Crystal structure of sepaconitine, a C19-diterpenoid alkaloid from the roots of Aconitum sinomontanum Nakai

The title compound [systematic name: [(1α,14α,16β)-20-ethyl-8,9,10-trihydroxy-1,14,16-trimethoxyaconitan-4-yl 2-aminobenzoate], C30H42N2O8, a natural C19-diterpenoid alkaloid, possesses an aconitane carbon skeleton with four six-membered rings and two five-membered rings. The fused ring system contains two chair, one boat, one twist-boat and two envelope conformations. Intramolecular N—H...O hydrogen bonds are observed between the amino and carbonyl groups. The molecules are linked together via O—H...O hydrogen bonds, forming a three-dimensional framework.