老鼠艻内生曲霉HU0206的抗细菌活性代谢成分

Antibacterial Metabolites of Endophytic Aspergillus sp. HU0206 Isolated from Spinifex littoreus

摘要:

为阐明老鼠艻内生曲霉Aspergillus sp.HU0206发酵物的抗细菌物质基础，采用色谱分离法从其玉米发酵物中分离得到7个化合物，分别鉴定为6个甲基苯酚类化合物：sydowiol F (1)、5-methoxy-3,5'-dimethyl-2,3'-oxybiphenyl-1,1',2'-triol (2)、corynesidone A (3)、鹿蹄草素(4)、3-羟基鹿蹄草素(5)、4-乙氧基-3-羟甲基苯酚(6)和1个甲基环己酮二聚体epoxydine A (7)，其中化合物1为新化合物。载样量为40 μg时，化合物1、2和4对金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、黑胫病菌和青枯病菌抑菌效果较好，抑菌圈半径≥2 mm，最小抑菌浓度(MIC)为50或100μg/mL；化合物3对这4种菌虽有1~2 mm的抑菌圈，但MIC大于400 μg/mL。所有化合物对大肠杆菌均无抑制活性。

关键词:内生曲霉;代谢产物;甲基苯酚;甲基环己酮;抗细菌活性

Abstract:

In order to explore the antibacterial metabolites of endophytic Aspergillus sp. HU0206, seven compounds were obtained from the corn fermentation of endophytic Aspergillus sp. HU0206 isolated from Spinifex littoreus using chromatographic separation method. On the basis of spectral data, they were identified as six methylphenol derivatives, such as sydowiol F (1), 5-methoxy-3,5'-dimethyl-2,3'-oxybiphenyl-1,1',2'-triol (2), corynesidone A (3), pyrolin (4), 3-hydroxylpyrolin (5), 4-ethoxy-3-hydroxymethylphenol (6), and a methylcy-clohexanone, epoxydine A (7). Compound 1 was a new compound. At the dose of 40 μg, compounds 1, 2 and 4 showed obvious antibacterial effects on Staphylococcus aureus, methicillin-resistant S. aureus, Pectobacterium atroseptica, and Ralstonia solanacearum with radius of inhibition zone ≥ 2 mm, and minimum inhibitory concentrations (MICs) was 50 or 100 μg/mL. The radius of inhibition zone of compound 3 was 1-2 mm for above bacteria with MIC higher than 400 μg/mL. However, all compounds did not inhibit the growth of Escherichia coli.

Key words:Endophytic Aspergillus;Metabolite;Methylphenol;Methylcyclohexanone;Antibacterial activity