- Isomeric Ellipticines. Part 1. Synthesis of two Linear Isomers of the Antitumour Alkaloid Ellipticine
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Two linear isomers of the parent 5,11-dimethyl-6H-pyridocarbazole ellipticine 1a, belonging to the 6H- and 10H-pyridocarbazoles series and their methoxylated derivatives, have been synthesized by three different methods using the Skraup reaction and the Fischer-Borsche cyclization.One of these (method A) afforded an angular monomethyl-7H-pyridocarbazol 9 instead of the expected linear 6H-isomer 8a on cyclisation of 5,8-dimethyl-6-hydrazinoquinoline 21 with cyclohexanone via the Fischer-Borsche indol synthesis.The two other methods (B and C) afforded the desired linear isomers 7 and 8 when the Skraup reaction was performed with aminocarbazoles 26 or with tetrahydroaminocarbazoles 17 and 27 respectively, followed by aromatization of the A ring.Oxidized species were isolated after the aromatization step in method C and were tentatively assigned structures 30-33.
- Alunni-Bistocchi, Giovanni,Orvietani, Pierluigi,Mauffret, Olivier,Antri, Said El,Deroussent, Alain,et al.
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p. 2935 - 2942
(2007/10/02)
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- Etude de la cytotoxicite in vitro de derives du carbazole III. 3-Amino et 3-nitro-1,4-dimethyl-9H-carbazoles diversement substitutes en position 6
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The synthesis of a series of nitro and amino-1,4-dimethyl-9H-carbazoles is described.The cytotoxic activities, as assayed in vitro using clonogenic cell culture of murine leukemia L1210, vary greatly with the nature and position of substituents.The most cytotoxic derivatives, 3-amino-6-hydroxy 1,4-dimethyl-9H-carbazole, displays an activity similar to that of N2-methyl-9-hydroxy ellipticinium acetate (NMHE).These results, together with those previously published by us, allow a detailed analysis of structure-activity relationships in the 9H-carbazole and1,4-dimethyl-9H-carbazole series.For the 3-amino-1,4-dimethyl 9H-carbazole derivatives, a mechanism of action similar to that of ellipticine derivatives is proposed.
- Letois, B,Lancelot, J C,Rault, S,Robba, M,Tabka, T,et al.
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p. 775 - 784
(2007/10/02)
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