Antimicrobial evaluation of new metallic complexes with xylitol active against P. aeruginosa and C. albicans: MIC determination, post-agent effect and Zn-uptake.

Xylitol (xylH5) is metabolized via the pentose pathway in humans, but it is unsuitable as an energy source for many microorganisms where it produces a xylitol-induced growth inhibition and disturbance in protein synthesis. For this reason, xylitol is used in the prophylaxis of several infections. In the search of better antimicrobial agents, new copper and zinc complexes with xylitol were synthesized and characterized by analytical and spectrosco pic methods: Na2[Cu3(xylH−4)2]·NaCl·4.5H2O (Cu-xyl) and [Zn4(xylH−4)2(H2O)2]·NaCl·3H2O (Zn-xyl). Both copper and zinc complexes presented higher MIC against Pseudomona aeruginosa than the free xylitol while two different behaviors were found against Candida albicans depending on the complex. The growth curves showed that Cu-xyl presented lower activity than the free ligand during all the studied period. In the case of Znxyl the growth curves showed that the inhibition of the microorganism growth in the first stage was equivalent to that of xylitol but in the second stage (after 18 h) Zn-xyl inhibited more. Besides, the PAE (post agent effect)obtained for Zn-xyl and xyl showed that the recovery from the damage of microbial cells had a delay of 14 and 13 h respectively. This behavior could be useful in prophylaxis treatments for infectious diseases where it is important that the antimicrobial effect lasts longer. With the aim to understand the microbiological activities the analysis of the particle size, lipophilicity and Zn uptake was performed.

Copper complexes with heterocyclic sulfonamides: synthesis, spectroscopic characterization, microbiological and SOD-like activities: crystal structure of [Cu(sulfisoxazole)2(H2O)4] . 2H2O.

The synthesis, characterization and comparative biological study of a series of antibacterial copper complexes with heterocyclic sulfonamides were reported. Two kinds of complexes were obtained with the stoichiometries [Cu(L)2] . H2O and [Cu(L)2(H2O)4] . nH2O. They were characterized by infrared and electronic spectroscopies and the crystal structure of [Cu(sulfisoxazole)2(H2O)4] . 2H2O was determined by single crystal X-ray diffraction. It crystallized in the C2/c with Z = 8 monoclinic space group C2/c with Z = 8. The Cu(II) is in a slightly tetragonal distorted octahedron formed by four oxygen atoms from water molecules and two nitrogen atoms from two isoxazole rings. The antimicrobial activity was evaluated for all the synthesized complexes and ligands using the agar dilution test. The results showed that the complexes with five-membered heterocyclic rings were more active than the free sulfonamides while the pyrimidine, pyridine and pyridazine complexes had similar or less activity than the free ligands. In order to find an explanation for this behavior lipophilicity and superoxide dismutase-like activity were tested, showing that the [Cu(sulfamethoxazol)2(H2O)4] . 3H2O presented the highest antimicrobial potency and a superoxide dismutase-like activity comparable with pharmacological active compounds.

Blepharo-cheilo-dontic (BCD) syndrome in two Mexican patients.

The combination of lagophthalmia, ectropion of the lower eyelids, distichiasis, euryblepharon, cleft lip/palate, and oligodontia was recently named blepharo-cheilo-dontic (BCD) syndrome. Different combinations of these signs have been found sporadically, with autosomal dominant inheritance. Ectropion of the lower eyelids, lagophthalmia, and bilateral cleft lip/palate appear to be the more common manifestations. We report on two unrelated patients with bilateral cleft lip/palate and lagophthalmia. One of these two patients had familial cleft lip/palate in two generations, probably as a variable expression of an autosomal dominant gene.

Spectroscopic, magnetic, and electrochemical behavior of the copper(II) complex of carnosine.

Different physicochemical studies were undertaken with polycrystalline samples of the complex [Cu2(carnosine)2(H2O)2].2H2O. The infrared spectrum was discussed in comparison with that of free carnosine and on the basis of the known structural data. Magnetic susceptibility measurements were performed between 4.2 and 300 K, showing an effective magnetic moment of 1.79 BM. Both the electronic (reflectance) and ESR spectra were compatible with the existence of a dx2-y2 ground state. The axial reversed ESR spectrum could be explained on the basis of a very weak interdimeric coupling mechanism. The electrochemical behavior, investigated by cyclic voltammetry, shows that the complex possesses a very high redox stability. The possible SOD-like activity was tested using the NBT/superoxide reduction assay. The results show a negligible SOD activity.