N(4)-tolyl-2-benzoylpyridine thiosemicarbazones and their copper(II) complexes with significant antifungal activity: crystal structure of N(4)-para-tolyl-2-benzoylpyridine thiosemicarbazone

• Autor(a) principal: Mendes,Isolda C.
• Data de Publicação: 2006
• Outros Autores: Moreira,Juliana P., Speziali,Nivaldo L., Mangrich,Antonio S., Takahashi,Jacqueline A., Beraldo,Heloisa
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532006000800013
• topic: thiosemicarbazones; copper(II) complexes; antifungal activity; Candida albicans

Three new copper complexes of general formula [Cu(HL)Cl2] have been obtained with N(4)-ortho (H2Bz4oT, HL1), N(4)-meta (H2Bz4mT, HL2) and N(4)-para-tolyl-2-benzoylpyridine thiosemicarbazone (H2Bz4pT, HL3), in which the thiosemicarbazone attaches to the metal through the Npy-N-S chelating system. H2Bz4pT (HL3) crystallizes in the P1 space group, with a = 9.509(3) Å, b = 9.807(4) Å, c = 11.564(4) Å; alpha = 100.76(2)°, beta = 105.99(2)°, gamma = 114.59(2)°. The thiosemicarbazones and their copper(II) complexes exhibit high antifungal activities against Candida albicans with low values of minimum inhibitory concentration (MIC), in the 8-0.3 µg mL-1 (23 - 0.7 µmol L-1) range for the free bases and in the 1-0.1 µg mL-1 (2 - 0.3 µmol L-1) range for the complexes. Our results suggest that coordination to copper(II) could be an interesting strategy for dose reduction.