Transcriptome Analysis Reveals the Putative Polyketide Synthase Gene Involved in Hispidin Biosynthesis in Sanghuangporus sanghuang

Isolation and Antioxidant Mechanism of Polyphenols from Sanghuangporous vaninii

Sanghuangporous vaninii, as an edible and medicinal macrofungus, represents a high source of polyphenols with considerable antioxidant activities. However, due to the significant differences in polyphenol content and bioactivity caused by different cultivation substrates, its antioxidant mechanism has not been fully determined. In this paper, five groups of S. vaninii fruiting bodies were collected from cultivation substrates from different areas. The ethanol extracts of mulberry sawdust from Haining City (HNMS) had the highest polyphenol content, as well as excellent antioxidant activity. HNMS3, a polyphenol component with promising antioxidant capacity, was further isolated through optimization with different extractants, silica gel column chromatography, and thin layer chromatography analysis. UPLC-Q-TOF-MS analysis showed that HNMS3 was composed of 33 compounds, corresponding to 257 targets of oxidative stress by network pharmacology analysis, which were strongly associated with mental health and neurodegenerative diseases. Protein-protein interaction and molecular docking analysis indicated that eight hub genes (PPARG, IL-6, STAT3, PTGS2, SRC, MTOR, ERS1, and EGFR) are attributed to the regulation of the key compounds hispidin, inoscavin A, inoscavin_C, and phellibaumin B. Consequently, this study obtains S. vaninii polyphenolic component HNMS3 with excellent antioxidant capacity, simultaneously revealing its potential antioxidant mechanisms, providing new insights into the application of S. vaninii.

From the forest floor to the lab: Insights into the diversity and complexity of mushroom polyketide synthases

Mushroom-forming fungi exhibit a distinctive ecology, which is unsurprisingly also reflected in unique and divergent biosynthetic pathways. We review this phenomenon through the lens of the polyketide metabolism, where mushrooms often deviate from established principles and challenge conventional paradigms. This is evident not only by non-canonical enzyme architectures and functions but also by their propensity for multi-product synthases rather than single-product pathways. Nevertheless, mushrooms also feature many polyketides familiar from plants, bacteria, and fungi of their sister division Ascomycota, which, however, are the result of an independent evolution. In this regard, the captivating biosynthetic pathways of mushrooms might even help us understand the biological pressures that led to the simultaneous production of the same natural products (via convergent evolution, co-evolution, and/or metaevolution) and thus address the question of their raison d'être.

First genome assembly and annotation of Sanghuangporus weigelae uncovers its medicinal functions, metabolic pathways, and evolution

Sanghuangporus, also known as "Sanghuang" in China, is a well-known genus of traditional Chinese medicinal macrofungi. To make more effective use of Sanghuangporus resources, we completed the first genome assembly and annotation of a monokaryon strain of S. weigelae in the present study. A 33.96-Mb genome sequence was assembled as 13 contigs, leading to prediction of 9377 protein-coding genes. Phylogenetic and average nucleotide identity analyses indicated that the S. weigelae genome is closely related to those of other Sanghuangporus species in evolutionary tree, which clustered in one clade. Collinearity analysis revealed a high level of collinearity of S. weigelae with S. baumii, S. vaninii, and S. sanghuang. Biosynthesis pathways potentially involved in medicinal properties, including terpenoid and polysaccharide synthesis, were identified in S. weigelae, while polysaccharides were identified as the main medicinal metabolites in S. weigelae, with flavonoids more important in Sanghuangporus than other medicinal mushroom groups. Genes encoding 332 carbohydrate-active enzymes were identified in the S. weigelae genome, including major glycoside hydrolases and glycosyltransferases predicted, revealing the robust lignocellulose degradation capacity of S. weigelae. Further, 130 genes, clustered in seven classes were annotated to encode cytochromes P450 in the S. weigelae genome. Overall, our results reveal the remarkably medicinal capacity of S. weigelae and provide new insights that will inform the study of evolution and medicinal application of S. weigelae. The data are a reference resource for the formulation of scientific and rational ecological protection policies for Sanghuangporus species.