Gf. Pauli et al., STRUCTURE ASSIGNMENT OF NATURAL QUINIC ACID-DERIVATIVES USING PROTON NUCLEAR-MAGNETIC-RESONANCE TECHNIQUES, Phytochemical analysis, 9(4), 1998, pp. 177-185
The proton nuclear magnetic resonances (NMR) of seven naturally occurr
ing hydroxycinnamoylquinic acids were analysed in order to obtain full
sets of shift values and spin-spin coupling constants, as well as inf
ormation about solution conformation. Based on this study, specific ru
les for proton substituent chemical shifts are derived, allowing the d
istinction of position isomers and single caffeoyl subunits in oligosu
bstituted quinic acids. (C) 1998 John Wiley & Sons, Ltd.