Complexation of 2-acetylpyridine- and 2-benzoylpyridine-derived hydrazones to copper(II) as an effective strategy for antimicrobial activity improvement

Complexes [Cu(2AcPh)Cl]center dot 2H(2)O (1), [Cu(2AcpClPh)Cl]center dot 2H(2)O (2), [Cu(2AcpNO(2)Ph)Cl] (3), [Cu(2BzPh)Cl] (4). [Cu(2BzpClPh)Cl] (5) and [Cu(2BzpNO(2)Ph)Cl] (6) were obtained with 2-acetylpyridine-phenylhydrazone (H2AcPh), 2-acetylpyridine-para-chloro-phenylhydrazone (H2AcpClPh), 2-acetylpyridine-para-nitro-phenylhydrazone (H2AcpNO(2)Ph), 2-benzoylpyridine-phenylhydrazone (H2BzPh), 2-benzoylpyridine-para-chloro-phenylhydrazone (H2BzpClPh) and 2-benzoylpyridine-para-nitro-phenylhydrazone (H2BzpNO(2)Ph). The hydrazones showed poor antibacterial effect against Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa but demonstrated significant antifungal activity against Candida albicans. Upon coordination to copper(II) the antibacterial and antifungal activities appreciably increased. H2AcpClPh, H2BzpClPh and their copper(II) complexes (2) and (5), respectively, were as active as fluconazole against C. albicans. (C) 2012 Elsevier Ltd. All rights reserved.

A broad study of two new promising antimycobacterial drugs: Ag(I) and Au(I) complexes with 2-(2-thienyl)benzothiazole

Synthesis, characterization, DFT simulation and biological assays of two new metal complexes of 2-(2-thienyl)benzothiazole - BTT are reported. The complexes [Ag(BTT)(2)NO3] - AgBTT2 and [Au(BTT)Cl]center dot 1/2H(2)O - AuBTT were obtained by mixing the ligand with silver (I) nitrate or gold(I) chloride in methanolic solution. Characterization of the complexes were based on elemental (C, H, N and S), thermal (TG-DTA) analysis, C-13 and H-1 NMR, FT-IR and UV-Vis spectroscopic measurements, as well as the X-ray structure determination for AgBTT2. Spectroscopic data predicted by DFT calculations were in agreement with the experimental data for both complexes. The ligand BTT was synthesized by the condensation of 2-thiophenecarboxaldehyde and 2-aminothiophenol in a microwave furnace. AgBTT2 has a monomeric structure. Both complexes show a good activity against Mycobacterium tuberculosis. Free BIT shows low antitubercular activity. (C) 2012 Elsevier Ltd. All rights reserved.

Antimycobacterial activity of 2-phenoxy-1-phenylethanone, a synthetic analogue of neolignan, entrapped in polymeric microparticles

Conventional treatment of tuberculosis (TB) demands a long course therapy (6 months), known to originate multiple drug resistant strains (MDR-TB), which emphasizes the urgent need for new antituberculous drugs. The purpose of this study was to investigate a novel treatment for TB meant to improve patient compliance by reducing drug dosage frequency. Polymeric microparticles containing the synthetic analogue of neolignan, 1-phenyl-2-phenoxiethanone (LS-2), were obtained by a method of emulsification and solvent evaporation and chemically characterized. Only representative LS-2-loaded microparticles were considered for further studies involving experimental murine TB induced by Mycobacterium tuberculosis H37Rv ATCC 27294. The LS-2-loaded microparticles were spherical in shape, had a smooth wall and showed an encapsulation efficiency of 93% in addition to displaying sustained release. Chemotherapeutic potential of LS-2 entrapped in microparticles was comparable to control groups. These findings are encouraging and indicate that LS-2-loaded microparticles are a potential alternative to conventional chemotherapy of TB.

1,3-Azoles from ortho-naphthoquinones: Synthesis of aryl substituted imidazoles and oxazoles and their potent activity against Mycobacterium tuberculosis

Twenty-three naphthoimidazoles and six naphthoxazoles were synthesised and evaluated against susceptible and rifampicin- and isoniazid-resistant strains of Mycobacterium tuberculosis. Among all the compounds evaluated, fourteen presented MIC values in the range of 0.78 to 6.25 mu g/mL against susceptible and resistant strains of M. tuberculosis, Five structures were solved by X-ray crystallographic analysis. These substances are promising antimycobacterial prototypes. (C) 2012 Elsevier Ltd. All rights reserved.