Self-Assembly and Biorecognition of a Spirohydantoin Derived from alpha-Tetralone: Interplay between Chirality and Intermolecular Interactions

Abstract

A racemic spirohydantoin derivative with two aromatic substituents, a tetralin and a 4-methoxybenzyl unit, was synthesized and its crystal structure was determined. To define the relationship between molecular stereochemistry and spatial association modes, development of the crystal packing was analyzed through cooperativity of intermolecular interactions. Homo and heterochiral dimeric motifs were stabilized by intermolecular N-H...O, C-H...O, C-H...pi interactions and parallel interactions at large offsets (PILO), thus forming alternating double layers. The greatest contribution to the total stabilization came from a motif of opposite enantiomers linked by N-H...O bonds (interaction energy=-13.72 kcal/mol), followed by a homochiral motif where the 4-methoxybenzyl units allowed C-H...pi, C-H...O interactions and PILO (interaction energy=-11.56 kcal/mol). The number of the contact fragments in the environment of the tetralin unit was larger, but the 4-methoxybenzyl unit had greater contribution to the total stabilization. The statistical analysis of the data from the Cambridge Structural Database (CSD) showed that this is a general trend. The compound is a potential inhibitor of kinase enzymes and antigen protein-coupled receptors. A correlation between the docking study and the results of the CSD analysis can be drawn. Due to a greater flexibility, the 4-methoxybenzyl unit is more adaptable for interactions with the biological targets than the tetralin unit.