Microwave Assisted Synthesis and Antimicrobial Potential of Quinoline‐Based 4‐Hydrazide‐Hydrazone Derivatives

Abstract

Quinoline is a benzo‐fused pyridine which is a therapeutically important heterocycle in medicinal chemistry research and new drug development. A series of 12 new hydrazide‐hydrazone motifs bearing quinoline core 4a–l was successfully synthesized by microwave irradiation technique. The synthesis involved four steps strategies which was initiated by ring‐opening synthetic modification of isatin to quinoline‐4‐carboxylic acid through Pfitzinger approach. The structure of the reactive intermediates 1, 2, and 3 as well as the targeted quinoline 4a–l were confirmed by the result of physicochemical parameters and spectroscopic means which include FTIR, UV, 1H and 13C NMR as well as DEPT 135 NMR. The in vitro antimicrobial screening of the targeted hydrazide‐hydrazones 4a–l alongside with gentamicin (clinical standard) against six microorganisms was determined using agar diffusion. The result from the MIC test showed that this series of hydrazide‐hydrazones exhibited remarkable efficacy as antimicrobial agents with 4e being the most active antibacterial agent with MIC value ranging from 3.13 to 0.39 μg/mL on the six organisms tested.

Hybrid Quinoline-Sulfonamide Complexes (M2+) Derivatives with Antimicrobial Activity

“…Having in view the biological potential of quinoline and sulfonamide scaffolds (especially antimicrobial) [9][10][11][12][13][14][15], as well as those one of quinoline-sulfonamide combined scaffold (especially anti-HIV-1) [16], we decide to combine the pharmacophoric properties of these core scaffolds with the complementary biological properties of counter cation M 2+ (M 2+ : Zn 2+ , Cu 2+ , Co 2+ and Cd 2+ ), with the final goal of obtaining better biological activity and better pharmacokinetic properties for our compounds. In this respect, we design two new classes of hybrid quinoline-sulfonamide complexes, namely N-(quinolin-8-yl)-4-R-benzene sulfonamide metal (II) (QBSC) and N-(quinolin-8-yl)-quinoline -8-sulfonamide metal (II) (QQSC), Scheme 1.…”

Coumarins: The Antimicrobial agents

“…Olayinka O. Ajani et al reported synthesis and biological activities of some substituted coumarins All the compounds (1,2,3,4) showed good activity against Staphylococcus aureus and Escherichia coli and, Bacillus subtilis. 33 Al-Amiery et al have synthesized 4-[(5-mercapto-4-phenyl-4H-1,2,4triazol-3-yl)-methoxy]-2H-chromen-2-one as coumarin derivatives and their antifungal activity was determined based on the growth inhibition rates of the mycelia of strains of Aspergillus niger and Candida albicans in Potato Dextrose Broth medium (PDB) against concentrations ranging from 10 to 100µgml -1 . Two compounds (5,6) showed good activity as antifungals against fluconazole standard drug.…”

Microwave Assisted Reactions of Azaheterocycles Formedicinal Chemistry Applications

“…Ajani et al [55] synthesized a new class of quinolines (62a-l) bearing hydrazide-hydrazone moiety, while using MW assisted reactions, in continuation of their work in the field of antimicrobial derivatives. The reactions under MW allowed for them to obtain very good yields, high purity of compounds, and a very short reaction time (1-3 min).…”