Screening And Nature Study And Preliminary Separation And Purification Of Microbial A-glucosidase Inhibitor

?-glucosidase inhibitor is used widely for preventing or treating diabetes,AIDS,hepatitis B,tumor and other related diseases,and has broad pharmaceutical development value.This study obtained a strain UN-8,high yield of a-glucosidase inhibitor from the soil microbial through reasonable vitro screening model.By analyzing cultural,individual morphological,physiological and biochemical characteristics and 16SrDNA sequence and phylogenetic tree of the strain,identified initially the target strain UN-8 is Streptomyces lavendulae.By single factor and orthogonal experimental analysis for strain UN-8 producing a-glucosidase inhibitor,got the optimal medium composition as follows(g/L):corn flour 30,yeast extract 12,KNO3 0.3,K2HP04 0.5,NaCl 0.5,FeSO4·7H2O 0.01,MgSO4·7H2O 0.5.And got the optimal culture conditions as follows:liquid volume 30 mL/250 mL,inoculums 4%,shaking speed 160 r/min,fermentation time 3 d,initial pH value 8,and fermentation temperature 34?.Under this condition,the inhibitory rate of a-glucosidase inhibitor produced by strain UN-8 is 79.25%,which is as 1.3 times as pre-optimization.By analyzing the nature of the a-glucosidase inhibitor produced by strain UN-8,proved that the active substance had a better stability of temperature,pH,and belonged to polar substances.By a series of methods of preliminary separation and purification,such as,fermentation broth pretreatment,dialysis,Sephadex G-25 gel chromatography,Sephadex peptine 10/300 gel filtration chromatography,weak anion column and thin layer chromatography,isolated the active substance,whose inhibitory rate of a-glucosidase inhibitor is 94.12%,and determined the substance's molecular weight range is between 1000?3500.Finally,by comparing the inhibitory effect of active substance gotten by initial separation and purification with acarbose,a-glucosidase inhibitor got has good prospect for research and development of hypoglycemic agents.