de Carvalho Camila Rodrigues, Vieira Mariana de Lourdes Almeida, Cantrell Charles L, Wedge David E, Alves Tânia M A, Zani Carlos Leomar, Pimenta Raphael Sanzio, Sales Junior Policarpo A, Murta Silvane M F, Romanha Alvaro J, Rosa Carlos Augusto, Rosa Luiz H
a Department of Microbiology , Federal University of Minas Gerais , Belo Horizonte , Brazil.
b USDA-ARS, Natural Products Utilization Research Unit , Oxford , MS , USA.
Nat Prod Res. 2016;30(4):478-81. doi: 10.1080/14786419.2015.1022777. Epub 2015 Mar 27.
Endophytic fungi represent ubiquitous microbial organisms able to live in the tissues of different plants around the world and represent a prolific source of bioactive metabolites. In the present study, the endophytic fungus Aspergillus calidoustus was isolated from the medicinal plant Acanthospermum australe (Asteraceae), and identified using molecular, physiological and morphological methods. A methylene chloride crude extract of A. calidoustus has been produced and subjected to antifungal bioassay-directed fractionation which resulted in the isolation of the two bioactive compounds: ophiobolin K and 6-epi-ophiobolin K. These pure compounds displayed antifungal activity against fungal plant pathogens, protozoal activity against Trypanosoma cruzi, and cytotoxic activity against human tumoral cell lines. The results show that A. calidoustus was able to produce the antifungal and cytotoxic metabolites ophiobolin K and 6-epi-ophiobolin K, which may help the fungus to colonise and occupy the substratum as well as survive in natural environments.
内生真菌是普遍存在的微生物，能够在世界各地不同植物的组织中生存，是生物活性代谢物的丰富来源。在本研究中，从药用植物刺苞果（菊科）中分离出内生真菌热栖曲霉，并采用分子、生理和形态学方法进行鉴定。制备了热栖曲霉的二氯甲烷粗提物，并进行了抗真菌生物测定导向的分级分离，结果分离出两种生物活性化合物：蛇孢菌素K和6-表蛇孢菌素K。这些纯化合物对植物真菌病原体具有抗真菌活性，对克氏锥虫具有原生动物活性，对人肿瘤细胞系具有细胞毒性活性。结果表明，热栖曲霉能够产生抗真菌和细胞毒性代谢物蛇孢菌素K和6-表蛇孢菌素K，这可能有助于真菌在自然环境中定殖、占据基质并生存。
