Diterpenoid Alkaloids from the Roots of Aconitum iochanicum

Three new diterpenoid alkaloids, namely 1- N -deethyl-1,16-demethoxy-1,16-dihydroxy- N (19)-enaustroconitine A ( 1 ), 1- N -deethyl-1,16-demethoxy-1,16-dihydroxy-18-methoxy- N (19)-en-austroconitine A ( 2 ), and 1- N -deethyl-1,16-demethoxy-1,16-dihydroxyranaconidine ( 3 ), were isolated from the 80% ethanol extract of the roots of Aconitum iochanicum . Structural elucidation of all the compounds was performed by spectral methods such as 1D and 2D ( 1 H– 1 H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high-resolution mass spectrometry.