BIOLOGICALLY-ACTIVE PEPTIDES AND THEIR MASS-SPECTRA

A general procedure, relying heavily on mass spectrometry, has been developed for assigning structures to polypeptides. In the current version, amino acids are identified by HRFABMS, GC/MS, and GC on chiral columns, and quantitated by GC. FAB mass spectrometry assigns the peptide's molecular weight and amino acid sequence, supported sometimes by selective hydrolysis to oligopeptides. The procedure has been applied to several pore-forming peptaibophol antibiotics, as well as to the didemnins, cyclic depsipeptides isolated from a marine tunicate. The didemnins are active antitumor agents and show promise in the treatment of viral infections, including Rift Valley fever. © 2013, Walter de Gruyter. All rights reserved.