About Terpenes

Terpenes: Gifts from Nature – Natural Chemical Raw Materials

Terpenes are substances extracted from plants such as pine trees and orange peels. They are environmentally friendly resources that can be repeatedly produced through the blessings of sunshine.

樹液を採集する様子 — Collecting tree sap (crude pine resin)

柑橘類の皮（オレンジピール）等に含まれる油分。 — Oils extracted from citrus peels (e.g., orange peel)

What Are Terpenes?

Terpenes are biosynthesized within plants and are composed of isoprene units, typically represented by the chemical formula (C₅H₈)n. One of the typical terpene compounds, alpha-pinene, brings about the relaxing effects of forest bathing for us. And for plants, it is considered one of the important chemicals, phytoncides, that help to prevent their external enemies and protect themselves.
Terpenes are widely found in nature, especially in essential oils of plants. Some of the stable and large quantities of terpenes that can be used as industrial raw material include turpentine oil from pine trees and orange oil from citrus peels.
Unlike petroleum resources, which are at risk of depletion, terpenes are renewable and valuable resources that plants can continuously produce using the blessing of sunshine.

松の木からテレビン油 — Turpentine oil from pine trees

柑橘類からオレンジオイル — Orange oil from citrus peel

Terpenes as Chemical Raw Materials

The term “terpene” refers to hydrocarbons with the molecular formula C₁₀H₁₆. Its origine is from the word “turpentine”, common components of the essential oil found in pine tree sap. The chemical structure is characterized by several series of isoprene (C₅H₈) units. A group of terpene and terpene-like compounds, including derivatives and analogs, is called “terpenoids”. These terpenoids are widely used in everyday life—not only as chemical raw materials but also in fragrances, pharmaceuticals, etc.

Structure of Isoprene

Isoprene is the basic unit of terpenes. Terpenes are classified based on the number of isoprene units.

Terpenes = Multiple linked isoprene unit compounds

Examples of Terpenes/Terpenoids and typical Compounds

Monoterpenoids (C₁₀, 2 isoprene units)

モノテルペノイド（炭素数１０：イソプレン２unit） — α-Pinene (component of turpentine oil)、Limonene (component of orange oil)

モノテルペノイド（鎖状β-ミルセンと環状l-メントール） — β-Myrcene (linear terpene, raw material for l-menthol)、l-Menthol (aromatic component of mint)

Sesquiterpenoids (C₁₅, 3 isoprene units)

セスキテルペノイド（炭素数１５：イソプレン３個） — β-Cadinene (component of Hinoki[cypress tree] essential oil)、β-Farnesene (linear sesquiterpene, chemical raw material)、Nootkatone (aromatic component of grapefruit)

Diterpenoids (C₂₀, 4 isoprene units)

ジテルペノイド（炭素数２０：イソプレン４個） — Abietic acid (component of pine resin/rosin)、Stevioside (sweetener from Stevia rebaudiana)

Triterpenoids (C₃₀, 6 isoprene units)
Carotenoids (C₄₀, 8 isoprene units)

トリテルペノイド（炭素数３０：イソプレン６個）& カロチノイド（炭素数４０：イソプレン８個） — Squalene (moisturizing component found in olive oil)、Lycopene (red pigment in tomatoes)

Terpenes – Used as SAF in Japan during WW II

During World War II, Japan faced a shortage of petroleum due to disrupted imports. To make up for this, turpentine oil was produced from pine roots as a national policy. Dry distillation plants for pine roots were established across the country and operated under military protection, the pine root turpentine was supplied to the military as an alternative fuel. After World War II, these plants and their facilities were converted from military to civilian use, contributing to Japan’s postwar recovery.