Several aza-fused rhodacyanines were synthesized and assessed for their in vitro and in vivo antimalarial activities against Plasmodium falciparum K1 and P. berghei. All synthetic compounds showed strong selective antimalarial in vitro activity. Class II azarhodacyanines, 3, consisting of four heterocyclic units, were found to display good parasitemia suppression and low acute toxicity in vivo. Among them, 3c appeared to be the most effective at a dose of 20-25 mg kg-1 day-1 (ip).
Singh,G.C., Journal of the Indian Chemical Society, 1968, vol. 45, p. 27 - 28