Synthesis, characterisation & useful therapeutic activity of novel 2-quinolone derivatives

A series of novel 2-oxo-1,2,3,4-Tetrahydroquinolin-7-yl benzoate derivatives were synthesised and obtained in moderate yields (55-85%) by the reaction of parent 7-hydroxy-1,2,3,4-Tetrahydroquinolin- 2-one (7-hydroxy-3,4-dihydroquinolin-2(1H)-one) with substituted benzoyl chlorides. The synthesised test compounds were characterised by spectral analysis. Partition coefficient was determined for all test compounds and was found to be in the range of 1.2-2.9. Further, the compounds were screened for their antibacterial and antioxidant activities. They were also randomly screened for their antidiabetic potential by non-enzymatic glycosylation of haemoglobin assay. However, the results revealed that test compounds did not possess antioxidant and antidiabetic potential comparable to that of their respective standards. The results also revealed that most of the compounds exhibited antibacterial action against four bacterial strains namely Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Further, the test compound VIIl (at 500 μg mL-1), showed zone of inhibition comparable to that of the standard ciprofloxacin (at 500 μg mL-1).