Mesaconitine.

The title compound, (1α,3α,6α,14α,15α,16β)-3,8,13,14,15-penta-hydr-oxy-1,6,16-trimeth-oxy-4-methoxy-methyl-20-methyl-acon-itan-8,14-diyl 8-acetate 14-benzoate, C(33)H(45)NO(11), a C(19) diterpenoid alkaloid, obtained from the roots of Aconitum kusnezoffii, has been crystallographically characterized in this study. Rings A, B and E have chair conformations, rings C and F display envelope conformations, and ring D adopts a boat conformation. There are inter- and intra-molecular O-H⋯O hydrogen bonds, the latter resulting in the formation of a non-planar seven-membered ring. The inter-molecular inter-actions link the mol-ecules into a two-dimensional network.