Binding properties of carbohydrate sulfamates based on ab initio 6–31 + G∗∗ calculations on N-methyl and N-ethyl sulfamate anions

2-Deoxy-2-sulfoamino-d-glucopyranoside anions are uniquely found in heparin-like biopolymers. Due to the bioactivities of these biopolymers, there is considerable interest in developing heparin mimetics as potential therapeutic agents. The chemical bonding of such anions is analyzed by topological analysis of the electron-density distribution based on ab initio 6–31 + G∗∗ calculations. The results support an amine-like pyramidal geometry for nitrogen with a well-defined maximum in the Laplacian of the charge density consistent with a lone pair of electrons. Water complexes of the N-methyl sulfamate anions give insight into binding motifs, including bifurcated hydrogen-bonded systems and hydrogen-bond properties for the sulfoamino nitrogen. Finally, by systematic variation of the structural parameters of these N-alkyl sulfamate anions, MM + parameters for this group in sugars were determined. The structural properties calculated by molecular modeling agree well with the ab initio results and with three crystal structures of sodium 2-deoxy-2-sulfoamino-α-d-glucopyranose derivatives.