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Planta Med 1992; 58(1): 43-48
DOI: 10.1055/s-2006-961387
Paper

© Georg Thieme Verlag Stuttgart · New York

Indole Alkaloids with in vitro Antiproliferative Activity from the Ammoniacal Extract of Nauclea orientalis 1

C. A. J. Erdelmeier2 , 5 , U. Regenass3 , T. Rali4 , O. Sticher2
  • 2Department of Pharmacy, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092 Zürich, Switzerland
  • 3Research Department, Pharmaceuticals Division, Ciba-Geigy Ltd., CH-4002 Basel, Switzerland
  • 4Department of Chemistry, The University of Papua New Guinea, Port Moresby, Papua New Guinea
  • 5Dr. Willmar Schwabe Arzneimittel, Research and Development, D(W)-75OO Karlsruhe, Federal Republic Germany
1 Part 3 in the series: ‘Medicinal plants from Papua New Guinea’; for Part 2, see Ref. (2)
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Publication History

1991

Publication Date:
04 January 2007 (online)

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Abstract

Nine angustine-type alkaloids were isolated from ammoniacal extracts of Nauclea orientalis L. (Rubiaceae). Three of them, 10-hydroxyangustine and the two diastereoisomeric 3,14-dihydroangustolines, have not been described in the literature thus far. The structures of the isolates were determined with spectroscopic methods, mainly 1D- and 2D-NMR spectroscopy. The compounds were found to exhibit in vitro antiproliferative activity against the human bladder carcinoma T-24 cell line and against EGF (epidermal growth factor)-dependent mouse epidermal keratinocytes. By using overpressure layer chromatography, it was shown that minor quantities of these alkaloids occur in dried Nauclea orientalis leaves. The use of ammonia in the extraction process results in a significant increase in the formation of angustine-type alkaloids from stric-tosamide-type precursors.

Key words

Nauclea orientalis - angustine-type alkaloids - antiproliferative activity - ammonia extraction - strictosamide-type precursors