Sesquiterpenoid oligomers from chloranthaceae plants: Structural diversity, biological activities and total syntheses

The Chloranthaceae family has four genera with nearly 75 species, including Ascarina, Chloranthus, Hedyosmum, and Sarcandra, which are mainly distributed throughout the tropics and subtropical zones (not including the African continent) and Madagascar (only Ascarina). Sesquiterpenoid oligomers, particularly lindenane-type sesquiterpenoid dimers, are a class of specific secondary metabolites of Chloranthaceae plants. Sixteen species from Chloranthaceae have been reported the presence of sesquiterpenoid oligomers, which show diverse structural frameworks (34 carbon skeletons) and a broad spectrum of bioactivities. This review systematically covers extensive aspects of 196 sesquiterpenoid oligomers that have appeared in the literature up to March 2022 from the Chloranthaceae family, including their occurrence, classification, distribution, and biogenesis, critically highlighting their biological activities and relevant total syntheses, which will supply inspiration for the further phytochemical, biomimetic synthesis, and pharmacological investigations of the sesquiterpenoid oligomers.