Steam-distillation from the leaves of Melaleuca alternifolia produces tea tree oil, a mixture of about 100 components, mostly consisting of monoterpenes, sesquiterpenes, and their alcohol derivatives. The major constituent, terpinen-4-ol, is known for its antibacterial, antifungal, antiviral, and anti-inflammatory properties. A collaborative research problem on tea tree oil was proposed by students in a junior capstone course and conducted in subsequent semesters. The antioxidant activity of the four most abundant compounds in tea tree oil, terpinen-4-ol, α-terpinene, γ-terpinene, and terpinolene, was examined by DPPH assay. These components were quantified by GC-MS for five different commercial tea tree essential oils. The extent of oxidation of tea tree oil constituents to p-cymene was investigated and compared to limits and “use by” dates established by the International Organization for Standardization. Thin-layer chromatography, column chromatography, and HPLC were also employed in isolating and identifying these components from tea tree oil.

Antioxidant activity and GC-MS evaluation of tea tree oil components in a capstone laboratory

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.