Bioactive metabolites from Samsoniella sp. KY1174: isolation, characterization, and cytotoxicity against cancer cell lines

Samsoniella entomopathogens possesses substantial economic, medicinal, and ecological value, with recent studies revealing accelerated metabolite discovery rates and genomic evidence of extensive underexplored biosynthetic potential. In this study, two new compounds 1–2 and eleven known compounds were isolated and characterised from Samsoniella sp. KY1174. Structures were assigned by integrating high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) with 1D/2D nuclear magnetic resonance (NMR) datasets after purification. Among them, compound 2 showed measurable cytotoxicity against U-251, U87 MG, DLD-1 cell lines. Specifically, its activity against DLD-1 cells (IC50 = 7.23 ± 0.15 μM) exceeded that of the positive control cisplatin (IC50 = 8.90 ± 0.15 μM).