Pedrolane, a Polycyclic Diterpene Scaffold Containing a Bicyclo[2.2.1]heptane System, from <i>Euphorbia pedroi</i>
Ricardo J. Ferreira, Gabriella Spengler, Andreas Orthaber, Daniel J. V. A. dos Santos, Maria‐José U. Ferreira
Abstract
Pedrolide (1), a diterpenoid with an unprecedented carbon skeleton, pedrolane, containing a bicycle[2.2.1]heptane system, is reported. This structural feature is hypothesized to involve an intramolecular cyclization, via Michael addition, and a ring contraction, via 1,2-alkyl shift or a Pinacol rearrangement of rings A and B, from a tigliane-type 5/7/6/3-tetracyclic ring precursor. The structure of 1 was established using spectroscopic techniques, single-crystal X-ray diffraction, and ab initio calculations. Pedrolide reversed multidrug resistance mediated by P-glycoprotein.
Topics & Concepts
ChemistryDiterpeneIntramolecular forceStereochemistryRing (chemistry)Bicyclic moleculeHeptaneNorbornaneDemethylationCrystal structureCrystallographyOrganic chemistryGeneGene expressionDNA methylationBiochemistryBioactive Natural Diterpenoids ResearchPhytochemistry and Biological ActivitiesPlant-based Medicinal Research