The High Performance Liquid Separation And The Electrospray Mass Spectrometry Analysis Of The Oxidative Degradation Products From The Black-bone Silky Fowl Melanin

As the good varieties of silky fowl,Taihe silky fowl is one of the famous local characteristic resources in Jiangxi province.It has been demonstrated that the silky fowl melanin is the material basis of the silky fowl.Now the chemical structure of the melanin remains unknown.It is difficult to do deep research on the melanin because of the stable character of the melanin.Chemical degradation is one of the methods of studying the melanin.Soluble degradation products could be obtained by chemical degradation.In my study,silky fowl was degraded by NaOH-H2O2 method,which could fracture the aggregation structure of the silky fowl.It is expected to find the main structural fragments of silky fowl melanin,separate and identify the fragments,in order to acquire the information of silky fowl melanin structure and provide a scientific basis to the following research on the silky fowl melanin.The details and results of the study were present as follows:1.The silky fowl melanin was degraded by NaOH-H2O2 method.The NaOH-H2O2 method:The reaction medium was pH=12 NaOH-H2O2 solution.The reaction was controlled when was added 3.4%H2O2 in constant speed.The reaction was controlled in 90 ? with 24 h.It has been calculated that the degradation product F occupied 8%in quality of the melanin.In the research with respect to chemical composition,it has been found that under 365 nm sample F presented fluorescence.It has been proved that there were organic acids,amino acids and peptides in the sample F with the TLC spray reagents.2.In the water-acetonitrile system,the sample F got satisfactory separation.Thirteen chromatographic peaks was present in the study and four of the peaks got good separation.The sample F was separated by the analytical column.Four components in the sample F was separated well and collected by C18 analytical column.The four collected components was analysed by HPLC.3.The four collected components were demonstrated to be the peptides by the Ninhydrin color reaction.The num.1?2 and 4 peaks were proved to be the cyclic peptides and the num.3 peak was proved to be the linear peptide.4.The precise molecular weights of the four collected components were analysed and calculated by the electrospray ionization-quadrupole time-of-flight mass spectrometry,which were 452.3355,565.4226,678.5033 and 791.5896.5.The molecular formulas of the four components were analysed and calculated by the analysis of the MS/MS with the MassHunter software,which were C24H44N4O4,C30H55N5O5,C36H66N6O6,and C42H77N7O7.