放线菌A19菌株抑菌活性成分的研究

Studies on the Secondary Metabolites of Actinomycetes Strain-A19

从土壤中筛选到一株对多种植物病原菌有强烈抑菌作用的放线菌菌株,编号为A19。采用活性追踪法从A19菌株发酵液中分离得到H-1、H-2和H-3 3个化合物。经结构鉴定,化合物H-1为环(脯氨酸-亮氨酸),化合物H-2为环(4-羟基-脯氨酸-亮氨酸),化合物H-3的结构式尚待解析。抑菌活性测定结果表明:化合物H-3表现强烈的抑菌活性,在剂量为5μg时对枯草芽孢杆菌(Bacillus subtilis)、金黄色葡萄球菌(Staphylococcus aureus)、蜡状芽孢杆菌(Bacillus cereus)、白菜软腐病菌(Erwinia carotovora)的抑菌圈直径分别为13.5 mm1、1.0 mm、12.5 mm和14.0 mm,对小麦赤霉病菌(Fusarium graminearum)、番茄叶霉病菌(Fulvia fulva)、马铃薯干腐病菌(Fusarium solani)、玉米大斑病菌(Exserlhilum turcicum)和玉米弯孢叶斑病菌(Curvularia lunata)孢子的抑制中浓度EC50分别为123μg/mL、154μg/mL、130μg/mL、87μg/mL和173μg/mL。化合物H-2对供试病原菌也表现一定的抑菌活性,而化合物H-1对供试病原菌无明显的抑菌活性。

The fermentation broth of actinomycetes A19-strain had potent antimicrobial activities.Three compounds（H-1,H-2 and H-3） were isolated from the fermentation broth by means of bioassay-guided.Based on the spectral data and compared with literatures,H-1 was identified as cyclo-（Pro-Leu）,H-2 was identified as cyclo-（4-hydroxyl-Pro-Leu）,H-3 is on the way of identification.The antibioactive activities of these compounds against bacteria and phytopahogenic fungi were tested.Compound H-3 showed obviously antibacterial activities,the diameter of inhibition zone of it against pathogenic bacteria Bacillus subtilis,Staphylococcus aureus,Bacillus cereus and Erwinia carotovora were 13.5 mm,11.0 mm,12.5 mm and 14.0 mm,respectively.The EC50 value of compounds H-3 against phytopathogenic fungi Fusarium graminearum,Fulvia fulvum,Fusarium oxysporium,Exserlhilum turcicum and Curvularia lunata were 123 μg/mL,154 μg/mL,130 μg/mL,87 μg/mL and 173 μg/mL,respectively.Compound H-2 showed slight antimicrobial activities,and compound H-1showed no antimicrobial activities.