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Solid‐state supramolecular architecture of carbenoxolone – comparative studies with glycyrrhetinic and glycyrrhizic acids
Author(s) -
Tykarska Ewa,
Gdaniec Maria
Publication year - 2015
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520614026419
Subject(s) - chemistry , triterpene , hydrogen bond , crystal engineering , supramolecular chemistry , crystallography , molecule , stereochemistry , substituent , cocrystal , carbenoxolone , crystal structure , organic chemistry , medicine , alternative medicine , pathology , intracellular , biochemistry , gap junction
Carbenoxolone (CBXH 2 ), a pharmaceutically relevant derivative of glycyrrhetinic acid, was studied by X‐ray crystallography. The crystal structures of its unsolvated form, propionic acid and dimethoxyethane solvates and a solvated cocrystal of the free acid with its monobasic sodium salt CBXH 2 ·CBXHNa·(butan‐2‐one) 2 ·2H 2 O reveal that the recurring motif of supramolecular architecture in all crystal forms is a one‐dimensional ribbon with closely packed triterpene fragments. It does not result from strong specific interactions but solely from van der Waals interactions. The ribbons are further arranged into diverse layer‐type aggregates with a hydrophobic interior (triterpene skeletons) and hydrophilic surfaces covered with carboxylic/carboxylate groups. Solvent molecules included at the interface between the layers influence hydrogen‐bonding interactions between the carbenoxolone molecules and organization of the ribbons within the layer. Comparison of crystal structures of carbenoxolone, glycyrrhizic acid and its aglycone–glycyrrhetinic acid have shown the impact of the size and hydrophilic character of the substituent at the triterpene C3 atom on the supramolecular architecture of these three closely related molecules.