Triterpene Glycosides Tricycloiridals A–D with Cytotoxicity Isolated from Fungus Chrysosporium sp. YX1242

Keratinophilic
fungi are significant pathogens that cause dermatomycoses.
Here, we report the discovery of four novel triterpene glycosides,
tricycloiridals A–D (1–4),
from the keratinophilic fungus Chrysosporium sp. YX1242, guided by mass-spectrometry-based molecular networking.
Their structures, featuring unprecedented triterpene skeletons, were
elucidated through comprehensive NMR, HRESIMS, and Snatzke’s
and advanced Mosher’s methods. Notably, compound 1 exhibited potent cytotoxicity against human keratinocytes HaCaT
(IC50 = 2.50 ± 0.2 μM), suggesting a potential
role as a virulence factor in fungal pathogenesis. Additionally, bioinformatic
analysis was used to predict the biosynthetic gene cluster responsible
for these triterpene glycosides.