Interaction of metal ions with N-glycosylamines: isolation and characterization of the products of 4,6-O-benzylidene-N-(o-carboxyphenyl)-β-D-glucopyranosylamine with different metal ions

Abstract

Metal-ion complexes of Li⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Ba²⁺, Pb²⁺, Cd²⁺, Hg²⁺ with 4,6-O-benzylidene-N-(o-carboxyphenyl)-β-D-glucopyranosylamine were synthesized and isolated as solid products and characterized by analytical means as well as by spectral techniques, such as, ¹H and ¹³C NMR, FTIR, absorption, FAB mass spectrometry, optical rotation and CD. While the alkali metal ions formed ML type of complexes, the other metal ions formed ML₂ type complexes. Molecular weights of the complexes of Li⁺, Na⁺ and K⁺ were established based on the molecular-ion peaks in the FAB mass spectra. The saccharide portion remians in the β-anomeric form even after the complexation. The spectral data, as well as the trends observed in the chemical shifts, indicate the interaction preferences between this glycosyl amine and different metal ions, and further reveal certain structural features of the complexes.