Asymmetric total synthesis and anti-hepatocellular carcinoma profile of enantiopure euphopilolide and jolkinolide E

A flexible asymmetric synthesis of both enantiomers of euphopilolide ( 1 ) and jolkinolide E ( 2 ) [(+)-and (−)- 1 , (+)-and (−)- 2 ] has been accomplished. This synthesis features an intramolecular oxa -Pauson-Khand reaction ( o -PKR) to expeditiously construct the challenging tetracyclic [6.6.6.5] abietane-type diterpene framework, elegantly showcasing the complexity-generating features of o -PKR synthetic methodology leveraging on a judiciously chosen suitable chiral pool scaffold. Furthermore, the anti-hepatocellular carcinoma (HCC) activity of synthetic (−)-euphopilolide ( 1 ), (−)-jolkinolide E ( 2 ) and their analogues was evaluated. We found that (−)-euphopilolide ( 1 ) and (−)-jolkinolide E ( 2 ) inhibited the proliferation and induced apoptosis in HCC cells. These findings lay a good foundation for further pharmacology studies of abietane lactone derivatives and provide valuable insight for the development of anti-HCC small molecule drug of natural product origin.