A Note on sym-Dibenzoyl Acetone. Polyoxo Compounds. Vll

In the 3rd communication .of this series Balenovic and Munk described a compound obtained by alkaline hydrolysis of 2,6-diphenyl pyrone, which, after a molecule of water was split off, yielded the original pyrone. They came to the conclusion that this compound is identical with the hitherto undescribed sym-dibenzoyl acetone. The ketonic form of this compound should contain very reactive methylene groups in 1,3-positions, and should, therefore, readily read with sodium nitromalondialdehyde

A Note on sym-Dibenzoyl Acetone. Polyoxo Compounds. Vll

In the 3rd communication .of this series Balenovic and Munk described a compound obtained by alkaline hydrolysis of 2,6-diphenyl pyrone, which, after a molecule of water was split off, yielded the original pyrone. They came to the conclusion that this compound is identical with the hitherto undescribed sym-dibenzoyl acetone. The ketonic form of this compound should contain very reactive methylene groups in 1,3-positions, and should, therefore, readily read with sodium nitromalondialdehyde

Calorimetric Study of Ligand Binding to Fumarase

A microcalorimetric method has been used to study the binding of inhibitors, succinate and citrate, to pig heart fumarase at single conditions, i.e. 37 °c, pH 7.4 and I\u27/2 0.03, but by using three buffer systems with different heats of ionization. Binding processes with succinate and citrate were endothermic and the same general pattern was obtained for the inhibitors used (~G0 - 37 or 38 kJ. mol-1). It has been shown that 0.1 or 0.2 moles of H+ per mol of enzyme was absorbed when the enzyme was saturated with succinate or citrate, respectively. Binding processes in buffer systems with different heats of ionization made possible the calculations of enthalpies of binding (~H0 \u27 - 16.4 or 16.8 kJ moi-1) in a hypothetical buffer system with zero. heat of ionization

Inhibition of Urease by Some Triazole, Urea, and Guanidine Derivatives

Series of aminotriazole, guanidine and urea derivatives were prepared and tested as urease inhibitors. A greater part of the tested compounds, all containing the sequence ressembling the substrate, have shown an inhibitory effect on urease

Synthesis of Di(s-triazinyl) Sulphides and Disulphides. The-Promoting Effect of Oxidants on the Cleavage of the Thioether Bond

Synthesis of a number of di(s-triazinyl) sulphides and disu1phides is described. The behaviour of these compounds on oxidative attack has been examined. It has been found that instead of the expected sulphoxide and/or sulphone formation upon oxidation, a simple scission of the thioether linkage takes place, yielding a hydroxytriazine and the corresponding disulphide

Zwitterion Structure in Some 1-Carboxymethylimidazoles and Their Analgetic Activity

The ratio (R) of zwitterions to neutral molecule was determined for the derivatives of 1-carboxymethylimidazole. 1-Carboxymethylimidazole (I) and its 2-methyl derivate (III) were found to be entirely in the form of zwitterion. Of the two 1-carboxymethyl- 2-methyl-nitroimidazoles (V and VII) the 4-nitroisomer (V) possesses no zwitterionic structure, but the 5-nitroisomer (VII) was found to be about 65Q/o in the zwitterionic form. The results obtained are discussed in view of the significant analgetic and sedative effect observed with tlie compounds having a zwitterionic structure