The EI‐MS Fragmentation Mechanisms of the Bacterial Diterpenes Polytrichastrene A and Wanju‐2,5‐diene

Abstract

The fragmentation mechanisms leading to the formation of several pronounced fragment ions formed during EI mass spectrometry of the diterpene hydrocarbons polytrichastrene A and wanju-2,5-diene were investigated by isotopic labelling experiments. All twenty singly 13 C-labelled isotopomers of these diterpenes were enzymatically synthesised from the twenty isotopomers of ( 13 C)geranylgeranyl diphosphate using the polytrichastrene synthase from Chryseobacterium polytrichastri. Their mass spectrometric investigation allowed for conclusions on the fragmentation mechanisms leading to the observed fragment ions.