Absolute Configurations and Bioactivities of Guaiane-Type Sesquiterpenoids Isolated from Pogostemon cablin

Seven novel guaiane sesquiterpenoids (1–7) and three known seco-guaianes were isolated from the volatile oil of Pogostemon cablin. Their structures including absolute configurations were determined by spectroscopic analyses, a modified Mosher’s method, and X-ray diffraction and ECD data. The results indicated that the ECD Cotton effects arising from one or two nonconjugated olefinic chromophores could be applied to define the absolute...