| The compound has a
peroxide group in its structure. When the peroxide comes into
contact with high
iron
concentrations, the molecule becomes unstable and "explodes" into free
radicals. This is because the oxygen atoms are highly electronegative,
and the iron in the body is in the form of positively charged ions. This
results in a high mechanical strain on the chemical bonds of the
peroxide group. High concentrations of iron are found in
red blood cells, which is also where the malaria parasites are
found. When the compound enters the red blood cell, it will release the
free radicals, which are highly destructive to the parasites. An
alternative theory suggests that artemisinins inhibit a calcium
transporter in the parasite and by specifically inhibiting this target,
they kill parasites. The peroxide group in artemisinins is still crucial
to activity, but the target is highly selected rather than a result of
"explosion" into activity by free radicals. |
