β-Cyclodextrin (β-CD) dimers have been prepared using the bioorthogonal Staudinger ligation for the first time. In addition to a known linker, methyl 2-(diphenylphosphanyl)terephthalate, a doubly active linker was specifically developed that enabled connection of two β-CD units in a single step and in aqueous/organic media, under mild conditions and with good yields. A three-carbon spacer betwe...

Excised guinea pig ciliary body-iris preparations accumulated <C-labeled L-ascorbate. The concentrating mechanism required glucose as well as Na+, K+, and Ca++ ions in the media and is inhibited by ouabain, dinitrophenol, iodoacetate, cyanide, fluoride, desoxycorticosterone, and hydrocortisone. It demonstrates saturation kinetics with increasing concentrations of Lascorbate in the media and is ...

A novel quinoline-coumarin (QC) fluoroionophore conjugated by means of a triazolyl-pyrrolidinyl linker exhibits differential dual selectivity for Zn(2+) and Al(3+) in mixed media. QC acts as a turn on fluorescence sensor for Zn(2+) while exhibiting overall ratiometric selectivity for Al(3+) in aqueous media. Moreover, QC exhibited preferential second mode of selectivity for Al(3+) as it ratiome...

The oxidation of beta-D-glucose by the enzyme glucose oxidase was studied in aqueous medium, in solutions of surfactants AOT (2-ethylhexylsulfosuccinate, sodium salt) TX-100 (polyethylene glycol p-tert octyl phenyl ether) and in w/o microemulsion medium (water/AOT/decane) at different water/AOT mole ratio (omega), pH, temperature and in presence of additives. The time-dependent activities of th...

The free radical scavenging activity of Trolox was studied for aqueous and lipid environments using the Density Functional Theory. Several reaction mechanisms and free radicals of different chemical nature have been included in this study, as well as the influence of the pH. Trolox was found to be a powerful ˙OH and alkoxy scavenger, regardless of the conditions under which the reaction takes p...

Barium sulfate (BaSO4) nanoparticles (\100 nm) are of interest to provide improved performance over microscale BaSO4 particles, which are currently used clinically as an X-ray contrast agent or radiopacifier, and to further enable passive or targeted delivery of BaSO4 contrast agents. The stability of BaSO4 nanoparticle dispersions in aqueous media is critical for these uses but has received li...

β-cyclodextrin sulfuric acid as a green lewis acid catalyst has been applied for the preparation of bis(indolyl)methanes, tris(indolyl)methanes and 3,3&apos;-diindolyloxindole derivatives by the condensation of indoles with various carbonyl compounds in aqueous media with high to excellent yields.

A simple protocol, involving the green synthesis for the construction of novel bis-pyrimidine derivatives, 3a-i and 4a-e are accomplished by the aqueous diethylamine media promoted tandem Aldol-Michael reaction between two molecules of barbituric acid derivatives 1a,b with various aldehydes. This efficient synthetic protocol using an economic and environmentally friendly reaction media with ver...

Heterogeneous catalysts have been synthesi zed by the conjugation of Hoveyda-Grubbs second-generation catalyst with a lipase. The catalytic properties of the organometallic compound in solution were firstly optimized, evaluating the activity of Ru in the ring-closing metathesis of diethyldiallymalonate at 25 °C at different solvents and in the presence of different additives. The best result wa...