Apocholic acid inclusion compounds

Deoxycholic acid (DCA), apocholic acid (ACA), and cholic acid (CA) form channel-type inclusion compounds with a wide variety of organic molecules. Of these DCA has been extensively investigated. 

In contrast to DCA, there were no detailed reports on the inclusion abilities of its related compounds. There are only a few descriptions of apocholic acid [5] (ACA, see later, in Figure 5) with a very similar bilayer structure to DCA. In 1986, Miyata and Miki et al. discovered lots of inclusion compounds of CA with the similar bilayer structures [6], On the other hand, it took a long time to determine the hexagonal crystal structures of CDCA inclusion compounds, and LCA exhibits no inclusion abilities as yet. In this way, it was confirmed that an increase or decrease of only one atom brings about completely different inclusion behaviors and crystal structures. This fascinating fact has given us adequate and continuous motivation to investigate the inclusion compounds of bile acid derivatives. 

Porous host substructures with parallel channels are typical of many inclusion compounds formed by bile acids and their derivatives (see Deoxycholic, Cholic, and Apocholic Acids). In this class of compounds, host molecules are always optically active, and the resulting host networks are chiral. The best known among them are inclusion compounds of deoxycholic acid (DCA) (also known as choleic acidsj. With most guests. DCA molecules assemble via hydrogen bonds into a coiTugated... 

Channel Inclusion Compounds, p. 223 Clathrate Hydrates, p. 274 Deoxycholic, Cholic, and Apocholic Acids, p. 441 Gossypol, p. 606... 

A chiral host could readily be available from a naturally occurring compound. The use of steroidal acid, deoxycholic acid (Fig. 3d), yielded coinprehensive polymers, particularly, optically active polymers from pro-chiral monomers. Many derivatives of deoxy cholic acid have the corresponding characteristic inclusion abilities. For example, use of apocholic acid (Fig. 3e), cholic acid (Fig. 3f), and chenodeoxycholic acid (Fig. 3g) enabled us to perform one-dimensional inclusion polymerization of various diene and vinyl monomers. 

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