论文部分内容阅读
Dehydro-streptopyrrole(DS)is a new class chemical of dehydrobenzoxazin that was first found in the endophytic streptomyces Streptomyces armeniacusi CGMCC 7129.It has a more widely antimicrobial spectrum than streptopyrrole.Meanwhile,we found that metal ions(Pb2+,Mn2+,Cu2+and Cd2+)could improve the output of DS.In order to meet its sample supply for further in vivo pharmacological investigation,an efficient method was developed for the preparation of DS by a combination of response surface methodology(RSM)and preparative high performance liquid chromatography(PHPLC)from strain CGMCC 7129.The heavy metal ion content in the culture was optimized by the RSM to enhance DS production.The results revealed a model(P<0.0001)that was highly significant and this could consequently be utilized for optimizing media.The maximum concentration of DS was measured at 800.00,382.31,599.97 and 600.00 μM levels of Pb2+,Mn2+,Cu2+and Cd2+,respectively.Under the optimized fermentation conditions,DS production was 75.36 μg/mL compared to 17.44 μg/mL under the original standard fermentation conditions.Subsequently,a rapid and efficient method for the separation and purification of DS from crude culture extract was developed using high performance countercurrent chromatography(HPCCC).The liquid phase solvent system employed for HPCCC separation was composed of n-hexane-ethyl acete-methanol-water(5:7:6:5,v/v).The isolation was accomplished within 140 min and the significantly purity of DS was over 97%.Collectively,we have therefore established the new technique of production and fast-separation of DS.