Two new abietane diterpenoids from Pinus massoniana

Two new abietane diterpenoids, massonianene A (1) and massonianene B (2), were isolated from the extract of Pinus massoniana. Their structures were elucidated based on HR-ESI-MS, IR, UV, NMR, ECD and X-ray diffraction analysis. Compound 2 exhibited significant inhibitory effect against LPS-induced NO production in RAW 264.7 cells, with an IC₅₀ value of 7.00 ± 1.73 μM.