title: 1HNMR Chemical Shift Values for Aromatic Protons in 2,3,9,10- and 2,3,10,11-tetrasubstituted Tetrahydroprotoberberine Alkaloids.
abstract: The (1)HNMR (CDCl (3)) data on 28 tetrahydroprotoberberine alkaloids have shown that it is possible, from the chemical shift values observed for the aromatic protons, not only to determine the substitution pattern but also the type of substituents carried on the two sites in rings A and D within this class of alkaloids.
authors.affiliation: Department of Pharmacognosy, State University of Leiden, Gorlaeus Laboratories, Leiden, The Netherlands.
authors.forename: F C
authors.initials: FC
authors.lastname: Ohiri
authors.forename: R
authors.initials: R
authors.lastname: Verpoorte
authors.forename: A B
authors.initials: AB
authors.lastname: Svendsen