Synthesis and antimalarial property of orally active phenoxazinium salts

Phenoxazinium salts were found to display good antimalarial efficacy in vivo against Plasmodium berghei. Several compounds provided 100% parasitemia clearance at a dose of 20−30 mg kg-1 × 4 days (ip) and good survival effects without obvious acute toxicity. They also showed excellent potency by oral administration. A preliminary pharmacokinetic study revealed that the oral availability of 1a was excellent.