Secondary metabolites isolated from plant endophytic fungi have been getting more and more attention. Some secondary metabolites exhibit high biological activities, hence, they have potential to be used for promising lead compounds in drug discovery. In this review, a total of 134 journal articles (from 2017 to 2019) were reviewed and the chemical structures of 449 new metabolites, including polyketides, terpenoids, steroids and so on, were summarized. Besides, various biological activities and structure-activity relationship of some compounds were aslo described.

Extremophilic fungi have been found to develop unique defences to survive extremes of pressure, temperature, salinity, desiccation, and pH, leading to the biosynthesis of novel natural products with diverse biological activities. The present review focuses on new extremophilic fungal natural products published from 2005 to 2017, highlighting the chemical structures and their biological potential.

Procaspase-3-activating compound 1 (PAC-1) induces procaspase-3 activation via zinc chelation. However, whether PAC-1 employs other mechanisms remains unknown. Here we systematically screened for potent PAC-1 targets using 29 enhanced green fluorescent protein-labeled reporter cell lines and identified hypoxia-inducible factor 1α (HIF1α) and RAD51 pathways as PAC-1 targets. These results were verified in HepG2 cells and two other cancer cell lines. Mechanistically, PAC-1 specifically blocked HIF1α hydroxylation and upregulated HIF1α target genes. In addition, DNA damage, G₁/S cell cycle arrest, and the inhibition of DNA synthesis were induced following PAC-1 administration. Interestingly, by using ferrozine-iron sequestration and iron titration assays, we uncovered the iron sequestering capacity of PAC-1. Additionally, the expression levels of iron shortage-related genes were also increased in PAC-1-treated cells, and iron (II) supplementation reversed all of the observed cellular responses. Thus, our results indicate that PAC-1 induces HIF1α stabilization and DNA damage by sequestering ferrous iron.

The secondary metabolites isolated from soil fungi have received more and more attention, especially new compounds that exhibited good biological activities. In this review, a total of 546 new compounds are included in the relevant literature since 2011. The new compounds are isolated from soil fungi, We divided these compounds into seven categories, including alkaloids, terpenoids, steroids, ketones, phenylpropanoids, quinones, esters, lactones, etc. In addition, the biological activities and structure–activity relationships of these compounds have also been fully discussed. The activities of these compounds are roughly divided into eight categories, including anticancer activity, antimicrobial activity, anti-inflammatory activity, antioxidant activity, antiviral activity, antimalarial activity, immunosuppressive activity and other activities. Since natural products are an important source of new drugs, this review may have a positive guiding effect on drug screening.