Two classes of rotaxanes are described in which photoinduced processes modulate a large-amplitude motion. In the first type, E–Z-isomerization of a fumaric diamide unit to a maleic diamide leads to a substantial weakening of the hydrogen bonds between the diamide and the macrocyclic ring that surrounds it. As a result, the rate of the pirouetting motion is increased approximately by six orders ...

Two thread-shaped cations, pyridinium nicotinamide and imidazolium, as their chloride and hexafluorophosphate salts, were studied with regards to complexation with hydrogen-bond-donating acyclic and macrocyclic ligands. In the latter case, the cations form pseudorotaxanes templated by the chloride anion but not hexafluorophosphate. This formation is a function of the coupling of ion-pairing bet...

in this research work, we report the synthesis of macrocyclic diamides from the reaction of diesters and aliphatic diamines in the presence of caesium carbonate. it has been demonstrated that among the carbonate of alkali metals (li2co3, na2co3, k2co3 and cs2co3), cs2co3 appear to be the best catalyst for macrocyclization. diesters with different substitution patterns on the aromatic ring react...

A PVC-membrane electrode based on a recently synthesized 18-membered macrocyclic diamide is presented. The electrode reveals a Nernstian potentiometric response for Co2+ over a wide concentration range (2.0 x 10(-6)-1.0 x 10(-2) M). The electrode has a response time of about 10 s and can be used for at least 2 months without any divergence. The proposed sensor revealed very good selectivities f...

Diamide is a membrane-permeable, thiol-oxidizing agent that rapidly and reversibly oxidizes glutathione to GSSG and promotes formation of protein-glutathione mixed disulfides. In the present study, the acute effect of diamide on free cytosolic Ca2+ concentration ([Ca2+]i) was examined in fura-2-loaded bovine aortic endothelial cells. At low concentrations (50, 100 μM), diamide reversibly increa...

Nitric oxide (NO) controls several physiological functions of the cardiovascular system. The study on the effect of diamide (N(2)H(4).H(2)O) on NO production in vascular endothelial cells (VEC) may provide significant reference for VEC's modeling in studying cardiovascular diseases. The objective of this study was to elucidate how high concentration diamide (V(diamide)/V(culture miedium) = 5 ml...

The results of studying the effect central metal ion on stability gadolinium and holmium complexes with 1,10'-phenanthroline-2,9-dicarboxylic acid diamide are presented. obtained values constants turned out to be an order magnitude lower than previously known for these elements 4,7-dichloro-1,10'-phenanthroline-2,9-dicarboxylic diamide. Keywords: spectrophotometry, gadolinium, holmium, contrast...

Lock JT, Sinkins WG, Schilling WP. Effect of protein S-glutathionylation on Ca homeostasis in cultured aortic endothelial cells. Am J Physiol Heart Circ Physiol 300: H493–H506, 2011. First published December 10, 2010; doi:10.1152/ajpheart.01073.2010.— Diamide is a membrane-permeable, thiol-oxidizing agent that rapidly and reversibly oxidizes glutathione to GSSG and promotes formation of protein...