Distribution of C- and O-glycosyl flavonoids, (3-hydroxy-3-methylglutaryl)glycosyl flavanones and furocoumarins in Citrus aurantium L. juice
Introduction
The positive effects of citrus fruit consumption on human health was of common knowledge centuries before researchers begun to unravel the complexity of such food matrices. Over the past decades, a large number of studies have been carried out with the aim of identifying the bioactive components present in different parts of citrus fruits, in an attempt to gain a deeper understanding of the correlation between diet, health benefits and reduced risk of diseases.
Nowadays, a great amount of data has been collected on the biomedical properties of many relevant nutraceuticals (Patil, Jayaprakasha, Murthy, & Vikram, 2009). In this context, several epidemiological studies have associated the consumption of phenolic compounds, and more specifically flavonoids, with lower risks of different types of cancer (Nichenametla, Taruscio, Barney, & Exon, 2006) and cardiovascular diseases (Kris-Etherton et al., 2002), and have shown that they possess antioxidant, anti-inflammatory and anti-ageing activity (Benavente-García & Castillo, 2008). Citrus fruits are among the richest dietary sources of flavonoids (Berhow et al., 1998, Tripoli et al., 2007) and, in their juices, flavonoids usually occur as O-glycosyl and C-glycosyl derivatives (Gattuso, Barreca, Gargiulli, Leuzzi, & Caristi, 2007).
Citrus aurantium L. (commonly known as sour or bitter orange) has long been used in food industry as an ingredient of liqueurs and marmalades, and its extracts have also been employed in traditional Chinese medicine to activate vital energy and circulation, eliminate phlegm, and disperse stagnation (Ou, 1989). Recently, products containing sour orange have been exploited for the production of ephedrine-free dietary supplements for weight loss and appetite control.
However, the growing interest in sour orange products is due to the fact that they are rich in different classes of bioactive compounds such as synephrine alkaloids (Santana, Sharpless, & Nelson, 2008), which showed controversial effects on blood pressure and heart rate, limonoids and phytosterols (Jayaprakasha, Jadegoud, Gowda, & Patil, 2010) and flavonoids (Barreca et al., 2009, Bellocco et al., 2009), which are associated with anticancer activity and apoptotic activation. As for the latter, previous studies (Kawaii et al., 1999, Nogata et al., 2006) reported the chromatographic separation of the main flavonoid components of C. aurantium. The main components of C. aurantium juice were identified as neoeriocitrin, naringin, and neohesperidin, similarly to what we recently reported on two closely related taxons, C. myrtifolia Raf. (Barreca, Bellocco, Caristi, Leuzzi, & Gattuso, 2010), which is a mutation of sour orange, and C. bergamia Risso (Gattuso et al., 2007, Gattuso et al., 2006), which is a hybrid between sour orange and citron. In the present paper, by applying a methodology based on a single chromatographic course by reverse-phase LC–DAD–ESI–MS–MS, we are reporting the identification and quantification of 14 compounds (five flavones, eight flavanones and a furocoumarin), eight of which were found in sour orange juice for the first time. Our study on the antioxidant activity of crude sour orange juice is also reported.
Section snippets
Samples
The fruits of Citrus aurantium L. (sour orange) were orange-coloured, oblate spheroids, with a diameter of about 10–12 cm, and they were harvested in Calabria, Italy. The fruits were harvested in December, about 5 months after the flowering period. The specimens were identified by Prof. G. Tripodi, Università di Messina, Italy. The investigation was carried out on 10 samples from the 2009–2010 fruit season.
Reagents and standard solutions
HPLC-grade acetonitrile and methanol were supplied by Sigma–Aldrich (St. Louis, MO, USA),
Identification of flavonoids and furocoumaris
The DAD chromatograms recorded at 278, 325 and 310 nm (Fig. 1) and the UV spectra obtained in correspondence of each chromatographic peak, revealed that C. aurantium juice contains both flavonoids and furocoumarins. In fact, the comparison of the relative absorbances at 278 and 325 nm (Fig. 1A and B) made the discrimination of flavanones and flavones possible. On this basis, compounds 1–4 and 9 were assigned a flavone skeleton, whereas derivatives 5–8 and 10–13 were found to belong to the
Conclusions
In this paper, a comprehensive profile of the flavonoids and furocoumarin components of C. aurantium juice has been presented. The HPLC–DAD–ESI–MS–MS procedure we have developed over the past few years allowed us to identify and simultaneously quantify 14 different components in a single chromatographic course, even at very low concentrations. Among these, two statin-like flavanones (melitidin and brutieridin), a furocoumarin (epoxybergamottin), three C-glucosyl flavones (lucenin-2, vicenin-2
Acknowledgments
The Authors are grateful to Prof. G. Tripodi (Dipartimento di Scienze della Vita “M. Malpighi”, Università di Messina) for his valuable advice.
References (28)
- et al.
Flavone-di-C-glycosides in Citrus juices from southern Italy
Food Chemistry
(2006) - et al.
Bioactive compounds in foods: Their role in the prevention of cardiovascular disease and cancer
American Journal of Medicine
(2002) - et al.
Determination of para-synephrine and meta-synephrine positional isomers in bitter orange-containing dietary supplements by LC/UV and LC/MS/MS
Food Chemistry
(2008) - et al.
Citrus flavonoids: molecular structure, biological activity and nutritional properties: A review
Food Chemistry
(2007) - et al.
Flavonoid composition and antioxidant activity of juices from chinotto (Citrus × myrtifolia Raf.) fruits at different ripening stages
Journal of Agricultural and Food Chemistry
(2010) - et al.
Influences of flavonoids on erythrocyte membrane and metabolic implication through anionic exchange modulation
Journal of Membrane Biology
(2009) - et al.
Influence of l-rhamnosyl-d-glucosyl derivatives on properties and biological interaction of flavonoids
Molecular and Cellular Biochemistry
(2009) - et al.
Update on uses and properties of Citrus flavonoids: New findings in anticancer, cardiovascular, and anti-inflammatory activity
Journal of Agricultural and Food Chemistry
(2008) - Berhow, M., Tisserat, B., Kanes, K., & Vandercook, C. (1998). Survey of phenolic compounds produced in Citrus. USDA ARS...
- et al.
Flavonoids detection by HPLC–DAD–MS–MS in lemon juices from Sicilian cultivars
Journal of Agricultural and Food Chemistry
(2003)
Statin-like principles of pergamot fruit (Citrus bergamia): isolation of 3-hydroxymethylglutaryl flavonoid jlycosides
Journal of Natural Products
Determination of oxygen heterocyclic components in Citrus products by HPLC with UV detection
Journal of Agricultural and Food Chemistry
Distribution of flavonoids and furocoumarins in juices from cultivars of Citrus bergamia Risso
Journal of Agricultural and Food Chemistry
Flavonoid composition of Citrus juices
Molecules
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