Title:Facile Synthesis, Antimicrobial Studies and Structure - Activity Relationship Studies of Some Novel Pyrazole Analogs
VOLUME: 15 ISSUE: 1
Author(s):Sony Jacob K.* and Swastika Ganguly
Affiliation:Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi - 835215, Jharkhand, Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi -835215, Jharkhand
Keywords:Pyrazole, anti-bacterial activity, anti-fungal activity, broad spectrum chemotherapeutic agents.
Abstract:Background: The pyrazole moiety hold a unique position in heterocyclic chemistry. Novel
pyrazole scaffolds with more potency can be very effective against resistant strains of various microorganisms.
Objective: To carry out the synthesis, characterization and antimicrobial screening of novel 3, 5 dimethyl
pyrazole analogs.
Method: A series of novel pyrazole scaffolds were synthesized by treating 3, 5 dimethyl pyrazole with
various propionamide under nitrogen atmosphere. Compounds were evaluated for their in vitro antibacterial
activity in comparison to ciprofloxacin and norfloxacin, against both Gram-positive (S.aureus,
B.subtilis) and Gram-negative (E.coli, P.aeruginosa, S.typhi, K.pneumonia) bacteria. They were also
screened for their antifungal activity against C.albicans and A.niger using fluconazole as a standard
drug.
Results: The structures of synthesized pyrazole analogs were successfully elucidated using their 1H
NMR, Mass, IR, elemental analysis data. Compounds 28 and 29 showed a relatively good inhibitory
profile against both Gram-positive and Gram-negative bacteria. Compound 21, 28 and 29 were found to
be more active against both Gram-positive bacteria and compound 26, 28, 29, and 38 exhibited good inhibitory
activity against all Gram-negative bacteria. Antifungal screening results showed that compounds
20, 22, 25, 26, 27, 30, 31, 32, 33, 36 and 37 were equally potent when compared to fluconazole.
Thus, from the results of anti-microbial screening data, it was evident that the presence of a halogen
group at different positions of the aromatic ring was responsible for their potency.
Conclusion: These newly synthesized pyrazole analogs are better scaffolds to be developed as broad
spectrum chemotherapeutic agents.
