INCLUSION-COMPOUNDS OF BILE-ACIDS AND THE IR DERIVATIVES

Inclusion behavior and crystal structures of inclusion compounds of bi le acids and their derivatives are described. Molecular recognition pr operties of the steroidal hosts are dependent on molecular structure. Especially, cholic acid, deoxycholic acid and their amides are found t o be versatile hosts to include a wide variety of organic compounds. H owever, Some derivatives of cholic acid provide only guest-free crysta ls, and they can not form inclusion crystals with common organic solve nts at all. X-ray crystallographic studies reveal that the crystal str uctures consist of stacked bilayers except that of lithocholic acid. F acially amphiphilic molecular structure of the bile acids gives the mu ltibilayer structure in crystalline state. Side chain of the steroidal skeleton controls the structural variety of multibilayer structure. O n the basis of molecular recognition and dynamic properties of inclusi on crystals of the steroidal bile acid, we can say that bile acids hav e similar structure and function to proteins through molecular assembl y.