SYNTHESIS, METAL-BINDING PROPERTIES AND POLYPEPTIDE SOLUBILIZATION OFCROWNED ARBOROLS

The first dendritic crown ether polymers ('crowned' arborols: G1, G2 a nd G3) have been synthesized and characterized. The convergent synthet ic method was found to be more convenient than the divergent synthetic method. The building block in the branch was prepared from bonyl-1,4, 10,13-tetraoxa-7,16-diazacyclooctadecane and 3,5-bis(ethoxycarbonyl-me thoxy)benzoyl chloride. Since the basic repeating unit is the amino di carboxylic acid, one can utilize the methods developed for peptide syn thesis. Final products were obtained in moderate yields by coupling of each generational fragment with a core (benzene-1,3,5-tricarbonyl tri chloride) followed by reduction of all amide linkages to tertiary amin e linkages by borane-dimethyl sulfide. The complexation ability of the se 'crowned' arborols was estimated by two-phase solvent extraction of alkali picrate salts. We found that some of these arborols can solubi lize proteins in organic solvents.