2-Arylaminoquinoxalines were prepared by the condensation of 2-chloroquinoxaline with the appropriate Mannich bases in the presence of HCl. To synthesize the Mannich bases, 4-acetamidophenol was reacted with formaldehyde and dialkylamine to yield 3-[(dialkylamino) methyl]-4-hydroxyacetanilide, followed by hydrolysis. Antimalarial activities of the new arylaminoquinoxalines were evaluated against the rodent malaria parasite Plasmodium yoelii at a dose of 75 mg kg(-1). Three compounds synthesized (2-[3-[(diethylamino) methyl]-4-hydroxyanilino]-quinoxaline dihydrochloride (2b), 2-[3-[(pyrrolidinyl) methyl]-4-hydroxyanilino]-quinoxaline dihydrochloride (2f), and 2-[3-[(piperidinyl) methyl]-4-hydroxyanilino]-quinoxaline dihydrochloride (2g)) showed moderate antimalarial activity.

Shrivastava et al.: Moringa oleifera (Lam.) as an AntimalarialMalaria kills a lot of people every year in the world, yet this has been observed with little progress in controlling this disease. Moreover, the number of cases is increasing, resulting from the rise of drugresistant parasites and insecticide-resistant mosquitoes. In the present study the antimalarial efficiency of flowers and leaves of the Moringa oleifera (Lam.) plant was evaluated against rodent malaria parasite: Plasmodium yoelii (Chloroquine resistant N-67 strain) infected Swiss albino mice. For the study, crude extracts of flowers and leaves of the Moringa oleifera (Lam.) plant were given at different doses i.e., 125, 250, 500 and 1000 mg/kg to Plasmodium yoelii infected Swiss albino mice, then various parameters llike percent of suppression of parasites, haematological parameters, survival time and body weight of mice, were determined. Percent of suppression of parasites were evaluated by observing Giemsa stained blood smears, which were prepared from different treated groups of experimental mice and haematological testing was done with an automated haematological analyser. The percent of suppression exerted by the flower and leaf against Plasmodium yoelii count ranged between 59 to 41% and 56 to 32%, respectively. Both extracts were found to give positive results as they prevented the major changes in haematological parameters i.e., count of red blood cells, white blood cells and platelets, haemoglobin concentration and haematocrit value which occurred due to Plasmodium infection. Maximum antimalarial effect was observed with the highest dose of the flower extract at 1000 mg/kg followed by leaf extract at the same dose. The crude extract prolongs the survival time of mice as well as prevents body weight loss compared to negative control groups. The results are collectively indicated that the Moringa oleifera (Lam.) plant has a promising anti plasmodial activity against Plasmodium yoelii. Thus, it might be considered as a potential source for the development of novel antimalarial agents.