Genome mining revealed that the genomes of basidiomycetes may include a considerable number of biosynthetic gene clusters (BGCs), yet numerous clusters remain unidentified. Herein, we report a combination of genome mining with an OSMAC (one strain, many compounds) approach to characterize the spectrum of melleolides produced by Armillaria tabescens CPCC 401429. Using F1 fermentation medium, the metabolic pathway of the gene cluster mel was successfully upregulated. From the extracts of the wild-type strain, two new melleolides (1 and 2), along with five new orsellinic acid-derived lactams (10–14), were isolated, and their structures were elucidated by LC-HR-ESIMS/MS and 2D-NMR. Several melleolides exhibited moderate anti-carcinoma (A549, NCI-H520, and H1299) effects with IC50 values of 4.0–48.8 μM. RNA-sequencing based transcriptomic profiling broadened our knowledge of the genetic background, regulation, and mechanisms of melleolide biosynthesis. These results may promote downstream metabolic engineering studies of melleolides. Our study demonstrates the approach is effective for discovering new secondary metabolites from Armillaria sp. and will facilitate the mining of the unexploited biosynthetic potential in other basidiomycetes.

Gestational diabetes mellitus (GDM) is a common disorder characterized by abnormal glucose metabolism during pregnancy, affecting 2% to 5% of pregnant women. Currently, clinical treatment for GDM is very limited. The present study was designed to investigate the effect and underlying molecular mechanism of tertiary butylhydroquinone (TBHQ) in a pregnant C57BL/KsJ‐Lep db/+ (referred to as db+) GDM mouse model. The results showed that nonpregnant db/+ mice did not show a diabetic phenotype, and TBHQ had no effect on glucose and insulin tolerance in these mice. Moreover, in db/+ pregnant mice exhibiting typical diabetes symptoms, such as hyperglycemia and hypoinsulinemia, TBHQ could remarkably decrease the blood glucose level, increase insulin level, and improve glucose and insulin intolerance. The results also revealed that TBHQ could inhibit oxidative stress in pregnant db/+ mice. Furthermore, TBHQ greatly improved offspring survival rate, glucose metabolism, and insulin tolerance. In addition, TBHQ inhibited oxidative stress by reducing malondialdehyde (MDA) and reactive oxygen species (ROS) levels and increased superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities. Moreover, we found that TBHQ activated the nuclear factor erythroid 2‐related factor 2 (Nrf2), thereby increasing the levels of Nrf2, and ultimately upregulating the expression of heme oxygenase 1 (NO‐1) and superoxide dismutase 2 (SOD2). In conclusion, our findings demonstrated that TBHQ alleviated GDM via Nrf2 activation.

Terpenoids constitute a structurally diverse class of secondary metabolites with wide applications in the pharmaceutical, fragrance and flavor industries. Desarmillaria tabescens CPCC 401429 is a basidiomycetous mushroom that could produce anti-tumor melleolides. To date, no studies have been conducted to thoroughly investigate the sesquiterpenes biosynthetic potential in Desarmillaria or related genus. This study aims to unravel the phylogeny, terpenome, and functional characterization of unique sesquiterpene biosynthetic genes of the strain CPCC 401429. Herein, we report the genome of the fungus containing 15,145 protein-encoding genes. MLST-based phylogeny and comparative genomic analyses shed light on the precise reclassification of D. tabescens suggesting that it belongs to the genus Desarmillaria. Gene ontology enrichment and pathway analyses uncover the hidden capacity for producing polyketides and terpenoids. Genome mining directed predictive framework reveals a diverse network of sesquiterpene synthases (STSs). Among twelve putative STSs encoded in the genome, six ones are belonging to the novel minor group: diverse Clade IV. In addition, RNA-sequencing based transcriptomic profiling revealed differentially expressed genes (DEGs) of the fungus CPCC 401429 in three different fermentation conditions, that of which enable us to identify noteworthy genes exemplified as STSs coding genes. Among the ten sesquiterpene biosynthetic DEGs, two genes including DtSTS9 and DtSTS10 were selected for functional characterization. Yeast cells expressing DtSTS9 and DtSTS10 could produce diverse sesquiterpene compounds, reinforced that STSs in the group Clade IV might be highly promiscuous producers. This highlights the potential of Desarmillaria in generating novel terpenoids. To summarize, our analyses will facilitate our understanding of phylogeny, STSs diversity and functional significance of Desarmillaria species. These results will encourage the scientific community for further research on uncharacterized STSs of Basidiomycota phylum, biological functions, and potential application of this vast source of secondary metabolites.

Stroke is a complicated disease with an increasing incidence and a very high mortality rate. A classical Chinese herbal medicine, Dengzhan Shengmai (DZSM), has shown to have therapeutic effects on stroke; however, its chemical basis and molecular mechanism are still unclear. In this study, a systems biology approach was applicable to elucidate the underlying mechanism of action of DZSM on stroke. All the compounds were obtained from databases, and pendant-related targets were obtained from various data platforms, including the TCM Systematic Pharmacology (TCMSP) database, TCM Integrated Database (TCMIP), High Throughput Experimental Reference Database (HERB), Comparative Toxicogenomics Database (CTD), SwissTargetPredicition, and SymMap, The Human Gene Database (GENECARD) and Comparative Toxicogenomics Database (CTD) were used for stroke disease target data, followed by network pharmacology analysis to predict the potential effect of DZSM on stroke. Animal experiments were intended to validate the underlying mechanisms. A total of 846 chemical components were compiled for the targets of DZSM drug, and quercetin, kaempferol, and Wuweizisu C are the highest chemical components compiled from DZSM. Overlapping with 375 disease-specific targets and 149 core targets, the core targets include TNF, IL-6, ALB, and AKT1, which are shown to regulate the disease process from an anti-inflammatory perspective. 198 enrichment messages were obtained by KEGG enrichment analysis, and we believe that the role of the AGE-RAGE signaling pathway in diabetic complications, TNF signaling pathway, and IL-17 signaling pathway is more important. Based on rat experiments, we also demonstrated that DZSM could effectively modulate the inflammation level of brain infarct tissues and effectively alleviate behavioral characteristics. Grouped together, our study suggests that the combination of network pharmacology prediction and experimental validation can provide a useful tool to describe the molecular mechanisms of DZSM in Chinese medicine (TCM).