New steroid produced by Periconia pseudobyssoides K5 isolated from Toona sureni (Meliaceae) and its heme polymerization inhibition activity.

A new ergostane-type steroid named (22 E )-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 IC 50 HPIA value of 1 is 8.24 ± 0.03 mg/ml.