Diterpenoids and sesquiterpenoids from the stem bark of Metasequoia glyptostroboides

A phytochemical study on the stem bark of Metasequoia glyptostroboides led to the isolation of sixty-one diterpenoids and sesquiterpenoids, including seventeen previously undescribed compounds, metaglyptins A-Q. Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HRESIMS, and 1H, 13C and 2D NMR). The absolute configurations of metaglyptins I, J, and O were determined by the ECD data and single-crystal X-ray...