“…It is a remarkable fact that the special metal binding activity of substances such as hydroxamic acids and biheterocyclic ring compounds, which have been used by coordination chemists in the past half century for detection and study of ferric and ferrous ion, respectively, have been "discovered" and exploited through-C02H out antiquity by microorganisms. Actually, the coordination characteristics of systems containing 2-ketopyridine or pyridine aldehyde, a primary amine, and ferrous iron have been studied rather extensively in recent years (Krumholz, 1965;Green et al, 1964). However, compounds of the type reported here, wherein the Schiff base-forming primary amine is covalently anchored to the 2-ketopyridine, have not previously been reported in nature.…”