Hedychins E and F: Labdane-Type Norditerpenoids with Anti-Inflammatory Activity from the Rhizomes of <i>Hedychium forrestii</i>

Abstract

Hedychin E (<b>1</b>), a novel labdane-type norditerpenoid, and hedychin F (<b>2</b>), a new labdane-type dinorditerpenoid, were isolated from the rhizomes of <i>Hedychium forrestii</i>. Their structures were determined through a combination of spectroscopic analysis and X-ray single-crystal diffractions. Hedychin E (<b>1</b>) is an unprecedented 6-norditerpenoid with a fused tetrahydrofuran-lactone motif, and a reasonable biosynthetic pathway for <b>1</b> was proposed. Compound <b>2</b> showed a significant anti-inflammatory effect against LPS-induced NO production in macrophage RAW264.7 cells with an IC₅₀ value of 21.0 μM.