Pterolobirins A and B, Oxygen-Bridged Cassane Diterpenoid Dimers from the Fruits of <i>Pterolobium macropterum</i>
Achara Raksat, Thammarat Aree, Khanitha Pudhom
Abstract
Two dimeric cassane diterpenoids with an unprecedented 6/6/6/6/6/5/6/6/6 nonacyclic framework, pterolobirins A and B (1 and 2), were isolated from the fruits of Pterolobium macropterum. Their structures were assigned by interpreting the spectroscopic data. The absolute configuration of 1 was unequivocally confirmed by single-crystal X-ray diffraction data. A putative biosynthetic pathway is proposed based on a regular intermolecular Diels–Alder reaction and an intramolecular nucleophilic addition.
Topics & Concepts
TerpenoidStereochemistryChemistryDiterpeneOxygenTraditional medicineOrganic chemistryMedicineBiological Stains and PhytochemicalsNatural product bioactivities and synthesisBioactive Natural Diterpenoids Research