New Azaphilones from Nigrospora oryzae Co-Cultured with Beauveria bassiana.

In this study, the co-culture of Nigrospora oryzae and Beauveria bassiana, the endophytes in the seeds of Dendrobium officinale, were examined for metabolite diversity. Five new azaphilones were isolated, and their structures were determined by spectral analysis. In terms of azaphilones, compound 2 had an unprecedented skeleton, with a bicyclic oxygen bridge. The antifungal selectivities of the metabolite produced by N. oryzae against its co-culture fungus, B. bassiana, and common pathogens exhibited competitive interaction in this mix-culture. Compounds 1 and 2 showed obvious nitric oxide (NO) inhibitory activity with ratios of 37%, and 39%, respectively, at a concentration of 50 μM.

在这项研究中，对铁皮石斛种子内生真菌稻黑孢霉（Nigrospora oryzae）和球孢白僵菌（Beauveria bassiana）的共培养物的代谢产物多样性进行了检测。分离出了5种新的氮杂蒽酮类化合物，并通过光谱分析确定了它们的结构。就氮杂蒽酮类化合物而言，化合物2具有一种前所未有的骨架，带有一个二环氧桥。稻黑孢霉产生的代谢产物对其共培养真菌球孢白僵菌以及常见病原菌的抗真菌选择性在这种混合培养中表现出竞争相互作用。在浓度为50 μM时，化合物1和2分别显示出明显的一氧化氮（NO）抑制活性，抑制率分别为37%和39%。