Tricholosterols A-D, four new ergosterol derivatives from the mushroom Tricholoma terreum.

Four ergosterol derivatives, named tricholosterols A-D (1-4), have been isolated from the fruiting bodies of Tricholoma terreum. Their chemical structures have been determined using a combination of spectroscopic analysis as well as computational methods. Compound 1 possesses a rare D-ring opening ergosterol skeleton, while compounds 2-4 are rare degraded ergosterols. Compounds 1 and 4 exhibited moderate inhibitory activity against NO production with IC50 values of 27.6 and 31.8 µM, respectively. This is the first report of steroids from T. terreum.

Structure and cytotoxicity of trichothecenes produced by the potato-associated fungus Trichothecium crotocinigenum.

Seven previously undescribed trichothecenes, named trichothecrotocins M-S (1-7), along with five known compounds, were isolated from rice cultures of the potato-associated fungus Trichothecium crotocinigenum. Their structures and absolute configurations were determined through spectroscopic methods, single-crystal X-ray diffraction, and quantum chemistry calculations on ECD. Compound 1 possesses a rare 6,11-epoxy moiety in the trichothecene family. Compound 6 exhibited strong cytotoxic activity against MCF-7 cancer cell lines with an IC50 value of 2.34 ± 0.45 µM. It promoted apoptosis induction in MCF-7 cells. Moreover, cell cycle analysis showed cell cycle arrest caused by compound 6 at the G2/M phase which resulted to cell proliferation inhibition and pro-apoptotic activity. Further quantitative real-time PCR (qRT-PCR) analysis confirmed that the G2/M arrest was accompanied by upregulation of p21 and down regulation of cyclins B1 in 6-treated MCF-7 cells.