Cytotoxic neo-clerodane diterpenes from Stachys aegyptiaca

Abstract Two new E/Z neo -clerodane diterpene isomers, trivially named stachaegyptin D ( 1 ) and E ( 2 ), together with known compounds, stachysolon monoacetate ( 3 ) and stachysolon diacetate ( 4 ), were isolated from an organic-solvent extract of the medicinal herb Stachys aegyptiaca . Structures were elucidated by a combination of spectroscopic methods, including HREIMS, 1 H, 13 C, DEPT, and 2D NMR analysis, as well as, first time X-ray analysis for stachysolone ( 3 ). All isolated metabolites showed some activity against the human hepatocellular cell line, HepG2. Compound 4 was the most active with an IC 50 of 59.5 μM.