The synthesis of (3R )-3-[Boc-Lys(biotinyl)-O ]-11-cis-retinol bromoacetate and 3-[Boc-Lys(biotinyl)-O ]-all trans-retinol chloroacetate is described. These biotinylated retinoids are instrumental in labeling the retinol binding proteins (RBPs) via a nucleophilic displacement of the haloacetate by a residue in the binding site of the protein. The covalently linked biotin will allow for a facile...

Benzofurans are very interesting heterocycles, which are available in nature and show a wide range of pharmacological activities. Hence, different benzofurans having 4-thiazolidinones have been synthesized for the purpose of pharmacological evaluation. The desired compounds were prepared using simple starting materials like salicylaldehyde and ethyl bromoacetate. The reaction between these comp...

Vanol is a member of the vaulted biaryl family of ligands and it has been proven to be very effective in a number of asymmetric catalytic reactions. The previous synthesis of vanol, while effective, is limited by the cost of reagents involved. The present work evaluates three different approaches to the synthesis of 3-phenyl-1-naphthol, a key intermediate in the synthesis of vanol. The first ap...

The reactions of iodoacetate and bromoacetate with ribonuclease have already provided some information on the relationship between the chemical structure and the catalytic a(*tivity of the enzyme. It is the purpose of this and the following paper to extend this information. In earlier studies, Gundlach, Stein, and Moore (1) showed that although alkylation at lysine, mrthioninc, or histidine res...

Ribonuclease A has been subjected to reaction at pH 8.5 with a series of homologous cr-bromo acids and with iodoacetamide. At this pH, carboxyalkylation occurs predominantly at the 3 amino acid residues which have been implicated in the catalytic function of the enzyme: histidine-12, histidine-119, and lysine-41. The histidine reactions proceed at rates which vary from 3 to 25% of those observe...