Bioactive metabolites from Alternaria brassicicola ML-P08, an endophytic fungus residing in Malus halliana
Bioactive metabolites from Alternaria brassicicola ML-P08, an endophytic fungus residing in Malus halliana
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DOI：
10.1007/s11274-009-0062-y
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发表时间：
2009-09-01
影响因子：
4.1
通讯作者：
Gu, Wen
中科院分区：
文献类型：
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作者：
Gu, Wen
从垂丝海棠的正常组织中分离得到48株菌株，并对其培养物的乙酸乙酯提取物进行了抗4种试验细菌和3种真菌的初步抗菌筛选。结果，22株菌株对至少一种测试微生物表现出抗微生物活性。筛选出活性较强的芸苔链格孢菌ML-P08（MIC为0.31-2.50 mg/ml），对其次生代谢产物进行了研究。其液体培养物的EtOAc提取物的生物测定引导的分级分离得到七种化合物，其被鉴定为交链孢酚（1）、交链孢酚9-甲基醚（2）、altechromone A（3）、herbarin A（4）、cerevisterol（5）、3 β，5 α-二羟基-（22 E，24 R）-麦角甾-7，22-二烯-6-酮（6）和3 β-羟基-（22 E，24 R）-麦角甾-5，8，22-三烯-7-酮（7）的化合物，分别通过光谱手段（MS，IR，（1）H-和（13）C-NMR）测定。体外抑菌试验表明，化合物3对枯草芽孢杆菌、大肠杆菌、荧光假单胞菌和白色念珠菌具有较好的抑菌活性，MIC分别为3.9、3.9、1.8和3.9 μ g/ml。化合物4对红色毛癣菌和念珠菌也表现出明显的抗真菌活性。白色念珠菌，MIC均为15.6 μ g/ml。此外，化合物1显示出强的黄嘌呤氧化酶抑制活性，IC（50）为15.5 μ M，与阳性对照别嘌呤醇（IC（50）：10.7 μ M）相当。
A total of 48 strains were isolated from the normal tissues of Malus halliana and the EtOAc extracts of their cultures were subjected to primary antimicrobial screening against four test bacteria and three fungi. As a result, 22 strains exhibited antimicrobial activity against at least one test microbe. Among them, Alternaria brassicicola ML-P08 showing strong activity (MICs: 0.31-2.50 mg/ml) was selected for further investigation on its secondary metabolites. Bioassay-guided fractionation of the EtOAc extract of its liquid culture afforded seven compounds, which were identified as alternariol (1), alternariol 9-methyl ether (2), altechromone A (3), herbarin A (4), cerevisterol (5), 3 beta,5 alpha-dihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (6) and 3 beta-hydroxy-(22E,24R)-ergosta-5,8,22-trien-7-one (7), respectively, by spectral means (MS, IR, (1)H- and (13)C-NMR). In vitro antimicrobial assay showed that compound 3 was substantially active against Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens and Candida albicans with the MICs of 3.9, 3.9, 1.8, and 3.9 mu g/ml, respectively. Compound 4 also showed pronounced antifungal activity against Trichophyton rubrum and C. albicans with MICs of both 15.6 mu g/ml. In addition, compound 1 exhibited strong xanthine oxidase inhibitory activity with the IC(50) of 15.5 mu M, comparable to that of positive control, allopurinol (IC(50): 10.7 mu M).