Comparison of physicochemical and biochemical properties of natural and arginine‐modified melanin from medicinal mushroom Ganoderma lucidum

Abstract

Melanin is a hydrophobic biomolecule produced widely in fungi. Compared with other fungi, health benefits have been associated with medicinal mushrooms, which may provide an excellent source of natural melanin. Nevertheless, the hydrophobicity of melanin may limit its applications. Consequently, the present study was carried out on isolation of melanin from the medicinal mushroom Ganoderma lucidum (GLM) and modification with arginine to improve its solubility. The physicochemical and biochemical properties of melanin were evaluated including structural characterization, solubility, stability, antioxidant activities, and inhibitory effect on pancreatic lipase activity. Arginine‐modified melanin showed better solubility, higher color value, stronger antioxidant activity, and stronger inhibitory effect on pancreatic lipase activity in vitro than GLM. In addition, both have good stability in the dark and natural light. These results opened possibilities for providing an excellent source of natural melanin in health food or food additives fields.

Anti-ultraviolet, antibacterial, and biofilm eradication activities against Cutibacterium acnes of melanins and melanin derivatives from Daedaleopsis tricolor and Fomes fomentarius

“…The purified melanin samples were modified with L-arginine following Xu et al (2020) with some modifications. Based on our previous study, the arginine was mixed with F. fomentarius melanin in a ratio of 1:1 (w/w) and 1:1.5 (w/w) with D. tricolor melanin, and then dissolved in 5 mL of distilled water.…”

“…Fortunately, initial studies found that melanin modification with amino acids could enhance their water solubility and subsequently, some of their bioactivities. For example, modification of fungal melanin with either arginine or glucosamine increased the anti-radiation, antioxidant, and antitumor activities of the samples ( Ye et al, 2012 ; Song et al, 2016 ; Li et al, 2018 ; Shi et al, 2018 ; Xu et al, 2020 ).…”

Genome Sequencing of Inonotus Obliquus Reveals Insights Into Candidate Genes Involved In Secondary Metabolite Biosynthesis

“…The second melanin pathway is named the L-DOPA pathway after L-3,4-dihydroxyphenylalanine [27]. There is more DOPA-type melanin in edible mushrooms, such as G. lucidum [28], Termitomyces albuminosus [29], A. bisporus [30], and Auricularia auricula [31]. We found only one polyphenol oxidase gene in I. obliquus, but A. bisporus had four genes (Table S11).…”

Hepatoenteric Protective Effect of Melanin from Inonotus hispidus on Acute Alcoholic Liver Injury in Mice

“…[15] Natural fungus melanin has arose concern because of its biological activities, such as scavenging free radicals, preventing radiation, and binding heavy metal ions. [19][20][21] A previous study obtained melanin from a rice medium of I. hispidus and found that it has antioxidant activity in vitro. [15] However, there are no reports on the protection mechanisms of the liver by melanin from I. hispidus fruiting bodies (IHFM).…”