Research progress on chemical composition and biological activity of Nigrospora fungi
Nigrospora fungi belong to Ascomycotina, Sordariomycetes, Xylariales, and Apiosporaceae, and are widely distributed in nature. Although they are common plant pathogens, they are also important medicinal plant endophytes. Their active secondary metabolites are novel and diverse, making them abundant resources of medicinal active substances. In recent years, the research on the chemical components of endophytic fungi in the Nigrospora genus has shown an upward trend. The main types of chemical components discovered from them include polyketones, anthraquinones, terpenes, steroids, and alkaloids. Moreover, most compounds have excellent pharmacological effects such as antibacterial, antioxidant, cytotoxic, antiviral, and anti-tumor effects, and have shown great application prospects in agricultural plant protection and human disease treatment. However, there is currently no comprehensive review report on the secondary metabolites and biological activities of this genus of fungi both domestically and internationally. Therefore, this article focuses on the chemical components and biological activities of Nigrospora fungi, providing a systematic review for the first time to demonstrate the medicinal development value of this genus of fungi and provide reference for further research and development of active substances in this genus of fungi.

 

 

Nigrospora fungi, as widely distributed endophytic fungi in plants and animals, produce abundant and diverse secondary metabolites. This article reviews 199 compounds, including polyketones, anthraquinones, terpenes, steroids, and alkaloids. Among them, polyketones have the highest number of reported compounds, and most of them have significant biological activities such as antibacterial and cytotoxic effects (see Table 1). However, there are still shortcomings in the current research on Nigrospora fungi, such as a single activity screening model, limited activity at the surface level, and a lack of in-depth mechanism studies. Moreover, the exploration of metabolites in Nigrospora fungi is not yet sufficient, and further in-depth research is needed by combining multiple methods. Therefore, in future research, the author suggests improving from the following aspects: (1) expanding multiple activity screening models to increase the possibility of discovering more novel active substances; (2) In depth mechanism exploration of compounds with significant activity in phenotype screening to verify the possibility of drug development; (3) Pay attention to fungi from special environmental sources. While fungi cope with harsh environments, their metabolic pathways may evolve, and it is highly likely to discover highly active substances. For example, the extract of Nigrospora sp. NIOT, a fungal strain isolated from 800 meters deep underwater, such as Arumugam, showed strong antibacterial activity against 12 Gram negative and positive bacteria, and exhibited strong cytotoxic activity against various tumor cells; (4) Using methods such as fungal co culture or strain host co culture, as well as genome mining techniques, to activate silenced genes and enhance the ability of fungi to produce novel metabolites. At present, the research on the active ingredients of Nigrospora fungi is still in its early stages. With the increase of newly discovered metabolites and in-depth activity studies, it is believed that the metabolites of Nigrospora fungi can be fully developed and applied.