Synthesis and antibacterial profile of novel azomethine derivatives of β-phenylacrolein moiety

Purpose: To develop some novel molecules effective against antibiotic-resistant bacterial infections.Methods: A series of azomethines (SB-1 to SB-6) were synthesized from β-phenyl acrolein moiety. The structures of the synthesized compounds were confirmed on the basis of their UV ultra-violet (UV) spectroscopy (λmax: 200 - 400 nm), Fourier transform infra-red (FTIR, vibrational frequency: 500-4000 cm-1), 1H nuclear magnetic resonance (NMR, chemical shift: 0 - 10 ppm), 13C NMR (chemical shift: 0 - 200 ppm), mass spectrometry (m/z values: 0 - 500) and carbon hydrogen nitrogen (CHN) elemental analysis. The new compounds were screened for antibacterial activity by test-tube dilution and disc diffusion methods using gentamicin as reference standard.Results: The structures of azomethine were in full agreement with their spectral data. Among all the synthesized compounds, compounds SB-5 and SB-6 exhibited the highest minimum inhibitory concentration (MIC) of 62.5 μg/mL. At MIC of 250 μg/mL, all compounds SB-1 to SB-6 displayed significant antibacterial activity, compared to gentamycin (p < 0.05). SB-5 and SB-6 were active against S. aureus, P. aeruginosa and K. pneumoniae; SB-3 was active against B. subtilis and S. aureus. SB-4 was active against P. aeruginosa and S. aureus while SB-1 and SB-2 were active against S. aureus.Conclusion: The synthesized compounds possess antibacterial activities compared to those of gentamycin.Keywords: Acrolein, Imines, Azomethine, Antibacterial, Gentamycin, Minimum inhibitory concentratio

Development and Validation of a lc-ms/ms Method for the Determination of Raltegravir in Sprague Dawley Rat Serum and Its Application to Pharmacokinetic Study

Abstract A novel bio-analytical method was developed and validated for the quantitative determination of raltegravir in rat serum by using the liquid-liquid extraction chromatography and tandem mass spectrometric detection (HPLC-MS/MS). Separation of raltegravir from the endogenous substances is achieved after liquid-liquid extraction by using HPLC-MS/MS system. Raltegravir was eluted in isocratic mode with acetonitrile, methanol and 0.1% acetic acid in water ( 40:30:30) at a flow-rate of 0.5 mL/min on Waters, Exterra C18, 50*4.6 mm, 5µm particle size column. Didanosine was used as the internal standard. The liquid-liquid extraction recovery was found 70% indicates good recovery. The validation results demonstrated that the present method was found to be precise and accurate. The stability tests indicated that the raltegravir in rat serum is stable for three freeze-thaw cycles at both -20 ºC and -70 ºC, 18-h ambient storage, 15-day frozen storage at both -20 ºC and -70 ºC. The results also showed no significant matrix effect (<6.2%). The present method was found to be sensitive and selective at very low levels of linearity range 1-1000 ng/mL, based on a sample volume of 50 µL, with a linear correlation coefficient of ≥ 0.99. The validated method has been successfully applied to support a preclinical pharmacokinetic study

QUANTITATIVE ESTIMATION AND ANTIMICROBIAL POTENTIAL OF ETHANOL EXTRACT OF DURIO ZIBETHINUS MURR. LEAVES

Objectives: Current research is aimed to investigate the natural antimicrobial potential of Durio zibethinus murr. ethanol leaves extract (DZL).Methods: DZL was subjected to the preliminary phytochemical screening along with quantitative analysis of phenols and flavonoids. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were recorded. The agar well diffusion method was used to measure the antibacterial activity against gram positive and gram negative bacteria. The microorganisms used for the study were the ATCC strains of Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Streptococcus pyogenes, Neisseria gonorrhoeae, Pseudomonas aeruginosa and Escherichia coli.Results: DZL exhibited the highest MIC of 0.1mg/mL and MBC of 0.25 mg/mL against gram negative bacteria, Pseudomonas aeruginosa and Escherichia coli. At MIC of 0.1mg/mL, DZL displayed significant zone of inhibition against Pseudomonas aeruginosa and Escherichia coli compared to gentamycin.Conclusion: This research has shown that DZL has natural antibacterial properties against gram negative human pathogens