The Sunlight Experiment

Compound Monograph

1,8-cineole

1,8-cineole (eucalyptol) — a fragrant monoterpenoid oxide that is a characteristic component of many medicinal essential oils, valued for its aromatic, expectorant and carminative qualities.

Work in progress

Classification

1,8-cineole is a monoterpenoid cyclic ether (oxide), part of the terpenoids class. The largest class of plant compounds, built from five-carbon isoprene units — the essential-oil aromatics, resins, bitter principles, saponins, and plant sterols.

Terpenoids Monoterpenes

Where Does It Come From? (14)

1,8-cineole is a naturally occurring monoterpenoid cyclic ether (oxide), found in Yarrow, Feverfew, Turmeric and 11 other sources. It is well tolerated orally (low toxicity).

Bay laurel Damiana Turnera diffusa Eucalyptus Feverfew Tanacetum parthenium Hyssop Hyssopus officinalis Lavender Lavandula angustifolia Peppermint Mentha piperita Rosemary Rosmarinus officinalis Rosewood Aniba rosaeodora Thyme Thymus vulgaris Turmeric Curcuma longa Wormwood Artemisia absinthium Yarrow Achillea millefolium Yerba Santa Eriodictyon californicum

Research & Evidence

1,8-cineole (also called eucalyptol) is a monoterpenoid oxide and one of the most widely encountered constituents of plant volatile oils. On the source-herb pages in this database it appears chiefly as a characteristic component of the essential-oil fraction rather than as an isolated compound with its own pharmacology, so the evidence here describes where it occurs and in what proportion:

  • In yarrow (Achillea millefolium), 1,8-cineole is one of the major volatile-oil components, reported at around 9.6% of the oil alongside camphor, sabinene and the pinenes 1Reference 1Battaglia · 2003The Complete Guide to Aromatherapy (2nd ed.).
  • In feverfew (Tanacetum parthenium), it is listed among the sesquiterpene/monoterpene volatiles of the plant’s essential oil 2Reference 2Akpulat H et al. · 2005Composition of the essential oils of Tanacetum argyrophyllum (C.
  • In turmeric (Curcuma longa), 1,8-cineole makes up roughly 1% of the rhizome essential oil, with the turmerones and zingiberene dominating 3Reference 3Battaglia · 2003The complete guide to aromatherapy (2nd ed.).
  • In damiana (Turnera diffusa), it is one of at least twenty constituents of the aromatic volatile oil (which can reach about 1% of the leaf), together with p-cymene, the pinenes and thymol 4Reference 4Taylor · 2005The healing power of rainforest herbs: A guide to understanding and using herbal medicinals.

Across these herbs 1,8-cineole contributes to the aromatic, warming and carminative character of the oil. The monographs do not attribute a specific isolated activity to it, so this is an honest occurrence summary; the section will grow if compound-specific research is added.

Toxicity & Safety

In the small amounts present in herbal preparations, 1,8-cineole is well tolerated, and the herbs that contain it (yarrow, turmeric, damiana, feverfew) are themselves considered low in toxicity at normal doses. As a concentrated essential-oil component, however, cineole-rich oils should be treated with the usual care given to volatile oils: they are not taken neat in large amounts, and concentrated eucalyptus-type oils carry well-known cautions around high-dose ingestion and use in or near the face of infants and very young children. None of the source monographs flag 1,8-cineole itself as toxic at the levels found in these herbs.

References

  1. Battaglia, S. (2003). The Complete Guide to Aromatherapy (2nd ed.). Brisbane, Australia: The International Centre of Holistic Aromatherapy. (Pg 276-277).
  2. Akpulat H, Tepe B, Sokmen A, Daferera D, Polissiou M. (2005). Composition of the essential oils of Tanacetum argyrophyllum (C. Koch) Tvzel. var. argyrophyllum and Tanacetum parthenium (L.) Schultz Bip. (Asteraceae) from Turkey. Biochem Syst Ecol. 33:511–6.
  3. Battaglia, S. (2003). The complete guide to aromatherapy (2nd ed.). Brisbane, Australia: International Centre of Holistic Aromatherapy.
  4. Taylor, L. (2005). The healing power of rainforest herbs: A guide to understanding and using herbal medicinals. Garden City Park, NY: Square One Publishers.