Hemp & Cannabinoid Science / Terpene Monographs / Ocimene
Ocimene
An acyclic monoterpene of the herbivore-induced plant volatile system, dominant in Helichrysum petiolare at 17.21 percent of the oil. Ecologically well characterised, pharmacologically thin.
At a glance
| Structure class | acyclic monoterpene, an isomeric triene series |
|---|---|
| Molecular formula | C10H16 |
| Molar mass | about 136.24 g/mol |
| Isomers | alpha-ocimene and the (E)- and (Z)- isomers of beta-ocimene; (E)-beta-ocimene is the form usually reported in botanical analyses |
| Boiling point at 1 atm | about 175 to 177 degrees Celsius (347 to 351 degrees Fahrenheit); reported figures vary with isomer and source |
| Vaporization band | about 155 to 175 degrees Celsius (311 to 347 degrees Fahrenheit) |
| Documented biology | well characterised as a herbivore-induced and floral plant volatile with signalling roles in plant-insect interaction; human pharmacology is sparse |
| Aroma | sweet, herbaceous, woody, green |
| Stability | a conjugated triene, so among the least stable monoterpenes; oxidises and polymerises readily |
On this page
Structure, isomers, and why the isomer label matters
Ocimene is C10H16 at about 136.24 g/mol, an acyclic monoterpene triene occurring as a family of isomers: alpha-ocimene, (E)-beta-ocimene and (Z)-beta-ocimene. The conjugated triene makes it the least stable monoterpene on this shelf — it oxidises and polymerises readily, isomerises on standing, and is easily lost or altered between harvest and injection. Analytically that means an ocimene figure is only as good as the sample handling behind it, and that a report giving "ocimene" without specifying the isomer has discarded information: the isomers differ in odour and in their ecological roles, and a chromatographic assignment to the wrong isomer is a common error. Atmospheric boiling point is in the region of 175 to 177 degrees Celsius, with reported values varying by isomer and source.
Sources: Compiled from public compound databases (PubChem 2026* · Lourens ACU 2008
What is actually documented: plant signalling, not human pharmacology contested in vitro
The strongest body of evidence about ocimene is ecological rather than pharmacological. (E)-beta-ocimene is one of the best-characterised herbivore-induced plant volatiles: plants under insect attack emit it, and it functions in indirect defence by attracting predators and parasitoids of the attacking herbivore, as well as in floral signalling to pollinators and in honeybee brood pheromone communication. That is a real, well-replicated body of work and it is the honest headline for this compound. Human pharmacology is another matter. Scattered in-vitro reports describe antifungal, antiviral and anti-inflammatory activity for ocimene-containing oils or for ocimene itself, but there is no receptor target, no replicated animal behavioural model and no human study of the kind that exists for myrcene, linalool or cineole. This shelf therefore does not give ocimene a pharmacology section it has not earned. Ocimene is present, it is analytically useful as a chemotype marker, and its human effects are undetermined.
Contested — caveat. LOW EVIDENCE for human pharmacology. No receptor target, no replicated animal behavioural data, no human trial. The well-supported ocimene literature is plant-ecological. Claims of specific therapeutic effects for ocimene in consumer material are not supported by the sources available to this shelf.
Sources: Booth JK 2019 · Lourens ACU 2008
Where ocimene actually is, and at what percent contested
The operator's Helichrysum petiolare analysis makes (E)-beta-ocimene one of the two defining compounds of that material, alongside faurinone — a profile that distinguishes H. petiolare from the pinene- and cineole-dominated H. odoratissimum and H. cymosum, and is part of why the species are chemically distinguishable even though tradition treats them as interchangeable.
| Botanical | Reported ocimene content | Basis | Source |
|---|---|---|---|
| Imphepho, Helichrysum petiolare | 17.21 percent, reported as (E)-beta-ocimene | percent of essential oil | operator Temple Pharmacopoeia 2026 |
| Sweet basil (Ocimum basilicum), the namesake genus | present in several chemotypes | percent of essential oil | reference compilation |
| Cannabis sativa | a common minor to moderate terpene, frequently reported as beta-ocimene | percent of terpene fraction | Booth and Bohlmann 2019 |
| Hops, lavender, orchids, mint | present as a minor constituent and as a floral volatile | percent of volatile fraction | reference compilation |
| Many plants under herbivore attack | induced emission; the quantity is a response, not a constant | emission rate | plant-volatile literature, summarised in Booth and Bohlmann 2019 |
Contested — caveat. The H. petiolare figure is a single reported analysis in the operator document. Note also that ocimene emission in many plants is inducible, so a measured content depends on the plant's recent stress history as well as its genotype.
Sources: Van Kush Family Research Institute (operator) 2026* · Booth JK 2019 · Compiled from public compound databases (PubChem 2026* · Lourens ACU 2008
Industry notes
Ocimene is the terpene most likely to disappear between the field and the report. If ocimene matters to a product specification — and for Helichrysum petiolare material it is a defining constituent — the chain of custody, temperature and time between harvest and analysis has to be controlled and documented, not assumed. For a lab tech, resolve and report the isomer. For a buyer, an ocimene figure on an old certificate of analysis is weak evidence about current material.
Sources: Compiled from public compound databases (PubChem 2026* · Van Kush Family Research Institute (operator) 2026*
See also
- Terpenes and Terpenoids: How to Read This Shelf — Terpene Monographs
- Faurinone — Terpene Monographs
- Vaporization Temperature Bands: An Industry Reference — Terpene Monographs
- Imphepho — South African Helichrysum — Botanical Monographs
- The Panels: What Each One Covers, and What It Does Not — Reading a Certificate of Analysis
References
- Compiled from public compound databases (PubChem, NIST WebBook) and supplier specification sheets (2026) Physical constants for terpenes and terpenoids: formula, molar mass, atmospheric boiling point Reference compilation; individual values vary between sources and are given as ranges here. [identifier unverified]
- Lourens ACU, Viljoen AM, van Heerden FR (2008) South African Helichrysum species: a review of the traditional uses, biological activity and phytochemistry Journal of Ethnopharmacology 119(3):630-652. doi:10.1016/j.jep.2008.06.011
- Booth JK, Bohlmann J (2019) Terpenes in Cannabis sativa — from plant genome to humans Plant Science 284:67-72. doi:10.1016/j.plantsci.2019.03.022
- Van Kush Family Research Institute (operator) (2026) Temple Pharmacopoeia knowledgebase: botanical preparations, extraction science and formulation frameworks Internal operator document, compiled January 2026. [identifier unverified]
4 references, of which 2 carry no resolved identifier and are marked as such. A DOI is only recorded here when it was resolved against Crossref and the returned title matched the one printed. None was guessed.
Absence is not safety. A substance or a pair that is not in this section was not checked and is not thereby safe. This is a curated mechanism reference built from primary literature and regulatory reference works — not a comprehensive interaction database, and not a substitute for a clinician or a pharmacist.
Posture
Education and harm reduction. Not medical, legal or financial advice. Every factual claim carries a source; contested and single-source claims are marked as such on the page.
The boundary. This section teaches separation, purification, formulation, dosing arithmetic and analytical chemistry with real parameters, because withholding that detail from someone who will proceed anyway is the harm this library exists to prevent. It does not publish preparative routes for converting one cannabinoid into a more intoxicating one; those are described structurally and cited to the literature, without procedures.