Peptaibols are a class of linear peptides with a high content of α-aminoisobutyric
acid, an acylated N-terminus, while the C-terminus may consist of a free amino acid,
2-amino alcohol, or sugar alcohol, among others [1]. These compounds have been widely
studied due to their interesting biological properties, such as antibiotics, anthelmintic
and cytotoxic agents [2]. In this context, MSX 70741 (Trichoderma sp.), a peptaibols producing fungus from the Mycosynthetix library was chemically
reinvestigated. This study led to the isolation of three new peptaibols (1-3), as well as the known compounds alamethicin F50 (4), alamethicin II (5), atroviridin J (6), and trichobranchin D-I (7). The structures of the isolates were established using a set of spectroscopic (1D
and 2D NMR) and spectrometric (HRESIMS/MSn) techniques. The absolute configuration of compounds was determined by Marfey's analysis
of the individual amino acids. The cytotoxic activity of compounds was evaluated in
an MTT assay against a panel of cancer cell lines.
Keywords: Peptaibols, 1D and 2D NMR, HRESIMS/MSn, biological activity.
References:
[1] Degenklob T, Berg A, Gams W, Schlegel B, Gräfe U. The occurrence of peptaibols and structurally related peptaibiotics in fungi and
their mass spectrometric identification via diagnostic fragment ions. J Pept Sci 2003;
9: 666 – 678
[2] Ayers S, Ehrmann BM, Adcock AF, Kroll DJ, Carcache de Blanco EJ, Shen Q, Swanson SM,
Falkinham III JO, Wani MC, Mitchell SM, Pearce CJ, Oberlies NH. Peptaibols from two unidentified fungi of the order Hypocreales with cytotoxic,
antibiotic, and anthelmintic activities. J Pept Sci 2012; 18: 500 – 510
