Anthocyanin antioxidants from edible fruits
Linda S. Einbonda,1, Kurt A. Reynertsona, Xiao-Dong Luoa,2, Margaret J. Basileb, Edward J. Kennellya,*
Department of Biological Sciences, Lehman College, and The Graduate Center, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468,USA b Department of Neurology, University of Miami School of Medicine, 1501 NW 9th Avenue, Miami, FL 33136, USA Received 6 November 2002; received in revised form 24 March 2003; accepted 24 March 2003
Abstract The edible fruits of 12 plants were extracted in methanol and subjected to solvent–solvent partitioning to yield three fractions, hexane, ethyl acetate, and aqueous. The semi-puriﬁedaqueous fractions were separated over Diaion HP-20SS resin to remove sugars and ascorbic acid. These fractions were then screened for antioxidant activity using the 1,1-diphenyl-2-picrylhydrazyl assay. Nine of the semi-puriﬁed fractions exhibited high antioxidant capacity. Cyanidin-3-O-b-glucopyranoside, an anthocyanin antioxidant, was identiﬁed from semi-puriﬁed aqueous fractions of the tropicalfruit star apple (Chrysophyllum cainito), Surinam cherry (Eugenia uniﬂora), and jaboticaba (Myrciaria cauliﬂora). Delphinidin-3-O-b-glucopyranoside was identiﬁed from E. uniﬂora. # 2003 Elsevier Ltd. All rights reserved.
Keywords: 1,1-Diphenyl-2-picrylhydrazyl, cyanidin-3-O-b-glucopyranoside; Delphinidin-3-O-b-glucopyranoside; HPLC
1. Introduction Oxidative damage in the human body plays animportant causative role in disease initiation and progression (Jacob & Burri, 1996; Kelly, 1998). Damage from free radicals and reactive oxygen species has been linked to some neurodegenerative disorders (Floyd, 1999; Youdim & Joseph, 2001) and cancers (Goodwin & Brodwick, 1995), and oxidation of low-density lipoprotein is a major factor in the promotion of coronary heart disease (CHD) andatherosclerosis (Frankel, Kanner, German, Parks, & Kinsella, 1993; Steinberg, 1997). Diets high in fruits and vegetables and low in cholesterol and fats are inversely correlated with the incidence of CHD and cancer (Hertog, Feskens, Hollman, Katan, & Kromhout, 1993; Hertog et al., 1995; Knekt, Jarvinen, Reunanen, & Maatela, 1996). Natural ¨ antioxidants from fruits and vegetables provide a
* Correspondingauthor. Tel.: +1-718-960-1105; fax +1-718-9608236. E-mail address: firstname.lastname@example.org (E.J. Kennelly). 1 Present address: Center for Complementary and Alternative Medicine Research in Aging and Women’s Health, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA. 2 Present address: Kunming Institute of Botany, Kunming 650204, 0308-8146/03/$ - see front matter # 2003Elsevier Ltd. All rights reserved. doi:10.1016/S0308-8146(03)00162-6
measure of protection that slows the process of oxidative damage (Jacob & Burri, 1996). Recent studies have shown that many ﬂavonoids and related polyphenols contribute signiﬁcantly to the total antioxidant activity of many fruits and vegetables (Luo, Basile, & Kennelly, 2002; Vinson et al., 1999). Fruits and vegetables arehigh in ﬂavonoid content; it is estimated that humans consume between a few hundred milligrams and one gram of ﬂavonoids every day (Hollman & Katan, 1999; Pietta, 2000). Human studies have found that ﬂavonoids appear in blood plasma, at pharmacologically active levels, after eating certain foods but do not accumulate in the plasma (Cao, Booth, Sadowski, & Prior, 1998; Hollman & Katan, 1999). Certainﬂavonoids are excreted in urine within 4 h of ingestion (Milbury, Cao, Prior, & Blumberg, 2002). Regular consumption of ﬂavonoids may increase longevity by reducing inﬂammation and contributing to a reduction in CHD (Frankel et al., 1993). There are over 4000 naturally occurring ﬂavonoids (Harborne & Baxter, 1999). The anthocyanins, a subclass of ﬂavonoids, are important ﬂower and fruit...