Elemene

Aroma and sensory profile

Elemene is a quiet name for a family. Fragrance references describe (−)-beta-elemene, the natural form, in a single word, sweet [1], and the beta-elemene entry as herbal, waxy, and fresh [2]; gamma- and delta-elemene, which share the skeleton and move the double bonds, are typed herbal. None is a strong odorant. In the rhizome oils where beta-elemene is abundant it contributes a soft, waxy, faintly floral herbaceousness under the sharper curcumenes and turmerones, and the elemenes as a group are credited with part of the floral character of magnolia and juniper.

The molecule is a monocyclic sesquiterpene with three stereocenters and three double bonds, two of them terminal vinyl groups, and it is chiral. The natural material is (−)-beta-elemene [1]. No panel description of (+)-beta-elemene was found, so no claim about how the two enantiomers differ in odor is made here. The generic name on this page covers beta-elemene, the isomer with the pharmacology below; gamma-elemene has its own entry.

Effects and research

Elemene is the one compound on this site that is a licensed anticancer drug. A 2019 review describes beta-elemene as a sesquiterpene extracted from Curcuma rhizome and used in traditional Chinese medicine to treat several types of cancer, and catalogues its molecular targets: kinase inhibition, cell-cycle arrest, apoptosis, autophagy, and suppression of angiogenesis and metastasis proteins, with sensitization of tumors to chemotherapy [3].

The human data are large and come from China. A meta-analysis of 15 randomized trials in 1,410 patients with stage III or IV non-small cell lung cancer found that elemene injection added to platinum chemotherapy improved disease control (risk ratio 1.23) and objective response (risk ratio 1.62), improved quality of life, and reduced severe toxicities [4]. A meta-analysis of 16 trials in 969 patients with advanced gastric cancer found higher response rates (risk ratio 1.41) and less leukopenia, neutropenia, and thrombocytopenia with the combination [5]. A 2023 systematic review across cancer types confirmed better response, disease control, and survival with chemotherapy, but found that elemene significantly increased phlebitis and that its benefit diminished with longer treatment and more cycles [6].

Two cautions apply. These trials are open-label, Chinese, and of variable quality, and the drug is an emulsion given intravenously or into body cavities, not a terpene inhaled or eaten. Nothing here transfers to elemene in a plant sample or an essential oil.

Natural sources

Elemene is a rhizome and seed terpene. Its pharmaceutical source is the zedoary group of Curcuma species: the review names Curcuma rhizome [3], the injectable is made from Curcuma phaeocaulis and Curcuma wenyujin [7], and Curcuma wenyujin essential oil carried beta-elemene at 7.1 percent [9] with supercritical carbon dioxide extract reaching 27.8 percent [8]. The richest reported botanical source is the seed oil of Nigella damascena, love-in-a-mist, at 47 percent beta-elemene [8]. Fragrance databases log the beta isomer at 1.7 percent in Moroccan armoise, 1.2 percent in Baccharis oil, 0.5 to 0.9 percent in sweet basil oils and absolute, and traces in allspice, amyris, angelica seed, star anise, and lemon myrtle, with the (−) form recorded in juniper and southern magnolia [1][2]. In cannabis beta-elemene is a minor sesquiterpene, reported in a number of chemotypes at a small fraction of the caryophyllene level.

Boiling point and vaporization

No measured boiling point for beta-elemene appears in PubChem or in a primary paper found for this profile, so none is listed. Fragrance references quote 251 to 253 °C at 760 mmHg but mark the value as an estimate [1][2], and the 228 °C the site previously listed had no traceable source. What can be said is that elemene is a fifteen-carbon hydrocarbon sesquiterpene in the same volatility band as caryophyllene and humulene, so it belongs among the base notes and persists in dried rhizome and stored oil long after the monoterpenes have gone. Its three double bonds, two of them terminal, make it oxidation-prone in air. No thermal degradation study of elemene was found.

Safety and regulation

Elemene is not listed by name in the FDA flavoring tables at 21 CFR 172.515, no European classification notifications for it were found in PubChem, and no Research Institute for Fragrance Materials assessment was found. Its regulatory standing is pharmaceutical: elemene injection and the related zedoary turmeric oil injection are licensed anticancer preparations in China, and their safety record comes from clinical use rather than from fragrance or flavor toxicology [4][6][7].

Its known adverse effects are those of the injectable. Across the trials, elemene significantly increased phlebitis at the infusion site [6], and a 2024 study traced the serious dyspnea reported with zedoary turmeric oil injection to beta-elemene binding hemoglobin, altering its structure, reducing oxygen-carrying capacity, and upregulating hypoxia-inducible factor 1-alpha [7]. None of this describes exposure to elemene in a plant or an oil, where it is a trace sesquiterpene with no hazard data at all.

Industries and uses

Fragrance: elemene contributes a soft, sweet, waxy-herbal note in rhizome, magnolia, and juniper accords and is used as a natural constituent of those oils rather than as an isolate [1][2]. Pharmaceuticals: beta-elemene is the active ingredient of elemene injection, an adjunct to chemotherapy for lung, gastric, and other cancers in China with meta-analytic evidence of benefit and defined risks [3][4][5][6].