Supramolecular Chemistry of Bile Acid Derivatives: Formation of Gels

Abstract

Summary: This article describes some of the exciting results obtained during the study of the gelation behavior of bile acid derivatives in the authors laboratory. The serendipitous discovery of charge-transfer interaction promoted gelation of organic solvents by (steroid)pyrene derivatives/TNF is presented. In this class of molecules, the effect of the location of the chiral center in chiral gelators on the overall chirality of the aggregates in the gel was studied. Also described are the aggregation behavior of bile acid based aqueous gelators which led us to postulate design principals to obtain bile acid based aqueous/organogelators.

Bile acid alkylamide derivatives as low molecular weight organogelators: Systematic gelation studies and qualitative structural analysis of the systems

“…This can lead to hydrogelation, which was the subject of the few earliest reports dealing with gel-related bile salts [10,17,18]. Although further research on the subject was slow to catch on [10], by now, the potential of bile acid derivatives to act as low molecular weight gelators has been well established [19,20]. Several bile acid/salt-derived organo-and hydrogelators have been reported in the literature, having structural features such as alkylamide-phenylurea [21], amino acid alkyl ester [22,23], amidoalcohol [24,25], ester [26], alkyl amide [27][28][29], urea [27], aromatic rings [30], and cationic salts [25,31].…”

Thermosensitivity of Bile Acid‐Based Oligo(ethylene glycol) Stars in Aqueous Solutions

“…Fibrillar aggregates have also been observed for a group of bile acid derivatives with gelating properties in organic solvents [30,31] or in aqueous solutions. [32] However, a common feature for these gelators is a large number of interacting hydroxyls, amide groups, or charges, [33] which is not the case with LCA(PEG 4 ) 2 . Further investigations are necessary to elucidate the structure of the self-assembled lithocholate derivative.…”

Ppy-Cholic Acid Composite for Ethanol Sensing Through Impedance Spectroscopy Measurement

“…The material has beenunder intensive research in the field of pathology and pharmacology for long years.Of late, it has attracted the attention of material scientists also due to their potential application as building block in designing chiral templates [2], supramolecular structure in soft material [3][4][5], cation and anion receptors [6][7], artificial ion channel [8] and as surfactant in nanotechnology [9].Bile acids include a group of molecules with similar but non-identical chemical structure, with surprisingly different bio-physical properties. Conventionally,they have24 carbon atoms (abbreviated C 24) with presence of "non-equivalent hydroxyl group" (in 3, 7 and/or 12 C) and the side chain structure supporting a carboxylic acid group; which attribute to its peculiar physical and chemical properties [10].…”