Studies On Extraction And Separation And Some Biological Activities Of Peptides From Fruiting Bodies Of Cordyceps Militaris

Cordyceps militaris, also known as Cordyceps or North Cordyceps. Research shows that Cordyceps militaris and Cordyceps are extremely similar with the active component and pharmacodynamic action. Such as increasing pneuma and consumptive disease, bacteriostasis, depressurization, conscious-sedation, reducing the temperature, immunifaction and so on. But the natural Cordyceps resources are limited and very expensive and artificial breeding also need better circumstance and nutrition than Cordyceps militaris. So many people think of the Cordyceps militaris can take the place of Cordyceps to some extent. To analyse the chemical components from fruiting bodies of Cordyceps militaris, there are protein, fat, cordyceptic acid,3-deoxyadenosine, cordyceptic polysaccharide, SOD enzymes and some trace element in it, demonstrating the nutritional and medicinal value of Cordyceps. As we all know, the polypeptide is essential substance for the body to complete a variety of physiological activity. It plays an irreplaceable role in biological metabolism and disease treatment. Therefore this research has become a hot spot at home and abroad, but the reports about Cordyceps militaris protein and polypeptide are not many. This article studied on extraction and separation and some biological activities of peptides from fruiting bodies of Cordyceps militaris. In order to provide some theory basis and references for the research and application about protein and peptides for future.The experimental research and the results are as follows:1. To obtain the polypeptide extract from Cordyceps militaris by water extraction and alcohol precipitation method and enzyme preparation method. Two methods are both using the single factor test and orthogonal test to determine the best process conditions. The optimal condition for the water extraction and alcohol precipitation method are the temperature at4℃, time about6h, dosage liquor ratio1:10, pH9and water alcohol ratio1:1; the optimal condition for the enzyme preparation method are double enzyme hydrolysis between pepsin and trypsin, the temperature at42℃, time about8h and the concentration of substrate is6%, in the case of2.5%enzyme.2. The fruiting bodies of Cordyceps militaris extract of physical and chemical properties were identified, and identified the small molecule peptide existence by Tricine-SDS-Page electrophoresis. The results showed:the preparations of the extract are yellowish-brown transparent liquid, and the protein qualitative reactions are all positive. Through UV spectrophotometer in the range of190.0-400.Onm scans, there are two absorption peak in208nm (203nm) and260nm. Electrophoresis results revealed that the extract contains small molecular peptides.3. The method of separation was the two-step gel chromatography. Their separation conditions were Sephadex G-100:column:30cm*4.0cm, eluent was deionized water, eluting rate was50mL/h, the sample volume of4mL, UV detector in280nm; Sephadex G-25:column:40cm*3.0cm, eluent was deionized water, eluting rate was100mL/h, the sample volume of3mL, UV detector in280nm, respectively. There was one chromatographic peak from Sephadex G-100column. Then by Sephadex G-25column separation and detection, it obtained two fractions.4. Isolated fractions were analyzed for amino acid composition and content. The results show that they have rich and variety of amino acids, and the body of essential amino acids contents was high.5. Study on some biological activities of the isolated components. Including the use of chemical model systems for studying on antioxygenation in vitro, antibacterial activity and immunological activity. The study found that the separated components had a certain reducibility and ability to remove hydroxyl radical and superoxide anion. And the experimentation also indicated that they have the T cellular immunity activity. But the antibacterial activity was not obvious.