The 3-Deoxyanthocyanidins and their glycosides (3-deoxyanthocyanins or 3-DA) are molecules with an anthocyanidins backbone lacking an hydroxyl group at position 3 on the C-ring.
This nomenclature is the inverse of that which is commonly used in flavonoids, where the hydroxy-group is assumed absent if it is not specified, e. g. flavan-3-ol, flavan-4-ol, flavan-3,4-ol and flavonol.
3-Deoxyanthocyanidins are yellow anthocyanidins that can be found primarily in ferns and mosses (Timberlake and Bridle, 1975, 1980),[1] in Sorghum bicolor[1][2] and in purple corn (Nakatani et al., 1979)[1] (maíz morado).
[3] Synthetic 3-deoxyanthocyanidins with a carboxylate group at carbon 4 show unusually stable colorant properties at pH 7.
[1] In Sorghum, the SbF3'H2 gene, encoding a flavonoid 3'-hydroxylase, seems to be expressed in pathogen-specific 3-deoxyanthocyanidin phytoalexins synthesis,[4] for example in Sorghum-Colletotrichum interactions.