Pinnatifidenyne-Derived Ethynyl Oxirane Acetogenins from Laurencia viridis

Red algae of continue to provide wide structural diversity and complexity of halogenated C acetogenin medium-ring ethers. Here, we described the isolation of three new C acetogenins ( - ), and one truncated derivative ( ) from collected on the Canary Islands. These compounds are interesting variations on the pinnatifidenyne structure that included the first examples of ethynyl oxirane derivatives ( - ). The structures were elucidated by extensive study of NMR (Nuclear Magnetic Resonance) data, -based configuration analysis and DFT (Density Functional Theory) calculations. Their antiproliferative activity against six human solid tumor cell lines was evaluated.