Mass spectral studies of the carboxylic acid ionophore antibiotic griseochelin and its derivatives

The electron impact (EI) mass spectra (75 eV) of the new carboxylic acid ionophore griseochelin and some of its derivatives are discussed. The mass spectral fragmentation was studied using exact mass measurements and deuterium labelling. Furthermore, the negative ion mass spectra (2–4 eV) of these compounds are compared with their EI mass spectra.