Activity and mechanism of the action of zeylasterone against Bacillus subtilis

Abstract

Aims: To investigate the antimicrobial properties of 6‐oxophenolic triterpenoids isolated from Maytenus blepharodes against different micro‐organisms and the mode of action on Bacillus subtilis. Methods and Results: The activity of zeylasterone and demethylzeylasterone was evaluated by microdilution method. Zeylasterone showed a higher activity, being active against Gram‐positive bacteria (minimum inhibitory concentration 3–20 μg ml−1) and Candida albicans (10 μg ml−1). Killing curves revealed a bacteriostatic effect on B. subtilis that was dependent on the growth phase and inoculum size. Zeylasterone caused cell membrane alterations in B. subtilis, as shown by potassium leakage and formation of mesosome‐like structures. However, membrane disruption was not revealed by either LIVE/DEAD Baclight assay or measurement of intracellular constituent efflux. Zeylasterone showed an early effect on N‐acetyl‐glucosamine and uridine incorporation and later on that of thymidine and leucine. Conclusions: Diverse micro‐organisms exhibit sensitivities towards compounds studied. The permeability changes in the cytoplasmic membrane and nonsimultaneous ceasing of macromolecular synthesis suggest that zeylasterone could act on multiple targets on B. subtilis. Significance and Impact of the Study: The activity showed against B. subtilis as a model of spore‐forming bacteria would provide valuable information for further studies in the development of 6‐oxophenolic triterpenoids as antiseptic and disinfectant properties.

Effect of the derivatives of andrographolide on the morphology of Bacillus subtilis

“…Treating B. subtilis with a series of 6-oxophenolic triterpenoids (zeylasteral, demethylzeylasteral and zeylasterone) isolated from Maytenus blepharodes Lundell resulted in abnormally long cells (De León et al, 2005;De León and Moujir, 2008) and multiseptate filaments (De León et al, 2005). The compounds were found to damage the cytoplasmic membrane and compromise cell wall synthesis, leading to loss of cytoplasmic material.…”

“…Previously, several antibacterial compounds from natural products had been reported to cause cell elongation or filamentation in B. subtilis (Beuria et al, 2005;De León et al, 2005;Jaiswal et al, 2007;De León and Moujir, 2008). Treating B. subtilis with a series of 6-oxophenolic triterpenoids (zeylasteral, demethylzeylasteral and zeylasterone) isolated from Maytenus blepharodes Lundell resulted in abnormally long cells (De León et al, 2005;De León and Moujir, 2008) and multiseptate filaments (De León et al, 2005).…”

Characterization and Evaluation of the Ag+‐Loaded Soy Protein Isolate‐Based Bactericidal Film‐Forming Dispersion and Films

“…Another method is to plate the bacteriocin onto the resin film. The metal ions may destroy the cell membrane of the bacterial cells (de León and Moujir 2008). Both the silver (Ag) ions and Ag nanoparticles in food packages have attracted great interest in recent years due to the significant antimicrobial effects of this material (Lok and others 2007; An and others 2008; Miura and Shinohara 2009).…”

Evaluation of the anti-Listeria potentials of some plant-derived triterpenes

“…The mechanism of action of some triterpenoids against Gram positive bacteria have also been shown to be a combination of plasma membrane disruption and inhibition of macromolecular synthesis such as RNA synthesis [[32]]. A study by Cristani et al .…”