Complete NMR Structural Elucidation, Conformation, and Cytotoxic Evaluation of Polystachyne I, a New neo ‐Clerodane Diterpenoid From Salvia polystachya

Chemical investigation of the aerial parts of Salvia polystachya Ortega afforded a new neo ‐clerodane‐type diterpenoid named polystachyne I ( 1 ) and the previously known diterpenoid microphyllandiolide ( 2 ). Their structures were elucidated by 1D and 2D NMR experiments. The absolute configuration of 1 was established by single‐crystal X‐ray diffraction. Compound 1 was tested for cytotoxicity against three human cancer cell lines, showing moderate activity.