DPPH free-radical scavenging ability, total phenolic content, and chemical composition analysis of forty-five kinds of essential oils
Forty-five kinds of commonly used essential oils were employed to investigate the DPPH (1,1-diphenyl2-picrylhydrazyl) radical scavenging ability and total phenolic content of major chemical compositions. The free-radical scavenging ability and total phenolic content of cinnamon leaf and clove bud essential oils are the best among these essential oils. One-half milliliter of cinnamon leaf and clove bud essential oils (10 mg mL EtOH) are shown to be 96.74% and 96.12% of the DPPH (2.5ml, 1.52 × 10-4 M) free-radical scavenging ability, respectively. Their EC50 (effective concentrations) are 53 and 36 (μg mL-1). One milligram per milliliter of cinnamon leaf, clove bud, and thyme red essential oils were shown to be 420, 480, and 270 (mg g-1 of GAE) of total phenolic content, respectively. Eugenol in cinnamon leaf and clove bud essential oils (82.87% and 82.32%, respectively) were analyzed by GC-MS. It is clear that the amounts of the phenol compounds in essential oils and the DPPH free-radical scavenging ability are in direct proportion.
Document Type: Abstract
Affiliations: 1: Department of Science and Technology for Bioindustry, Hungkuang University, Shalu, No. 34, Chung-Chie Road, Taichung 2: Lorien Vana Biotech. Inc., 10F, No. 176, Chang-chun Road, Taipei 3: Department of Applied Cosmetology, Hungkuang University, Shalu, No. 34, Chung-Chie Road, Taichung, Taiwan
Publication date: December 1, 2009