Characterization and Quantitation of Polyphenolic Compounds in Bark, Kernel, Leaves, and Peel of Mango (Mangifera indica L.) JACQUELINE C. BARRETO, †,‡ MARIA T. S. TREVISAN, ‡ WILLIAM E. HULL, ‡ GERHARD ERBEN, ‡ EDY S. DE BRITO, § BEATE PFUNDSTEIN, † GERD WU ¨ RTELE, † BERTOLD SPIEGELHALDER, † AND ROBERT W. OWEN* ,† German Cancer Research Center, Heidelberg, Germany, Universidade Federal do Ceara ´, Fortaleza, Brazil, and Embrapa Agroindu ´stria Tropical, Fortaleza, Brazil The contents of secondary plant substances in solvent extracts of various byproducts (barks, kernels, peels, and old and young leaves) in a range of Brazilian mango cultivars were identified and quantitated. The results show that the profiles of secondary plant substances such as xanthone C-glycosides, gallotannins, and benzophenones in different byproducts vary greatly but are fairly consistent across cultivars. The free radical scavenging activity of the solvent extracts was evaluated using a high-performance liquid chromatography-based hypoxanthine/xanthine oxidase assay and revealed dose-dependent antioxidant capacity in all extracts. Four (mangiferin, penta-O-galloyl- glucoside gallic acid, and methyl gallate) of the major phenolic compounds detected were also evaluated in additional in vitro bioassay systems such as oxygen radical absorbance capacity, 2,2- diphenyl-1-picrylhydrazyl, and ferric reducing ability of plasma. Mangiferin in particular, detected at high concentrations in young leaves (Coite ) 172 g/kg), in bark (Momika ) 107 g/kg), and in old leaves (Itamaraka ) 94 g/kg), shows an exceptionally strong antioxidant capacity. KEYWORDS: Benzophenones; DPPH assay; FRAP assay; gallotannins; HPLC-ESI-MS; mangiferin; ORAC assay; cancer chemopreventive polyphenolic compounds; xanthones INTRODUCTION Mango (Mangifera indica L.), which belongs to the family Anacardiaceae, order Rutales, is one of the most important fruits marketed in the world with global production exceeding 26 million tons in 2004 (1). It is grown naturally or cultivated mainly in tropical and subtropical regions and has been reported to be the second largest tropical fruit crop in the world (2). Extensive research in the area of plant breeding has generated hundreds of cultivars, the fruits of which show a pronounced diversity in size, color, flavor, seed size, and composition (3). In Brazil, mango is cultivated on a large scale in the South- eastern and Northeastern states. According to data published by the FAO, Brazil is the fifth largest producer of mangoes, although it represents just 2.7% of the total global production of 26 million tons. Extracts of M. indica Linn have been reported to possess antiviral, antibacterial, analgesic, anti-inflammatory, and immuno- modulatory activities (4); in vitro antiamoebic activity (5); interest- ing R-amylase and R-glucosidase inhibitory activities (6); and cardiotonic and diuretic properties (7). In traditional medicine, the use of mango extracts as herbal drugs is widespread. There are several reports available concerning the traditional uses of mango kernel in various parts of the world. In Fiji, fresh mango kernel is consumed as a cure for dysentery and asthma, while mango juice is used as a nose drop for sinus trouble (8). In India, dry seed power is applied to the head to remove dandruff and is also applied as an antidiarrheal agent (9). Kernel starch is eaten as a famine food (10), while hot water extracts of kernel are administered as anthelmintics, aphrodisiacs, laxatives, and tonics (11). The high carotenoid content, which is responsible for the yellow to orange color of ripe mango, provides a high provitamin A value and antioxidant capacity. Total carotenoid concentrations are usually in the range of 0.9-9.2 g/kg (12). Phenolic compounds play an important role in the color and flavor of foods and beverages, and regular consumption is associated with beneficial effects for human health (13). Some phenolic compounds present in mango are antioxidants, con- tributing to a reduction in the risk of cardiovascular diseases, while others such as gallic acid and quercetin are claimed to have activity against allergies, inflammation, hypertension, arthritis, and carcinogenesis (14, 15). Interest in the search for new natural antioxidants has grown dramatically over the past years because oxidative stress, * To whom correspondence should be addressed. Tel: +49-6221- 42-3317. Fax: +49-6221-42-3359. E-mail: r.owen@dkfz-heidelberg.de. † German Cancer Research Center. ‡ Universidade Federal do Ceara ´. § Embrapa Agroindu ´stria Tropical. J. Agric. Food Chem. 2008, 56, 5599–5610 5599 10.1021/jf800738r CCC: $40.75  2008 American Chemical Society Published on Web 06/18/2008