TY - JOUR
T1 - Design, synthesis and pharmacological studies of some new quinoline Schiff bases and 2,5-(disubstituted-[1,3,4])-oxadiazoles
AU - Bharadwaj, S. Shashidhar
AU - Poojary, Boja
AU - Madan Kumar, S.
AU - Byrappa, K.
AU - Nagananda, Govinahalli Shivashankara
AU - Chaitanya, Amajala Krishna
AU - Zaveri, Kunal
AU - Yarla, Nagendra Sastry
AU - Shiralgi, Yallappa
AU - Kudva, Avinash K.
AU - Dhananjaya, B. L.
N1 - Publisher Copyright:
© 2017 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
PY - 2017
Y1 - 2017
N2 - Our aim with the present work was to design and synthesize quinoline Schiff bases and quinolinyloxadiazole hybrid molecules and assess them for in vitro antioxidant activities and antimicrobial properties against clinical isolates. Synthesized compounds were characterized using FT-IR, 1H NMR, 13C NMR, mass spectra, and single crystal X-RD techniques. All compounds viz., 4a-g and 5a-g were efficiently synthesized in good yields in ranges of 76-84% and 80-85%, respectively. Newly synthesized compounds were screened for their antioxidant and antimicrobial potentials. Results were compared with standard antibacterial (amoxicillin and streptomycin) and antifungal (fluconazole) compounds which served as positive controls. Compounds 4b and 5g showed free radical scavenging activity of 26.55% (IC50 value 288.38 μg mL-1) and 27.22% (IC50 value of 167.69 μg mL-1), respectively. Compounds 4a, 4f, 5c, and 5e exhibited pronounced antimicrobial activity among all other synthesized compounds with zones of inhibition ranging between 10 ± 1 to 21 ± 1 mm and MIC 17 to 33.5 μg mL-1. Molecular docking studies of the synthesized compounds revealed good binding via hydrogen bond interactions with key residues on active sites as well as neighboring residues with an active site of glucosamine-6-phosphate (G6P) synthase, the target protein which is essential for formation of bacterial or fungal cell walls, and indicating inhibition of G6P synthase. Among the synthesized compounds 4f, 5c, and 5b show the least binding energies of -9.31, -6.7 and -6.21 kcal mol-1, respectively. Results from in silico investigation as well as in vitro antimicrobial studies suggest that the synthesized compounds may act as potential antimicrobial agents.
AB - Our aim with the present work was to design and synthesize quinoline Schiff bases and quinolinyloxadiazole hybrid molecules and assess them for in vitro antioxidant activities and antimicrobial properties against clinical isolates. Synthesized compounds were characterized using FT-IR, 1H NMR, 13C NMR, mass spectra, and single crystal X-RD techniques. All compounds viz., 4a-g and 5a-g were efficiently synthesized in good yields in ranges of 76-84% and 80-85%, respectively. Newly synthesized compounds were screened for their antioxidant and antimicrobial potentials. Results were compared with standard antibacterial (amoxicillin and streptomycin) and antifungal (fluconazole) compounds which served as positive controls. Compounds 4b and 5g showed free radical scavenging activity of 26.55% (IC50 value 288.38 μg mL-1) and 27.22% (IC50 value of 167.69 μg mL-1), respectively. Compounds 4a, 4f, 5c, and 5e exhibited pronounced antimicrobial activity among all other synthesized compounds with zones of inhibition ranging between 10 ± 1 to 21 ± 1 mm and MIC 17 to 33.5 μg mL-1. Molecular docking studies of the synthesized compounds revealed good binding via hydrogen bond interactions with key residues on active sites as well as neighboring residues with an active site of glucosamine-6-phosphate (G6P) synthase, the target protein which is essential for formation of bacterial or fungal cell walls, and indicating inhibition of G6P synthase. Among the synthesized compounds 4f, 5c, and 5b show the least binding energies of -9.31, -6.7 and -6.21 kcal mol-1, respectively. Results from in silico investigation as well as in vitro antimicrobial studies suggest that the synthesized compounds may act as potential antimicrobial agents.
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U2 - 10.1039/c6nj03913h
DO - 10.1039/c6nj03913h
M3 - Article
AN - SCOPUS:85027054959
SN - 1144-0546
VL - 41
SP - 8568
EP - 8585
JO - New Journal of Chemistry
JF - New Journal of Chemistry
IS - 16
ER -