Fragmentation study of clerodane diterpenes from Casearia species by tandem mass spectrometry (quadrupole time-of-flight and ion trap).

Through a rational analysis of the fragmentation mechanisms of Casearia diterpenes it was possible to suggest an annotation strategy based on the sequential cleavages of the ester groups related to the R2 , R3 and R5 substituents. These results will assist studies of the dereplication and metabolomics involving casearin-like compounds present in complex extracts of Casearia species.