MOLECULE

(+)-calarene

(+)-Calarene or Calarene belongs to the class of organic compounds known as aristolane sesquiterpenoids. These are sesquiterpenoids with a structure based on the aristolane skeleton. Aristolanes arise from the C6, C11 cyclization of the bicyclic eremophilane skeleton. Sesquiterpenoids are terpenes that contain 15 carbon atoms and are comprised of three isoprene units. The biosynthesis of sesquiterpenes is known to occur mainly through the mevalonic acid pathway (MVA), in the cytosol. However, recent studies have found evidence of pathway crosstalk with the methyl-eritritol-phosphate (MEP) pathway in the plastid (PMID: 19932496, 17710406). Farnesyl diphosphate (FPP) is a key intermediate in the biosynthesis of cyclic sesquiterpenes. FPP undergoes several cyclization reactions to yield a diverse number of cyclic arrangements. It was identified in the essential oil of leaves of Rhododendron aureum (rosebay) (10.4% - 66.4% relative to total oil constituents) (DOI: 10.2298/JSC1002209O), the essential oil from Valeriana jatamansi Jones (Indian valerian or Tagar) (DOI: 10.1080/10412905.2013.767757), the essential oil from Humulus lupulus (hop) (PMID: 24152289), the essential oil of Piper sarmentosum (wild pepper) (0.81%) (DOI: 10.1016/S2095-3119(17)61693-9), agarwood oil (24.7% relative to total volatile compounds), spikenard (PMID: 18404340), and cannabis (PMID: 26657499). It has been shown to have a sedative effect (PMID: 18404340).