Caesalpinaxin, a cassane-type diterpenoid with a 21-carbon core skeleton from the seeds of Caesalpinia minax possessing pro-angiogenetic property.

ABSTRACT

A novel cassane-type diterpenoid, caesalpinaxin (1), was isolated from the seeds of Caesalpinia minax Hance. The structure of caesalpinaxin was established by means of spectroscopic techniques (NMR, HR-ESIMS, UV and IR). The absolute configuration of caesalpinaxin was determined by quantum chemical calculations of its theoretical electronic circular dichroism (ECD) spectrum. Caesalpinaxin is the first cassane-type diterpenoid with 21 carbons core skeleton, containing an unusual δ-lactone ring. A plausible biosynthetic pathway was proposed for compound 1. Furthermore, caesalpinaxin was tested for the pro-angiogenetic activity on human umbilical vein endothelial cells(HUVECs). The results indicated that this compound significantly stimulated migration and tuber formation through enhancing the level of vascular endothelial growth factor (VEGF). Thus, caesalpinaxin might be applied in accelerating wound healing.