Tylopeptins A and B, new antibiotic peptides from Tylopilus neofelleus

Two new peptides, tylopeptins A and B, were isolated from the methanol extract of the fruiting body of the mushroom, Tylopilus neofelleus. These peptides were identified as peptaibols possessing an acetylated N-terminal residue, fourteen amino acids, and leucinol as the C-terminal amino alcohol. Sequential determination and complete ¹H and ¹³C resonance assignments were based on positive ion FAB mass spectroscopy and two dimensional NMR techniques. These peptides were subsequently shown to be active against some Gram-positive bacteria, but inactive against pathogenic fungi and Gram-negative bacteria.