Aconicatisulfonines A and B, Analgesic Zwitterionic C₂₀-Diterpenoid Alkaloids with a Rearranged Atisane Skeleton from <i>Aconitum carmichaelii</i>

Abstract

Two sulfonated C₂₀-diterpenoid alkaloid iminiums with a novel skeleton, named aconicatisulfonines A (<b>1</b>) and B (<b>2</b>), respectively, were isolated from a water extract of the <i>Aconitum carmichaelii</i> lateral roots. Structures of <b>1</b> and <b>2</b> were determined by spectroscopic data and quantum calculations as well as X-ray crystallographic analysis. Biosynthetic pathways via semipinacol rearrangements of atisane derivatives are proposed for <b>1</b> and <b>2</b>. Compounds <b>1</b> and <b>2</b> exhibited remarkable analgesic activities against acetic acid-induced mice writhing.