Syntheses and antimalarial activities of N-substituted 11-azaartemisinins.
A two-step reaction sequence between artemisinin and methanolic ammonia followed by treatment with Amberlyst 15 yielded 11-azaartemisinin in 65% yield. Substituting a variety of primary alkyl- and heteroaromatic amines for ammonia in the reaction sequence yields N-substituted 11-azaartemisinins in similar or greater yield. When Amberlyst 15 is replaced by a mixture of sulfuric acid/silica gel, both 11-azaartemisinin and the expected metabolite, 10-azadesoxyartemisinin, are formed in 45% and 15% yields, respectively. In vitro and in vivo test data for a number of novel N-substituted 11-azaartemisinins, against drug-resistant strains of Plasmodium falciparum, show they possess antimalarial activities equal to or greater than that of artemisinin. The most active derivative, N-(2'-acetaldehydo)-11-azaartemisinin, 17, was 26 times more active in vitro and 4 times more active in vivo than artemisinin.
Torok
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National Institutes of Health, Bethesda, Maryland 20892-0510, USA.
Ziffer
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Meshnick
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Ager
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D000818:Animals; D000962:Antimalarials / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D037621:Artemisinins; D004353:Drug Evaluation, Preclinical; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008288:Malaria / Q000188:drug therapy / Q000469:parasitology; D013058:Mass Spectrometry; D051379:Mice; D015394:Molecular Structure; D010962:Plasmodium berghei / Q000187:drug effects*; D010963:Plasmodium falciparum / Q000187:drug effects*; D012717:Sesquiterpenes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D000962:Antimalarials; D037621:Artemisinins; D004365:Drugs, Chinese Herbal; C097600:N-(2'-acetaldehydo)-11-azaartemisinin; D012717:Sesquiterpenes; C031327:artemisinin