[en] In this paper, we describe the isolation and structural determination of 2,7-dihydroxyapogeissoschizine, a new alkaloid from the root bark of Strychnos gossweileri. Elucidation of its structure is based mainly on 1D and 2D NMR studies; its conformation was optimized by energy minimization. This type of skeleton is related to geissoschizine but with the notable diffrence that the 1 and 17 positions are joined giving an additional fused ring. Such a seven-membered ring has ,to our knowledge, only been observed in apogeissoschizine, obtained after chemical tratment of two alkaloids ( geissospermine and geissoschizine). 2,7-dihydroxyapogeissoschizine is therefore, the first natural product possessing this skeleton. According to a preliminary test, this new alkaloid shows low toxicity to B16 melanoma cells, but not for non-cancer 3T3 fibroblasts cultured in vitro.THese results have to be confirmed by further tests.
Hesse Progress in Mass Spectrometry: Indolalkaloide, H. Budzikiewicz, Chemie, Weinheim; 1974.
Atta-ur-Rahman, Khanum Tetrahedron 1989, 45:3507.
Rapoport, Windgassen, Hugues, Onak (1960) Alkaloids of Geissospermum vellosii. Further Studies on Geissospermine and the Structures of the Indolic Cleavage Products, Geissoschizine1and Apogeissoschizine. Journal of the American Chemical Society 87:4404.
Rackur, Stahl, Walkowiak, Winterfeldt (1976) Reaktionen an Indolderivaten, XXX Die stereoselektive und stereospezifische Totalsynthese der Geissoschizin-Isomeren. Chemische Berichte 109:3817.
Fritz, Wieland (1958) Über die Alkaloide aus Calebassen-Curare XII. Umwandlung Von C-Mavacurin In C-Fluorocurin über Das C-Alkaloid-Y. Justus Liebigs Annalen der Chemie 611:268.
Massiot, Vercauteren, Jacquier, Levy, Le C. R. Acad. Sc. Paris 1981, 292:191.
Wenkert, Bringi (1958) A Stereochemical Interpretation of the Biosynthesis of Indole Alkaloids1. Journal of the American Chemical Society 81:1474.
Dewar, Zoebisch, Healy, Stewart J. Am. Chem. Soc. 1985, 107:3902.
Williams, Fleming Spectroscopic Methods in Organic Chemistry, McGraw-Hill, W. Clowes, London; 1989.
O'Rell, Lee, Boekelheide J. Am. Chem. Soc. 1972, 94:3205.
Hesse, von, Schumann, Spiteller, Spiteller-Friedmann, Taylor, Schmid, Karrer (1964) Die Strukturen von C-Fluorocurin, C-Mavacurin und Pleiocarpamin. 57. Mitteilung �ber Curare-Alkaloide. Helvetica Chimica Acta 47:878.