Antibacterial and Antifungal Studies on Some Schiff Base Complexes of Zinc(II)

Two Schiff base ligands L1 and L2 were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1 : 1 electrolytes. The IR data demonstrate the tetradentate binding of L1 and tridentate binding of L2. The XRD data show that Zn(II) complexes with L1 and L2 have the crystallite sizes of 53 and 61 nm respectively. The surface morphology of the complexes was studied using SEM. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by the disc diffusion method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.

Thermodynamic study on the complexation of dioxovanadium [V] with isoleucine and glycylglycine

The dissociation constants of isoleucine and glycylglycine have been determined using a suitable computer program which employs a nonlinear least squares method. The complexation of dioxovanadium [V] with glycylglycine was studied by a combination of potentiometric and spectrophotometric techniques in aqueous solution at 25 °C and 0.1 mol dm[-3] ionic strength [NaClO[-4] in the pH range 2.00 to 2.60. All of the calculations have been done by the computer program Excel 2000. Dioxovanadium [V] complexes formed by isoleucine in the pH range 1.30 to 2.5 and between t = 25 °C and 35 °C with one mole dm[-3] sodium perchlorate as the ionic medium, have been investigated potentiometrically and spectrophotometrically. Ultimately, the thermodynamic functions [delta G°, delta H°, delta S°] have been calculated for the complexation of dioxovanadium [V] with isoleucine

Actividad in vitro comparativa de la tigeciclina contra microorganismos causantes de infección en pacientes hospitalizados en Colombia: estudio de evaluación y vigilancia de tigeciclina, TEST / Comparative In Vitro activity of tygecycline against infection causing microrganisms among hospitalized patients in Colombia: evaluation and surveillance study of Tygecycline - TEST

Introducción: la tigeciclina, el primer representante el grupo de las glicilciclinas, nueva clase de antibióticos, ha sido recientemente introducida en Colombia y no se disponen aún de datos en el país de su actividad in vitro. Objetivo: evaluar la actividad in vitro de la tigeciclina contra aislamientos clínicos de pacientes hospitalizados en tres hospitales colombianos de tercer nivel. Materiales y métodos: los aislamientos de bacterias aerobias y anaerobias facultativas de pacientes hospitalizados de tres centros de alta complejidad fueron remitidos a un laboratorio de referencia para la determinación de la concentración inhibitoria mínima (CIM) por el método de microdilución en caldo para la tigeciclina y otros antibióticos. Para los puntos de corte se utilizaron los criterios de interpretación de la CLSI 2006 y para la tigeciclina sugeridos por la FDA. Resultados: la susceptibilidad a la tigeciclina de las cepas evaluadas y sus respectivas CIM50-90 fueron las siguientes: Staphylococcus aureus (n=78), 100 por ciento, 0,12 y 0,12 mg/L; Streptococcus pneumoniae (n=24)100 por ciento, 0,015 y 0,5 mg/L; Streptococcus agalactiae (n=10), 100 por ciento, 0,03 y 0,06 mg/L; Enterococcus spp. (n=43) 100 por ciento, 0,06 y 0,12 mg/L; Klebsiella pneumoniae (n=56), 96,4 por ciento, 0,5 y 1 mg/L; Klebsiella oxytoca (n=15), 93,3 por ciento, 0,25 y 2 mg/L; Escherichia coli (n=89) 100 por ciento, 0,12 y 0,5 mg/L; Enterobacter cloacae (n=48), 100 por ciento, 0,5 y 2 mg/L; Serratia marscescens (n=42) 96,2 por ciento, 0,5 y 2 mg/L. ParaHaemophilus influenza (n=15) y Acinetobacter baumannii (n=36), que no tienen puntos de corte definidos, las CIM50-90 fueron 0,06 y 0,12 y 0,5 y 2 mg/L, respectivamente. El 100 por ciento de los aislamientos productores de beta-lactamasas de espectro extendido de Escherichia coli (n=18) y el 94,4 por ciento de los de Klebsiella pneumoniae (n=18) fueron susceptibles a tigeciclina. Las CIM50-90 para Pseudomonas aeruginosa (n=63) fueron 8 y 16 mg/L...

Metabolism of dipeptides by isolated and perfused nonfiltering kidneys

Rehal metabolism of Glycyl-glycine (Gly-gly), Glycyl-proline (Gly-pro) and Prolyl-glycine (Pro-gly) was studied in the non-filtering, isolated perfused rat kidney. Gly-gly is metabolized by more than 90% after 120 min of perfusion. Gly-pro is more resistant to degradation and about 75% of the original peptide can be found intact in the perfusate at the end of perfusion. For Pro-gly only 25% reamins intact at the end of the experiment. Glycine was also monitored as another marker for dipepptide degratation and ins production increased throughout the perfusion time. In some experiments we also determined the production of proline. We conclude from these experiments that the basolateral membrane, or perhaps the kidney blood vessels, posses an efficient apparatus for the hydrolysis of Gly-gly and Pro-gly. This mechanism is less efficient in the case of Gly-pro. This confirms an earlier hypothesis that dipeptide metabolism does not occur solely in the brush-border membranes

Glycine and glycyl glycineenriched oral rehydration solutions in the management of infantile diarrhea

The study was conducted on 150 male formula-fed uncomplicated cases of acute diarrhea with dehydration. They were randomly classified into 3 groups: group A received standard WHO formula [51 cases], group II [49 cases] received ORS containing maltodextrin, glycine and glycyl-glycine while group III [50 cases] received ORS containing maltodextrin in addition to glycine alone. The two new ORS formulations contained the usual thee salts present in the standard ORS with the same concentration. The results showed that there were no significant differences between the thee studied groups as regards the mean number of diarheal motions, the mean daily amounts of diarrheal stools, the mean duration of the diarheal episode, time of first voiding of urine, time needed for initial rehydration, the mean daily amounts of ORS, other plain fluids, milk formula, solid and semisolid foods ingested by the thee groups and mean weight gain. No statistically significant differences were detected between the three studied groups regards the mean serum sodium, potassium and chloride, as well as blood pH and bicarbonate levels recorded levels recorded on admission and after 6, 24 and 48 hours from inclusion in the study and all were within the normal range. It could be concluded that the two study solutions containing maltodextrin together with glycine and glycyl glycine did not prove to have any statistically significant superiority over the standard conventional ORS on the clinical outcome of diarrhea

Studies of Enzymes in Hyman Skin Tissue / 대한피부과학회지

Gamma-glutamyl transpeptidase (GGTP) activity was measured in the homogenate of penile foreskin, using y-glutamyl-p-nitroanilide, as a substrate, and it was found that (GGTP) activity was present in the epidermis and dermis, being more active in the former. The optimum pH for the enzyme was 8.5 - 9.0 in Tris buffer, which was similar to those of the rat kidney and human serum enzymes. It was also revealed that glycylglycine was the most effective activator of the enzyme and some activation was also observed in the presence of L-glutamine. But L-rnethionine, L-homoserine, L-glutamic acid, L-arginine, L-aspartic acid, glycine and L-valine inhibited the activity, suggesting that these amino acids do not act as acceptors of p-glutamyl moiety. The enzyme was remarkably inhibited by bromosulphalein, oxidised gluta,thione, and by L-serine in the presence of borate, and the inhibitions were more severe than is the case with the rat kidney and human serum enzymes.