Novel fluorescent materials derived from 2,3-dicyanopyrazine were synthesized and subjected to photodimerization reaction. Styryl substituents were attached by Wittig reaction, and the [2+2] photocycloaddition of the 2,3-dicyanopyrazine, either in solution or as a thin film, was studied with irr...

A series of pyridomorphinans possessing an aryl (10a–s) or heteroaryl (11a–h) substituent at the 5′-position of the pyridine ring of 17-cyclopropylmethyl-4,5α-epoxypyrido[2′,3′:6,7]morphinan was synthesized and evaluated for binding and functional activity at the opioid δ, μ, and κ rece...

A new series of 2-amino-4-oxo-6-substituted pyrrolo[2,3-d]pyrimidines, with an isosteric replacement of the side chain amide moiety to a sulfur atom, were designed and synthesized as multitargeted antifolates as well as potential antitumor agents. Starting from previously synthesized 2-amino-4-o...

1,8-Bis[5′(2′-hydroxy-4′-methylbiphenyl)]naphthalene, 2, was prepared from 1,8-dibromonaphthalene and 4-methoxy-2-methylphenylboronic acid in four steps with 51% overall yield. The axially chiral anti-isomer of 2 is stable to racemization at room temperature and the free energy of activation ...

A library of over 20, mainly aryl or heteroaryl, N-methyliminodiacetic acid (MIDA) boronates have been synthesised. A rapid microwave-mediated (MW) method (5–10 min) has been developed using polyethylene glycol 300 (PEG 300) as solvent. However, acetonitrile (MeCN) and dimethylformamide (DMF) w...

An efficient synthesis of a library of 5-amino-thiazolo[4,5-d]pyrimidines is reported. Regioselective displacements of chlorines, as well as regioselective diazotation reactions are described, which allow the introduction of structural diversity on the scaffold by consecutive reactions. Screenin...

Single-crystal and powder X-ray diffraction, 13C CP/MAS NMR, and DFT-GIAO calculations of shielding constants were performed for methyl 3,4,6-tri-O-acetyl-2-O-(2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)-α-d-glucopyranoside (1) and methyl 2,4,6-tri-O-acetyl-3-O-(2,3,4,6-tetra-O-acetyl-β-d-ga...

Recent research indicated the potential of glycine under alkaline conditions as a lixiviant for copper from its ores and concentrates. In this research, a systematic study has been made of the effects of glycine concentration, temperature, dissolved oxygen, particle size, stirring speed, on the ...

The fundamental electrochemical properties of the copper-glycine system were investigated in this study to understand the factors that affect the dissolution of metallic copper. Potentiodynamic polarisation measurements were carried out over the pH range 9.0 to 11.5, at temperatures of 22 °C an...

Recently, an aqueous glycine solution has been proposed as a non-toxic environmentally friendly lixiviant to leach precious metals such as gold. In confined spaces, gold can be leached effectively using cyanide as a lixiviant. However, in unconfined applications, cyanide poses detrimental enviro...

An Ussing chamber study was conducted in order to investigate the transport behavior of copper glycinate complexes through a porcine gastrointestinal membrane. Organic copper complexes such as copper tri- and tetraglycinates (GGG–Cu(II) and GGGG–Cu(II)) were used as model system. In a novel an...

A conceptual flowsheet is proposed and the main processing steps are evaluated for the alkaline processing of chalcopyrite where glycine is the complexing agent. Glycine is utilised in an oxidising, alkaline environment to leach chalcopyrite at atmospheric pressure and mildly elevated temperatur...

This article has the principal aim of presenting a new method of chemical cleaning of tarnished silver–copper alloy objects. The chemical cleaning must be harmless to the health, selective to tarnish removal, and easy to use. Sodium glycinate was selected for the study. The reactions of sodium ...

The kinetics for the competitive adsorption of gold and copper onto activated carbon from synthetic alkaline glycine solutions was studied. The adsorption rate for both gold and copper at the initial stage was modelled using the Fleming k,n adsorption kinetic model. The coefficient of variation ...

Alkaline glycine/glycinate solutions have been shown to have significant potential in the leaching of gold and copper from ores, concentrates, and wastes bearing these metals. An attempt was made to understand the adsorption behaviour of the gold glycinate complex onto activated carbon in the pr...

SummaryUsing alkaline and neutral sucrose gradients, it was observed that administration of the hepatocarcinogen, 3-hydroxyxanthine, to rats, resulted in the slower sedimentation of liver DNA in alkaline and neutral sucrose gradients. Slower sedimentation of liver DNA in alkaline sucrose gradien...

UV, gamma-, or X-irradiation of several N-hydroxyxanthines as powdered solids produces radicals that are indefinitely stable in the solid state at room temperature, but are highly unstable in protic solvents. The ESR spectra are not sufficiently resolved to be definitive but are compatible with ...

N-Acetoxyderivatives of 3-hydroxyxanthine and several of its methyl derivatives of 1-hydroxyxanthine, and of 8-aza-3-hydroxyxanthine are described. The UV spectra of the 7 or 9-acetyl derivatives of 1- and 3-N-acetoxyxanthines indicate the presence of intramolecular H-bonding which influences th...

A model for a monoradical species formed in 77-K X-irradiated 3-hydroxyxanthine has been determined from a study of its radical pair EPR spectra. The monoradical and radical pairs were stable at room temperature and were studied at that temperature. The radical was found to be a π-type nitrogen...

1.1. Bovine milk xanthine oxidase (xanthine:oxygen oxidoreductase, EC 1.2.3.2) oxidises 3-hydroxyxanthine slowly to 3-hydroxyuric acid; the 1-methyl derivative of 3-hydroxyxanthine is attacked about twice as fast.2.2. The pH optimum for the reaction of 2-hydroxyxanthine is near 5, i.e. the neutr...