Multi-targeted quinazolinone-Schiff's bases as potent bio-therapeutics
B.J. Ullas, K.P. Rakesh, Jala Shivakumar, D. Channe Gowda, Paduvalahippe Gowdegowda Chandrashekara
Abstract
Two series of quinazolinone derived Schiff's bases were synthesized and characterized by analytical and spectroscopic techniques. All the compounds were screened for their in vitro biological studies. The in vitro antioxidant activities of these compounds were evaluated employing 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline-6-sufonic acid) (ABTS+) and N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD+) radical assay. The results revealed that compounds 31 (IC50: 35 μg/mL) and 32 (IC50: 40 μg/mL) showed excellent antioxidant activity and their IC50 is lower than the IC50 of standards such as butylated hydroxyl anisole, ascorbic acid and gallic acid in all the three performed assays. In anti-inflammatory activity, compounds 7–26 (IC50: 10-35 μg/mL) showed extraordinary activity compared to standards indomethacin (IC50: 40 μg/mL) and ibuprofen (IC50: 65 μg/mL). In antimicrobial activity, compounds 25–42 shows potent antibacterial activity and compounds 25–42 shows potent antifungal activity compared to standards streptomycin (ZoI: 10 mm) and bavistin (ZoI:10 mm) respectively. To study the structure activity relationship (SAR), electron donating groups (-OH and -OCH3) favors the antioxidant activity, electron withdrawing groups (F, Cl, Br and -NO2) favors the anti-inflammatory activity, and both electron donating (-OH and -OCH3) and electron withdrawing (F, Cl, Br and -NO2) groups (25–32) or heterocyclic moiety (33–42) favors antimicrobial activity.