Trichodermides A-E: New Peptaibols Isolated from the Australian Termite Nest-Derived Fungus Trichoderma virens CMB-TN16

Chemical analysis of a fermentation of the Australian termite nest-derived fungus Trichoderma virens CMB-TN16 yielded five new acyclic nonapeptides, trichodermides A-E (1-5). Amino acid residues, configurations, and sequences were determined by a combination of spectroscopic (NMR and MS-MS) and chemical (C-3 Marfey's) methods. The trichodermides adhere to the sequence homology pattern common to Trichoderma 11 amino acid residue peptaibols; however, unlike other peptaibols the trichodermides do not exhibit antibacterial or antifungal activity and exhibit low to no cytotoxicity against mammalian cells. This variability in biological activity highlights the importance of knowing both planar structures and absolute configurations when interpreting structure-activity relationships.