Abstract:
Background: Plant based medicines have over the years contributed to treat diseases and
illnesses. Infectious diseases have become a leading cause for premature deaths worldwide.
Evidence based validation of medicinal plants is the need of the day for developing better
and safe antimicrobial agents. Chromatography is a significant analytical technique that
plays an important role in natural product chemistry and it helps finding new therapeutic
agents. Croton tiglium is a plant belongs to the family Euphorbiaceae that has a long role as
traditional medicine.
Objectives: The current study was focused on the fractionation of crude ethyl acetate extract
of C. tiglium, step by step visual demonstration of fractions and screening of antibacterial
activity of those fractions.
Methodology: Crude extract was fractionated using a silica gel column chromatography
eluted with hexane and ethyl acetate in stepwise gradients with increasing polarity.
Antibacterial activity was evaluated by resazurin-based broth microdilution method against
three bacterial strains; Staphylococcus aureus, Escherichia coli and Pseudomonas
aeruginosa.
Results and conclusions: According to the results obtained, six fractions exhibited
significant antibacterial activity against S. aureus and P. aeruginosa with minimum
inhibitory concentration (MIC) in the range of 62.5- 125 µg/mL. Interestingly, four fractions
showed significant activity against S. aureus while five fractions showed significant activity
against P. aeruginosa. The high-performance liquid chromatography (HPLC) and nuclear
magnetic resonance (NMR) data indicated the presence of low-polar metabolites in the
extract; Thus, further studies are needed to isolate, purify and elucidate the structures of
these metabolites.