Abstract
The investigation of the MeOH extract of the leaves of Chisocheton weinlandii Harms (Meliaceae) revealed two new open-chain spermidine alkaloids, chisitine 1 (1) and chisitine 2 (2). Their structures were elucidated by NMR spectroscopy, tandem-mass spectrometry, and independant syntheses (Scheme 3). Detailed MS/MS fragmentation pathways are discussed for both compounds based on H/D exchange and 18O-labeling experiments (Schemes 1 and 2).