Our blueberry cultured cells produce anthocyanins in high quantity (Nawa et al., Biosci. Biotech. Biochem., 57, 770-774, 1993). Using high performance liquid chromatography/mass spectrometry (LC-MS), 14 anthocyanins in the red cells derived from leaves of rabbiteye blueberry cv. Tifblue (Vaccinium ashei Reade) were identified as 3-galactoside (gal), 3-glucoside (glc) and 3-arabinoside (ara) of cyanidin (Cy), delphinidin (Dp), petunidin (Pe), peonidin (Pn) and malvidin (Mv), except for Mv 3-ara. The fruits additionally contained 15 anthocyanins and Mv 3-ara, as a main anthocyanin. The autumn red leaves contained Cy 3-gal, Cy 3-ara and Cy 3-glc. In the red cells and the leaves, derivatives of Cy were the most abundant at 85.7% (Cy 3-gal 49.1%, Cy 3-glc 5.8%, Cy 3-ara 30.9%) and 100% (Cy 3-gal 51.0%, Cy 3-glc 6.5%, Cy 3-ara 42.5%) of the total anthocyanins, respectively. In contrast, the fruits contained Mv derivatives as main components that amounted to 50.9% of the total anthocyanins; Mv 3-gal, Mv 3-ara and Mv 3-glc constituted 21.2, 15.3 and 14.4%, respectively. Cy derivatives in fruit anthocyanins amounted to 18.0% . The red cells produced 107 mg of anthocyaninlIOO g fr wt, which was slightly lower than that of the fruits (129 mg). LC-MS analysis also suggested the presence of quercetin (Q) 3-glc, Q 3-rutinoside, and glycosides of myricetin (M) and Q in the red cells. This analysis showed the presence of (+)-catechin (C) and (-)-epicatechin (EC) in these cells as well as of (+)-C, (-)-EC and chlorogenic acid in the red leaves. These flavonoids and phenolics were also some of the main components in the leaves.Keywords: blueberry, cultured cell, anthocyanins, phenolics, flavonols, LC-MS.
IntroductionFlavonoids are polyphenolic phytochemicals that constitute a large group of secondary metabolites in plants, and are useful diet components. Dietary flavonoids consist mainly of anthocyanins, flavonols, flavones, catechins and flavanones; they are potent antioxidants, free radical scavengers and metal chelators. Thus, certain flavonoids are used for their health promoting properties. Anthocyanins from the fruit of bilberry (Vaccinium myrtillus) were reported to have the ability to decrease the permeability and fragility of capillaries, to inhibit urinary tract infection and to strengthen collagen matrices via cross linkages (Morazzoni & Bombardelli, 1996;Walt & Dufour, 1997). Pharmaceutical preparations of crude extracts of the fruits, including mainly anthocyanins, are used for curing. In the United States, blueberries have become of special interest in connection with studies on the total antioxidant activities in food using the automated oxygen radical absorbance capacity (ORAC) procedure; this is because of the high antioxidant capacity of blueberry anthocyanins and the wide range of their anthocyanin and flavonol content (Prior et al., 1998;. In Japan, anthocyanins of blueberry fruits E-mail: shioka@nfri.affrc.go. jp are usually used as a food colorant providing additional benefits for health. Furthermore...