Myrioneurinol: a novel alkaloid skeleton from Myrioneuron nutans

A new alkaloid, myrioneurinol ( 1 ), was isolated from the leaves of Myrioneuron nutans and its structure determined from spectral analysis, including mass spectrometry and 2D NMR. Myrioneurinol ( 1 ) presented an unprecedented fused tetracyclic skeleton. The absolute configuration was established by the modified Mosher's method, using ( R )- and ( S )-9-anthrylmethoxyacetic acid (9-AMAA). A plausible biosynthetic pathway starting from l -lysine via Δ-piperideine was proposed for 1 in comparison with nitraramine biosynthesis and related alkaloids.