Mass Spectral Investigations on Toxins. 10. Direct Analysis of Macrocylic Trichothecenes in Brazilian Baccharis Plants by Direct Thermospray-MS/MS Techniques

摘要

Several structurally similar, biological active macrocyclic trichothecenes were ionized under thermospray conditions followed by collisionally activated dissociations of the ammonium adducts. Most of the observed daughter ions were formed by bond cleavage at the exocyclic ester bridges. Compounds with similar ester bridges formed several common daughter ions and underwent similar neutral losses. Fragmentation pathways for the dissociation of the adducts were confirmed from the corresponding neutral loss spectra. Simple experiments designed for the sequential monitoring of the characteristic daughter ions were used for the rapid, direct, and accurate analysis of macrocyclic trichothecenes in real samples. The primary drawback of the method is its inability to distinguish between isomers. Keywords: Macrocyclic trichothecenes, Roridins, Baccharinoids, Verrucarins, Thermospray ionization. (mjm)