Design, synthesis and biological evaluation of quinoxaline N -propionic and O -propionic hydrazide derivatives as antibacterial and antifungal agents

AbstractNovel series of quinaxoline derivatives incorporatingN-propionic andO-propionic hydrazide moieties were synthesized. Alkylation of 3-methylquinoxalin-2(1H)-one with ethyl 2-bromopropanoate afforded a mixture ofO-alkylated andN-alkylated 3-methylquinoxaline. Hydrazide derivatives were afforded by reaction ofO-alkylated andN-alkylated 3-methylquinoxaline with hydrazine hydrate. Condensation of hydrazide derivatives with different aromatic aldehydes and formylpyrazoles afforded the corresponding hydrazone derivatives. The synthesized quinaxoline derivatives were evaluated for their expected antimicrobial activity; where, the majority of these compounds showed potent antibacterial and antifungal activities against the tested strains of bacteria and fungi. Hydrazone derivative which contain 3-p-tolyl-pyrazolyl moiety showed fourfold potency of amphotericin B in inhibiting the growth ofAspergillus fumigatus, twofold potency of gentamycin in inhibiting the growth ofNeisseriagonorrhoeae, equipotent potency of ampicillin in inhibiting the growth ofStreptococcuspyogenes, equipotent potency of gentamycin in inhibiting the growth ofProteusvulgaris andShigella flexneri, equipotent potency of amphotericin B in inhibiting the growth ofAspergillus clavatus,Geotrichumcandidum andPenicillium marneffei. Thus, these studies suggested that quinaxoline derivatives bearing a pyrazole moiety are interesting scaffolds for the development of novel antibacterial and antifungal agents.

Source: Medicinal Chemistry Research - August 17, 2018 Category: Chemistry Source Type: research