Isovitexin (homovitexin or saponaretin) is a flavonoid, namely the apigenin-6-C-glucoside. In this case, the prefix 'iso' does not imply an isoflavonoid (the position of the B-ring on the C-ring), but the position of the glucoside on the flavone, in comparison to vitexin.
Natural occurrence Isovitexin has been found in passion flower, Cannabis, oat, and the açaí palm. Buckwheat contained the highest concentration among the sources tested.
Metabolism Isovitexin beta-glucosyltransferase is an enzyme characterised from Silene alba that forms the glucoside, 2"-O-(β-D-glucosyl)isovitexin from isovitexin and UDP-glucose.
Saponarin is a related compound where the second glucose unit is attached at the 7-position of isovitexin.
See also Vitexin, the 8-C-glucoside of apigenin Isoorientin, the 3'-OH derivative
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