Flavone and Flavonol Glycosides

Abstract

In 1975, some 360 flavone and flavonol glycosides were known to occur in plants (Harborne and Williams, 1975). In the intervening five years, a similar number of new compounds have been recorded, bringing the total to about 720 structures (see the check list at the end of the chapter). This is, in fact, a conservative estimate, since a variety of partly characterized glycosides, probably differing in structure from those reported in the Tables in this chapter, have been omitted from this check list. In the present chapter, therefore, we provide an account of the new substances discovered during the period 1975–1980. References to the earlier literature will be included from time to time, since a number of structural reassignments have also taken place. The term ‘conjugate’ might be more apt than ‘glycoside’, since here, as in our previous account, we are including flavones and flavonols with acyl and sulphate substituents; these usually, but not invariably, have glycosidic attachments as well.