Modifying the acylation of flavonols in Petunia hybrida

• Published in: Phytochemistry (Oxford) 2008-07, Vol.69 (10), p.2016-2021
• Main Authors: Cunningham, Oliver D., Edwards, Robert
• Format: Article
• Language: English
• Subjects: Acylation; Acyltransferases; Agronomy. Soil science and plant productions; Biological and medical sciences; caffeic acid; Chemical constitution; coumaric acids; ferulic acid; flavonoids; flavonols; Flavonols - chemistry; Fluoroacylation; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; glycosides; Mass Spectrometry; methyl esters; Molecular Structure; Petunia - chemistry; Petunia hybrida; Phenylpropanoids; Plant Leaves - chemistry; Plant physiology and development; Propanols - chemistry; Varietal selection. Specialized plant breeding, plant breeding aims; Yield, quality, earliness, varia
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2008.04.014

Treatment of petunia leaves with methyl esters of caffeic and ferulic acid resulted in major increases in the concentrations of naturally-occurring caffeoylated and feruloylated flavonol glycosides. Feeding with methyl coumarate resulted in the formation of a acylated flavonoid, with the bioisostere 4-fluorocinnamic acid forming the corresponding fluoroacylated derivative. The potential for chemically-regulating the acylation of natural products in whole plants has been determined by treating petunia leaves with phenylpropanoid acyl donors supplied as the respective methyl esters. Treatment with derivatives of the naturally-occurring acylating species caffeic acid resulted in a general increase in flavonol derivatives, notably caffeoylated quercetin-3- O-diglucoside (QDG) and kaempferol-3- O-diglucoside (KDG). Similarly, methyl ferulate increased the content of feruloylated KDG 40-fold. Treatment with methyl coumarate resulted in the appearance of a coumaroylated derivative of quercetin-3- O-glucuronyl-glucoside (QGGA). When the feeding studies were repeated with the equivalent phenylpropanoid isosubstituted with fluorine groups a semi-synthetic 4-fluorocinnamoyl ester of QGGA was observed. Our results demonstrate the potential to regulate the acylation of flavonols and potentially other natural products by treating whole plants with methyl esters of natural and unnatural acyl donors.