title: Isolation, identification and quantitation of hydroxycinnamic acid conjugates, potential platform chemicals, in the leaves and stems of Miscanthus × giganteus using LC-ESI-MSn.
abstract: Miscanthus×giganteus is a source of platform chemicals and bioethanol through fermentation. Cinnamates in leaves and stems were analysed by LC-ESI-MS(n). Free phenols were extracted and separated chromatographically. More than 20 hydroxycinnamates were identified by UV and LC-ESI-MS(n). Comparative LC-MS studies on the leaf extract showed isomers of O-caffeoylquinic acid (3-CQA, 4-CQA and 5-CQA), O-feruloylquinic acid (3-FQA, 4-FQA and 5-FQA) and para-coumaroylquinic acid (3-pCoQA and 5-pCoQA). Excepting 3-pCoQA, all were also detected in stem. 5-CQA dominated in leaf; a mandelonitrile-caffeoylquinic acid dominated in stem. Three minor leaf components were distinguished by fragmentation patterns in a targetted MS(2) experiment as dicaffeoylquinic acid isomers. Others (M(r) 516) were tentatively identified as hexosylcaffeoyl-quinates. Three positional isomers of O-caffeoylshikimic acid were minor components. p-Hydroxybenzaldehyde was also a major component in stem. This is the first report of the hydroxycinnamic acid profile of leaves and stems of M.×giganteus.
authors: Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Gogerddan, Aberystwyth, UK. ifp@aber.ac.uk
authors: Ifat
authors: I
authors: Parveen
authors: Michael D
authors: MD
authors: Threadgill
authors: Barbara
authors: B
authors: Hauck
authors: Iain
authors: I
authors: Donnison
authors: Ana
authors: A
authors: Winters
mesh_terms: D005591:Chemical Fractionation; D002853:Chromatography, Liquid; D003373:Coumaric Acids / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006824:Hybridization, Genetic; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D006109:Poaceae / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D003373:Coumaric Acids; D010636:Phenols