The kinetics and mechanism of ligand substitution reactions of [Pt(SMC)Cl(2)] (SMC = S-methyl-l-cysteine) with biologically relevant ligands were studied as a function of chloride and nucleophile concentrations at pH 2.5 and 7.2. It was observed that the slope and intercept obtained from the linear dependence of the observed rate constant on the nucleophile concentration strongly depend on the ...

Starch acetates of degree of substitution 0.1–1.5 were prepared by heating corn starch, acetic acid and acetic anhydride in sealed, stirred, teflon vessels in a microwave reactor. Reaction efficiencies were typically O90% at reaction temperatures of 150–160 8C for 4–7 min. Starch acetates prepared by reaction at 160 8C to DS values of 0.4–0.9 wereO90% soluble in room temperature water. Acetylat...

Most phosphate-processing enzymes require Mg(2+) as a cofactor to catalyze nucleotide cleavage and transfer reactions. Ca(2+) ions inhibit many of these enzymatic activities, despite Ca(2+) and Mg(2+) having comparable binding affinities and overall biological abundances. Here we study the molecular details of the calcium inhibition mechanism for phosphodiester cleavage, an essential reaction i...