Abstract
The coordination chemistry of iron (III) (Fe3+) and copper (II) (Cu2+) in melanins synthesized by seven actinomycetes isolated from Brazilian latosol soils under savanna (cerrado) vegetation was investigated using electron paramagnetic resonance (EPR) and ultraviolet-visible (UV-Vis) spectroscopy. The EPR spectra indicated the presence of Cu2+ ions bound to oxygenated and nitrogenous functional groups, and rhombic coordinated Fe3+ ions. In some of the actinomycete melanins the EPR hyperfine splitting of Cu+2 ion complexes was well resolved, and indicated four magnetically equivalent nitrogen atoms in a plane. This result suggested the presence of Cu+2 porphyrin complexes, which was confirmed by Soret bands in the 400-nm region of the UV-Vis spectra. The concentration of Mn in actinomycete melanins, determined by inductively coupled plasma atomic emission spectroscopy, was lower than those of Cu and Fe.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 9 April 1997
Rights and permissions
About this article
Cite this article
Mangrich, A., Lermen, A., Santos, E. et al. Electron paramagnetic resonance and ultraviolet-visible spectroscopic evidence for copper porphyrin in actinomycete melanins. Biol Fertil Soils 26, 341–345 (1998). https://doi.org/10.1007/s003740050386
Issue Date:
DOI: https://doi.org/10.1007/s003740050386