Optimization Of Preparation Process Of Xylastriamide A From Xylaria Striata And Analyisis Of Its Biological Activity

Xylaria striata Pat.1887 is a fungus of the genus Xylaria of Ascomycetes.Xylastriamide A,has been isolated from the fruiting body and found to have good anti-tumor,antibacterial and anti-nematode activity in previous research by our group.In this study,the content of xylastriamide A was determined by HPLC,the extractiong and purification of xylastriamide A from the fruiting body of Xylaria striata was optimized,and the biological activity was studied.The results provide a basis for the rapid preparation and application of xylastriamide A.This paper mainly includes the following four aspects:（1）The content of xylastriamide A was determined by HPLC.Mobile phase:acetonitrile-water（65:35）,the flow rate:1 m L/min,the column temperature:35℃,the wavelength:216 nm,the method of isostatic elution was adopted,retention time was 14.918min.（2）Optimization of extraction process of xylastriamide A.The extraction process of xylastriamide A from Xylaria striata was studied.The ethanol concentration,liquid-solid ratio,temperature and extraction time were investigated in turn,and then the RSA was carried out.The best conditions are as follows:ethanol concentration was 70%,ratio of liquid to material was 28 m L/g,extraction temperature was 70℃,extraction time was 3.0 h.Under these conditions,the extraction amount of xylastriamide A in Xylaria striata could reach 0.538 mg/g.（3）Optimization of purification process of xylastriamide A.The xylastriamide A was purified by macroporous resin method,and a large amount of impurities were removed as much as possible and the target components were retained.After the screening of macroporous resin,D-101 macroporous resin was found to have good adsorption desorption effect,so it was selected for the follow-up test.The optimal process conditions of D-101macroporous resin for dynamic adsorption and desorption of xylastriamide A were as follows:D-101 macroporous resin was selected,The sample concentration was 3 mg/m L,the flow rate was 2 BV/h,and the loading volume was 7 BV;during desorption,40%ethanol 3 BV was used to remove non target substances,and then 100%ethanol 3 BV was used for desorption,and the flow rate was 2 BV/h.The average peak area of the purified product increased from 4.13%to 39.63%by HPLC analysis,and the purity was significantly improved.（4）The biological activity of xylastriamide A.The antibacterial activity of xylastriamide A was tested by 96-well plate method.The results showed that xylastriamide A has antibacterial activity obviously.It had strong inhibitory effect on Pseudomonas aeruginosa（MIC=31.3μg/m L）and good antifungal effect on Botryodiplodia theobromae Pat.（MIC=31.3μg/m L）.In the nematicidal activity test,xylastriamide A also had a certain nematicidal activity,the IC₅₀value was 107μg/m L.