Abstract
A low MW hydroxamic acid was produced by P. mildenbergii in Fe-deficient media associated with green fluorescent peptides. The chemical structure of this hydroxamic acid was investigated for comparison to known Fe-binding siderophores. The hydroxamic acid was extracted from lyophilized culture media with ethanol and methanol, and crystallized as the hydrochloride. The product had MW of 202.6 and an empirical formula of C9H11O2N.cntdot.HCl and contained hydroxylamine nitrogen. The IR, NMR and mass spectral data suggested that the chemical structure was N-methylphenylacetohydroxamic acid. N-Methylphenylacetohydroxamic acid was synthesized, and its melting point, elemental analysis and MW were identical with those of the natural product. The compound chelated Fe(III), producing a distinctive Fe chelate absorption band at 470 nm. Its relationship to the green fluorescent peptides is discussed.