Phellandrene is the name for a pair of organic compounds that have a similar molecular structure and similar chemical properties. α-Phellandrene and β-phellandrene are cyclic monoterpenes and are double-bond isomers.
In α-phellandrene, both double bonds are endocyclic and in β-phellandrene, one of them is exocyclic. Both are insoluble in water, but miscible with ether.
The phellandrenes are used in fragrances because of their pleasing aromas. The odor of β-phellandrene has been described as peppery-minty and slightly citrusy.It is colorless to light yellow oily liquid with peppermint aroma. Right-handed body exists in cinnamon oil, ginger oil, elemi oil, cumin oil etc. Left-handed body exists in eucalyptus oil, star anise oil, gump couch oil, laurel oil, pepper oil, etc.
α-Phellandrene was named after Eucalyptus phellandra, now called Eucalyptus radiata, from which it can be isolated. It is also a constituent of the essential oil of Eucalyptus dives.
alpha-Phellandrene is an oily liquid with colorless to light yellow colors. Has black pepper odor character. Flash point is 49°C. The boiling point (by 2133 pa.) of right-handed body at 66~88°C, and the left-handed body at 58~59°C. Soluble in ethanol and ethyl ether, insoluble in water.
The right-handed body is existed in cinnamon oil, ginger oil, elemi oil, cumin oil and other plants. The left-handed body is existed in eucalyptus oil, star anise oil, gump couch oil, laurel oil, pepper oil and other plants.
Limonene is found in citrus essential oil, the contents can be up to 90%. (-)-Limonene is naturally found in Pine needle oil, Turpentine, Cajeput oil and other essential oils. It appears liquid and has orange smell. It is make from Terpenes of orange oils by the method of fractionation.
Limonene has optical isomers, L-Limonene, R-Limonene and a meso isomer, Dipentene.
In the flavoring formulation of personal cares, the contents of Limonene can be up to 30%. Limonene is also mainly used as intermediate for synthesis Bergamot esters, Norone, Cymene, Tonalid and Phantolid.