Microwave assisted extraction, phytochemical and antimicrobial evaluation of ethyl acetate extracts of stem bark of Ficus exasperata (Vahl)

Stem bark of Ficus exasperata was extracted using ethyl acetate by microwave-assisted solvent extraction. Phytochemical screening and antimicrobial evaluation were carried out on the extract. Phytochemical screening revealed the presence of cardiac glycosides, tannins, flavonoids, triterpenes and steroids. Antimicrobial evaluation revealed that the extract is active against Methicillin – resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus pneumoniae, Salmonella typhi, Proteus mirabilis, Shigella dysenteriae, Candida stellatoidea and Candida tropicalis. The zones of inhibition (mm) for the test organisms were (24 - 31) mm. Minimum inhibition concentrations (mg/L) of extract against MRSA, Staphylococcus aureus, Streptococcus pneumonia, Salmonella typhi, Proteus mirabilis, Shigella dysenteriae, Candida stellatoidea and Candida tropicalis were 2.5, 1.25,1.25, 2.5, 1.25, 1.25, 1.25 and 2.5 respectively. Minimum bactericidal concentrations (mg/L) of extract against Methicillin – resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus pneumonia, Salmonella typhi, Proteus mirabilis Shigella dysenteriae Candida stellatoidea and Candida tropicalis were 5, 2.5, 2.5, 5, 5, 2.5,2.5 and 5 respectively. The extract showed high inhibition against MRSA and Candida tropicalis.

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF SOME NEW OXAZINE DERIVATIVES DERIVED FROM COUMARINYL CHALCONES

A series of novel substituted 3-(2-amino-6-phenyl-6H-1,3-oxazin-4-yl)-2H-chromen-2-ones(AO1-AO10) was synthesized upon refluxing ethanolic solution of substituted 3-cinnamoyl-2H chromen-2-one with urea in presence of 20 % NaOH. The intermediate chalcones, substituted 3-cinnamoyl-2H-chromen2-ones, were synthesized by condensing 3-acetyl coumarin with various substituted benzaldehydes in presence of 20 % NaOH. The structures of the final synthesized compounds were characterized by UV, IR, 1 H NMR and mass spectra. The antibacterial activity of the synthesized compounds was estimated by tube dilution method. The turbidity was observed for the synthesized compounds. Few compounds showed promising minimum inhibitory concentration by tube dilution method.

SYNTHESIS, MOLECULAR BIOINFORMATICS MODELLING, AND ANTIMICROBIAL EVALUATION OF SOME NOVEL OXADIAZOLE FLUOROQUINOLONE DERIVATIVES

Objective: The present study envisages a series of oxadiazole fluoroquinolone derivatives that were synthesized (D1–D12) with added derivatives such as phenyl, aminophenyl, amino hydroxyphenyl along with cyclopropyl, ethyl, piperazine, and imidazole. Methods: All of the newly produced molecules were characterized by infrared, 1H nuclear magnetic resonance, mass spectrometry, and elemental analysis technique and screened for docking stimulation to find out binding modes of synthesized derivatives with 3FV5, 5IMW, and 5ESE and evaluated for in vitro antimicrobial activity. Results: From this study, it was found that the compound D8 showed good antibacterial activity against Gram-positive (Staphylococcus aureus), compound D9 showed good antibacterial activity against Gram-negative (Escherichia coli), and compound D3 showed good antifungal activity against fungi (Saccharomyces cerevisiae) in comparison with standard drugs (Ciprofloxacin and fluconazole). The zone of inhibition and minimum inhibitory concentration studies was performed on synthesized compounds. Conclusion: The analogs of oxadiazole flouroquinolone are suggested to be potent inhibitors with sufficient scope for further exploration.

Novel topical combo-therapeutic formulation integrating honey, neomycin and bacitracin for diabetic wound management

This study evaluated the healing effects of honey as a topical therapy for diabetic ulcers singly and in combination with bacitracin and neomycin (Cicatrin®), formulated as ointments in experimental rats. Antimicrobial evaluation of the test agents against Vancomycin and Oxacillin resistant Staphylococcus aureus (VORSA) and Pseudomonas aeruginosa was done by the cup plate agar-diffusion technique using the Checkerboard method. Subsequently, the optimized combination was formulated into an ointment and administered as single therapy and in combination to hyperglycemic rats made diabetic by subcutaneous injection of alloxan (130 mg/kg) and inflicted with wounds. Administration was done daily on wounds for 21 days while infected wounds had the pus from them evaluated for presence of VORSA and Pseudomonas aeruginosa. The triple combo-therapeutics formulation had improved anti-bacterial activity, in comparison with the individual formulations, with the ratio (1:9) of Cicatrin®: Honey respectively giving the best activity against VORSA. Also, the triple combo-therapeutics exhibited positive wound contraction and size reduction. Furthermore, clinical signs of infection were absent at the end of the follow-up period in the rats administered the combo-therapeutic agents while other groups of rats administered the bland ointment, and the individual agents were infected with either Pseudomonas aeruginosa or VORSA. In addition, the triple combo-therapeutics formulation exhibited good physicochemical stability throughout the treatment duration and beyond (28 days), with insignificant (p > 0.05) changes in pH and spreadability. The triple combination therapeutics formulation showed superior effect to the singly administered agents (honey and Cicatrin®) in the management of diabetic wounds

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF SOME NEW BENZTHIAZOLE OXIME ETHER DERIVATIVES

Some new oxime ether derivatives containing benzthiazole heterocyclic nuclei are synthesized. The reaction of 2-mercapto benzthiazole with α-halo ketones followed by reaction with hydroxylamine gave oxime derivatives which on reaction with alkyl halides viz. ethyl chloride, n-propyl chloride, and n-butyl chloride in absolute ethanol afforded the target compounds 4a-l. The structure of all the synthesized compounds was confirmed by spectroscopic methods like mass and NMR. All compounds after structural confirmation were tested for biological activities.