Virostatic activity of 1,10-phenanthroline transition metal chelates: A structure-activity analysis

Structure-activity relationships have been studied for a series of doubly charged, fully co-ordinated, 1,10-phenanthroline transition metal chelates differing in the metal ion or in the number and nature of the substituent groups present on the 1,10-phenanthroline ligand by assaying their ability to inhibit the multiplication of influenza virus in chick allantoic cells in vitro. The most potent compounds are those derived from the highly labile metal ions Cd(II), Cu(II), Zn(II) and Mn(II) or highly lipophilic ligands. The rate of penetration of the active chelate species into the allantoic cell appears to be an important factor determining activity.