特殊生境中地衣内生菌次生代谢产物及其抗辐射作用研究

Research on Endolichenic fungi is becoming a hotspot because of the very novel structures and widespread bioactivities of its metabolites. While the influences of its metabolits on the lichens’ecology sutability still unclear. Preliminary research found a common phenomenon exist in all endolichenic fungi metabolites — hyperfluorescence under ultraviolet lamp, which hints us: the metabolites perhaps contributes unusual significance to high altitude lichens’ anti-ultraviolet properties. Our research group have consummate research routes and basis of endolichenic fungi, according to this project,we intend to isolate endolichenic fungi systematically from the lichens (Umbilicaria) grown under potent ultraviolet radiation, and select representative strains with notable anti-ultraviolet activity of its metabolites, abundant constitutes and high isolation frequency. After fermentation of the targeted fungi, we isolate the constitutes from the metabolites and elucidated the structures of pure compounds; on the basis of combined bioactivities assay of plant leaves and microbes, we look forward to validation of contributions of endolichenic fungi’ metabolites to its host’s (lichens) resistance of extreme habitat.

地衣内生菌由于其代谢产物具有非常新颖的化学结构和广泛的生物活性，成为近年国内外研究的热点，然而其代谢产物对极端生境(强紫外线辐射地区)下的地衣体的生态适应性有何影响，目前尚不清楚。前期研究发现，地衣内生菌代谢产物有一个共同特征-紫外灯下显强荧光，这提示我们：其可能会对高海拔环境地衣体的抗紫外线辐射作用具有特殊意义。本课题组拥有成熟的地衣内生菌的研究路线和良好的研究基础，本项目拟对生长于强紫外线辐射下的地衣体(Umbilicaria)进行系统内生菌分离，选择代谢产物抗紫外线活性强、成分丰富和分离频率高的代表性菌株，进行发酵，对其代谢产物进行分离、结构鉴定；通过对植物和微生物的联合抗紫外线辐射生物活性测定，验证地衣内生菌代谢产物对其寄主（地衣体）抗逆性的贡献。

地衣内生菌由于能够产生结构新颖，活性广泛的次生代谢产物，而成为近年来研究热点。本项目主要对采自特殊生境的地衣的内生菌进行分离，鉴定，次生代谢产物结构鉴定，以及生物活性评价，以期活性新型药物先导化合物。基于本项目共分离获得20余株内生菌，对其中三株内生菌的研究共获得40余个化合物，其中新颖结构化合物10个，具有抗菌，抑制根系伸长，抗肿瘤等活性的化合物6个。初步探讨了内生菌与寄主植物之间的互作关系，为相关医药领域和化学生态学研究提供重要借鉴。