Chemistry and biology of bile acids

This review makes an attempt to combine the insights gained into the biochemistry and physiology of bile acids with the elegant supramolecular systems designed from them. Bile acids are cholesterol-derived facial amphiphiles responsible for the solubilization of cholesterol and fat through mixed micelle formation with phospholipids. An intriguing aspect of bile acids is that their chemical structure has been postulated to correlate with vertebrate evolution. However, the etiology of molecular evolution of bile acids is still poorly understood. There has been a steady progress in the studies aimed at elucidating physiological functions and developing pharmacological applications of bile acids. In recent years, bile acids and their analogues have been extensively utilized as supramolecular receptors for various types of guest molecules and ions. Under certain defined conditions, the supramolecular association of bile acids and their derivatives leads to gel formation. Thus, modified bile acids might find use in the design of futuristic materials.