Phytotoxic, Antifungal and Immunosuppressive Metabolites from Aspergillus terreus QT122 Isolated from the Gut of Dragonfly
Phytotoxic, Antifungal and Immunosuppressive Metabolites from Aspergillus terreus QT122 Isolated from the Gut of Dragonfly
复制标题
从蜻蜓肠道中分离的土曲霉 QT122 的植物毒性、抗真菌和免疫抑制代谢物
DOI：
10.1007/s00284-016-1157-y
复制
发表时间：
2017-01-01
影响因子：
2.6
通讯作者：
Zhang, Ying-Lao
中科院分区：
文献类型：
--
作者：
Lu, Yi-Hui;Jin, Li-Ping;Zhang, Ying-Lao
昆虫肠道微生物被认为是生物活性代谢物的来源。本研究的目的是表征与蜻蜓肠道相关的真菌土曲霉QT122的化合物。从真菌QT122中分离到5种主要的植物毒性、抗真菌和免疫抑制物质。通过波谱分析，并与文献中相关数据进行比较，鉴定其结构分别为大黄素(1)、1-甲基大黄素(2)、terrein(3)、甲基6-乙酰-4-甲氧基-7,8-二羟基萘-2-羧酸甲酯(4)和二氢洋姜素(5)。其中化合物3对逆转录草根生长的抑制作用最强，IC50值分别为11.2和3.1 μ g/mL，与阳性对照2,4-二氯苯氧乙酸（2,4- d）的IC50值分别为8.1和1.6 μ g/mL相当。其中化合物2 ~ 3对番茄赤霉的生长具有较强的抑制作用，IC50值小于0.1 μ g/mL；化合物2对黄瓜尖孢镰刀菌的生长也有较强的抑制作用（IC50值< 0.1 μ g/mL），与参考环已酰亚胺的IC50值小于0.1 μ g/mL相当。化合物3 ~ 5对T细胞活性具有较强的免疫抑制作用，抑制率达99%以上，与20 μ m浓度下环孢素A的抑制率相当，表明化合物2 ~ 5具有作为农业生物防治剂或免疫抑制剂的潜力。
Insect gut microbes have been considered as a resource for bioactive metabolites. The aim of this study was to characterize the compounds of a fungus Aspergillus terreus QT122 associated with the gut of dragonfly. Five main phytotoxic, antifungal, and immunosuppressive substances were isolated from the fungus QT122. The structures of such compounds were identified as emodin (1), 1-methyl emodin (2), terrein (3), methyl 6-acetyl-4-methoxy-7,8-dihydroxynaphthalene-2-carboxylate (4), and dihydrogeodin (5) on the basis of spectroscopic analysis and by comparison of the corresponding data to those reported in the literature previously. The compound 3 exhibited the best phytotoxic activity against the radicle growth of A. retroflexus L. and E. crusgalli L. with their IC50 values of 11.2 and 3.1 mu g/mL, which were comparable to that of the positive control of 2,4-dichlorophenoxyacetic acid (2,4-D) with the IC50 values of 8.1 and 1.6 mu g/mL, respectively. The compounds 2-3 showed potent antifungal activity in the growth of Alternaria solani with the IC50 value of less than 0.1 mu g/mL and the compound 2 also had great inhibitory effect against the growth of Fusarium oxysporum f. sp. cucumerinum (IC50 < 0.1 mu g/mL), which was comparable to that of referenced cycloheximide with IC50 value of below 0.1 mu g/mL. The compounds 3-5 exhibited strong immunosuppressive activities against the T cell viability with the inhibition rates of more than 99%, which were comparable to positive cyclosporin A under the concentration of 20 mu M. These results suggest that the compounds 2-5 have the potential to be used as bio-control agents in agriculture or immunosuppressive agents.