A new tetracyclic triterpenoid from endophytic fungus .

Objective: To isolate bioactive compounds from the endophytic fungus isolated from , and investigate their pharmacological activities.

Methods: The chemical constituents were isolated and purified by combining with ODS column chromatography, silica gel column chromatography and by performing semipreparative HPLC. Their structures were established on the basis of 1D NMR (H-NMR and C-NMR) and 2D NMR (H-H COSY, HSQC, HMBC and NOESY), as well as HRESIMS and comparison with literature data. In addition, the absolute configuration of compound was determined by calculated ECD data.

Results: One previously undescribed tetracyclic triterpenoid derivative, named as integracide L (), 12-acetoxy-4,4-dimethyl-24-methylene-5-cholesta-8,14-diene-2,3,11-triol (), 12-acetoxy-4,4-dimethyl-24-methylene-5-cholesta-8-momoene-2,3,11-triol (), 12-acetoxy-4,4-dimethyl-24-methylene-5-cholesta-8,14-diene-3,11-triol (), and 12-acetoxy-4,4-dimethyl-24-methylene-5-cholesta-8-momoene-3,11-triol () were isolated from . Moreover, compound was rare tetracyclic triterpenoid with single methyl replacement at C-4 position.

Conclusion: Compound was a new tetracyclic triterpenoid isolated from the endophytic fungus In addition, compound could inhibit the growth of three different human cancer cells significantly. Compounds and were found to possess better cytotoxic activities on HepG-2 cells than the other compounds, with IC values of (2.8 ± 0.1) and (6.3 ± 0.3) μmol/L respectively.