Terpinen-4-ol
Terpinen-4-ol is an isomer of terpineol with the chemical formula C10H18O. A primary constituent of tea [tree oil], it is obtained as an extract from the leaves, branches, and bark of Melaleuca alternifolia Cheel. Despite considerable basic and preliminary clinical research of terpinen-4-ol and tea tree oil, its biological properties and potential for clinical uses have not been established as of 2019. It may be a factor in the contact dermatitis of tea tree oil when used topically.
Terpinen-4-ol occurs in Juniperus communis and is thought to be the reason why this wood is highly resistant to rot.