Charge-transfer complexes of hematoporphyrin having a pharmacological interest.

: Complexes formed by hematoporphyrin with donor molecules were prepared and isolated. Among these complexes particular attention is given to that formed by reacting dimethylaminoethanol with hematoporphyrin. Some data are reported on the chemical evidence of formation like u.v. spectra. The product, named Hematodeanol, determines some sufficiently specific effects on the CNS; it remarkably cuts down the depression induced by pentobarbital, moderately hinders convulsions by metrazole, delays hypothermia by reserpine, facilites the learning of conditioned avoidance response (CAR) and improves the learning of a sound discrimination at variable interval. The actions become evident when tests are carried out after a continuous treatment for 7 days and according to the data of the investigation of pharmacokinetic kind, the phenomenon may be attributed to the fact that the drug concentration in the nervous tissue, when it is administered several times at intervals of 24 h, inclines to increase progressively.