Novel Cyclic Peptide, Epichlicin, from the Endophytic Fungus, Epichloe typhina

Abstract

The novel cyclic peptide, epichlicin, was isolated from Epichloe typhina, an endophytic fungus of the timothy plant (Phleum pretense L.). Its structure was determined by NMR studies and by mass spectrometry. Enantiomers of 3-amino tetradecanoic acid, a constituent amino acid of epichlicin, were synthesized as authentic standards. The stereochemistry of each amino acid was elucidated through a combination of the advanced Marfey method and chemical manipulation. Epichlicin showed inhibitory activity toward the spore germination of Cladosporium phlei, a pathogenic fungus of the timothy plant at an IC₅₀ value of 22 nM.