title: Formation of novel flavonoids in apple (Malusxdomestica) treated with the 2-oxoglutarate-dependent dioxygenase inhibitor prohexadione-Ca.
abstract: Novel flavonoids were formed in young leaves of apple (Malusxdomestica) after treatment with the dioxygenase inhibitor prohexadione-Ca, which is known to reduce the incidence and severity of fire blight caused by Erwinia amylovora and other plant diseases. The compounds were isolated and identified as luteoliflavan, luteoliflavan 5-glucoside, eriodictyol 7-glucoside and 6"-O-trans-p-coumaroyleriodictyol 3'-glucoside. These flavonoids represent a novel biosynthetic pathway in apple leading to the formation of 3-deoxyflavans. Concomitantly, the content of regularly occurring phenylpropanoids is also influenced by prohexadione-Ca with increasing amounts of hydroxycinnamic acids and decreasing flavan-3-ols and flavonols. The altered flavonoid metabolism may be related to the lowered pathogen incidence though the isolated novel flavonoids do not exhibit antibacterial activity.
mesh_terms: D002726:Chlorogenic Acid / Q000032:analysis; D003373:Coumaric Acids / Q000032:analysis / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D044950:Flavanones / Q000032:analysis / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D007656:Ketoglutaric Acids / Q000378:metabolism* / Q000494:pharmacology*; D027845:Malus / Q000187:drug effects / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010105:Oxygenases / Q000037:antagonists & inhibitors*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D003373:Coumaric Acids; D004791:Enzyme Inhibitors; D044950:Flavanones; D005419:Flavonoids; D007656:Ketoglutaric Acids; C479018:prohexadione-Ca; D002726:Chlorogenic Acid; D010105:Oxygenases; C005273:naringenin