świeboda et al , ). A mixture of ethyl acetate:formic acid (98–100%):glacial acetic acid:water (100:11:11:26) was used as the mobile phase (Wagner and Bladt, ).…”

“…After generating montage of the stack of all subtracks, the signals were denoised by Savitzky–Golay Filter Plugin and subjected to baseline removal. More details concerning denoising and baseline removal procedures were specified previously (Świeboda et al , ). The montage stacks were transformed to greyscale intensity images and then the data of each subtrack were converted to the CSV file format and transferred to the SpecAlign software.…”

“…In the past few decades, new separation and spectroscopic techniques have been intensively developed. Most of them, including high performance liquid chromatography (HPLC), high performance capillary electrophoresis (HPCE), or mass spectrometry (MS) allow collection of a large amount of data (Pietraś et al , ; Świeboda et al , ). The multivariate nature of data obtained gives an opportunity to implement chemometric methods in order to explore and find hidden trends and properties of studied objectives.…”

“…The multivariate nature of data obtained gives an opportunity to implement chemometric methods in order to explore and find hidden trends and properties of studied objectives. The use of chemometric calculations for processing data obtained from analysis of complex samples, such as plant extracts, can provide a powerful and important tool for comprehensive authentication of herbal medicines, pharmaceuticals, and dietary supplements for food safety and quality standards as well as discrimination between plant families/species/varieties/populations for botanical classification and environmental studies (Gad et al , ; Świeboda et al , ; Wang et al , ; Casale et al , ). Previously, multivariate statistical and mathematical methods were successfully applied for thin‐layer chromatography (TLC), gas chromatography (GC), infrared (IR) spectroscopy, differential scanning calorimetry, and HPLC data in exploration and fingerprinting of essential oils (Pietraś et al , ; Wang et al , ) or phenolic compounds (Avula et al , ).…”

“…Additionally, the fingerprinting of propolis and evaluation of herbal medicines were performed based on chemometric analysis of data obtained from TLC (Tang et al , ), high performance thin layer chromatography (HPTLC) (Ristivojević et al , ), HPCE, and fluorescence spectroscopy (Mazina et al , ). The chemometric methods have also been useful in discrimination between different species of Potentilla (Świeboda et al , ) or between lichens that were unexposed and exposed to air pollution (Casale et al , ).…”