ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and antimicrobial activity of sulphamethoxazole-based ureas and imidazolidine-2,4,5-triones

Martin Krátký, Jana Mandíková, František Trejtnar, Vladimír Buchta, Jiřina Stolaříková, and Jarmila Vinšová

Department of Inorganic and Organic Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic

E-mail: martin.kratky@faf.cuni.cz

Abstract: Progression of drug resistance among bacterial and fungal pathogens justifies the development of novel antimicrobial agents. Thus, a series of novel sulphamethoxazole-based ureas and imidazolidine- 2,4,5-triones have been designed and synthesised. The urea derivatives were obtained by the reaction of sulphamethoxazole and isocyanates, and their cyclisation to imidazolidine-2,4,5-triones was performed via oxalyl chloride. All synthesised derivatives were evaluated in vitro to determine their activity against gram-positive and gram-negative bacteria, fungi, Mycobacterium tuberculosis, and atypical mycobacteria and their cytotoxicity. The growth of mycobacteria was inhibited within the range of 4-1000 μM and M. tuberculosis was the least-susceptible strain. 4-(3-Heptylureido)- N-(5-methylisoxazol-3-yl)benzenesulphonamide was identified as the most promising compound because it exhibited the highest activity against atypical mycobacteria at minimum inhibitory concentrations, from 4 μM, and with acceptable toxicity (selectivity indices for M. avium and M. kansasii higher than 16 and 62.5, respectively). Gram-positive bacteria, including methicillinresistant Staphylococcus aureus, were inhibited at concentrations starting from 125 μM, whereas the investigated derivatives exhibited almost no antifungal potency and activity against gram-negative species.

Keywords: antimicrobial activity – antimycobacterial activity – imidazolidine-2,4,5-triones – sulphamethoxazole – ureas

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0109

Chemical Papers 69 (8) 1108–1117 (2015)