Pyrolysis combined with gas chromatography and mass spectrometry (Py-GC/MS) was applied for structural investigations of the human substantia nigra neuromelanin. Using synthetic neuromelanins, we have demonstrated that Py-GC/MS is suitable for identification and differentiation of both eumelanin (dopamine-derived) and pheomelanin (cysteinyldopamine-derived) component of the pigment. Structural information on melanin monomers was inferred from their pyrolytic markers. When the human neuromelanin was subjected to pyrolysis, none of the heterocyclic, sulfur-containing markers of pheomelanin component was detected among the thermal degradation products. We have concluded that nigral pigment isolated from normal brain tissue does not contain benzothiazine-type monomers, and that cysteinyldopamine-originated units may be incorporated into the polymer in uncyclized form. The most abundant pyrolysis product was identified as limonene, which indicates that nigral pigment is tightly associated with an isoprenoid-type compound. Pyrolysis in the presence of the methylating reagent allowed identification of high levels of saturated and monounsaturated straight-chain C14-C18 fatty acid species chemically bound to the pigment macromolecule.

Fungal melanins are dark brown or black pigments located in cell walls. They also exist as extracellular polymers. Melanized fungi possess increased virulence and resistance to microbial attack as well as enhanced survival while under environmental stress. Melanins contain various functional groups which provide an array of multiple nonequivalent binding sites for metal ions. Pigmented Cladosporium cladosporoides was shown to biosorb 2.5- to four-fold more Ni, Cu, Zn, Cd, and Pb than albino Penicillium digitatum and at four- to six-fold higher rates. Metal desorption was significantly lower for extracellular melanin than from pigmented or albino biomass which indicated the strength of the melanin-metal bond. At equilibrium, tributyltin chloride (TBTC) concentrations of 2.5 mM, pigmented and albino Aureobasidium pullulans absorbed approximately 0.9 and 0.7 mumol TBTC mg -1 dry wt, respectively, whereas purified extracellular melanin exhibited uptake levels of approximately 22 mumol TBTC mg-1 dry wt at an equilibrium concentration of only 0.4 mM. Addition of melanin to the growth medium reduced the toxic effect of CuSO4 and TBTC due to melanin metal binding and sequestration.

A method for the quantitative analysis of eumelanin and pheomelanin in tissues, e.g., hair and melanoma, is described. The method is simple and rapid because it does not require the isolation of melanins from the tissues. The rationale is that permanganate oxidation of eumelanin yields pyrrole-2,3,5-tricarboxylic acid (PTCA) which may serve as a quantitatively significant indicator of eumelanin, while hydriodic acid hydrolysis of pheomelanin yields aminohydroxyphenylalanine (AHP) as a specific indicator of pheomelanin. The degradation products, PTCA and AHP, can be readily analyzed by high-performance liquid chromatography. Chemical degradations of synthetic melanins, prepared from dopa, 5-S-cysteinyldopa, and their mixtures in various ratios, gave PTCA and AHP in yields that correlated with the dopa/5-S-cysteinyldopa ratio. The PTCA/AHP ratio as well as the contents of PTCA and AHP reflected well the type of melanogenesis in hair and melanomas. The amounts needed for each degradation were 0.5 mg of melanin, 2 mg of hair, and 5 mg of tissue samples. As many as 20 samples can be analyzed within 3 working days.

In this study, melanin (BgM) was obtained from Boletus griseus. The chemical composition and structure of BgM were characterized by UV-visible absorption spectrum, Fourier transform infrared spectrum, elemental analysis, nuclear magnetic resonance, pyrolysis gas chromatography mass spectrometry, and ultra-performance liquid chromatography–high resolution mass spectrometry. The percentage contents of C, H, N, S and O elements were 56.38%, 5.86%, 6.17%, 2.44%, and 28.04%, and the S/N and C/N ratios were 0.17 and 10.66, respectively. The UV-vis spectrum of BgM showed a maximum absorption peak at 214 nm. Characteristic absorption peaks were observed at 3426, 1600 and 1105 cm-1, and BgM contained phenolic hydroxyl, amidogen, carbonyl, methylene, and methyl groups. Moreover, BgM is an eumelanin, and its main skeleton has both a benzene ring and an indole, and the branched chain mainly consists of alkanes, alcohols, and fatty acids. BgM was hydrolyzed by H2O2 and four compounds were tentatively analyzed from the UPLC-MS/MS profile. The chemical structure of BgM was characterized as 5,6-dihydroxyindole eumelanin, and the condensed molecular formula is [C28(OR1)4(OR2)3H11O6N4]n.

Auricularia has a worldwide distribution and is very important due to its edibility and medicinal properties. Morphological examinations and multi-gene phylogenetic analyses of 277 samples from 35 countries in Asia, Europe, North and South America, Africa, and Oceania were carried out. Phylogenetic analyses were based on ITS, nLSU, rpb1, and rpb2 sequences using methods of Maximum Likelihood and Bayesian Inference analyses. According to the morphological and/or molecular characters, 37 Auricularia species were identified. Ten new species, A. camposii and A. novozealandica in the A. cornea complex, A. australiana, A. conferta, A. lateralis, A. pilosa and A. sinodelicata in the A. delicata complex, A. africana, A. srilankensis, and A. submesenterica in the A. mesenterica complex, are described. The two known species A. pusio and A. tremellosa, respectively belonging to the A. mesenterica complex and the A. delicata complex, are redefined, while A. angiospermarum, belonging to the A. auricula-judae complex, is validated. The morphological characters, photos, ecological traits, hosts and geographical distributions of those 37 species are outlined and discussed. Morphological differences and phylogenetic relations of species in five Auricularia morphological complexes (the A. auricula-judae, the A. cornea, the A. delicata, the A. fuscosuccinea and the A. mesenterica complexes) are elaborated. Synopsis data on comparisons of species in the five complexes are provided. An identification key for the accepted 37 species is proposed.

对黑木耳黑色素进行鉴定，并对提取工艺进行优化。黑木耳黑色素性质研究中发现色素溶于碱性溶液，不溶于水、酸及有机溶剂。运用紫外- 可见光谱扫描、傅里叶红外光谱扫描初步研究黑木耳黑色素的基本结构性质，鉴定表明黑木耳黑色素与酪氨酸合成黑色素相一致，为3,4- 二羟基苯丙氨酸(DOPA)类黑色素。提取工艺优化实验发现，采用超声波辅助提取并通过单因素及正交试验优化提取条件，得到最佳提取条件为提取时间80min、超声功率80W、氢氧化钠溶液浓度1.25mol/L、料液比(g/mL)1:30，在优化提取条件下粗品得率达到9.107%，与常规方法相比较，超声波辅助提取具有萃取工艺简单、提取时间短、提取效果较好等优点。