Electron paramagnetic resonance (EPR) spectroscopy may be applied to examine interactions of melanin with metal ions and drugs. In this work EPR method was used to examination of changes in free radical system of DOPA-melanin--the model eumelanin after complexing with diamagnetic cadmium(II) ions. Cadmium(II) may affect free radicals in melanin and drugs binding by this polymer, so the knowledg...

A phellophytic fungus Phomopsis (Endophytic fungi residing in the Bark) of Azadirachta indica screened for the presence of melanin on their hyphae using an alkali procedure, yielded a dark brown pigment. The purified pigment was subjected to various chemical and physical tests that are diagnostic for melanin. The pigment responds positively for all the diagnostic tests for melanin. Further stud...

Host resistance and parasite virulence are influenced by multiple interacting factors in complex natural communities. Yet, these interactive effects are seldom studied concurrently, resulting in poor understanding of host-pathogen-environment dynamics. Here, we investigated how the level of opportunist pathogen virulence, strength of host immunity and the host condition manipulated via diet aff...

Accurate characterization of melanin using analytical methodologies has proved to be difficult due to its heterogeneity, insolubility in wide pH and broad range of solvents. The present study was undertaken to characterize melanin extracted from an environmental Aspergillus fumigatus AFGRD105 by studying its genes, chemical properties and spectral data. A gene based approach to confirm the type...

Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melan...

Many of the most widely consumed edible mushrooms are pigmented, and these have been associated with some beneficial health effects. Nevertheless, the majority of the reported compounds associated with these desirable properties are nonpigmented. We have previously reported that melanin pigment from the edible mushroom Auricularia auricula can protect mice against ionizing radiation, although n...

Melanin has been implicated in the pathogenesis of several important human fungal pathogens. Existing data suggest that the conidia of the dimorphic fungal pathogen Sporothrix schenckii produce melanin or melanin-like compounds; in this study we aimed to confirm this suggestion and to demonstrate in vitro and in vivo production of melanin by yeast cells. S. schenckii grown on Mycosel agar produ...

Transglutaminases catalyze the cross-linking and amine incorporation of proteins, and are implicated in various biological phenomena. Previously, we found a high molecular mass transglutaminase-inhibitory substance produced by Streptomyces lavendulae Y-200 that appeared to be a melanin substance. Here, we report that synthetic tyrosine melanin inhibited various types of transglutaminases. Tyros...

Cryptococcus neoformans is an important opportunistic fungal pathogen that causes life-threatening infection of the central nervous system. A major virulence factor for C. neoformans is the production of melanin in the cell wall. Using transmission electron microscopy, we studied the cell walls of three pairs of isolates obtained from patients with dual cryptococcal infections, where a melanoti...