New producers and new 11-, 19-, and 20-residue peptaibiotics: suzukacillins B and C

In the course of a project aimed to assess the significance of antibiotics for the producing organism(s) in the natural habitat, we screened a specimen of the fungicolous fungus Hypocrea phellinicola growing on its natural host Phellinus ferruginosus1. Using a peptaibiomics approach2,3, we detected 19- and 20-residue peptide sequences by (U)HPLC/HR-ESI-QqTOF-MS. Structures of peptaibiotics
found were independently confirmed by analyzing the peptaibiome of an agar plate culture of H. phellinicola CBS 119283 (ex-type) grown under laboratory conditions. Notably, H. phellinicola could be identified as a potent producer of 18-, 19-, (culture) and 20-residue (specimen) peptaibiotics of the suzukacillin-type4. Minor components of the 19-residue peptaibols, herein named suzukacillins C, are assumed to carry a C-terminal residue tentatively assigned as tyrosinol (Tyrol). In addition, the previously isolated suzukacillin B4 was sequenced and shown to be a microheterogeneous mixture of 11-residue peptaibols.