[Substituted 1,5,6,7-tetrahydro-4H-benzimidazol-4-ones as inhibitors of urease].

A comparative kinetic study of the inhibition of urea hydrolysis by 9 substituted 1,5,6,7-tetrahydro-4H-benzimidazol-4-ones (BI I-IX) has been carried out. The inhibition had reversibl competitive character; the inhibition constants K(i), varied from 29 up to 754 microM in dependence of the structure of BI I-IX. Three BI I-III, having the K(i) values from 29 to 82 microM, may be used as the potential therapeutic agents for gastroenterology for treatment of stomach and duodenal ulcers.

Synthetic heteroprostanoids of A- and E-types as novel non-comprehensive inhibitors of adenylyl cyclase in rat hepatocytes.

Treatment of rat hepatocyte plasma membranes with five novel synthetic heteroprostanoids of A- and E-types significantly decreased basal activity of adenylyl cyclase. Inhibition of forskolin-stimulated activity of the enzyme was seen as well. The maximal effective concentration for all substances tested was found at approximately 5x10(-6)-1x10(-5) M.

Intramolecular gamma-hydroxylations of nonactivated C-H bonds with copper complexes and molecular oxygen.

Copper(I) complexes incorporating the isomeric bidentate ligands IMPY (iminomethyl-2-pyridines) or AMPY (aminomethylene-2-pyridines) are quite unusual in their ability to bind and activate molecular oxygen. Using these complexes, hydroxylations of nonactivated CH, CH2, or CH3 groups in the gamma-position in relation to the imino-nitrogen atom, and with a specific orientation of one H atom with respect to the binuclear Cu-O species, can be achieved in synthetically useful yields. Through mechanistic studies employing conformationally well-defined molecules (for example, cyclic isoprenoids), coupled with solid-state X-ray structure analyses and force-field calculations, we postulate a seven-membered transition state for this reaction in which six atoms lie approximately in a plane.