. Biochemical systematics. Biochemical variation; Botany. PHENOLIC SUBSTANCES 199 ANTHOCYANINS The basic aromatic unit is referred to as a phenylbenzo- pyrilium salt with the configuration shown below. This class includes most of the red and blue plant 6' 5' All naturally occurring anthocyanins have the 4', 3, 5, and 7 positions occupied by an hydroxyl or some substituted group. They usually occur as glycosides with the sugars attached at positions 3 or 3 and 5. Sugars commonly reported are glucose, galactose, rhamnose, and arabinose. Disaccharides (for example, rhamnoglucose) may o
. Biochemical systematics. Biochemical variation; Botany. PHENOLIC SUBSTANCES 199 ANTHOCYANINS The basic aromatic unit is referred to as a phenylbenzo- pyrilium salt with the configuration shown below. This class includes most of the red and blue plant 6' 5' All naturally occurring anthocyanins have the 4', 3, 5, and 7 positions occupied by an hydroxyl or some substituted group. They usually occur as glycosides with the sugars attached at positions 3 or 3 and 5. Sugars commonly reported are glucose, galactose, rhamnose, and arabinose. Disaccharides (for example, rhamnoglucose) may occur as well as 3,5-dimonosides and even trisaccharides. In acylated anthocyanins the organic acid is frequently p- hydroxybenzoic, protocatechuic, p-hydroxycinnamic or other phenolic acid. The attachment of the acyl group is apparently at a free hydroxyl in the ring or an hydroxyl group of the sugar. The aglycone of the anthocyanin, which may be obtained by acid hydrolysis, is referred to as an anthocyanidin. Although dozens of anthocyanins have been described, only a few anthocyanidins are known, and some of these are rather rare. These compounds differ in the substitution pattern involving positions 3', 4', 5', 3, 5, and 7. Representative anthocyanidins. ,0H /^ B VOH OH OH pelargonidin cyanidin pCHa OH OH delphinidin OCH3 malvidin Hirsutidin is a 7-methoxy analog of malvidin. Capensinidin, a 5- methoxy analog of malvidin, has been obtained from Plumbago capensis (Harborne, 1962). QCH3 peonidin Rosinidin, a 7-methoxy analog of peonidin, has been reported to occur in Primula rosea (Harborne, 1958).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Alston, Ralph E; Turner, B. L. (Billie Lee), 1925-. Englewood Cliffs, N. J. , Prentice-Hall
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