Molecular networking and computational NMR analyses uncover six polyketide-terpene hybrids from termite-associated Xylaria isolates.

Fungi constitute the Earth's second most diverse kingdom, however only a small percentage of these have been thoroughly examined and categorized for their secondary metabolites, which still limits our understanding of the ecological chemical and pharmacological potential of fungi. In this study, we explored members of the co-evolved termite-associated fungal genus Xylaria and identified a family of highly oxygenated polyketide-terpene hybrid natural products using an MS/MS molecular networking-based dereplication approach. Overall, we isolated six no yet reported xylasporin derivatives, of which xylasporin A (1) features a rare cyclic-carbonate moiety.

A type III polyketide synthase cluster in the phylum Planctomycetota is involved in alkylresorcinol biosynthesis.

Members of the bacterial phylum Planctomycetota have recently emerged as promising and for the most part untapped sources of novel bioactive compounds. The characterization of more than 100 novel species in the last decade stimulated recent bioprospection studies that start to unveil the chemical repertoire of the phylum. In this study, we performed systematic bioinformatic analyses based on the genomes of all 131 described members of the current phylum focusing on the identification of type III polyketide synthase (PKS) genes.

Targeted Isolation of Saalfelduracin B-D from Using LC-MS/MS-Based Molecular Networking.

High-resolution tandem mass spectrometry (HR-MS)-based metabolomic studies of , isolated from the "Saalfelder Feengrotten" caves in Germany, led to the isolation of three ribosomally synthesized and post-translationally modified type II thiopeptides, saalfelduracin B-D (-) and the known saalfelduracin A (). The structures of all four compounds were determined by comparative two-dimensional NMR analysis and high-resolution tandem mass spectrometry.