著者

Natsu Tanikawa Hiroyuki Sano Fumi Tatsuzawa

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-067, (Released:2023-06-14)

被引用文献数

1

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We investigated bluish-purple Platycodon grandiflorus flowers for yet unidentified flavonoid-related compounds and their flower coloration mechanisms. We identified a new polyacylated anthocyanin, delphinidin 3-O-[6-O-(α-rhamnopyranosyl)-β-glucopyranoside]-7-O-[6-O-(4-O-(6-O-(4-O-(6-O-(4-O-(β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranoside] (3) as the minor anthocyanin component along with four known anthocyanins, four known flavones, and chlorogenic acid. The major anthocyanin of the bluish-purple P. grandiflorus flowers is platyconin. While platyconin has two caffeic acids linked in series via glucose molecules at the 7-position of delphinidin, anthocyanin 3 has three caffeic acids linked in series via glucose molecules at the 7-position of delphinidin. To investigate the effects of the number of aromatic acyl groups in polyacylated anthocyanin on bluing and stability, the color and stability of anthocyanin 3 in diluted aqueous solution (5 × 10−5 M) at a weak acidic condition (pH 5.7, the same pH as the petal sap) were compared with those of platyconin. Results showed that even if the three caffeic acids were bound in series at the 7-position of delphinidin, there was no further bluing or stabilizing effects of anthocyanin 3 compared to platyconin, but a tendency toward weakening color intensity was observed. Investigation of the change in anthocyanin content at the flower developmental stages showed that delphinidin 3-rutinoside-7-glucoside, which is the deacylated form of platyconin, first accumulated up to sufficient amounts at the bud stage, followed by an increase in platyconin content. At the bud stage, the petals were not purple or violet, except for veins, despite the presence of a good amount of delphinidin 3-rutinoside-7-glucoside, indicating the delphinidin 3-rutinoside-7-glucoside was present in some colorless state.

著者

Natsu Tanikawa Hiromichi Inoue Masayoshi Nakayama

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.MI-114, (Released:2016-02-02)

被引用文献数

5

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Flowers of wild Camellia japonica L. are usually red, but infrequently the flowering trees of this species may have purple flowers. Such purple flowers are a highly desired horticultural property, but the color expression is not fixed. Even if a tree has splendid purple flowers in the spring, they may revert back to the red color of a wild C. japonica flower the next year. We investigated the factors responsible for the purple coloration using red, purplish-red, and purple flowers of the cultivar ‘Sennen-fujimurasaki’. The epidermal cells of purplish-red and purple petals were composed of both red and purple colored cells, whereas those of the red petals were uniformly red. Many of the purple cells contained blue-black granules. Cyanidin 3-glucoside and cyanidin 3-p-coumaroylglucoside, major pigments of red-flowered C. japonica, were the major anthocyanins of ‘Sennen-fujimurasaki’. The anthocyanin contents were not noticeably different among flowers of these different colors. Potential co-pigments such as flavones, flavonols, and cinnamic acid derivatives were negligibly detected. No significant differences were found in the Ca, Mg, Mn, Fe, Cu, and Zn ion contents or in the pH of petal homogenates; however, a significant difference was found in the Al ion content. The Al content of the purplish-red and the purple petals was 4–10 times higher and 14–21 times higher than that of red petals, respectively. A cyanidin 3-glucoside solution prepared at pH 4.8 was pale red with no precipitates. When Al ions were added to the cyanidin 3-glucoside solution, the solution became purple and produced blue-black precipitates similar to the blue-black granules observed in the purple colored cells. Differences in the spectral properties of the petals from those of the prepared solution could be caused by the co-occurrence of red and purple cells and may be influenced by other Al-chelating compounds and/or substantial Al concentrations in the vacuoles. We conclude that the purple flower color of ‘Sennen-fujimurasaki’ is generated by chelation of Al ions by anthocyanins. In other purple-flowered C. japonica exhibiting unstable flower coloration similar to that of ‘Sennen-fujimurasaki’, Al-anthocyanin chelation is also likely associated with the purple flower color.

著者

Natsu TANIKAWA Kumi YOSHIDA Tadao KONDO Takayuki MIZUNO Tsukasa IWASHINA Masayoshi NAKAYAMA

出版者

Japan Society for Bioscience, Biotechnology, and Agrochemistry

雑誌

Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)

巻号頁・発行日

pp.1109052652, (Released:2011-10-07)

参考文献数

8

被引用文献数

5

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A new tetraglycosyl flavonol, 3-O-[2-O-xylosyl-6-O-(3-O-glucosyl-rhamnosyl) glucosyl] kaempferol was isolated from pale purplish-pink petals of Wabisuke camellia cv. Tarokaja with three known flavonols. It was named urakunoside after the species name of Tarokaja, Camellia uraku. Urakunoside was a major flavonol component in the Tarokaja petals, but was not detected in petals of Tarokaja’s presumed ancestor species.