biostudies-literatureUnknown26(18)Randrianarivo SChemical and biological investigation of the Madagascar endemic plant <i>Saldinia proboscidea</i> led to the isolation of an isomer of artemisinin, (-)-6-epi-artemisinin (<b>2</b>). Its structure was elucidated using a combination of NMR and mass spectrometry. The absolute configuration was established by chemical syntheses of compound <b>2</b> as well as a new stereoisomer (<b>3</b>). The comparable bioactivities of artemisinin (<b>1</b>) and its isomer (-)-6-epi-artemisinin (<b>2</b>) revealed that this change in configuration was not critical to their biological properties. Bioactivity was assessed using an apoptosis induction assay, a SARS-CoV-2 inhibitor assay, and a haematin polymerization inhibitory activity (HPIA) assay. This is the first report of an artemisinin-related compound fMolecules (Basel, Switzerland)5540https://www.ebi.ac.uk/biostudies/studies/S-EPMC8472513biostudies-literature(-)-6-epi-Artemisinin, a Natural Stereoisomer of (+)-Artemisinin in the Opposite Enantiomeric Series, from the Endemic Madagascar Plant <i>Saldinia proboscidea</i>, an Atypical Source.PMC8472513Rafanomezantsoa SRandrianarivo SRandriamampionona HHaramaty LRasolohery CRafanomezantsoa RMAndrianasolo EHfalse(-)-6-epi-Artemisinin, a Natural Stereoisomer of (+)-Artemisinin in the Opposite Enantiomeric Series, from the Endemic Madagascar Plant <i>Saldinia proboscidea</i>, an Atypical Source.Chemical and biological investigation of the Madagascar endemic plant <i>Saldinia proboscidea</i> led to the isolation of an isomer of artemisinin, (-)-6-epi-artemisinin (<b>2</b>). Its structure was elucidated using a combination of NMR and mass spectrometry. The absolute configuration was established by chemical syntheses of compound <b>2</b> as well as a new stereoisomer (<b>3</b>). The comparable bioactivities of artemisinin (<b>1</b>) and its isomer (-)-6-epi-artemisinin (<b>2</b>) revealed that this change in configuration was not critical to their biological properties. Bioactivity was assessed using an apoptosis induction assay, a SARS-CoV-2 inhibitor assay, and a haematin polymerization inhibitory activity (HPIA) assay. This is the first report of an artemisinin-related compound f2021-01-01T00:00:00Z2021 Sep2026-05-02T03:12:32.447Z2022-02-11T11:37:17.473ZS-EPMC84725133457701110.3390/molecules26185540