A 6/5/6/5-Fused Indeno[7,1- <i>bc</i> ]furan Diterpenoid Skeleton from <i>Pinus yunnanensis</i> Resins with Anti-Neuroinflammatory and Antidepressant Activities

Pinynditerpene A ( 1 ), an unprecedented abietane diterpenoid featuring a unique 6/5/6/5-fused indeno[7,1- bc ]furan skeleton with 5 consecutive chiral centers, was isolated from Pinus yunnanensis resins. Its structure was elucidated by spectroscopic, computational, and crystallographic methods. 1 was found to be able to alleviate inflammation associated depression-like behaviors in mice, exerting its significance in mood disorders.