Borneol

Borneol is a bicyclic organic compound and a terpene derivative. The hydroxyl group in this compound is placed in an endo position. There are two different enantiomers of borneol. Both d -(+)- borneol and l -(–)- borneol is found in nature. Almost insoluble in water, borneol is poorly soluble in Propylene glycol, very soluble in alcohol, miscible with most perfume oils.

It is a colorless, crystalline solid.

Discovery:

Borneol is easily oxidized to the ketone (camphor). One historical name for it is Borneo camphor which explains the name. (The compound was named in 1842 by the French chemist Charles Frédéric Gerhardt.) It can be synthesized by reduction of camphor by the Meerwein–Ponndorf–Verley reduction (a reversible process). Reduction of camphor with sodium borohydride (fast and irreversible) gives instead the isomer isoborneol as the kinetically controlled reaction product.

Natural Occurrence:

This terpene derivate can be found in several species of Heterotheca, Artemisia, Callicarpa, Dipterocarpaceae, Blumea balsamifera and Kaempferia galanga.
It is one of the chemical compounds found in castoreum. This compound is gathered from the beaver's plant food.

Other Uses:

Whereas the dextro was the enantiomer that used to be the most readily available commercially, the more commercially available enantiomer now is laevo, which also occurs in nature.
Borneol is used in traditional Chinese medicine. An early description is found in the Bencao Gangmu.
Borneol is a component of many essential oils and it is a natural insect repellent.

Profile:

• 📂 CAS N° 507-70-0

• ⚖️ MW — 154.25 g/mol

• 📝 Odor Type — Fresh (can be found classified as balsamic)

• 📈 Odor Strength — medium

• 👃🏼 Odor Profile — Pine woody camphor balsamic. Has a camphoraceous odor, with a slightly sharp, earthy-peppery note, which is less evident in laevoborneol. Dry, woody-peppery odor. The dryness is characteristic and constitutes the main difference from the odor of the iso version. The odor is often compared to that of a good grade Rosemary oil (in which is present) (careful with that).

• 👅 Flavor Profile — Woody, somewhat minty and slightly burning taste.

• ⚗️ Uses — Used in Nut and Spice flavor compositions, usually in mere traces. Borneol is also used in the reconstitution of the essential oils in which it occurs naturally. This alcohol blends excellently with Olibanum products for “incense” type fragrances, and it forms a good background in many herbaceous-camphoraceous fragrances, Lavender and Citrus cologne types, many types of Room freshener fragrance, Pine odors, etc.
  Recommended use up to 3% in the fragrance concentrate

Production:

1. by Sodium-reduction of d-Camphor. This yields a mixture of d-Borneol and l-iso-Borneol,

2. by MPV reduction of Camphor. Yields 50/50 mixture of above.

3. Pinene via Pinene hydrochloride to Bornyl acetate to Borneol. Purification by dehydration to which Borneol is resistant.

Notes:

Although it is classified as having relatively low toxicity, it has a remarkable pharmacological effect upon many animals. It affects primarily the central nervous system.

Interesting article on leffingwell

FEMA Gras No.2157

Sources:

• Fulvio Ciccolo

• Wikipedia

• ChemSpider

• Perfume and Flavor Chemicals - Steffen Arctander.

• Common Fragrance and Flavor Materials - Kurt Bauer, Dorothea Garbe, Horst Surburg.

• National Center for Biotechnology Information (2020). PubChem Compound Summary for CID 64685, Borneol. Retrieved November 24, 2020 from https://pubchem.ncbi.nlm.nih.gov/compound/Borneol.