[Complexes of pteridines with phenothiazine and phenoxazine derivatives]

Folic acid and pteroylaspartic acid form solid complexes with N-dialkylaminoalylphenothiazines and with N-dialkylaminoalkylphenoxazines. Folic acid forms 1:2 solid complexes with derivatives having the amine nitrogen in gamma position to heterocyclic nitrogen; the complexes are not formed with those derivatives in which the amine nitrogen is in the beta position to the heterocyclic nitrogen. Pteroylaspartic acid forms 1: 1 solid complexes with classes of compounds having aminic nitrogen in both gamma or beta position to the heterocyclic nitrogen.