A new ergostane-type steroid named (22E)-3α,6α,9α-ergosta-7,22-diene-3,6,9-triol (1), along with six known steroids 5α,8α-epidioxy-24-ethyl-cholest-6-en-3β-ol (2), ergosterol-5,8-peroxide (3), cerevisterol (4), isocyathisterol (5), 6β-hydroxystigmast-4-en-3-one (6), 6β-hydroxy-4-campesten-3-one (7), were isolated from the fermented unpolished rice media by Periconia pseudobyssoides K5 (Periconiaceae), an endophytic fungus from medicinal plant Toona sureni (Meliaceae). The fermentation takes at 28 ± 2 °C for 30 days. The structure of new steroid (1) was elucidated by extensive spectroscopic measurements (IR, HR-ESI-TOFMS, and 1D and 2D NMR) analyses. The isolated compounds (1-7) were evaluated for heme polymerization inhibition assay (HPIA). The IC50 HPIA value of 1 is 8.24 ± 0.03 mg/ml.
Keywords: Endophytic fungi; Periconia pseudobyssoides K5; Toona sureni; heme polymerization inhibition assay.