Amino acid and peptide hemin derivatives as new promising virucidal agents

We synthesized a series of hemin derivatives (HDs) substituted by residues of amino acids and peptides at either one or two propionic-acid residues, and studied the virucidal activity of the compounds obtained against herpes simplex virus. Compounds 6,7-bis-(methyl ester N-0 L-seryl)-protohemin (IX) (2) and 6,7-bis-[methyl ester N-0-L-arginyl)-protohemin (IX) (6) shown the highest virucidal activity. We also investigated the interaction between HDs and lipid-membrane components as a possible mechanism of virucidal action. A model system including Clark's electrode and a micellar solution of methyl linoleate was used to quantitatively assess the capability of HDs to catalyze the oxidation of polyunsaturated fatty acids as components of lipid membranes. Another model system including liposomes that consisted of dioleoylphosphatydylcholine and was loaded with the fluorescent dye carboxyfluorescein was employed to examine the effect of HDs on lipid-membrane permeability. The kinetics and efficacy of increasing liposome-membrane permeability on exposure to HDs appeared to depend on the nature of the substituents in the HDs. The findings are strongly suggestive of the presence of two different modes of interaction between an HD and the lipid membrane, i.e. oxidative and non-oxidative mechanisms possibly underlie the virucidal action of HDs.