Research On Mycotoxins From Fusarium Graminearum And Their Biological Activitie

In this study,a pathogen SDH was isolated from the diseased rice leaves collected from the rice field at the foot of Maoer Mountain in Heilongjiang Province.Morphological observation and ITS sequence analysis were used to determine the Fusarium graminearum.In the fermentation process of strain SDH,the small molecular epigenetic reagent nicotinamide was applicated to regulate it,and the n-butanol extract was analyzed by HPLC.It was found that the new chromatographic peak appeared at22.5 min.It is presumed that the addition of the histone deacetylase inhibitor nicotinamide can bind to the active site of histone deacetylase and inhibit the activity of the enzyme,thereby increasing the level of histone acetylation,Transcription factor and synergistic transcription factor binding to DNA molecules to enhance the transcriptional level of activation of silencing gene expression.Resulting in the secondary metabolites do not appear in the normal environment.The target monomer compound SDH-A was obtained by using of silica gel column chromatography,dextran gel Sephadex LH-20 column chromatography and high performance liquid chromatography(HPLC).The target monomer compound SDH-A was got by magnetic resonance chromatography,mass spectrometry Analysis and identification of SDH-A as known substances with anti-AIDS activity.Integracide A.The substance was first isolated by Brill in 1996 and was isolated from wheat metabolites of Fusarium graminearum and found possessing the effect of anti-HIV.In this study,the strain SDH,which did not produce Integracide A in the general living environment,was produced by adding epigenetic reagent nicotinamide to the antiviral substance during the fermentation.At the same time,the highest yield of Integracide A was acquired by adding nicotinamide to the final concentration of 120μmol/L,and adding macroporous adsorption resin AB-8 1.5 g/100 m L on the third day of fermentation.Under this condition,the output of Integracide A can reach 101.05 ±3.52 mg/L level.In addition,in the process of adding macroporous adsorption resin,the method of rapid separation of SDH-A was obtained by the method of adding macroporous adsorption resin AB-8,followed by distilled water,30% ethanol,60% ethanol,90%Ethanol,100% ethanol,respectively,and got after by 90% ethanol eluting fraction by sephadex according to molecular weight separation,the mobile phase of methanol,followed by HPLC preparation,separation of Integracide A.In addition to the reported anti-HIV activity,the qualitative analysis of the antimicrobial activity of the three tested bacteria by the double-layer plate perforation agent diffusion method indicated that Integracide A exsisted Bacillus subtilis and Pseudomonas solanacearum effect,but no obvious antibacterial activity against E.coli.In this study,we added the small molecule epigenetic reagent nicotinamide to produce the active substance without showing up Integracide A under normal conditions.The active substance was generated by the experiment and the specific method of increasing the yield.Mean time,the rapid separation and purification process of the Integracide A,laid a solid foundation for further research.