Crystal structure of tuguaconitine, a diterpene alkaloid from Aconitum sibiricum

• Published in: Archives of pharmacal research 2008, 31(2), , pp.259-263
• Main Authors: Kang, Chang Kyun, Lee, Soo Jae, Kim, Yang Bae, Lee, Hyeong Kyu, Jeong, Eun Ju, Park, Il Yeong
• Format: Article
• Language: English
• Subjects: Aconitine - analogs & derivatives; Aconitine - chemistry; Aconitine - isolation & purification; Aconitum - chemistry; Chloroform; Crystallization; Hexanes; Hydrogen Bonding; Medicine; Models, Molecular; Molecular Conformation; Pharmacology/Toxicology; Pharmacy; Solvents; X-Ray Diffraction; 약학
• ISSN: 0253-6269; 1976-3786
• DOI: 10.1007/s12272-001-1150-1

The three-dimensional structure of a natural product, tuguaconitine (C 23 H 35 NO 7 ) from Aconitum sibiricum was determined by single crystal X-ray diffraction analysis. The compound was recrystallized from a methanol solution into orthorhombic crystal system, with a =18.093(4), b =12.075(11), c =9.824(4) Å, D m = 1.35, D x = 1.354 g/cm 3 , space group P 2 1 2 1 2 1 , and Z =4. The structure was solved by direct method and refined by least-squares procedure to the final R value of 0.046 for 1495 observed reflections with I ≥2σ( I ). Aconitines are diterpene alkaloid composed of six rings. In the molecule, two 6-membered rings have stable chair conformation, but other two 6-membered rings have unstable boat conformation because of their bonding strain and hydrogen bonds. Based on the three-dimensional structure of tuguaconitine, we suggest another 2D-diagram for the compound which is far better in imagination of the spatial shape of the molecule than the ordinary one.