Separation, Purification And Structure Study Of Melanin From Neurospora Crassa

Melanin is a polymer structure of a living body during the oxidative polymerization of the phenolic complex and diverse substances or indole produced exists.Melanin can be extracted from animal and plant community,roduced by a microorganism melanin variety,which melanin from Neurospora crassa strains of eukaryotic model.Physicochenical and structural analysis by means of spectra,media components and conditions for Neurospora crassa were studied.The results in detail were stated as follows:Study the produce ability of melanin from Neurospora crassa.By single-factor experiment,The studies showed that the influence of different carbon and nitrogen sources,tyrosine concentration,liquid volume,pH and other factors.We found the medium with glucose,peptone,0.5g/L-tyrosine is the best one.The optimum conditions of extraction were obtained by orthogonal experiment,temperature is 60?,NaOH concentration is 0.5mol/L,solid-liquid ratio of 1:1,pH 3.0 by 6mol/L or12mol/L of HCL when settlement melanin extraction rate reached 0.331g/100mL.Further extracted with ethyl acetate,chloroform,ethanol and organic solvent to purify melanin,through Sephadex G-50 purification,we obtain a single peak of three organic solvent purified melanin.Study the properties from Neurospora crassa of melanin and activity.Melanin poor solubility in aqueous solution at room temperature,but the solubility under different temperature gradients melanin dissolved 90?is better;In the presence of food additives stability is best;the amount of 0.5g/100mL when the clearance rate of 60%DPPH.superoxide anion 60%,OH.85%,of the nitrite ion clearance rate of 50%,However,clearance rate are better than commodity melanin;Studied of UV radiation from E.coli,Bacillus subtilis,Staphylococcus aureus;radiation lowest capacity of the anti-logarithmic growth phase test strain.the maximum number of surviving bacteria in concentration 0.09g/100mL;when strains survived the experimental group improved significantly at 30min.Analysis structure of melanin by spectral wavelength scanning,IR,~1H NMR,mass spectrum.It is found that the mass wavelength at 316nm by spectral wavelength scanning,the outer spectra show that containing indolyl linked hydroxy,amino,carboxyl group and other group.~1H NMR and mass spectrometry show that the Neurospora crassa of melanin molecular weight is 604.It has indole ring,phenolic hydroxyl,carboxyl groups in the structure.