Determination of the Protonation Constants of Some 4-(Substituted benzylamino)-4,5-dihydro- 1H-1,2,4-triazol-5-ones by the Potentiometric Method in Ethanol–Water Mixtures

To gain more information about the effect of solvent on 4,5-dihydro-1H-1,2,4-triazol-5-ones, the stoichiometric protonation constants of thirteen triazoles in ethanol–water mixtures were determined at an ionic strength of 0.10MNaCl and at 25.0±0.1 °C under nitrogen atmosphere. A potentiometric method was used and the  calculation was carried out using the PKAS computer program. The correspondingpKa values of these triazoles were determined in ethanol–water mixtures. Thus, the effects of solvent and molecular structure upon acidity were investigated. The logarithm of the protonation constants of the title 4,5-dihydro- 1H-1,2,4-triazol-5-ones decreased linearly with increasing ethanol content, but the values determined with 80% ethanol did not follow this linear trend. The variation of these constants is discussed on the basis of specific solute–solvent  interactions.KEYWORDS: Potentiometry, protonation constants, solvent effect, triazoles

Myocardial infarction secondary to unintentional ingestion of hydrogen peroxide

Ingestion of acid-containing household products, either accidentally or as a suicide attempt, is a common form of intoxication. A clear and odorless liquid, hydrogen peroxide is an oxidizing agent found in most households and many industrial environments. Cardiovascular manifestations of hydrogen peroxide ingestion are extremely rare. Here we report a 60 year-old woman with acute inferolateral myocardial infarction (MI) after hydrogen peroxide ingestion, who had no history of coronary artery disease. Physicians dealing with hydrogen peroxide ingestion in the emergency department should be aware of the probability of MI and obtain an electrocardiogram, even if the patient has no cardiac complaint. (Cardiol J 2012; 19, 1: 86–88

Investigation of free radical scavenging enzyme activities and lipid peroxidation in liver tissue of zinc deficient rats

The aim of this study was to evaluate the lipid peroxidation and free radical scavenging enzyme activities in liver tissue of zinc (Zn)-deficient rats and investigate relationship among these parameters in either group. 16 Male rats with a weight of 35-40 g were used for the experiment. The rats were divided into control (n = 8) and Zn-deficient groups. After 4 weeks of feeding, the rats were killed by cervical dislocation and liver tissues were removed. Biochemical measurements in liver tissue were carried out using a spectrophotometer. Catalase, glutathione peroxidase, glutathione reductase, glutathione S transferase activities, total (enzymatic plus non-enzymatic) superoxide scavenger activity, superoxide dismutase, non-enzymatic superoxide scavenger activity, superoxide dismutase activities and Zn level in the Zn-deficient group were significantly lower than those of the control group, whereas malondialdehyde level was significantly higher than those of the control group. Slightly increased non-enzymatic superoxide scavenger activity was not significantly different from the controls. The results obtained in this study demonstrate that Zn-deficiency causes a decrease in antioxidant defence system and an increase in oxidative stress in liver tissue in rats