TLC fingerprint with chemometrics and antioxidant activity of selected lichens

Abstract

Selected lichens, collected in forests near Lublin (Poland) were extracted using Soxhlet apparatus with dichloromethane and methanol as solvents. The obtained extracts were analyzed using the Thin Layer Chromatography with silica gel as adsorbent and the mixture of toluene, ethyl acetate and formic acid (10/10/0.5; v/v/v, respectively) as mobile phase. Developed chromatographic plates were sprayed using the Naturstoff reagent to confirm the presence of some phenolic compounds. The images of plates were digitalized using TLC Analyzer software and the obtained chromatograms were exported to Excel and converted to csv files. Next csv files were loaded to SpecAlign program, where the smoothing, subtraction (original word misspelled) of background and normalization were performed. The chemical differences between samples were confirmed using the similarity (Pearson correlation coefficient) and distance (Euclidean distance) indices with cluster analysis and Principal Component Analysis (PCA). Additionally, the preliminary evaluation of the antioxidant activity of the examined extracts of lichens was performed by use of the DPPH TLC test.

Graphical Abstract

Keywords:

• Chemometrics
• DPPH
• fingerprint
• lichens
• TLC
• phenolic compounds