Fragmentation pathways of polycyclic polyisoprenylated benzophenones and degradation profile of nemorosone by multiple-stage tandem mass spectrometry

摘要: Nemorosone is a polycyclic polyisoprenylated benzophenone (PPBs) with strong cytotoxic activity. It the major constituent of Clusia rosea floral resin and brown Cuban propolis. Other PPBs found in propolis are oxidized cyclized derivatives nemorosone. The instability carrying an enolizable 1,3-diketone system has been suggested, elucidation this aspect very fundamental for evaluation their biologic Electrospray ionization multistage tandem mass spectrometry (ESI-MSn) was employed to shed light on origin these nemorosone define stability natural product. For purpose, we initially performed MSn experiments seven related obtain useful information structural characterization class compounds identify degradation products proposed fragmentation pathways, supported by exact measurements, allowed nature side chains bicyclo core type position modifications be established. In second part, profile under different conditions investigated assess possible effects isolation procedures, climatic, storage its stability. Our results reveal that undergoes rapid n-hexane chloroform solutions. products, identified HPLC-ESI/MSn NMR, identical previously isolated from plants. Thus, artefacts formed predominantly during extraction purification procedures.