裙带菜内生真菌Guignardia sp.的活性次生代谢产物

摘要

AIM:To isolate new and/or bioactive constituents from EtOAc extract of liquid culture of endophyte Guignardia sp.from the leaves of Undaria pinnatifida (Harv.) Sur..METHODS:Isolation and purification were performed through silica gel column chromatograph,Sephadex LH-20 and reversed-phase ODS column and the structures of the compounds obtained were identified through a combination of spectral and chemical methods (IR,MS,1H and 13C NMR).In vitro bioactive assays including antifungal activity against three human pathogenic fungi Microsporum canis,Tricophyton rubrum and Epidermophytonfloccosom and cytotoxic activity against the human nasopharyngeal epidermoid tumor KB cell line were evaluated.RESULTS:Seven compounds have been obtained from the liquid culture of the title endophyte:ergosterol peroxide (6, 22-diene-5,8-epidioxyergosta-3-ol) (1),ergosterol (2),cyclo-(Tyr-Leu) (3),cyclo-(Phe-Phe) (4),cyclo-(Val-Leu) (5),cyclo-(Phe-Pro) (6) and cyclo-(Leu-Ile) (7).Compounds 1-3 and 6 inhibited the growth of M.canis with MICs of 10.0,20.0,50.0 and 5.0 μg·mL~,respectively and compounds 1,2 and 6 against T.rubrum with MICs of 15.0,20.0 and 10.0 μg·mL-1,respectively and 1 and 6 against E.floccosom with MICs of 20.0 and 50.0 μg·mL-1,respectively.In addition,compounds 1,3 and 6 exhibited cytotoxic activity against KB cell line with IC5o of 20.0,10.0,10.0 μg·mL-1,respectively.CONCLUSION:Compounds 1-7 were obtained from Guignardia sp.of U.pinnatifida for the first time,and compounds 1 and 6 had potent cytotoxic and antifungal activity.%目的:对裙带菜内生真菌Guignardia sp.发酵液的乙酸乙酯萃取物进行分离纯化,寻找具有新和/或强生物活性的化合物.方法:采用硅胶柱层析、Sephadex LH-20凝胶柱层析和ODS反相柱层析等色谱方法进行成份的分离纯化,并利用波谱学技术对化合物进行结构鉴定.采用纸片法和MTT法分别评价化合物的抑茵活性和细胞毒活性.结果:从发酵液中分离获得7个化合物,分别鉴定为过氧麦角甾醇(1)、麦角甾醇(2)、环-(酪氨酸-亮氨酸)(3).环-(苯丙氨酸-苯丙氨酸)(4)、环-(缬氨酸-亮氨酸)(5)、环-(苯丙氨酸-脯氨酸)(6)、环-(亮氨酸-异亮氨酸)(7).其中化合物1,2,3和6能抑制犬小孢子生长,其MIC分别为10.0,20.0,50.0和5.0 μg·mL-1；化合物1,2和6对红发毛癣菌有抑制活性,其MIC分别为15.0,20.0和10.0 μg·mL-1并且1和6有抑制絮状表皮癣茵的活性,其MIC分别为20.0和50.0 μg·mL-1.另外,化合物1,3和6对人鼻咽癌KB细胞有抑制活性,其IC50分别为20.0, 10.0和10.0 μg·mL-1.结论:化合物1-7均首次从裙带内生茵Guignardia sp.中分离得到,并且化合物1和6显示出较好的细胞毒和抗菌活性.