Authors: Sarina M Duckstein Florian C Stintzing
Publish Date: 2011/05/31
Volume: 401, Issue: 2, Pages: 677-688
Abstract
Aqueous and acetone/water extracts from Hamamelis virginiana leaves were investigated to obtain a thorough insight into their phenolic composition To secure compound integrity a gentle extraction method including the exclusion of light was used Liquid chromatography tandem mass spectrometry LCMS/MS analyses yielded a fingerprint including 27 phenolic constituents Quantification of the key compounds on an equivalent basis by highperformance liquid chromatography diodearray detection HPLCDAD showed that gallotannins consisting of six to 11 galloyl units constitute the main fraction whereas procyanidins and catechin represented only a minor part Closer inspection revealed that both extracts possess virtually the same galloyl hexose distribution and the octagalloyl hexose represents the major tannin constituent Additionally eight flavonol glycosides and their corresponding aglycones quercetin and kaempferol as well as three chlorogenic acid isomers and other hydroxycinnamic acids were identified Moreover stability studies on the aqueous extract 5 °C dark room temperature dark room temperature light revealed that the phenolic profile underwent changes when exposed to light Especially the gallotannins proved to be considerably unstable which may result in phytochemically altered Hamamelis leaf extracts upon transport and storage
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