Two lines of investigation supported the premise that killing of Staphylococcus aureus, 502A, by hydrogen peroxide involves formation of the more toxic hydroxyl radical (.OH) through the iron-dependent Fenton reaction. First, growing S. aureus overnight in broth media with increasing concentrations of iron increased their content of iron and dramatically enhanced their subsequent susceptibility...

A tripodal urea and tripodal thiourea with the same cyclic peptide core have been synthesised and their anion binding ability investigated. In CDCl(3), the tripodal urea self-associates whereas the thiourea does not. Neither compound shows self-association in the more polar 10% v/v DMSO-d(6)/CDCl(3). Both compounds bind strongly and selectively to sulfate ions in CDCl(3) and 10% v/v DMSO-d(6)/C...

Membrane and nuclear proteins of poor solubility have been separated by high resolution two-dimensional (2-D) gel electrophoresis. Isoelectric focusing with immobilized pH gradients leads to severe quantitative losses of proteins in the resulting 2-D map, although the resolution is usually high. Protein solubility could be improved by using denaturing solutions containing various detergents and...

Friedel-Craft acylation at 100 °C of 2,5,9,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocycloheptene [ar-himachalene], a sesquiterpenic hydrocarbon obtained by catalytic dehydrogenation of α-, β- and γ-himachalenes, produces a mixture of two compounds: (3,5,5,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocyclohepten-2-yl)-ethanone (2, in 69% yield), with a conserved reactant backbone, and 3, with a diff...

Ethylene or thiourea can substitute for gibberellic acid but not for red light in breaking the secondary dormancy induced by extended dark storage of fully hydrated lettuce seeds (Lactuca sativa cv. Grand Rapids). After 10 days of storage, ethylene, thiourea, or gibberellic acid applied either separately or in any combination in conjunction with red light induced near maximal germination. When ...

The catalytic activity of different supported bifunctional thioureas on sulfonylpolystyrene resins has been studied in the nitro-Michael addition of different nucleophiles to trans-β-nitrostyrene derivatives. The activity of the catalysts depends on the length of the tether linking the chiral thiourea to the polymer. The best results were obtained with the thiourea derived from (L)-valine and 1...