Metabolites from Aspergillus fumigatus, an Endophytic Fungus Associated with Melia azedarach, and Their Antifungal, Antifeedant, and Toxic Activities
Metabolites from Aspergillus fumigatus, an Endophytic Fungus Associated with Melia azedarach, and Their Antifungal, Antifeedant, and Toxic Activities
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DOI：
10.1021/jf300146n
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发表时间：
2012-04-04
影响因子：
6.1
通讯作者：
Gao, Jin-Ming
中科院分区：
文献类型：
--
作者：
Li, Xiao-Jun;Zhang, Qiang;Gao, Jin-Ming
从苦楝（Melia azedarach）茎皮内生真菌烟曲霉（Aspergillus fumigatus）LN-4的发酵液中分离得到39个真菌代谢产物1-39，其中包括两个新生物碱：12 β-羟基-13 α-甲氧基疣状原TR-2（6）和3-羟基富米喹唑啉A（16）。它们的结构进行了详细的光谱分析（质谱和一维和二维NMR实验）的基础上，并通过比较其NMR数据与文献中报道的。这些分离的化合物进行了体外抗真菌活性对一些植物病原真菌，对盐水虾的毒性，并对粘虫幼虫（Mythimna separata步行者）的拒食活性进行了评价。其中16个化合物对植物病原真菌（灰葡萄孢、早疫病菌、互隔交链孢、胶孢炭疽菌、早疫病镰刀菌、尖孢镰刀菌等）具有较强的抑菌活性。sp. niveum、尖孢镰刀菌f. sp. vasinfectum和Gibberella saubinettii），其中四种，12 β-羟基-13 α-甲氧基疣状原TR-2（6）、烟曲霉素B（7）、疣状原（8）和香草酸（39），显示出抗真菌活性，MIC值为6.25-50 μ g/mL，与两种阳性对照多菌灵和恶霉灵相当。此外，在对卤虫产生中等致死性的18个化合物中，化合物7和8均显示出显著的毒性，半数致死浓度（LC 50）值分别为13.6和15.8 μ g/mL。在9个具有拒食活性的化合物中，化合物7和8的拒食活性最高，拒食指数分别为50.0%和55.0%。并对代谢产物的构效关系进行了讨论。
Thirty-nine fungal metabolites 1-39, including two new alkaloids, 12 beta-hydroxy-13 alpha-methoxyverruculogen TR-2 (6) and 3-hydroxyfumiquinazoline A (16), were isolated from the fermentation broth of Aspergillus fumigatus LN-4, an endophytic fungus isolated from the stem bark of Melia azedarach. Their structures were elucidated on the basis of detailed spectroscopic analysis (mass spectrometry and one- and two-dimensional NMR experiments) and by comparison of their NMR data with those reported in the literature. These isolated compounds were evaluated for in vitro antifungal activities against some phytopathogenic fungi, toxicity against brine shrimps, and antifeedant activities against armyworm larvae (Mythimna separata Walker). Among them, sixteen compounds showed potent antifungal activities against phytopathogenic fungi (Botrytis cinerea, Alternaria solani, Alternaria alternata, Colletotrichum gloeosporioides, Fusarium solani, Fusarium oxysporum f. sp. niveum, Fusarium oxysporum f. sp. vasinfectum, and Gibberella saubinettii), and four of them, 12 beta-hydroxy-13 alpha-methoxyverruculogen TR-2 (6), fumitremorgin B (7), verruculogen (8), and helvolic acid (39), exhibited antifungal activities with MIC values of 6.25-50 mu g/mL, which were comparable to the two positive controls carbendazim and hymexazol. In addition, of eighteen that exerted moderate lethality toward brine shrimps, compounds 7 and 8 both showed significant toxicities with median lethal concentration (LC50) values of 13.6 and 15.8 mu g/mL, respectively. Furthermore, among nine metabolites that were found to possess antifeedant activity against armyworm larvae, compounds 7 and 8 gave the best activity with antifeedant indexes (AFI) of 50.0% and 55.0%, respectively. Structure-activity relationships of the metabolites were also discussed.