Bile acid–cysteamine conjugates: Structural properties, gelation, and toxicity evaluation

Design, synthesis, and characterization of six novel bile acid–cysteamine conjugates together with investigation of their structural studies, gelation properties, and preliminary toxicity evaluation, are reported. Solid state properties of selected compounds were studied by means of X-ray diffraction and 13C CPMAS NMR spectroscopy. N-(2-thioethyl)-3α,7α,12α-trihydroxy-5β-cholan-24-amide was shown to exhibit (pseudo)polymorphism, and a single crystal structure of its non-stoichiometric hydrate is reported herein. Cholyl and dehydrocholyl derivatives bearing three functionalities in their steroidal backbone were shown to undergo self-assembly leading to gelation in certain organic solvents. Preliminary morphology studies of the formed gels by scanning electron microscopy (SEM) were performed. The standard model mouse fibroblast cell line together with the MTT and NR tests were utilized for evaluating the toxicity of the prepared compounds. Lithocholyl, ursodeoxycholyl, and dehydrocholyl derivatives turned out to be relatively non-toxic in the conditions studied.

► Six new bile acid–cysteamine conjugates synthesized and characterized.
► X-ray structure of N-(2-thioethyl)-3α,7α,12α-trihydroxy-5β-cholan-24-amide solved.
► Cholyl and dehydrocholyl derivatives self-assemble to form organogels.
► Three compounds show capability for further studies for the use in drug purposes.