Structural Elucidation of Tetrahydrofuranic Acetogenins by Means of Precursor-ion Scanning Method

Tetrahydrofuranic (annonaceous) acetogenins are a new class of bioactive natural products isolated from several genera of Annonaceae plants. We have isolated nearly thirty these acetogenins from the seeds of Annona squamosa and A. reticulata Their structures have been elucidated by the application of precursor-ion scanning method in mass spectrometry. Thus, these compounds were converted into lactam derivatives on treatment with amines such as N, N-dimethylethylenediamine. Precursor-ion scanning spectra of the derivatives from a specific fragment ion due to C-N bond cleavage were measured. This newly developed method allowed to establish unambiguously the planar structures of tetrahydrofuranic acetogenins. Biological activity and stereochemical aspects of annonaceous acetogenins are also reviewed.