Two caryolane-type sesquiterpenoids from Pogostemon cablin (Blanco) Benth.

By means of several chromatographic techniques, such as silica gel, Sephadex LH-20 and semi-preparative high performance liquid chromatography (HPLC), two caryolane-type sesquiterpenoids were isolated from the petroleum ether soluble fraction of the aerial parts of Pogostemon cablin (Blanco) Benth., and their structures were identified as caryolanol A (1) and 1α-ethoxy-9α-hydroxy-senecrassane (2) by various spectroscopic methods, including NMR and HR-ESI-MS. Compounds 1 and 2 were a pair of C₅ epimers, and compound 1 was a new compound. In addition, the anti-influenza virus activity of compounds 1 and 2 was evaluated.