Computational mass spectrometry-guided discovery of bioactive compounds from the underexplored, polyextremotolerant, marine-derived actinobacterium Streptomyces tritolerans

The phylum Actinomycetota is remarkably vast, encompassing species with extensive biological and chemical diversity, such as those within the genus Streptomyces , renowned for producing bioactive compounds and explored for their biotechnological potential. Almost two decades ago, the species Streptomyces tritolerans was discovered [ 1 ], yet it remains largely underexplored, both biologically and chemically, especially considering its specialized metabolites. In continuation of our research of Streptomyces spp. [ 2 ], we present the investigation of extracellular chemical profile of three S. tritolerans extracts derived from culture supernatants of two strains, guided by a computational mass spectrometry. The extracts were obtained via liquid-liquid and sorbent-assisted extraction and subsequently analyzed using UHPLC-HRMS. The MS/MS data from the crude extracts were used to: (a) preliminarily identify known bioactive compounds, (b) annotate their related unknown features, and (c) assist in planning their isolation strategy. For feature dereplication, we employed spectral library matching via the GNPS platform, in silico fragmentation tree analysis, and chemical class prediction. We then constructed molecular networks to annotate the related unknown features and design their purification strategy. This integrated approach led to the discovery, isolation, and structural elucidation—based on LC/MS and NMR—of five α-pyrone analogs: germicidins A, B, D, M, and N, for the first time in S.tritolerans ([ Fig. 1 ]). Although several of these compounds demonstrate antimicrobial and antioxidant capabilities, some evidence suggests their potential for simple and effective conversion into α-pyridones, known for their broad spectrum of bioactivities. Fig. 1 Molecular network of α-pyrone analogs (germicidins), isolated and structurally elucidated from the extracts of Streptomyces tritolerans Acknowledgements : EUʼs Horizon2020 Research and Innovation Programme (Grant Agreement No. 101000794). Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany