ent-Abietane Lactones from Euphorbia

Extracted from Euphorbia, ent-Abietane lactones can be classified into several categories, such as Jolkinolides and Helioscopinolides, according to their structural features. The study of ent- Abietane lactones could date back to 1972, when Jolkinolide A and B were first isolated from Euphorbia jolkini Boiss. Since then, many other ent-Abietane lactones have been extracted from different species of Euphorbia. Their bio-activities include anti-tumor activity, anti-inflammatory activity as well as anti-bacterial activity. Among them, derivatives of Jolkinolide B draw the most attention for their high anti-tumor activity. There are many studies focus on the syntheses of Jolkinolides. In 1989, the first and efficient synthesis of Jolkinolides was accomplished by Katsumura et al. Their strategy to construct the last ring of Jolkinolides contributes a lot to the following studies. In the following thirty years, there are also other semi-syntheses of Jolkinolides conducted, basing on different starting materials. In this review, we will give a brief clarification of ent-Abietane lactones, as well as their bio-activities and syntheses.