Section 6
Chapter 5,468

Flavonoids from eustoma grandiflorum flower petals

Asen, S.; Griesbach, R.J.; Norris, K.H.; Leonhardt, B.A.

Phytochemistry 25(11): 2509-2514


ISSN/ISBN: 0031-9422
DOI: 10.1016/s0031-9422(00)84498-2
Accession: 005467025

The major flavonoids responsible for flower colours of Eustoma grandiflorum were characterized by TLC, HPLC, spectral and chemical analyses. Anthocyanins were delphinidin 3-rhamnosylgalactoside-5-glucoside and delphinidin 3-galactoside-5-glucoside, each acylated with p-coumaric acid, from the purple cultivar 'Murasaki no Homare' and the pelargonidin analogues, each acylated with either p-coumaric or ferulic acids, from the pink cultivar 'Mono no Mine'. The major flavonol copigments were the 3-rhamnosylgalactoside-7-rhamnoside of myricetin, kaempferol and isorhamnetin and the 3-rhamnosylglucose-7-rhamnoside of kaempferol and isorhamnetin. Flavonols present acylated with p-coumaric acid were myricetin 3-rhamnosylgalactoside-7-rhamnoside and robinin in both cis and trans forms, and isorhamnetin 3-rhamnosylgalactoside-7-rhamnoside. Robinin also was present acylated with caffeic or ferulic acids. Simulated in vitro colours obtained from the flavonoids present in this germplasm indicated that good blue colours were not attainable. Good blue colours were formed with delphinidin 3-p-coumaroylrhamnosylgalactoside-5-glucoside and c-glycosylflavone copigments such as swertisin and isoorientin. These copigments are readily available in other members of the Gentianaceae and this suggests the possibility of genetical engineering endeavours for increasing the color range of this important new ornamental plant.

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