ABSTRACT
Pyrazoles are a class of pharmaceutically important compounds with diverse pharmacological activities. They posses antibiotic, antiviral, anti-inflammatory, and antiamoebic properties. Pyrazofurin, a naturally occurring pyrazole is used clinically as an anticancer agent while Celecoxib, a synthetic pyrazole is used as a non steroidal anti-inflammatory agent. Chalcones, the intermediate product in the synthesis of pyrazoles are also known to posses anticancer, antileishmanial, antimalarial and anti-inflammatory activities.
This research work involved the synthesis of pyrazoles by the condensation of chalcones with hydrazine hydrate in absolute ethanol. The chalcones were synthesized in accordance with the Claisen-Schmidt condensation of equimolar amount of 3, 4, 5-trimethoxy acetophenones and benzaldehydes (2, 4-dimethoxy benzaldehyde and 4-nitro benzaldehyde) in basic methanolic medium.
The synthesized chalcones 1-(3,4,5-trimethoxy phenyl)-3-(2,4-dimethoxyl phenyl)-2-propen-1-one and 1-(3,4,5-trimethoxy phenyl)-3-(4-nitrophenyl)-2-propen-1-one) and the pyrazoles 3-(3,4,5-trimethoxy phenyl)-5-(2,4-dimethoxyl phenyl) pyrazoline and 3-(3,4,5-trimethoxy phenyl)-5-(4-nitro phenyl) pyrazoline) were characterized by spectroscopic techniques such as infrared spectrometry, nuclear magnetic resonance (1H and 13C), mass spectrometry and elemental analysis.
The synthesized compounds were screened for antibacterial and antifungal activities using the agar-well diffusion method. There were no statistical differences in the antifungal activities between the synthesized compounds as the zones of inhibition ranged from 12.5± 0.2mm to13.0 ± 0.3mm for the chalcones and 12.5± 0.4mm to13.0 ± 0.3mm for the pyrazoles .The compounds however lacked both bacteriocidal and bacteriostatic activity against the clinical isolates and typed culture of bacteria tested against.
