Publications scientifiques
Joseph Thierry Ndongo* (Auteur correspondant)
Autres affiliations : University of Göttingen
Dieudonné Emmanuel Pegnyemb
Aymeric Monteillier
Autres affiliations : University of Lausanne
Muriel Cuendet
Autres affiliations : University of Lausanne
Michel Feussi Tala
Hartmut Laatsch* (Auteur correspondant)
Michael Rütten
Daniel Mombers
Birger Dittrich
Journal of Natural Products
Three new alkaloids, janetinine ( 1a ), pleiokomenine A ( 2 ), and huncaniterine B ( 3a ), and 13 known compounds, pleiomutinine ( 3b ), huncaniterine A ( 3c ), 1-carbomethoxy-β-carboline ( 4 ), evoxanthine ( 5 ), deformyltalbotine acid lactone ( 6 ), pleiocarpamine ( 7 ), N 4 -methyl-10-hydroxygeissoschizol ( 8 ), spegatrine ( 9 ), neosarpagine ( 10 ), aspidofractinine ( 11 ), N 1 -methylkopsinin ( 12 ), pleiocarpine ( 13 ), and N 1 -methylkopsinin- N 4 -oxide ( 14 ), were isolated from the stem bark of Pleiocarpa pycnantha . Janetinine ( 1a ) is a carbazole alkaloid; in pleiokomenine A ( 2 ), two aspidofractinine-type alkaloids are bridged by a methylene unit in an unprecedented way, and huncaniterine B ( 3a ) is a pleiocarpamine–aspidofractinine-type dimer. The structures and relative configurations of these compounds were elucidated on the basis of NMR and MS analyses. Their absolute configurations were defined by means of experimental and calculated ECD data, and additionally, the structures of 5 and 13 were determined by single crystal X-ray diffraction. Compounds 1a, 2, 3b, 4, 6, 9, and 12 displayed cancer chemopreventive properties through either quinone reductase induction ( CD = 30.7, 30.2, 29.9, 43.5, and 36.7 μM for 1a, 4, 6, 9, and 12, respectively) and/or NF-κB inhibition with IC 50 values of 13.1, 8.4, 9.4, and 8.8 μM for 2, 3b, 6, and 12, respectively.
