SEARCH Articles Figures Tables Cinchona Cinchona alkaloid derived quaternary ammonium salts Cinchona alkaloids, ammonium salts Cinchona ammonium salts Cinchona quaternary ammonium salts Cinchona, quaternary ammonium salts bromide Cinchona, quaternary ammonium salts ester, alkylation Cinchona-based quaternary ammonium salts Dimeric quaternary ammonium salts cinchona-derived