4.1 General Remarks:
Most of the reactions were carried out in oven dried glass wares with magnetic stirrer and and reflux condenser using freshly solvents. Reactions are monitored on aluminium coated thin layer chromatography (TLC) with UV light and iodine as developing agents. Melting points were determined on melting point apparatus. Proton magnetic spectra were recorded on Brucker 400MHz spectrometers using tetramethylsilane (TMS) as internal standard. Chemical shifts has been expressed in δ values downfield from TMS, multiplicity of NMR signal is designated as s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet).Infrared spectra were recorded on Agilent Technologies FT-IR spectrophotometer. All solvents and reagents were purified
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4 Melting point Sentwin India
5 NMR Bruker Advance II 400MHz
7 Heating Mantle Inco
6 Structure builder Chem draw Ultra 8.0
4.2 Experimental work:
4.2.1 General procedure for Chalcones:
2’-hydroxy acetophenone or 2’-hydroxy propiophenone (0.2ml) and substituted benzaldehydes (0.5 g) were mixed in the round bottom flask. After that 40% NaOH solution (4g NaOH in 10 ml of distilled water) and ethanol were added in round bottom flask. The reaction mixture was stirred upto 6-48 hours. Completion of reaction was monitored in TLC plate (n-Hexane: Ethyl acetate 9:1). The reaction mixture was poured into ice cold water acidify with 1% HCl and precipitates were collected, filtered and dried and recrystalized with ethanol.
4.2.2 General procedure for synthesis of flavones:
50mg of chalcone was taken in round bottom flask. After that 15-20 ml of DMSO was added and mixed properly, 5-6 granules of iodine were added and reflux the reaction mixture up to 3-6 hours and kept for overnight. Then reaction mixture was poured into ice water and the precipitates were neutralized with sodium thiosulphate, to remove the unreacted iodine, washed with water, filtered, dried and recrystalized with
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In vitro susceptibility tests are done by the following methods:
1) Agar diffusion method
2) Tube dilution method
3) Micro-dilution method
4.3.2 Protocol:
Synthesized compounds were assessed for their antibacterial activity using Agar diffusion method. Antibacterial activity of the compounds was carried out against pathogenic bacterial strains namely E.Coli: ATCC 50992 (Gram-ve), Staphylococcus aureus: ATCC 29213 (Gram+ve), Pseudomonas aureginosa: ATCC 27853 (Gram+ve), Bacillus subtilis: ATCC 10231(Gram- ve).
The antibacterial activity of the compounds was determined by observing the zone of inhibition in the comparison to standard antibiotic Ciprofloxacin.
Test compounds were dissolved in the DMSO to make a stock solution of 1000 ppm (1mg dissolved in 1ml DMSO).
The fresh subculture of strains in the normal saline was added to the sterile assay medium (Nutrient agar) at 40-45°C and mixed well.
The medium was poured in to each of the petridishes. Sterile discs of diameter 6mm were