Tolypocaibols: Antibacterial Lipopeptaibols from a Tolypocladium sp. Endophyte of the Marine Macroalga Spongomorpha arcta

Two new lipopeptaibols, tolypocaibols A ( 1 ) and B ( 2 ), and the mixed NRPS-polyketide-shikimate natural product maximiscin [( P / M )- 3 )] were isolated from a Tolypocladium sp. fungal endophyte of the marine alga Spongomorpha arcta . Analysis of NMR and mass spectrometry data revealed the amino acid sequences of the lipopeptaibols, which both comprise 11 residues with a valinol C-terminus and a decanoyl acyl chain at the N-terminus. The configuration of the amino acids was determined by Marfey’s analysis. Tolypocaibols A ( 1 ) and B ( 2 ) showed moderate, selective inhibition against Gram-positive and acid-fast bacterial strains, while maximiscin [( P / M )- 3 )] showed moderate, broad-spectrum antibiotic activity.