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Identification of two isomeric meroterpenoid naphthoquinones from Cordia linnaei by liquid chromatography–mass spectrometry and liquid chromatography–nuclear magnetic resonance spectroscopy
Author(s) -
Ioset JeanRobert,
Wolfender JeanLuc,
Marston Andrew,
Gupta Mahabir P.,
Hostettmann Kurt
Publication year - 1999
Publication title -
phytochemical analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 72
eISSN - 1099-1565
pISSN - 0958-0344
DOI - 10.1002/(sici)1099-1565(199905/06)10:3<137::aid-pca445>3.0.co;2-u
Subject(s) - chemistry , mass spectrometry , chromatography , nuclear magnetic resonance spectroscopy , high performance liquid chromatography , spectroscopy , fraction (chemistry) , organic chemistry , physics , quantum mechanics
The structures of two meroterpenoid naphthoquinones have been elucidated in a fraction of the dichloromethane extract from Cordia linnaei Stearn (Boraginaceae). These naphthoquinones were shown to be closely related structural isomers not separable by preparative chromatographic methods. High performance liquid chromatography coupled with mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy was used for their structure determination within the mixture. Assignment of proton and carbon signals was achieved by a combination of on‐flow liquid chromatography–proton NMR, and NMR experiments on the crude fraction. Copyright © 1999 John Wiley & Sons, Ltd.