Conformational energetics of cationic backbone rearrangements in triterpenoid biosynthesis provide an insight into enzymatic control of product

László Kürti, Rong Jie Chein, E. J. Corey

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

2,3-(S)-Oxidosqualene (C30H50O) serves as a versatile starting point for the remarkable biosynthesis of many isomeric naturally occurring triterpenoids of formula C30H50O. These biosyntheses all involve polycyclization via cationic intermediates. The fully cyclized primary products then are converted to various structures by cationic rearrangements involving the polycyclic backbone. The energetics of these rearrangements has been examined by B3LYP 6-31 G* DFT calculations and by ab initio Hartree-Fock calculations at the 6-31G* or 3-21G(*) level. The results have led to the conclusion that the biosynthesis of friedelin, the most drastically rearranged of the pentacyclic triterpenes, involves a complex nonstop process, with no stable intermediates between 2,3-(S)-oxidosqualene and friedelin. It is proposed that this single-reaction biosynthesis consists of pentacyclization to the lupanyl cation followed directly by a sequence of 10 suprafacial 1,2-shifts of carbon and hydrogen, driven by the large exergonicity of the pentacyclization and electrostatic acceleration of the rearrangement steps.

Original languageEnglish (US)
Pages (from-to)9031-9036
Number of pages6
JournalJournal of the American Chemical Society
Volume130
Issue number28
DOIs
StatePublished - Jul 16 2008

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Conformational energetics of cationic backbone rearrangements in triterpenoid biosynthesis provide an insight into enzymatic control of product'. Together they form a unique fingerprint.

  • Cite this