2.4.5 Isoflavonoid Glycosides
Unlike most other flavonoids, the isoflavonoid glycosides possess a rather limited taxonomic distribution, chiefly confined to the family Leguminosae. On the contrary, their chemical structures display an exceptionally broad spectrum of modifications. Wong (1975)* carried out an extensive review of the chemistry as well as taxonomic distribution of isoflavonoids. A few major classes of isoflavonoids along with their enormous prevailing structural variations are exemplified in Table 4.1.
Table 4.1 Major Classes of Isoflavonoids
However, there exists a close relationship with the structure of isoflavones to the skeleton of the rotenoids (or rotenone), whereas both of them may be regarded as being derived from 3-phenyl chroman as shown below:
* Wong, E ‘The Flavonoids’ Chapman & Hall, London, p. 743-800, 1975.
