Iron overload is a medical condition where the body cannot cope with abnormally high levels of iron

Question:

Iron overload is a medical condition where the body cannot cope with abnormally high levels of iron in the system. Chelation therapy by administering desferrioxamine, 7.31, is used to treat the problem. Suggest the origin of the name chelation therapy. What form should the iron be in for the therapy to be most effective? Suggest how the therapy works using compound 7.31; donor sites in the ligand are marked with red arrows and the OH groups can be deprotonated.