Abstract：
The increased demands for natural bioactive compounds have induced the search for unusual sources. Microorganisms, especially fungi are a potent source of secondary metabolites, which could act mainly as antioxidant compounds to prevent oxidative stress. In the present study three soil-isolated fungi Aspergillus niger, Aspergillus heteromorphus and Aspergillus fumigatus, were screened for their oleaginous property as well as their potential for the production of bioactive compounds. Fungal biomasses were freeze dried and extracted with methanol using a cold percolation process for the production of intracellular metabolites and the fungal culture media after fermentation were examined for extracellular metabolites. Intracellular and extracellular extracts of the isolated fungi along with the single-cell oils extracted from those fungi were screened for phytochemicals, which showed the presence of alkaloids, flavonoides, glycosides, phenols, saponins and terpenoids. All strains showed potent antioxidant activity, determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) activity. Extracellular extract and single-cell oil of A. heteromorphus showed the highest antioxidant activity with maximum ABTS radical scavenging activity and reducing potential. Highest content of phenolic and flavonoid compounds within the isolated fungi was found to be 37.58 mg gallic acid equivalent (GAE)/g and 62.07 mg catechine equivalent (CE)/g, respectively. Chromatographic analysis of the intracellular and extracellular extracts of the fungi showed the presence of gallic acid, di-hydroxy benzoic acid, ferulic acid, quercetin, epigerin, kampferol, trans cinnamic acid, chlorogenic acid and rutin, which made them biologically important and beneficial for human health.
摘要：
对天然生物活性化合物的需求增加引发了对不寻常来源的寻找。微生物,特别是真菌是次生代谢产物的有效来源，它可以主要作为抗氧化化合物来防止氧化应激。在本研究中，三种土壤分离的黑曲霉，异形曲霉和烟曲霉，筛选了它们的油质性质以及它们生产生物活性化合物的潜力。将真菌生物质冷冻干燥，并使用冷渗滤工艺用甲醇提取，以生产细胞内代谢物，并检查发酵后的真菌培养基中的细胞外代谢物。对分离的真菌的细胞内和细胞外提取物以及从这些真菌中提取的单细胞油进行植物化学物质筛选。这表明生物碱的存在，黄酮类化合物，糖苷，酚类物质,皂苷和萜类。所有菌株均显示出有效的抗氧化活性，使用1,1-二苯基-2-吡啶酰肼(DPPH)测定，2,2-偶氮-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）和铁还原抗氧化能力（FRAP）活性。异形A的细胞外提取物和单细胞油显示出最高的抗氧化活性，具有最大的ABTS自由基清除活性和还原潜力。发现分离的真菌中酚类和类黄酮化合物的最高含量为37.58mg没食子酸当量（GAE）/g和62.07mg儿茶碱当量（CE）/g，分别。对真菌的细胞内和细胞外提取物的色谱分析显示存在没食子酸，二羟基苯甲酸,阿魏酸,槲皮素,epigerin,Kampferol,反式肉桂酸，绿原酸和芦丁，这使得它们在生物学上很重要，对人类健康有益。
