Crystal structure ofN-deacetyllappaconitine

Abstract

The title compound, C30H42N2O7[systematic name: (1S,4S,5S,7S,8S,9S,10S,11S,13R,14S,16S,17R)-20-ethyl-4,8,9-trihydroxy-1,14,16-trimethoxyaconitan-4-yl 2-aminobenzoate], isolated from roots ofAconitum sinomontanumNakai, is a typical aconitane-type C19-diterpenoid alkaloid, which crystallizes with two independent molecules in the asymmetric unit. The conformations of the two independent molecules are closely similar. Each molecule comprises four six-membered rings (A,B,DandE) including one six-membered N-containing heterocyclic ring (E), and two five-membered rings (CandF). RingsA,BandEadopt chair conformations, while ringDdisplays a boat conformation. Five-membered ringsCandFexhibit 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 molecules into zigzag chains propagating in [010].