Analytical Sciences

Abstract − Analytical Sciences, 30(2), 251 (2014).

Quantification of Antioxidants by Using Chlorpromazine Hydrochloride: Application of the Method to Food and Medicinal Plant Samples
Padmarajaiah NAGARAJA, Narayanan ARADHANA, Aandamurthy SUMA, Anantharaman SHIVAKUMAR, and Nelligere Arkeshwaraiah CHAMARAJA
Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore-570006, Karnataka, India
Chlorpromazine hydrochloride (CPH) (3-(2-chloro-phenothiazine-10-yl)-propyl] dimethylamine hydrochloride) has been the subject of a large number of studies employing a broad spectrum of oxidants, and chosen to examine the course of electron transfer reactions. We report on a method to determine the antioxidant activity of some food and medicinal plants using the oxidation of CPH by chromium(VI) to form a stable CPH radical in the 1:1 orthophosphoric acid–ethyl alcohol (OPA-EtOH) medium. The pink color of the control solution was measured at λmax of 530 nm. Nine standard antioxidants have been studied by this method, along with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The EC50, TEC50, antioxidant efficacy and the stoichiometric values for antioxidants have been evaluated. The radical scavenging activity expressed as EC50 ranged from 9.2 μg/mL in Camellia sinensis to 448.18 μg/mL in Cuminum cyminum. The application of a simple and versatile antioxidant capacity assay for dietary polyphenols and medicinal plant extracts, which are commonly used in Ayurveda opens its relevance in the field of antioxidant analysis.