The present invention relates to N-Benzyl-Substituted Pyridyl Porphyrin Compounds and compositions comprising an effective amount of N-Benzyl-Substituted Pyridyl Porphyrin Compounds. The N-Benzyl-Substituted Pyridyl Porphyrin Compounds include compounds of the following formula: ##STR00001## wherein: M is Fe or Mn; f is 0 or 1; each R is independently --C(O)(amino acid residue) or --SO.sub.2(amino acid residue); and n is the number of counterions sufficient to balance the charges of the compound of Formula (A).