title: Synthesis of 9-O-substituted derivatives of 9-hydroxy-5, 6-dimethyl-6H-pyrido[4,3-b]carbazole-1-carboxylic acid (2-(dimethylamino)ethyl)amide and their 10- and 11-methyl analogues with improved antitumor activity.
abstract: Analogues of the antitumor drug S 16020-2 modified at the 9, 10, or 11 position were synthesized and evaluated in vitro and in vivo on the P388 leukemia and B16 melanoma models. Starting from 9-methoxy-5, 11-dimethyl-6H-pyrido[4,3-b]carbazole-1-carboxylic acid ethyl ester, the 11-CH3 analogue of 9-hydroxy-5,6-dimethyl-6H-pyrido[4, 3-b]carbazole-1-carboxylic (2-(dimethylamino)ethyl)amide (1), compound 4, was synthesized using a four-step sequence, whereas its 10-CH3 analogue 5 was prepared using a two-step pathway, starting from compound 1. Finally starting from the 9-OH compounds 1, 4, and 5, a series of variously 9-O-substituted derivatives were synthesized. In these series, the most active compounds resulted from esterification of the 9-OH group with various aliphatic diacids, which led to 9-O-CO-( )-COOH derivatives of 1, 4, and 5. For these compounds, the number of long-term surviving mice obtained at the optimal dose were 60-100% in the ip/iv P388 leukemia and 10-35% in the ip/ip B16 melanoma, corresponding to an improved therapeutic index with respect to 1 and 4. This high antitumor activity, with curative examples in both models, was not due to a higher cytotoxicity since these compounds were equally or slightly less potent in vitro than 1 and 4. The most active compounds were thus selected for further in vivo evaluation.
authors.affiliation: Division Chimie A and Division de Cancérologie Expérimentale, Institut de Recherches Servier, 11 rue des Moulineaux, 92150 Suresnes, France.
authors.forename: C
authors.initials: C
authors.lastname: Guillonneau
authors.lastname: PierréA
authors.forename: Y
authors.initials: Y
authors.lastname: Charton
authors.forename: N
authors.initials: N
authors.lastname: Guilbaud
authors.forename: L
authors.initials: L
authors.lastname: Kraus-Berthier
authors.forename: S
authors.initials: S
authors.lastname: Léonce
authors.forename: A
authors.initials: A
authors.lastname: Michel
authors.forename: E
authors.initials: E
authors.lastname: Bisagni
authors.forename: G
authors.initials: G
authors.lastname: Atassi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D004611:Ellipticines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D007941:Leukemia P388 / Q000188:drug therapy / Q000473:pathology; D008546:Melanoma, Experimental / Q000188:drug therapy / Q000473:pathology; D008745:Methylation; D051379:Mice; D009368:Neoplasm Transplantation; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D004611:Ellipticines; C101591:S 16020-2