Acta Pharm. 64 (2014) 335-344
Original research paper
Novel ethyl
1,5-disubstituted-1H-pyrazole-3-carboxylates as a new class of
antimicrobial agents
AWWAD A.
RADWAN, MOSTAFA M. GHORAB, MANSOUR S. ALSAID and FARES K. ALANAZI
mmsghorab@yahoo.com;
dhna_2001@hotmail.com
1
Department
of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457,
Riyadh 11451, Saudi Arabia
2
Department
of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Assiut University,
Assiut-71527, Egypt
3 Department of
Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, P.O. 2457,
Riyadh 11451, Saudi Arabia
4 Department of Drug Radiation Research, National
Centre For Radiation Research and Technology, Atomic Energy Authority, P.O. Box
29, Nasr City, Cairo, Egypt
Accepted May 15, 2014
A series of pyrazole derivatives 9-22 were designed and synthesized. All the newly synthesized compounds were assayed for their antimicrobial activity against the Gram-positive bacteria Staphyllococcus aureus and Bacillius subtilis and the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, in addition to the fungi organisms, Candida albicans, C. parapsilosis and C. tropicalis. Ethyl 5-(2,5-dimethylthiophen-3-yl)-1-phenyl-1H-pyrazole-3-carboxylate (21) (MICE.coli =0.038 µmol mL–1, MICP. aerug = 0.067 µmol mL–1) is nearly as active as ampicillin (MIC = 0.033 and 0.067 µmol mL–1, respectively). Ethyl 5-(4-bromo-2-chlorophenyl)-1-phenyl-1H-pyrazole-3-carboxylate (16) (MIC = 0.015 µmol mL–1) is more active than fluconazole (0.020 µmol mL–1) as a reference drug against C. parapsilosis.
Keywords: pyrazole-3-carboxylates, antimicrobial screening