Study On Extraction,Purification And Biological Activity Of Alkaloids From Cordyceps Militaris

Cordyceps militaris is not only rich in amino acids,protein,vitamins and trace elements,but also has enhanced human immunity,anti-tumor,anti fatigue and other functions.Cordyceps militaris is a kind of edible and medicinal fungi with high edible value and medicinal value.The sporocarp of Cordyceps was used as raw material for the extraction,separation and purification of alkaloids.And exploring the antioxidant capacity and antibacterial ability of alkaloids to provide reference for further development and utilization of Cordyceps.Results are as follows:1.The specific color reaction and precipitation reaction of alkaloids were used to identify the crude extracts,and the results were further confirmed by UV and HPLC.The alkaloids contained in the crude extracts could be preliminarily confirmed by color reaction,precipitation reaction,UV Spectrum and HPLC chromatography,and the determination wavelength was 268 nm.2.The results of UV absorption spectrum,high performance liquid chromatography,stability test and precision test show that the UV direct determination method can be used for the determination of alkaloids in Cordyceps.This method is simple and easy to operate.Although many people are using acid dyes colorimetric method,acid dye colorimetric method is cumbersome,and the destruction of the sample is larger than that of the UV direct determination method.Acid dye colorimetric method is not conducive to the collection and purification of alkaloids.3.On the basis of single factor,the response surface methodology was used to optimize the extraction process of alkaloids from Cordyceps.Under the conditions of extraction temperature of 52 ℃,extraction time of 23 min,solid-liquid ratio of 1:5 and ethanol concentration of 64 %,the concentration of alkaloid was 0.79 mg/mL.The RSD(Relative Standard Deviation)of the actual value from the predicted value of 0.80mg/mL was 0.62 %.Indicating that the model is reliable.The rate of extraction is 3.93mg/g,which is nearly 1.6 times higher than that before optimization(2.46 mg/g).4.The properties of five kinds of resins,such as adsorption rate,desorption rate,static adsorption kinetics and so on,were studied to filter out the more suitable resin on the alkaloid purification process.The results show that the 732 cationic resin is suitable for the purification of alkaloids in Cordyceps.Then a simple study of the purification process was carried out on 732 resin.The results showed that the adsorption was carried out under the condition that the pH was 4.0,the concentration of the solution was 1.8mg/mL and the flow rate was 2 BV/h and with 0.8 % ammonia,2 BV / h flow rate for elution.,the alkaloids content was increased to 84.71 %which was nearly 2 times higher than that before the purification(43.15 %).5.The antibacterial effect of purified alkaloids in vitro was studied by the method of drilling.The 8 strains were tested with different concentration gradients.The minimum inhibitory concentration of alkaloid on each strain was investigated by using the diameter of inhibition zone as the response value.The results showed that the minimum inhibitory concentrations of total alkaloids from Cordyceps were E.coli 20mg/mL,Salmonella typhi 40 mg/mL,Shigella flexneri 20 mg/mL,Pseudomonas aeruginosa 20 mg/mL,Candida albicans 60 mg/mL.The results showed that the alkaloids of Cordyceps militaris had a good antibacterial effect.6.In vitro antioxidant tests were carried out on purified alkaloids,including superoxide anion scavenging ability,hydroxyl radical scavenging ability and the determination of free radical scavenging capacity of diphenylzylphenylhydrazine(DPPH).The results showed that the total alkaloid of Cordyceps militaris had good antioxidant ability in vitro and had a significant positive correlation with its concentration.The scavenging rate of DPPH was 90.60 %,the removal rate of superoxide anion was 85.46 %,the scavenging rate of hydroxyl radical was 77.41 %,and it was better than that of dibutylhydroxytoluene(BHT)in the experimental concentration range Antioxidant capacity.The results showed that the total alkaloid ofCordyceps militaris had good antioxidant ability in vitro.