Electron spin resonance spectrometry of fungal melanins

5 pages, 4 tables, 34 references.We investigated electron spin resonance (ESR) parameters (free radical concentrations, g values, and linewidths) of a variety of fungal melanins. The influences of oxygen, culturing conditions, methylation, solvent extraction, acid hydrolysis, and persulfate oxidation on ESR parameters were also studied. Our major objective was to gain a better knowledge of the similarities of fungal melanins with soil humic acids. We suggest that these biopolymers are different from soil humic acids with regard to ESR parameters.This work was supported by a grant from the Fundación Juan March, Spain.Peer reviewe