Hemicucurbiturils as receptors in extraction and transport of some amino acids

AbstractThe molecular recognition properties of hemicucurbit[6]uril (HemiCB[6]) and hemicucurbit[12]uril (HemiCB[12]) towards a series of amino acid native and methyl esters (L-phenylalanine, L-leucine, L-valine, L-cysteine, L-tryptophan, L-isoleucine, L-phenylalanine methyl ester hydrochloride (L-PheOMe), L-tyrosine methyl ester hydrochloride (L-TyrOMe), L-valine methyl ester hydrochloride (L-ValOMe), L-leucine methyl ester hydrochloride (L-LeuOMe), L-serine methyl ester hydrochloride (L-SerOMe) and L-cysteine methyl ester hydrochloride (L-CysOMe) were investigated. In this respect, by means of liquid–liquid extraction, a series of amino acid native and methyl esters were extracted from an aqueous phase (pH = 5.5) into a chloroform phase as ion pairs in the presence of tropaeolin 00 as counterion. Based on results obtained in extraction experiments, the active transport assisted by pH gradient of amino acids as ion pairs through chloroform liquid membrane employing HemiCB[6] as carrier was performed. Bot...