Binding of organic anions to a macrocyclic alkaloid d-tubocurarine

An alkaloid d-tubocurarine in aqueous solution binds 8-anilino-1-naphthalenesulfonate and anions of substituted benzoic, aliphatic dicarboxylic, and N-acetyl-α-amino acids. The binding constants vary from ca. 50 to 3300 M−1 depending on the anion structure, charge and hydrophobicity. The binding of N-acetyl-α-amino acids is enantiospecific.