Synthesis and in vitro antiprotozoal activities of dicationic 3,5-diphenylisoxazoles.
3,5-bis(4-amidinophenyl)isoxazole (3)-an analogue of 2,5-bis(4-amidinophenyl)furan (furamidine) in which the central furan ring is replaced by isoxazole-and 42 novel analogues were prepared by two general synthetic pathways. The 43 isoxazole derivatives were assayed against Trypanosoma brucei rhodesiense (T. brucei rhodesiense) STIB900, Plasmodium falciparum (P. falciparum) K1, and rat myoblast L6 cells (for cytotoxicity) in vitro. Eleven compounds (3, 13, 16-18, 22, 26, 29, 31, 37, and 41) exhibited antitrypanosomal IC50 values less than 10 nM, five of which displayed cytotoxic indices (ratios of cytotoxic IC50 to antiprotozoal IC50 values) at least 10 times higher than that of furamidine. Eighteen compounds (4-8, 12, 14, 18-22, 25, 26, 28, 29, 32, and 43) were more active against P. falciparum than furamidine, with IC50 values less than 15 nM. Fourteen of these compounds had cytotoxic indices ranging between 10 and 120 times higher than that of furamidine, and five analogues exhibited high selectivity for P. falciparum over T. brucei rhodesiense.
Patrick
Donald A
DA
Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7525, USA.
Bakunov
Stanislav A
SA
Bakunova
Svetlana M
SM
Kumar
E V K Suresh
EV
Lombardy
Richard J
RJ
Jones
Susan Kilgore
SK
Bridges
Arlene S
AS
Zhirnov
Oksana
O
Hall
James Edwin
JE
Wenzler
Tanja
T
Brun
Reto
R
Tidwell
Richard R
RR
D000818:Animals; D000962:Antimalarials / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001550:Benzamidines / Q000494:pharmacology; D002412:Cations; D002460:Cell Line; D020650:Combinatorial Chemistry Techniques; D007555:Isoxazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010963:Plasmodium falciparum / Q000187:drug effects; D051381:Rats; D013329:Structure-Activity Relationship; D014344:Trypanocidal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D016833:Trypanosoma brucei rhodesiense / Q000187:drug effects
D000962:Antimalarials; D001550:Benzamidines; D002412:Cations; D007555:Isoxazoles; D014344:Trypanocidal Agents; C033286:furamidine