Biosynthesis of steroidal alkaloids in Solanaceae plants: incorporation of 3β-hydroxycholest-5-en-26-al into tomatine with tomato seedlings

Bioorg Med Chem Lett. 2014 Aug 1;24(15):3556-8. doi: 10.1016/j.bmcl.2014.05.048. Epub 2014 May 23.


The C-26 amino group of tomatine, a representative Solanaceae steroidal alkaloid, is introduced in an early step of its biosynthesis from cholesterol. We recently proposed a transamination mechanism for the C-26 amination as opposed to the previously proposed mechanism involving a nitrogen nucleophilic displacement. In the present study, a deuterium labeled C-26 aldehyde, (24,24,27,27,27-(2)H5)-3β-hydroxycholest-5-en-26-al, was synthesized and fed to a tomato (Solanum lycopersicum) seedling. LC-MS analysis of the biosynthesized tomatine indicated that the labeled aldehyde was incorporated into tomatine. The finding strongly supports the intermediacy of the aldehyde and the transamination mechanism during C-26 amination.

Keywords: Biosynthesis; Solanum lycopersicum; Steroidal alkaloid; Tomatine; Transamination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / biosynthesis*
  • Alkaloids / chemistry
  • Cholesterol / analogs & derivatives*
  • Cholesterol / chemical synthesis
  • Cholesterol / chemistry
  • Cholesterol / metabolism
  • Molecular Conformation
  • Seedlings / chemistry
  • Seedlings / metabolism*
  • Solanaceae / chemistry
  • Solanaceae / metabolism*
  • Steroids / biosynthesis*
  • Steroids / chemistry
  • Tomatine / chemistry
  • Tomatine / metabolism*


  • Alkaloids
  • Steroids
  • Tomatine
  • Cholesterol