X-ray structure analysis of lappaconitine

Lappaconitine is an important alkaloid of the aconite family and its biological activity is closely related to its structure. Through an X-ray structure analysis of hydrated lappaconitine hydrobromide, which was synthesised by us through a new method, the absolute configuration of lappaconitine was determined: monoclinic, P2 1 , a = 10.619(2) A, b = 12.196(3) A, c = 12.282(2) A, β = 90.87(1)° and Z = 2; Flack parameter is −0.0083(0.0046) and S = 0.867. Rings A, B, C, D, E and F, respectively, present boat, chair, envelope, boat, boat and envelope forms. The absolute stereo configuration of lappaconitine was determined as 1S, 4S, 5S, 7S, 8S, 9S, 10S, 11S, 13R, 14S, 16S and 17R.