Z. Naturforsch. 2012,
67b, 1159 – 1165
doi:10.5560/ZNB.2012-0115
Naucleactonin D, an Indole Alkaloid and other Chemical Constituents from Roots and Fruits of Mitragyna inermis
Erik V.
Donfack1,2,
Bruno N.
Lenta3,
Michel D. T.
Kongue2,
Yannick F.
Fongang1,
Silvère
Ngouela1,
Etienne
Tsamo1,
Birger
Dittrich4, and
Hartmut
Laatsch2
1 Department of Organic Chemistry, Faculty of Science, TWAS Research Unit (TRU) of the University of Yaoundé I, P. O. Box 812 Yaoundé, Cameroon
2 Institute of Organic and Biomolecular Chemistry, Georg-August University, Tammannstr. 2, D-37077 Göttingen, Germany
3 Department of Chemistry, Higher Teachers' Training College, University of Yaoundé I, P. O. Box 47, Yaoundé, Cameroon
4 Institute of Inorganic Chemistry, Georg-August University, Tammannstr. 4, D-37077 Göttingen, Germany
Received April 23, 2012 / published online November 12, 2012
Phytochemical investigation of the roots and fruits of Mitragyna inermis (Rubiaceae) resulted in the isolation of a new indole alkaloid, named naucleactonin D (1), together with fourteen known compounds: nauclefiline (2), naucleficine (3), nauclefidine (4), angustoline (5), angustine (6), barbinervic acid (7), quinovic acid 3-O-α-l-rhamnopyranoside (8), betulinic acid (9), a mixture of ursolic (10) and oleanolic acid (11), a mixture of stigmasterol and β-sitosterol, β-sitosterol 3-O-β-d-glucopyranoside, and strictosamide (12) as the major compound. The structures of the isolated compounds were elucidated by detailed
spectroscopic analysis and by comparison with published data. No 13C NMR data for 2 and 3 exist in the literature and compounds 2, 3, 5, 7, and 12 are reported for the first time from the genus Mitragyna. The crude extract and isolated compounds were tested in vitro for their preliminary cytotoxicity against brine shrimps (Artemia salina).
Key words: Mitragyna inermis, Rubiaceae, Indole Alkaloids, Naucleactonin D, NMR, Cytotoxicity Activity