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ARS Home » Research » Publications at this Location » Publication #123147
Title: ANTIOXIDANT ACTIVITY AND PHENOLIC COMPOUNDS IN SELECTED HERBS

Author
item ZHENG, WEI - ZHEJIANG UNIV, CHINA
item Wang, Shiow

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Herbs have been used for many purposes including medicine, nutrition, flavorings, beverages, and industry. Since the prehistoric times, herbs have been the basis for nearly all medicinal therapy until synthetic drugs were developed in the Nineteenth Century. Today herbs are still found in 40 percent of prescription drugs. Culinary herbs also have been grown and used for their ability to enhance and complement the flavors of a wide variety of foods. Even though a variety of herbs are known to be remarkable sources of phenolic compounds, data on the composition and antioxidant activities of herbs are insufficient. We found herbs to contain a number of phytochemicals, many of which have significant antioxidant capacities. This study revealed that herbs are an effective and potential source of natural antioxidants. The results from this study will be useful to plant breeders, other researchers and the general public who are interested in the antioxidant potentials of various herbs as dietary supplements.

Technical Abstract: The antioxidant capacities (oxygen radical absorbance capacities, ORAC) and total phenolic contents in extracts of 27 culinary herbs and 12 medicinal herbs were determined. The ORAC values and total phenolic contents for the medicinal herbs ranged from 1.88 to 22.30 micromol of Trolox equivalents (TE)/g fresh weight and 0.57 to 7.13 mg of gallic acid equivalents (GAE)/g fresh weight, respectively. The Origanum x majoricum, Origanum vulgare ssp. hirtum, and Poliomintha longiflora have higher ORAC and phenolic contents compared to other culinary herbs. These also were much higher than values found in the medicinal herbs. The medicinal herbs with the highest ORAC values were Catharanthus roseus (22.30 micromol of TE/g), Thymus vulgaris (19.49 micromol of TE/g), Hypericum perforatum (16.77micromol of TE/g), and Artemisia annua (15.69 micromol of TE/g). A linear relationship existed between ORAC and total phenolic content in the medicinal and culinary herbs. High-performance liquid chromatography coupled with diode-array was used to identify and quantify the phenolic compounds in selected herbs. Among the identified phenolic compounds, rosmarinic acid was the predominant phenolic compound in Salvia officinalis, Thymus vulgaris, Origanum x majoricum, and Poliomintha longiflora whereas quercetion- glucoside and kaempferol-glucoside were predominant phenolic compounds in Ginkgo biloba leaves.