Antitumor Benzothiazoles. 7. Synthesis of 2-(4-Acylaminophenyl)benzothiazoles and Investigations into the Role of Acetylation in the Antitumor Activities of the Parent Amines
摘要:
2-(4-Aminophenyl)benzothiazoles display potent and selective antitumor activity against inter alia breast, ovarian, colon, and renal cell lines, but their mechanism of action, though yet to be defined, may be novel. Metabolism is suspected to play a central role in the mode of action of these benzothiazoles since drug uptake and biotransformation were observed in sensitive cell lines (e.g., breast MCF-7 and MDA 468 cells) in vitro, whereas insensitive cell lines (e.g., prostate PC 3 cells) showed negligible uptake and biotransformation. N-Acyl derivatives of the arylamines have been synthesized, and in vitro studies confirm N-acetylation and oxidation as the main metabolic transformations of 2-(4-aminophenyl)benzothiazoles, with the predominant process being dictated by the nature of the 3'-substituent. The prototype amine 3 underwent mainly N-acetylation in vitro, while 3'-substituted analogues 4 and 5 were primarily oxidized. N-Acetylation of 4 to 11 exerts a drastic dyschemotherapeutic effect in vitro, but acetylation of the halogeno congeners 5-7 gave acetylamines 12-14 which substantially retain selective antitumor activity. In vivo pharmacokinetic studies in rats confirmed rapid and exclusive N-acetylation of the 3'-methyl analogue 4, but less acetylation with the 3'-chloro analogue 5. Distinct expression patterns of N-acetyltransferase NAT1 and NAT2 have been demonstrated in our panel of cell lines.
(EN) There are disclosed herein 2-phenylbenzazole compounds having a 3'-substituent and a 4'-NR5R6 substituent in the phenyl group where R5 and R6 are each hydrogen or alkyl, or where the 4'-NR5R6 substituent is N-acyl (or N-benzoyl). There are also disclosed 2-phenylbenzazole compounds in the form of 4'-N sulphamate salts. Such compounds exhibit significant selective cytotoxic activity in respect of tumor cells and provide potentially useful chemotherapeutic agents for selective treatment of a range of cancers.(FR) Cette invention concerne des composés 2-phénylbenzazole ayant un substituant en 3' et un substituant NR5R6 en 4' dans le groupe phényle, R5 et R6 étant chacun l'hydrogène ou un alkyle, ou le substituant NR5R6 en 4' étant un N-acyle (ou un N-benzoyle). L'invention se rapporte également à des composés 2-phényl-benzazole sous la forme de sels de sulphamate portant N en 4'. De tels composés présentent une activité cytotoxique sélective significative vis-à-vis des cellules tumorales et permettent de disposer d'agents chimiothérapeutiques potentiellement utiles pour le traitement sélectif d'un certain nombre de cancers.