Cyklitole

Cyclitols constitute important structural elements of a variety of biologically active compounds, such as aminoglycosides antibiotics, phospholipid inositols referred to as "secondary messengers", and coordination compounds with metals, e.g. platinum, interest in many areas of natural sciences. In spite of the fact that cyclitols have been known since the 18th century, the majority of significant achievements in this field is seen during the late 90-ties of the 20th century. The first section of this review deals with general information on the nomenclature, structural features, configuration and conformation of the cyclitols. The second section is concerned with the occurrence and biological properties of the inositols, in particular of myo-inositol and its derivatives. A mechanism of action of myo-inositol 1,4,5-triphosphate (1,4,5-IP3) as a secondary messenger has been outlined in Scheme 9. The third section discusses the occurrence and biological activity of the other cyclitols of structures illustrated by the formulae in Schemes 10 through 15. The fourth section is confined to aminocyclitols antibiotics. Their names occurrence, mode of action and formulae of main representatives of this class of compounds are summarized in Table 3 and in Figs. 1 through 8. The last section descibes common methods of preparation of the cyclitols. These are as follows: (i) syntheses using sugar precursors; (ii) syntheses utilizing the Diels-Alder cycloaddition (iii) hydrogenation of polyhydroxybenzenes; (iv) molecular modification of known cyclitols.