Abstract
The binding of 8-anilino-1-naphthalenesulfonate and 15 anions of substituted benzoic, aliphatic dicarboxylic, and N-acetyl-α-amino acids to a macrocyclic alkaloid d-tubocurarine in aqueous solution has been studied by fluorometry, conductometry, and 1H NMR. The binding constants vary from ca. 50 to 3300 M−1 depending on the guest structure, charge and hydrophobicity. The results of fluorescence and NMR studies show that the host-guest complexation of the anions of aromatic acids involves the formation of a salt bridge between the quaternary nitrogen of the alkaloid and the anionic group of the guest as well as hydrophobic/Van der Waals interactions between the guest and host aromatic moieties. The binding of dianions of aliphatic dicarboxylic acids most probably is purely electrostatic. In general, d-tubocurarine possesses binding ability comparable to that of synthetic cyclophanes. It binds enantiospecifically anions of N-acetyl-α-amino acids and discriminates between positional isomers of anions of hydroxy and carboxy substituted benzoic acids.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.