High performance thin layer chromatography fingerprint on cyano-bonded stationary phase of selected Stachys and Betonica species and their antioxidant activity with chemometric calculations

The methanolic extracts of selected Stachys and Betonica species were analyzed by high performance thin layer chromatography (HPTLC) method using cyano bonded stationary phase and mobile phase consisted of methanol and water 45:55 (v/v) with Natural product reagent derivatization. The HPTLC method was validated (linearity, precision, accuracy, robustness, LOD, LOQ) and the validation results confirm the usefulness of the method used. The obtained images of fingerprint chromatograms presented as numerical data (using the TLC analyzer program) were next processed using Excel and SpecAlign softwares. The phytochemical similarity between analyzed plant extracts was evaluated using the similarity index (Pearson correlation coefficient) and the results were presented as hierarchical cluster analysis dendrograms and as graph for principal component analysis (PCA). The total phenolic content (TPC) by Folin-Ciocalteu method and the antioxidant activity with Ferric Ion Reducing Antioxidant Potential (FRAP) technique were determined for studied extracts using gallic acid as standards in both methods.