101. Polyacylated Anthocyanins in Bluish-Purple Petals of Chinese Bellflower, Platycodon grandiflorum .
- Author
-
Kondo T, Hagihara S, Takaya Y, and Yoshida K
- Subjects
- Acylation, Anthocyanins chemistry, Biosynthetic Pathways genetics, Color, Flowers chemistry, Flowers genetics, Platycodon chemistry, Platycodon genetics, Anthocyanins genetics, Flowers anatomy & histology, Pigmentation, Platycodon anatomy & histology
- Abstract
The bluish-purple petals of Chinese bellflower, Platycodon grandiflorum (kikyo in Japanese), contain platyconin ( 1 ) as the major anthocyanin. Platyconin ( 1 ) is a polyacylated anthocyanin with two caffeoyl residues at the 7-position, and its color is stable in a diluted, weakly acidic aqueous solutions. HPLC analysis of the fresh petal extract showed the presence of several minor pigments. Photo-diode array detection of minor pigments suggested that some of these were polyacylated anthocyanins. To establish the relationship between structure and stability of the acylated anthocyanins and to obtain information on their biosynthetic pathways, minor pigments were isolated from the petals, and their structures were determined by MS and NMR analyses. Four known ( 2 - 5 ) and three new anthocyanins ( 6 - 8 ) were identified, which contained a delphinidin chromophore, and four of these ( 5 - 8 ) were diacylated anthocyanins, in which the acyl-glucosyl-acyl-glucosyl chain was attached at the 7- O -position of the delphinidin chromophore. These diacylated anthocyanins exhibited a bluish-purple color at pH 6, which was stable for more than a week.
- Published
- 2021
- Full Text
- View/download PDF