ACETOGENIC ISOQUINOLINE ALKALOIDS .60. 5'-O-DEMETHYL-8-O-METHYL-7-EPI-DIONCOPHYLLINE-A AND ITS REGULARLY CONFIGURATED ATROPISOMER FROM TRIPHYOPHYLLUM-PELTATUM
G. Bringmann et al., ACETOGENIC ISOQUINOLINE ALKALOIDS .60. 5'-O-DEMETHYL-8-O-METHYL-7-EPI-DIONCOPHYLLINE-A AND ITS REGULARLY CONFIGURATED ATROPISOMER FROM TRIPHYOPHYLLUM-PELTATUM, Phytochemistry, 36(4), 1994, pp. 1057-1061
The isolation and structure elucidation of two new minor naphthylisoqu
inoline alkaloids from the stem bark of Triphyophyllum peltatum is des
cribed. From extended spectroscopic investigations, mainly NMR and CD
spectroscopy, one of the alkaloids is deduced to be 5'-O-demethyl-8-O-
methyl-7-epi-dioncophylline A. This new natural product is, thus, the
first dioncophylline A analogous naphthylisoquinoline alkaloid from T.
peltatum with an opposite configuration at the biaryl axis. Moreover,
low amounts of an additional new alkaloid were isolated, whose spectr
al data suggest 5'-O-demethyl-8-O-methyl-dioncophylline A, i.e. the co
rresponding 'normal' atropodiastereomer.