4631370013

KWASY ŻÓŁCIOWE W CHEMII SUPRAMOLEKULARNEJ 1095

ABSTRACT

One of the most important fields in modem synthetic chemistry is the prepara-tion of moleeuies which can recognizc and bind others and then catalyze transfor-mations of the bound moleeuies i.c. „artificial enzymes”, and the construction of Systems which can rcproduce themsclvcs or otherwise storę and process informa-tion at the moleeular lcvcl [5-8]. The abovc mentioned properties of these novel synthetic structurcs will rcsult not only from the presence therein of the various reąuircd elcmcnts, but also from their rclativc arrangements in space and the three-dimensional shapc of the ovcrall asscmbly. In other words, spatially separated ele-ments combinc to achicvc an overall cffect in these structures. Hence, there will be a rcąuircmcnt for moleeuies with wcll-defined geometries in which conformational freedom is kept under elose control. This criterion can be met by designs based on rigid frameworks. The steroid nuclcus is one of the largest rigid units which is rea-dily available. There arc many stcroidal compounds which might be chosen as star-ting matcrials for morę elaboratc frameworks. However, bile acids are the most valu-able group of these compounds due to their chcmically different hydroxyl groups, enantiomerie purity, uniąuc amphiphilicity, availability and Iow cost.

Bile acids arc natural polyhydroxylated steroidal acids existing in bile as so-dium salls of A-acyl derivativcs of glycine and taurine. They are synthesized from cholesterol and can solubilize hydrophobic substances by the formation of micellar aggrcgatcs and thus help in the digestion of fat lipids.

In this review applications of bile acids as building blocks in the synthesis of macrocyclic and also open-chaincd supramoleeular hosts are presented.