Isolation and Total Synthesis of Albu­peptins A–D: 11-Residue Peptaibols from the Fungus Gliocladium album

摘要: Four new 11-mer peptaibols, named albupeptins A–D (1–4), were isolated from cultures of the fungus Gliocladium album. Their structures elucidated on basis 1D and 2D NMR spectroscopy, as well ESI-HRMSn analysis. The sequence albupeptin A (1) was thus identified Ac-Aib1-Aib2-Val3-Leu4-Aib5-Pro6-Iva7-Leu8-Gln9-Aib10-Leuol11. Albupeptins B (2) C (3) feature an exchange Aib5 by Iva5 Aib1 Iva1, respectively, D (4) contains both Iva1 residues. stereochemistry peptaibols 1–4 unambiguously assigned 1H chemical shift analysis in conjunction with solid-phase peptide synthesis. By using this approach, absolute configuration Iva residues determined to be D, whereas additional residue L configuration. Thus, belong rare class that have stereoisomers same sequence.