title: Crystal structure of N-de-acetyl-lappa-coni-tine.
abstract: The title compound, C30H42N2O7 [systematic name: (1S,4S,5S,7S,8S,9S,10S,11S,13R,14S,16S,17R)-20-ethyl-4,8,9-trihy-droxy-1,14,16-tri-meth-oxy-aconitan-4-yl 2-amino-benzoate], isolated from roots of Aconitum sinomontanum Nakai, is a typical aconitane-type C19-diterpenoid alkaloid, which crystallizes with two independent mol-ecules in the asymmetric unit. The conformations of the two independent mol-ecules are closely similar. Each mol-ecule comprises four six-membered rings (A, B, D and E) including one six-membered N-containing heterocyclic ring (E), and two five-membered rings (C and F). Rings A, B and E adopt chair conformations, while ring D displays a boat conformation. Five-membered rings C and F exhibit envelope conformations. IntramolecularN-H⋯O hydrogen bonds between the amino group and carbonyl O atom help to stabilize molecular structure. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into zigzag chains propagating in [010].
authors.affiliation: Xi'an Botanical Garden, Institute of Botany of Shaanxi Province, Xi'an 710061, People's Republic of China.
authors.forename: Xin-Wei
authors.initials: XW
authors.lastname: Shi
authors.affiliation: Xi'an Botanical Garden, Institute of Botany of Shaanxi Province, Xi'an 710061, People's Republic of China.
authors.forename: Qiang-Qiang
authors.initials: QQ
authors.lastname: Lu
authors.affiliation: Xi'an Botanical Garden, Institute of Botany of Shaanxi Province, Xi'an 710061, People's Republic of China.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Zhou
authors.affiliation: Xi'an Botanical Garden, Institute of Botany of Shaanxi Province, Xi'an 710061, People's Republic of China.
authors.forename: Xin-Ai
authors.initials: XA
authors.lastname: Cui
keywords: C19-diterpenoid alkaloid; N-de­acetyl­lappaconitine; O—H⋯O hydrogen bonding.; crystal structure