Enantio-selective optrode for optical isomers of biologically active amines using a new lipophilic aromatic carrier

摘要

This paper presents a method for optically sensing enantiomers (optical isomers) of biological amines such as norephedrine, and drugs such as the $Beta@-blocker propranolol. It is based on the use of a new lipophilic aromatic ammonium ion carrier (DODD) and a highly fluorescent lipophilic proton carrier (DZ 49) dissolved in a pvc membrane. Recognition of one of the enantiomers is accomplished by specific interaction of the amine with the optically active lipophilic substrate in a pvc membrane. The amine, which is present as an ammonium ion at physiological pH, is carried into the pvc membranes. Simultaneously, a proton is released from the proton carrier (a lipophilic xanthene dye) that thereby undergoes a change in both color and fluorescence intensity. The sensors respond to three analytes in the concentration range from 0.01 to 10 mM for propranolol, 0.3 to 100 mM for norephedrine, and 1 to 100 mM for 1-phenylethylamine. The selectivity coefficients (K$+opt$/) are 0.8, 0.7, and 0.8 for propranolol, norephedrine,a nd 1-phenylethylamine, respectively. It is of potential utility for specifically recognizing one out of several isomers, in particular bioactive amines, where one form usually is active only. The carrier showed stronger affinity for compounds which contain naphthyl rather than phenyl substituents.