The synthesis and characterization of two cytosine-substituted calix[4]pyrrole conjugates, bearing the appended cytosine attached at either a beta- or meso-pyrrolic position, is described. These systems were tested as nucleotide-selective carriers and as active components of nucleotide-sensing ion-selective electrodes at pH 6.6. Studies of carrier selectivity were made using a Pressman-type mod...

Oxygen-dependent coproporphyrinogen III oxidase catalyzes the sequential decarboxylation of the propionate substituents present on the A and B rings of coproporphyrinogen III in the heme biosynthetic pathway. Although extensive experimental investigation of this enzyme has already afforded many insights into its reaction mechanism, several key features (such as the substrate binding mode, the c...

The title compounds, rac-(1'R,2R)-tert-butyl 2-(1'-hydroxyethyl)-3-(2-nitrophenyl)-5-oxo-2,5-dihydro-1H-pyrrole-1-carboxylate, C(17)H(20)N(2)O(6), (I), rac-(1'S,2R)-tert-butyl 2-[1'-hydroxy-3'-(methoxycarbonyl)propyl]-3-(2-nitrophenyl)-5-oxo-2,5-dihydro-1H-pyrrole-1-carboxylate, C(20)H(24)N(2)O(8), (II), and rac-(1'S,2R)-tert-butyl 2-(4'-bromo-1'-hydroxybutyl)-5-oxo-2,5-dihydro-1H-pyrrole-1-car...

This note describes a sequence converting an oxime-substituted pyrrolidine into a trisubstituted pyrrole structure. The synthetic route is based on a double chlorination of the pyrrolidine substrate followed by the base induced formation of both an imine and a nitrile oxide functionality. The latter reacts with an immobilized thiourea to yield an isothiocyanate which upon elimination generates ...

The hepatic pigment accumulated in 3,5-diethoxycarbonyl-1,4-dihydrocollidine-treated rats, which has been reported to inhibit ferrochelatase, has been isolated and purified. The pigment has been resolved into one major, one minor, and two trace components, all of which appear to be isomeric porphyrins. The major fraction has been unambiguously identified by spectroscopic methods as the isomer o...

A series of bisaryl-substituted fluorescent maleimides was synthesized via the Heck arylation. The compounds showed broad fluorescence emission bands in the visible region, a large Stokes shift in polar solvents and emission quantum yields varying from 0.04 to 0.71, depending on the structure and solvent medium. The difference in dipole moments of ground and excited electronic states of about 1...

Pyrroles are important compounds present in biological systems, used for drug synthesis and material chemistry. A typical strategy the pyrrolic ring formation is centered on Paal–Knorr reaction, where 1,4-dicarbonyl react with amines giving N-substituted pyrrole derivatives. Often, main problem of this approach availability appropriate carbonyl compounds. Here, we report a sustainable carboxyli...

Ovalbumin, as the major component of egg-white, is a globular, biocompatible, nontoxic and biodegradable phosphoglyco protein. This protein with the molecular weight of 44.5 kDa, contains 385 residues of amino acids with isoelectric point (pI) of 4.5. Many purification procedures have been reported for egg-white proteins such as gel permeation and anion exchange chromatography. In this study, w...