导　　师： 谭仁祥;焦瑞华

学科专业： 100705

授予学位： 硕士

作　　者： ;

机构地区： 南京大学

摘　　要： 共生菌是一类部分或全部生活史在宿主体内,而不会引起宿主病害的微生物。与致病菌相比,共生菌更微妙,很少制造病害,并且能与宿主在大多数环境下一起生存。由于长时间的共同生活,共同进化,共生菌获得了一些鲜明的特点,包括具有独特的生理和生化特征,这使得共生菌能产生一些结构新颖,活性特殊的次生代谢产物。共生菌不仅是一些次生代谢产物的可靠来源,也是宿主产物的条替代来源,还能在生理生化和遗传方面进行改良,从而可以提高代谢产物的产量并且可以生产有活性的代谢产物的替代物。 本论文对从络石/(Trachelospermum jasminoides/),狗牙根/(Cynodon dactylon/),中华稻蝗/(Oxya chinensis/),茼蒿/(Chrysanthemum coronarium/)中,分离得到的4株共生菌的次生代谢产物的结构和生理活性进行了研究。利用Silica gel、TLC、ODS反向柱、Sephadex LH20、HPLC等分离技术得到29个单体化合物,综合利用多种波谱技术/(UV、1H-NMR、13C-NMR、1H-1H COSY、HMBC、ROESY、 HRESIMS、EIMS、CD/)等波谱方法鉴定了21个单体化合物的结构。对于鉴定出结构的化合物,我们进行了活性测试。具体分述如下： 1.从络石/(T. jasminoides/)共生的露湿漆斑菌属内生真菌Myrothecium roridum /(IFB-E009/)液体发酵产物中分离得到了11个化合物,鉴定了其中9个的结构。其中化合物1-4为单端孢霉烯类化合物,化合物6为塑化剂,化合物5及7-9为含氮化合物和//或环二肽化合物,活性测试表明,化合物1-3有中等强度的细胞毒活性,对人肝癌细胞Hep-G2具有中等抑制活性。 2.从西沙群岛-赵述岛采的一株茼蒿/(C. coronarium/)内生真菌液体发酵产物中分离得到8个化合物,鉴定出6个化合物的结构,化合物12为恩镰孢菌素化合物,13-15为含硫原子的环二肽,16-17为含苯环的环二肽。 3.从狗牙根/(C. dactylon/)内生真菌IFB-E039的液体发酵产物中分离得到7个化合物,鉴定了其中的4个化合物的结构,化合物20-23为苯的衍生物, 4.从中华稻蝗/(O. chinensis/)内生放线菌发酵产物中分离得到3个化合物,鉴定了其中的2个化合物的结构,化合物27,28为糖脂类化合物。化合物28具有一定程度的免疫抑制活性,其选择系数/(离体细胞毒活性//免疫抑制活性/)较大。 另外,本论文对植物内生真菌次生代谢产物的研究作了简要的综述。 Symbionts are microorganisms that reside in the internal of living hosts during a variable period of their life, without causing any immediate overt negative effects. Compare with pathogenic bacterium, Symbiotic microorganisms are more subtle, rarely causing problems, coexisting with their hosts under most circumstances. Because of the long time coevolution with their hosts, Symbionts acquire some unique traits, including distinctive physiological and biochemical characteristics, which can produce secondary metabolites with novel structures and special bioactivity. Symbiotic microorganism represent a dependable source of specific secondary metabolites, and an alternative source of compounds which originally isolated from hosts, it can be manipulated physicochemically and genetically, so it is probably to increase yields of desired metabolites and to produce novel analogues of active metabolites. This dissertation reports four symbionts from Trachelospermum jasminoides, Cynodon dactylon, Oxya chinensis and Chrysanthemum coronarium. we investigated the structure and bioactivity of the secondary metabolites from the four symbionts. A total of29compounds were isolated by a combination of chromatographies over Silica gel, TLC, and ODS reverse column, gel filtration over Sephadex LH-20, and semipreparative HPLC.22compounds were elucidated on the basis of spectral Experiments/(UV、1H-NMR.13C-NMR、1H-1H COSY、HMBC、ROESY、HRESIMS、 EIMS、CD/). The cytotoxic activities of individual compounds were screened. The specific were described as follows: 1. Myrothecium roridum /(IFB-E009/) was isolated from T.jasminoides, from the liquid fermentation,11compounds were obtained.9compounds were elucidated. compounds1-4were trichothecenes, compound6was plasticizer compound,5and7-9were alkaloids or dipeptides.compounds1-3showed moderate activities to the human hepatoma cells Hep-G2. 2. An unknown fungi were isolated from C. coronarium in XiSha isoland, hainan province.11compouds were obtained from the liquid fermentation, and10of them were identified. compound12was enniatin, compounds13-15were dipeptides contain sulphur atoms, compounds16-17were dipeptides contain benzene ring. 3. IFB-E039was isolated from C. dactylon.7compouds were obtained from the liquid fermentation, and4of them were identified. compounds20-23were Benzene derivatives. 4. Amycolatopsis sp. HCal were isolated from O. chinensis.3compounds were obtained from the liquid fermentation, and2of them were identified. Compounds27,28were glycolipid compounds, compound28displayed modest immune suppressive activity and a better SI /(in vitro cytotoxicity//immune-suppressive activity/). Furthermore, natural bioactive products from the endophyte were reviewed briefly.

关 键 词： 植物内生真菌 共生菌 络石 单端孢霉烯 环二肽

分 类 号： [Q936]

领　　域： [生物学]