New azole antifungal agents with novel modes of action: synthesis and biological studies of new tridentate ligands based on pyrazole and triazole.

The synthesis and extensive biological study of two new tridentates ligands based on pyrazole and triazole are described. The antifungal activity against the budding yeast cells of the newly synthesized compounds was determined. These compounds were toxic to yeast cells. Cell cycle analysis suggested that treatment with these compounds impairs cell division in G1 of the cell cycle. Using yeast-based functional genomics technologies, we found that these compounds tolerance requires DNA repair pathway and SKI complex function. We have also found that the PKC1 heterozygous deletion strain was the most sensitive to these compounds using HaploInsufficiency Profiling, suggesting that the Pkc1 protein may be the target for these compounds. These results strongly suggest that these compounds induce DNA damage and thus exert a different mechanism of action compared to other azole derivatives. These two compounds might therefore represent promising lead compounds for further development of antifungal drugs for human therapy.

Synthesis of mono-, di- and tetra-alkyne functionalized calix[4]arenes: reactions of these multipodal ligands with dicobalt octacarbonyl to give complexes which contain up to eight cobalt atoms.

The functionalized mono-alkyne cone-monopropargyl p-tert-butylcalix[4]arene was synthesized by the reaction of p-tert-butylcalix[4]arene with K(2)CO(3) and 3-bromo-1-propyne. More prolonged reaction times led to the formation of the 1,3 cone bis(propargyl)calix[4]arene . The tetra-alkyne species cone-tetrapropargyl p-tert-butylcalix[4]arene and its conformational isomer, 1,3-alternate-tetrapropargylcalix[4]arene may both be prepared via related reaction sequences. The structures of the molecules and were both re-determined by single crystal X-ray diffraction studies. All four functionalized calixarenes react rapidly with dicobalt octacarbonyl to give [(calix[4]arene).{Co(2)(CO)(6)}(n)] species (n = 1, 2 or 4) in which the alkyne functionalities of the propargylcalix[4]arenes are ligated to one or more [Co(2)(CO)(6)] groups. Two products could be harvested from the reaction of [Co(2)(CO)(8)] with the bis-propargyl-calixarene , depending on the reaction conditions and relative molar quantities of the reactants: complex , [1,3-cone bis(propargyl)calix[4]arene.{Co(2)(CO)(6)}(2)], in which each alkyne group is bonded to a [Co(2)(CO)(6)] group, and complex , [1,3-cone bis(propargyl)calix[4]arene.{Co(2)(CO)(6)}], which contains a unligated alkyne and an alkyne group bonded to a Co(2)(CO)(6) unit. The structures of the tetracobalt and octacobalt complexes and were established by single crystal X-ray diffraction studies.

A pyrenyl-appended triazole-based calix[4]arene as a fluorescent sensor for Cd2+ and Zn2+.

The synthesis and evaluation of a novel calix[4]arene-based fluorescent chemosensor 8 for the detection of Cd(2+) and Zn(2+) is described. The fluorescent spectra changes observed upon addition of various metal ions show that 8 is highly selective for Cd(2+) and Zn(2+) over other metal ions. Addition of Cd(2+) and Zn(2+) to the solution of 8 results in ratiometric measurement.