Cytotoxic Substances Produced by Erioscyphella abnormis Strain FC-2579

Abstract

A chemotaxonomic study was conducted using secondary metabolites produced by Erioscyphella abnormis FC-2579, a fungus belonging to the family Lachnaceae of the order Helotiales, and chemical constituents of Lachnum , a closely related species of Erioscyphella . Although several Helotiales fungi are known to produce bioactive secondary metabolites, the chemical constituents of the genus Erioscyphella have not previously been investigated. Initial cytotoxicity screening of E. abnormis FC-2579 extract against HepG2, HL60, and PANC-1 cancer cell lines revealed significant activity, leading to detailed chemical investigation. Through a meticulous isolation process using various chromatographic techniques, two novel lachnochromonin derivatives, namely (+)-lachnochromonin D ( 1 ) and (+)-lachnochromonin G ( 2 ), were isolated along with the known compounds caprylic acid ( 3 ), lachnochromonin C ( 4 ), lignicol ( 5 ), 6,8-dihydroxy-3,5-dimethyl-1 H -2-benzopyran-1-one ( 6 ), and 6-demethylkigerin ( 7 ). Structural elucidation was performed using HR-ESI-MS and comprehensive 1D and 2D NMR analysis. The absolute configurations of the novel compounds were estimated by comparative analysis of the optical rotations of structurally similar known compounds. Subsequent cytotoxicity assays demonstrated that 1 , 2 , and 4 exhibited significant, concentration-dependent cytotoxicity against HepG2 and HL60 cells, while 7 showed only mild activity against HL60 cells. None of the tested compounds exhibited cytotoxicity against PANC-1 cells under the experimental conditions. Furthermore, comparative HPLC profiling of six Erioscyphella and six Lachnum strains revealed that caprylic acid ( 3 ) was consistently detected only in Erioscyphella extracts, suggesting its potential as a chemotaxonomic marker.