Octadeca-8,11-dienoic Acid Methylester, a New Fatty Acid Metabolite from Fistulina hepatica

A new fatty acid metabolite, octadeca-8,11-dienoic acid methylester (1) was isolated together with the known ergosterol (2) from Fistulina hepatica. The edible mushroom Fistulina hepatica is a relatively rarely occurring representative of the wood-rotting basidiomycetes for which no characteristic metabolites have been reported so far. The compounds 1 and 2 were purified by solvent extraction, silica gel column chromatography and preparative HPLC consecutively. The structures of the both compounds were unequivocally determined on the basis of NMR spectroscopic methods including 1D ( 1 H , 13 C and DEPT) and 2D (COSY, HSQC and HMBC ) and by mass spectrometry data (ESI, EI and HREI-MS). The new fatty acid methylester 1 displays no antimicrobial properties against Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Pseudomonas aeriginosa and Candida albicans, but very low activity against Escherichia coli and Proteus vulgaris.