ABSTRACT
References .......................................................................................................................... 790
Appendix A ........................................................................................................................ 808
Appendix B ........................................................................................................................ 824
Flavone and flavonol O-glycosides make up one of the largest classes of flavonoid constitu-
ents with over 2000 known structures. There are 279 glycosidic combinations of the most
common flavonol aglycone, quercetin, and 347 kaempferol O-glycosides listed in the check
list (Appendix B) for the period ending December 2003.The group includes any bound form
of flavone or flavonol such as acylated and sulfated derivatives and not only those with just
sugar. Thus, the number of possible combinations is enormous because of the wide structural
variation, i.e., in (1) the hydroxylation and methoxylation pattern of the aglycone; (2) the
number and nature of sugars and their position of attachment through hydroxyl groups to the
aglycone; (3) the nature of the sugar linkage to the aglycone, different interglycosidic linkages
and whether the sugars are in the pyranose or furanose form; (4) the nature, number, and
position of attachment of aliphatic or aromatic acyl groups to one or more sugars or directly
through a hydroxyl group to the aglycone; and (5) the presence and position of attachment of
one or more sulfate groups through a hydroxyl group of the aglycone or that of a sugar.
Sugars can also be attached through a carbon bond but these compounds, the C-glycosyl-
flavonoids, are dealt within Chapter 14.
