Physicochemical properties of borate derivatives of DOPA, dopamine, and their liposomic forms

To increase the solubility of L-3,4-dihydroxyphenylalanine (DOPA) and dopam ine (DA) incorporated in liposomes, it was suggested to convert them into a mmonium and 1-adamantylammonium berate complexes. The structure of these co mplexes was studied by B-11 and H-1 NMR, IR, and mass spectrometry and cond uctometry, The liposomic form of the complexes is characterized by a high a ctive compound/lipid molar ratio (0.5). Catechols in the form of complex sa lts are retained better within the inner volume of liposomes.