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The present study was carried out in an attempt to synthesize a new class of antimicrobial and antiplasmodial agents by copper catalyzed click chemistry to afford 25 compounds 10–14(a – e) of 1,4-disubstituted-1,2,3-triazole derivatives of chalcones and flavones. The structures of the newly synthesized compounds were established by elemental analysis, IR, 1 H NMR, 13 C NMR and Mass spectral data. The newly synthesized compounds were evaluated for their antibacterial activity against Gram positive bacteria ( Staphylococcus aureus , Enterococcus faecalis ), Gram negative bacteria ( Escherichia coli , Pseudomonas aeruginosa , Shigella boydii , Klebsiella pneumoniae ) and antifungal activity against ( Candida albicans , Candida tropicalis , Candida parapsilosis , Cryptococcus neoformans , Dermatophyte ) as well as molds ( Aspergillus niger , Aspergillus fumigatus ). The antiplasmodial and cytotoxic activities of these compounds were also evaluated against human malaria parasite Plasmodium falciparum strain 3D7 and human hepato-cellular carcinoma cells (Huh-7), respectively. Compounds 10a , 10c , 10d , 12c and 14e showed promising antibacterial activity while compounds 10e , 11d , 11e , 12c , 13a , 13b , 13e , 14a and 14d showed good antifungal activity as compared to the corresponding standard drugs. Compound 10b was found to be the most active against Plasmodium falciparum while the remaining compounds showed moderate to weak antiplasmodial activity. However, cytotoxic activities of all compounds were found ineffective against Huh-7 cells. [ABSTRACT FROM AUTHOR]

Abstract: In an attempt to design and synthesize a new class of antimicrobials, dialkyne substituted 2-aminobenzothiazole was reacted with various substituted aryl azides to generate a small library of 20 compounds (3a–t) by click chemistry. Structures of the newly synthesized compounds were established on the basis of spectral data. These compounds were screened for their antibacterial activity against Gram+ bacteria (Staphylococcus aureus and Enterococcus faecalis), Gram− bacteria (Salmonella typhi, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella boydii) and antifungal activity against Candida tropicalis, Candida albicans, Candida krusei, Cryptococcus neoformans) as well as molds (Aspergillus niger, Aspergillus fumigatus). The compound 3e showed maximum potency against all Gram+/gram− bacterial strains with MIC value 3.12 μg/ml, which is two fold more active as compared to standard drug ciprofloxacin (MIC 6.25 μg/ml). However, all compounds were found ineffective against S. boydii (clinical isolate). Further, only one compound 3n was found to be the most active against all fungal strains with MIC value in the range of 1.56 μg/ml–12.5 μg/ml while the remaining compounds showed moderate to weak antifungal activity. [Copyright &y& Elsevier]