Bis(imidazolium) salts derived from amino acids as receptors and transport agents for chloride anions

Complex Salts of Amino Acids and Peptides

Studies on the transport of anions and zwitterions of acidic amino acids in Streptomyces hydrogenans.

In Streptomyces hydrogenans, acidic amino acids are taken up either as anions by a specific transport system or as zwitterions via a nonspecific one. Variations in the zwitterion concentration caused by changes in pH influence the uptake and exchange diffusion by the nonspecific system. Differences in pH-optima for L-glutamate and L-aspartate transport are due to the different pK2-values of the...

Transport of amino acids.

Before amino acids nourish the cell they must be transported a) across the intestinal mucosa and b) across the plasma membrane of the cell where they are to be used. In addition, full consideration of their economy in the animal organism must include also their entry into the liver and their resorption from the renal tubule. All of these events appear to have much in common and probably to repr...

Polymer-supported Cinchona alkaloid-derived ammonium salts as recoverable phase-transfer catalysts for the asymmetric synthesis of alpha-amino acids.

Alkaloids such as cinchonidine, quinine and N-methylephedrine have been N-alkylated using polymeric benzyl halides or co-polymerized and then N-alkylated, thus affording a series of polymer-supported chiral ammonium salts which have been employed as phase-transfer catalysts in the asymmetric benzylation of an N-(diphenylmethylene)glycine ester. These new polymeric catalysts can be easily recove...

Design and synthesis of hydrophobic and chiral anions from amino acids as precursor for functional ionic liquids.

Hydrophobic ionic liquids composed of tetrabutylphosphonium cation and chiral anions derived from amino acids modified with trifluoromethane sulfonyl groups have been synthesized using a simple method.