1. Academic Validation
  2. Carbazole-, Aspidofractinine-, and Aspidocarpamine-Type Alkaloids from Pleiocarpa pycnantha

Carbazole-, Aspidofractinine-, and Aspidocarpamine-Type Alkaloids from Pleiocarpa pycnantha

  • J Nat Prod. 2018 May 25;81(5):1193-1202. doi: 10.1021/acs.jnatprod.7b00958.
Joseph T Ndongo 1 2 Joséphine N Mbing 3 Aymeric Monteillier 4 Michel F Tala 2 Michael Rütten 5 Daniel Mombers 5 Muriel Cuendet 4 Dieudonné E Pegnyemb 3 Birger Dittrich 5 Hartmut Laatsch 2
Affiliations

Affiliations

  • 1 Department of Chemistry, Higher Teacher Training College , University of Yaoundé 1 , P.O. Box 47, Yaoundé , Cameroon.
  • 2 Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstrasse 2 , D-37077 Göttingen , Germany.
  • 3 Department of Organic Chemistry, Faculty of Science , University of Yaoundé 1 , P.O. Box 812, Yaoundé , Cameroon.
  • 4 School of Pharmaceutical Sciences , University of Geneva, University of Lausanne , Rue Michel-Servet 1 , CH-1211 Genève 4 , Switzerland.
  • 5 Institute of Inorganic and Structural Chemistry, Heinrich-Heine University Düsseldorf , Universitätsstrasse 1 , D-40225 Düsseldorf , Germany.
Abstract

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), N4-methyl-10-hydroxygeissoschizol (8), spegatrine (9), neosarpagine (10), aspidofractinine (11), N1-methylkopsinin (12), pleiocarpine (13), and N1-methylkopsinin- N4-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 IC50 values of 13.1, 8.4, 9.4, and 8.8 μM for 2, 3b, 6, and 12, respectively.

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