Antibacterial activity of a bifunctionalized allene Ethanol extracts

Research Article
Ignatova-Ivanova TS, Ivelina Stefanova, Ismail E. Ismailov, Ivaylo K. Ivanov and Valerij Ch. Christov
BA-2 (Dimethyl 1-(1- hydroxyethyl)-3-methylpenta-1,2- dienephosphonate), antibacterial activity, antibiotic.

Background and Purpose: Antibacterial effects of a Bifunctionalized Allene with unprotected hydroxygroup (Dimethyl 1-(1-hydroxyethyl)-3-methylpenta-1,2-dienephosphonate) (BA-2) on pathogenic Grampositives and Gram-negatives bacteria had been established. BA-2 (50mg/ml, 25mg/ml, 12.5mg/ml,6.25mg/ml and 3.125mg/ml) exerted different inhibitory effect on different bacterial cells in vitro. The effects of BA-2 on prokaryotic cells have not been studied. The present study was aimed to assess the antibacterial activity of BA-2 on pathogenic Gram-positive and Gram-negative bacteria.Experimental approach: In vitro antimicrobial test: Escherichia coli 3398, Staphylococus aureus 745, Bacillus subtilis 6633, Salmonella Typhymurium 3591, Listeria monocytogen 863 and Enterobacter aerogenes 3691were treated for 24 hours with BA-2 (50mg/ml, 25mg/ml, 12.5mg/ml, 6.25mg/ml and 3.125mg/ml),Sefpotec (250 mg/ml).The antibacterialactivity was assayed by the well iffusionmethodwith digital caliper.Determination of minimum inhibitory concentrations(MICs): The MIC of BA-2, that shows antimicrobial activity, were determined by methods as described by [16] and MICs wereread in μg/ml after over night incubation at 37oC. All experiments were made in replicate.Determinationof Minimum bacteriocidal concentration(MBC): The MBC were carried out to check whetherthe testmicrobes were killed or only their growth was inhibited. Nutrient Agaragar was preparedand sterilized at121oC for 15 minutes, the medium waspoured into sterile petridishes and were allowed tocool and solidify.The contents of the MIC in the serial dilution were then subcultured onto the prepared medium, incubationwas made at 37oC for24 h, after which each plate was observed forcolony growth. The lowestconcentration of the BA-2 without a colony growth was recorded asthe MBC. BA-2had higherantibacterial activity than tested antibiotic– Sefpotec.Key Results: The results revealed variability in the inhibitory concentrations of BA-2 for given bacteria.BA-2 at concentration 50 mg/ml for 24 hours notably inhibited growth of Е. aerogenes 3691(25.52 mmmean zone of inhibition), E. coli 3398 (30.48 mm mean zone of inhibition) and S. Typhymurium 745(21.22 mm mean zone of inhibition). On the contrary, BA-2 had no activity against L. monocytogen 863(17.39 mm mean zone of inhibition), which are comparable to the inhibitory effectof standard drug. BA-2did not inhibited S. aureus 745 and B. subtilis 6633.Conclusions and Implications: Based on the results obtained we can conclude that the examined BA-2has bactericidal activity towards pathogenic bacteria, but in different concentrations.The BA-2 possesses biological activity, which is not well studied. We know only from literary data that
they are used for inhibiting the biosynthesis of sterol from the pathogen responsible for Pneumocystiscarinii pneumonia (PCP) -a disease similar to AIDS[1]. In our previous studies was shown that theBifunctionalized Allene with protected hydroxy group (Dimethyl 3-methyl-1-[1-(tetrahydro-2H-pyran-2-yloxy)-ethyl]-hepta-1,2-dienephosphonate) (BA-1) exhibited antibacterial [10] and antifungal activity[11]. The results obtained show for the first time the existence of antibacterial activity of BA-2 towardsvarious pathogenic bacteria.