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Updated: Sep 5, 2025
Thin-layer Chromatographic TLC Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds
Published on: March 27, 2014
The bioprofiling of antibacterials in olive leaf extracts via thin layer chromatography-effect directed analysis
Snezana Agatonovic-Kustrin1, Vladimir Gegechkori2, David W Morton1
1Department of Pharmaceutical and Toxicological Chemistry named after Arzamastsev of the Institute of Pharmacy, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow 119991, Russia; Department of Pharmacy and Biomedical Sciences, La Trobe University, Edwards Rd, Bendigo 3550, Australia.
Abstract:
In this study, effect-directed analysis (EDA) (i.e. TLC hyphenated with an in situ MTT (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) antimicrobial assay), was used for screening and identification of antimicrobials in olive leaf extract. EDA detected that the same compounds exhibited significant antimicrobial activity against bacterial species of the genera Enterococcus (E. faecalis), Escherichia (E. coli), Streptococcus (S. mutans) and Staphylococcus (S. aureus). Flash chromatography-fractionation was used to isolate antimicrobial compounds in olive leaf extract. The active compounds were identified as maslinic acid and oleanolic acid by comparing RF values of the detected active bands with the standard reference materials, with identity confirmed with NMR and ATR-FTIR spectroscopy. Maslinic and oleanolic acids were tested on the E. faecalis strain (which displayed the highest sensitivity in the MTT assay) to determine their inhibiting concentration 50% (IC50) and minimum bactericidal concentrations.
