Topsendines AeF, new 3-alkylpyridine alkaloids from a Hainan sponge Topsentia sp.

摘要

Six new 3-alkylpyridine alkaloids, topsendines AeF (1e6), and one new naturally occurring product, 2- methyl-12-(pyridine-3-yl)dodecanal (7), were isolated from an undescribed species of Hainan sponge Topsentia. The structures of the new compounds were determined by extensive 2D NMR experiments, HR-EI/ESI-MS spectrometry measurements, and by comparison of their NMR data with those of structurally related compounds in the literature. In bioassay, compounds 1, 3, and 5 showed inhibitory actions on delayed rectifier Kt currents (IK) in rat acutely dissociated hippocampal neurons at the concentration of 100 mM, with the percentage of inhibition of 85.9±3.9%, 87.1±4.4%, and 76.2±12.2%, respectively.