A novel heptacyclic diterpene from Alpinia pahangensis Ridley, a wild ginger endemic to Malaysia

Pahangensin D (1), a bis-labdanic diterpene featuring an unprecedented carbon skeleton, was isolated as a minor constituent from the rhizomes of Alpinia pahangensis Ridley. Its structure and relative stereochemistry were established on the basis of rigorous spectroscopic methods including 1D and 2D NMR techniques and LCMS-IT-TOF analysis.