To begin, preheat an oil bath to 80 degrees Celsius on a hot plate with a magnetic stirrer. Then with the help of a tube retort stand, half immerse the round bottom flask in the oil bath. Seal the upper mouth of the flask with a cork containing a purging needle connected to a syringe and an attached nitrogen balloon.
Tightly seal the other neck of the flask to prevent the leakage of nitrogen from the reaction medium. Preheat the entire assembly to 80 degrees Celsius in an inert atmosphere maintained through nitrogen purging. Pour 0.1 molar quinoline and 0.105 molar 1-bromohexadecane into the reaction system.
Stir the mixture continuously at 2, 500 to 3, 000 RPM for three days under an inert environment and constant temperature. Next, dissolve the obtained solid in a one is to two toluene ethyl ethanoate mixture. Cool the mixture to minus 15 degrees Celsius in a deep freezer.
To filter the mixture, attach a Buchner funnel to a vacuum pump and a filter flask through tubing. Place a polypropylene filter membrane with a pore size of 0.45 micrometers at the bottom of the funnel. Pour a small amount of the solvent mixture through the filter to create a proper seal.
After filtering, gradually pour cold toluene through the funnel to wash the filtered product. Measure one to 10 milligrams of the compound and dissolve it in one milliliter of deuterated chloroform. Using a one milliliter syringe, inject the dissolved compound into an NMR tube.
To predict ADMET properties, open the ADMET Lab 2.0 software and enter the canonical SMILES of the desired ionic liquid. Execute the program to obtain various parameters validating the biological potential of the compound. Subculture fungal strain of Candida albicans in yeast peptone dextrose broth for 16 hours at 37 degrees Celsius under shaking.
Meanwhile, pour 25 milliliters of freshly prepared yeast peptone dextrose containing 15%agar into a 90 millimeter Petri plate, and allow the medium to solidify. Using a glass spreader spread approximately 100 microliters of freshly prepared fungal inoculum over the media surface. After five to seven minutes, use forceps to place a sterile circular paper disc of five to six millimeters in the center of the plate.
Add 50 microliters of 0.1 millimolar synthesized ionic liquid water as solvent control and amphotericin B as positive control onto the disc. Place the plate in a refrigerator for 30 minutes to ensure proper diffusion of the ionic liquid into the agar. Incubate the plate at 37 degrees Celsius for 24 hours.
The next day, use a scale to measure the zone of inhibition. Using the given formula, calculate the area under the zone of inhibition. In the proton NMR spectra, the 1-hexadecylquinolin-1-ium-bromide product exhibited the expected proton signals at delta values of 9.34 and 7.20 confirming the structure of the synthesized compound.
The carbon 13 NMR spectra of 1-hexadecylquinolin-1-ium-bromide demonstrated clear signals at delta 143, 131, and 29 PPM. The compound exhibited significant antifungal potential against Candida albicans as demonstrated by a pronounced zone of inhibition in the disc diffusion assay.
