Over the past two decades, hypoxylaceous specimens were collected from several sites in Thailand. In this study, we examined their affinity to the genus Pyrenopolyporus using macroscopic and microscopic morphological characters, dereplication of their stromatal secondary metabolites using ultrahigh performance liquid chromatography coupled to diode array detection and ion mobility tandem mass spectrometry (UHPLC-DAD-IM-MS/MS), and molecular phylogenetic analyses. We describe and illustrate five novel species and a new record for the country, present multi-locus phylogenetic analyses that show the distinction between the proposed species, and provide proteomic profiles of the fungi using matrix associated laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) for the first time. Based on our findings, this strategy is useful as a complementary tool to distinguish species between Daldinia and Pyrenopolyporus in a consistent way with the phylogenetic analysis.

The Graphostromataceae ( Xylariales ) mainly contains species known for their endophytic lifestyle, although some may shift to opportunistic pathogenicity under host stress and subsequently colonize woody tissues as saprotrophs. The largest genus, Biscogniauxia , remains largely unexplored and would greatly benefit from a polyphasic taxonomic revision. Likewise, the secondary metabolism of these fungi has been only partially studied compared to related families within the Xylariales , despite their ecological versatility and potential latent pathogenicity. Herein, we introduce Biscogniauxia papillata as a new species from Thailand, based on morphological features and robust multi-locus phylogenetic analyses. Secondary metabolite profiling in different media, followed by preparative chromatography, led to the isolation of a cyclic pentapeptide named cyclobiscognioxin A ( 1 ), along with a mellein derivative among its main components. Preliminary biological testing revealed that 1 exhibits potent cytotoxic properties but lacks antimicrobial properties in our assays. The combined morphological and molecular phylogenetic evidence unequivocally distinguishes B. papillata from other members of the genus, confirming its status as a new species. Moreover, our chemical investigation highlights the underexplored biosynthetic potential of Biscogniauxia and expands the known chemical diversity within the genus, which might contribute to their opportunistic lifestyle.