Bactericidal Activity and Structural Studies of the Steviol Derivative 17- Hydroxy-16-hydroxyiminobayeran-19-oic Acid

Abstract

Background: According to the World Health Organization (WHO), the routine use of antibiotics has led to the increase of microbial resistance. Thus, the search for new compounds that present antimicrobial activity must be constant. This study reports the bactericidal activity assay of the steviol derivative 17-hydroxy-16-hydroxyiminobayeran-19-oic acid against various bacteria and structural studies by quantum chemistry and molecular dynamics. Methods: Bactericidal activity assays of the steviol derivative 17-hydroxy-16-hydroxyiminobayeran-19- oic acid against Salmonella typhimurium [ATCC 14028], Staphylococcus aureus [ATCC 6538], Bacillus cereus [ATCC 11778], Helicobacter pylori [ATCC 26695], Pseudomonas aeruginosa [ATCC 27853], Escherichia coli [ATCC 25922] and Bacillus subtilis [ATCC 23857] were performed, as well as structural studies by quantum chemistry and molecular dynamics. Results: The results show that the compound exhibits activity towards S. typhimurium, what makes it an interesting compound for future studies on the development of antibiotics against this bacteria. An intramolecular hydrogen bond does not seem to be maintained in solution, therefore, corresponding moieties should be prone to interactions with their surroundings. Conclusions: The results indicate that the title compound exhibits activity towards S. typhimurium, what sums up to similar results from other steviol derivatives and stevioside, thus reinforcing the potential of these compounds for future studies on the development of antibiotics against this bacteria. The potential energy surface for the selected torsion angles and molecular dynamics have revealed that an intramolecular hydrogen bond, though slightly energetically favorable, does not seem to be maintained in solution; therefore, corresponding moieties should be prone to interactions with their surroundings, an important feature in further studies involving inhibitor/drug design from this compound.