The location and analysis of melanins in the cell walls of some soil fungi

Abstract

Electron-dense particles of melanin were located in ultrathin sections of: the hyphal walls of Amorphotheca resume; the aleuriospore walls of Epicoccum nigrum and Humicola grisea; the sclerotial walls of Colletotrichum coccodes; and both within and between the microsclerotial cell walls of Verticillium dahliae. Melanin was extracted with KOH from each of the fungi, but, because of rapid oxidation of the pigment in air, extraction and analysis was carried out under nitrogen. The pigments were examined spectrophotometrically under UV and IR radiation and by means of x-ray diffraction. Characterization of the melanin in terms of its degradation products indicated it to be indolic in nature. These results are compared with published data on other melanins extracted from animal and plant sources.

Purification and characterisation of a sulphur rich melanin from edible mushroom Termitomyces albuminosus Heim

“…The log of optical density of a melanin solution when plotted against wavelength produces a linear curve with negative slopes. Such characteristic straight lines with negative slopes have been obtained from some melanogenic fungi such as Phyllosticta capitalensis and Auricularia auricula with slope ranging −0.0015 to −0.0030 (Ellis and Griffiths 1974; Suryanarayanan et al 2004; Bin et al 2012; Zhang et al 2015). The slopes of linear plots are often used to identify melanins and matching spectral features in the present work confirms the identity of T. albuminosus melanin.…”

Properties and Function of Pyomelanin

“…The electron transfer properties of L-DOPA melanin pigments have been demonstrated through the coupling of hydroxybenzene depigmenting-compound oxidation to ferric cyanide reduction (Menter & Willis, 1997). The electron transfer properties of melanin polymers, including pyomelanin, also constitute a mechanism of electron transfer to solid electron acceptors like metal oxides (Ellis & Griffiths, 1974, Turick et al 2002 and electrodes (Turick, et al 2009). Based on this information, the structure that most likely will provide for optimum electron transfer capacity is structure B in Figure 2.…”

Characterization of melanin extracted from apricot (Armeniaca sibirica) and its effect on hydrazine-induced rat hepatic injury

“…As a result of physicochemical properties that include heavy metal chelation, radical scavenging and strong UV absorption 1,2 , it has important biological activities, inter alia hepatoprotection, and plays key roles in stress resistance 3,4 . Melanin is also used for diverse purposes in the pharmaceutical 3,5 , cosmetic 6,7 , food 8 , electronics 9 , and other industries 10,11 , as it has strong antioxidant activities, anti-radiation functions, anti-virus functions, hepatoprotective effects, and photoconductivity.…”