Electroanalytical determinations of luteolin

Natural antioxidants have become very important in recent decades because of their well known benefits to human health and the increasingly restricted use of synthetic antioxidants. Flavonoids are one of the groups of natural antioxidants widely produced by the plants as secondary metabolites. They are molecules composed of two benzene rings linked through a chain of three carbon atoms. Flavonoids are widely found in fruits, seeds and vegetables. Luteolin (3',4',5,7-tetrahydroxy-flavone; LUT) belongs to the subclass of flavonoids known as flavones and is rated as one of the most bioactive flavonoids. LUT has a resorcinol group in ring A, and a catechol group in ring B. LUT has beneficial effects on human health, such as cardiovascular protection, anti-allergic, and anticancer activities, anti-ulcer effects, and prevents cataracts. LUT also inhibits platelet aggregation by vasodilating action. LUT is a compound as active as tert- butyl hydroxyanisole (BHA) but more active than α-tocopherol. Different analytical methods have been reported for the deter- mination of LUT. They include thin-layer chromatography, gas chromatography, high-performance liquid chromatography, and capillary electrophoresis, coupled to different detection techniques such as UV spectrophotometry, photo diode array, electrochemical array, etc. Even though these techniques have made possible the highly selective and sensitive quantification of LUT, they present some disadvantages such as high cost, high time consumption and reagents, and high complexity of operation. In recent years, electroanalytical techniques have become very important as analytical tools in the determination of different compounds of biological interest. Compared with chromatographic techniques, they require cheap equipment, short analysis times, low solvent consumption, etc. In this chapter, we report the application of electroanalytical techniques to determine LUT in real matrices. Both, results obtained in our laboratory and those reported by other authors are included. We also discuss the application of chemometric tools in those cases where LUT is present in real samples in the presence of other interfering electroactive species whose electrochemical signals show a strong overlap. © 2015 Nova Science Publishers, Inc.