The O’Connor and Tosin groups have published work on the use of high mass accuracy tandem mass spectrometry for characterising the structures of polyketides, including erythromycin A, lasalocid A and iso-lasalocid A. They report in Analytical Chemistry on the use of Collision Activated Dissociation (CAD) and Electron Induced Dissociation (EID) as tools for determining structural information on these types of molecules. EID was shown to cause greater fragmentation of the compounds, complementary to that obtained using CAD, leading to more detailed structural information being obtained. These techniques were also combined in multistage mass spectrometry experiments, in order to use the fragmentation patterns to distinguish between lasalocid A and its isomer, iso-lasalcoid A. This work illustrates the potential of these tools and will be applied to identifying unknown polyketides and their biosynthetic intermediates.
The full article can be found at: http://pubs.acs.org/doi/abs/10.1021/ac3022778