Seven novel sesquiterpenes with hemostasis activities from leaves of Callicarpa nudiflora

A pair of epimer with an unprecedented 4/7/6 tricyclic skeleton sesquiterpene (1 and 2) and five novel sesquiterpene (3-7) were isolated from Callicarpa nudiflora Hook. et Arn. Their structures were established by extensive spectroscopic analyses, single crystal X-ray diffraction, experimental electronic circular dichroism (ECD) spectra comparison and DP4+ probability analysis. In addition, the plausible biosynthetic pathways of 1 and 2 were proposed. Biological tests indicated that sesquiterpenes derived from the caryophyllene skeleton displayed hemostasis activities in vivo and in vitro, also possessed certain anti-inflammatory ability simultaneously.