A new tetracyclic triterpenoid from endophytic fungus Fusarium sporotrichioides

Abstract

ObjectiveTo isolate bioactive compounds from the endophytic fungus Fusarium sporotrichioides isolated from Rauwolfia yunnanensis, and investigate their pharmacological activities. MethodsThe 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 (1H-NMR and 13C-NMR) and 2D NMR (1H–1H COSY, HSQC, HMBC and NOESY), as well as HRESIMS and comparison with literature data. In addition, the absolute configuration of compound 1 was determined by calculated ECD data. ResultsOne previously undescribed tetracyclic triterpenoid derivative, named as integracide L (1), 12α-acetoxy-4,4-dimethyl-24-methylene-5α-cholesta-8,14-diene-2α,3β,11β-triol (2), 12α-acetoxy-4,4-dimethyl-24-methylene-5α-cholesta-8-momoene-2α,3β,11β-triol (3), 12α-acetoxy-4,4-dimethyl-24-methylene-5α-cholesta-8,14-diene-3β,11β-triol (4), and 12α-acetoxy-4,4-dimethyl-24-methylene-5α-cholesta-8-momoene-3β,11β-triol (5) were isolated from F. sporotrichioide. Moreover, compound 1 was rare tetracyclic triterpenoid with single methyl replacement at C-4 position. ConclusionCompound 1 was a new tetracyclic triterpenoid isolated from the endophytic fungus F. sporotrichioides. In addition, compound 2 could inhibit the growth of three different human cancer cells significantly. Compounds 3 and 5 were found to possess better cytotoxic activities on HepG-2 cells than the other compounds, with IC50 values of (2.8 ± 0.1) and (6.3 ± 0.3) μmol/L respectively.