ent-Dioncophylleine A and related dehydrogenated naphthylisoquinoline alkaloids, the first Asian dioncophyllaceae-type alkaloids, from the "new"plant species Ancistrocladus benomensis.
Three new fully dehydrogenated naphthylisoquinoline alkaloids, the 7,1'-coupled ent-dioncophylleine A (3a), the likewise 7,1'-coupled 5'-O-demethyl-ent-dioncophylleine A (4), and the 7,8'-linked dioncophylleine D (5), have been isolated from the leaves of the recently described Malaysian highland liana Ancistrocladusbenomensis. All of them lack an oxygen function at C-6; this so-called Dioncophyllaceae-type structural subclass had previously been found only in naphthylisoquinoline alkaloids from West and Central African plants. Moreover, compounds 3a and 4 are the first fully dehydrogenated, i.e., only axially chiral, naphthylisoquinoline alkaloids of this type that are optically active; compound 5, by contrast, is fully racemic, due to its configurationally unstable biaryl axis. The structural elucidation was achieved by spectroscopic and chiroptical methods. Biological activities of these alkaloids against different protozoan parasites are described.
Bringmann
Gerhard
G
Institut für Organische Chemie der Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany. bringman@chemie.uni-wuerzburg.de
Dreyer
Michael
M
Kopff
Hélène
H
Rischer
Heiko
H
Wohlfarth
Michael
M
Hadi
Hamid A
HA
Brun
Reto
R
Meimberg
Harald
H
Heubl
Günther
G
D000470:Alkaloids / Q000737:chemistry*; D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D002478:Cells, Cultured; D007546:Isoquinolines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008296:Malaysia; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects; D051381:Rats; D014344:Trypanocidal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D016833:Trypanosoma brucei rhodesiense / Q000187:drug effects; D014349:Trypanosoma cruzi / Q000187:drug effects
D000470:Alkaloids; D000962:Antimalarials; D007546:Isoquinolines; D009281:Naphthalenes; D014344:Trypanocidal Agents; C501711:ent-Dioncophylleine A