Anthocyanins with 4′-glucosidation from red onion, Allium cepa (original) (raw)

Characteristic Anthocyanin Pattern from Onions and other Allium spp

Journal of Food Science, 1996

Three red onion (Allium cepa) cultivars, top onion (A. cepa var. viviparum), A. altaicum and chive (A. schoenoprasum) contained several or all of the following anthocyanins: 3-(6"-malonyl-3"-glucosylglucoside), 3-(3",6"-dimalonylglucoside), 3-(6"-malonylglucoside), 3-(3"-malonylglucoside), 3-(3"-glucosylglucoside) and 3-glucoside of cyanidin. Trace amounts of two pelargonidin derivatives and the 3,5-diglucosides of cyanidin and peonidin were for the first time reported in red onion. Carbon NMR data showed that the sugars of the 3-(6"-malonyl-3"-glucosylglucoside), 3-(6"-malonylglucoside) and 3-glucoside of cyanidin were pyranoses. Substitution either by sugar or acid in the sugar 3position of an anthocyanin has never been reported outside the genus Allium.

Anthocyanins from red onion, Allium cepa, with novel aglycone

Phytochemistry, 2003

Four anthocyanins with the same novel 4-substituted aglycone, carboxypyranocyanidin, have been isolated from acidified, methanolic extracts of the edible scales as well as from the dry outer scales of red onion, Allium cepa L. The structures of 1 and 2 were identified as the 3-O-b-glucopyranoside and 3-O-(6 00 -O-malonyl-b-glucopyranoside) of 5-carboxypyranocyanidin, respectively. This aglycone, 5-carboxy-2-(3,4-dihydroxyphenyl)-3,8-dihydroxy-pyrano[4,3,2-de]-1-benzopyrylium, is with exception of the substitution pattern on the phenyl ring similar to carboxypyranomalvidin (vitisidin A) recently isolated from red wines. In addition to 1 and 2, two analogues of 2 methylated at the terminal carboxyl group of the acyl moiety (3) or at the aglycone carboxyl (4), respectively, were also identified. These latter compounds are most probably formed by esterification of 2 with the solvent (acidified methanol) during the isolation process. The structures were elucidated by 2D NMR spectroscopy and LC-MS. #

RP HPLC determination of some uncommon anthocyanins

Anthocyanins of Catharanthus roseus petals were found to be composed of pairs (3-galactosides and 3-rhamnosylgalactosides) mainly of 7-methylated anthocyanidins of " dephinidin series " (7-methyldelphinidin, 7-methylpetunidin and hirsutidin); though the same derivatives of " cyanidin series " are present in low concentrations. Flowers of Caesalpinia pulcherrima contain two 3-glucosides: of cyanidin and 5-methylcyanidin. The migration of CH 3-radical from 3'-OH group to 7-OH position results in increase of retention, while for the migration to 5-OH group a decrease of retention was observed. Different position of ring A OH-groups methylation can be predicted also by controversial shift of λ max of the solutes. Keywords: Reversed-phase HPLC, uncommon anthocyanins, 7-OH methylation; 5-OH methylation; regularities of retention alteration, electronic spectra. Установлено, что антоцианы лепестков цветков Catharanthus roseus образованы парами (3-галактозидами и 3-ра...

Proceedings of the 3rd International Workshop on Anthocyanins

Proceedings pf the 3rd International Workshop on Anthocyanins, 2004

Preface "Let food be the medicine and medicine be the food" stated the father of medicine, Hippocrates (460-377BC), over two thousands years ago. This statement is equally valid today: preventative healthcare through a well-balanced diet is the primary objective of many national and international research programs. Among bioactive phytochemicals with a safe history of human consumption are anthocyanins: water-soluble pigments almost ubiquitous to the plant kingdom, responsible for the red to purple to blue colours of fruits, vegetables, cereal grains, and flowers. Accumulated in plants frequently in response to environmental stress, anthocyanins are responsible for photo-protection against light-induced photooxidation and UV-B damage and regulation of drought and cold resistance through adjustment of the osmotic pressure of vacuole content. Perhaps because of their ability to impact colour to the plant or plant product in which they are present, but more certainly because of their pharmacological properties, anthocyanins were incorporated into herbal folk medicines and food products. Recent research data reports an array of health-beneficial effects arising from the consumption of anthocyanin-rich products and indicates new areas of their potential application in promoting good health. Anthocyanin-rich fruit and vegetable extracts evaluated in both in vitro and in vivo experimental systems demonstrated protection against oxidative damage caused by free radicals. Anthocyanins have been reported to provide protection against liver injuries and UV radiation, significantly reduce blood pressure, improve eyesight, exhibit strong anti-inflammatory and antimicrobial activities, inhibit reversed mutation caused by cooked food mutagens, and suppress proliferation of human cancer cells. Due to their wide physiological activities, anthocyanins may play a significant role in preventing lifestyle related diseases such as cancer, diabetes, and cardiovascular and neurological diseases. These qualities of anthocyanins have prompted researchers and the food industry towards the development of "anthocyanin-tailored" functional food products, which would deliver anthocyanins as nutraceuticals with specific health benefits. Application of biotechnology to engineer the anthocyanin biosynthetic pathway in order to produce the desired anthocyanins as a natural food colorant with specific colour qualities, increased stability, and/or health-promotive qualities, may create new opportunities for a commercial production of selected food colorants and/or nutraceuticals in a factory setting. Biotechnology application for development of novel ornamental plants with increased decorative characteristics or with enhanced disease-or stress-resistance through manipulation of anthocyanin biosynthetic pathway is another area of anthocyanin research with a commercial focus. We hope that scientific presentations enriched with displays of anthocyanincontaining food products by Australian and international companies as well as debates among researchers and industry managers at IWA2004 will contribute towards further understanding of the benefits that application of anthocyanins in food products can bring and their efficient utilization.

Chemical studies of anthocyanins: A review

Food Chemistry, 2009

Anthocyanins are natural colorants which have raised a growing interest due to their extensive range of colours, innocuous and beneficial health effects. Despite the great potential of application that anthocyanins represent for food, pharmaceutical and cosmetic industries, their use has been limited because of their relative instability and low extraction percentages. Currently, most investigations on anthocyanins are focused on solving these problems, as well as their purification and identification.

Isolation and Characterization of Anthocyanins from Blue-fleshed Potatoes (Solanum tuberosum L

During the last decade anthocyanin-related research has been intensified due to the fact that a high intake of anthocyanin-rich food has been linked to health-protecting effects. Pigmented potato (Solanum tuberosum L.) varieties constitute an important source of anthocyanins. So far, little information concerning the metabolism, bioactivity, and bioavailability of acylated anthocyanins has been published because it is still difficult to obtain pure pigments on a preparative scale. In our studies, the pigment composition of the blue-fleshed potato cultivars 'Hermanns Blaue', 'Vitelotte', 'Shetland Black', and 'Valfi' were examined. The preparative isolation of anthocyanins was carried out by applying two different methods of countercurrent chromatography (CCC), the so-called High-Speed Countercurrent Chromatography (HSCCC) and Low Speed Rotary Countercurrent Chromatography (LSRCCC), respectively. By application of LSRCCC, HSCCC, as well as preparative HPLC it was possible to isolate and characterize the major pigments, i.e. 3-p-coumaroylrutinoside-5-glucosides of petunidin, malvidin, and peonidin, of the four cultivars. From the cultivar 'Hermanns Blaue' LSRCCC enabled the isolation of the major pigment petunidin-3-p-coumaroylrutinoside-5-glucoside on a preparative scale. Furthermore, it was possible to separate and characterize several non-acylated 3,5-diglucosides, i.e. 3-rutinoside-5-glucosides of petunidin and malvidin, acylated 3,5-diglucosides, i.e. 3-feruloylrutinoside-5-glucosides of petunidin and malvidin as well as the 3-caffeoylrutinoside-5-glucoside of petunidin, and the p-coumaric acid derivative petunidin-3-p-coumaroylrutinoside. Purity and identity of the so-obtained anthocyanins were controlled by HPLC-DAD, ESI-MS n , and NMR-measurements.

Anthocyanin, the Natural Colorant and Its Implications in Health and Food Industry: A Search

Kongunadu Research Journal

Anthocyanins are unique plant pigments since they are critical for most of the red, purple and blue pigmentation of flowers, fruits and vegetables. Meanwhile, they are reactive in nature, anthocyanins degrade easily, or react with other compounds such as reactive metals such as iron, aluminum, and tin in the media, toform colorless or brown colored by products. Anthocyanins are glycosides of anthocyanidins (aglycones) and sugars. Anthocyanidins are almost always glycosylated in the 3-position, though glycosylation in other positions and in more than one position at a time is also encountered. Furthermore, the sugar moiety may be acylated with aliphatic or aromatic acids. Anthocyanidins are less in number but anthocyanins show much diversity offered by glycosylation and acylation. 635 anthocyanins were identified in nature, featuring six common aglycones and various types of glycosylations and acylations. Reports suggest that dietary consumption of anthocyanins is good for health. Ba...

Molar Absorptivity (ε) and Spectral Characteristics of Cyanidin-Based Anthocyanins from Red Cabbage

Food Chemistry, 2015

Red cabbage extract contains mono and di-acylated cyanidin (Cy) anthocyanins and is often used as food colorants. Our objectives were to determine the molar absorptivity (ε) of different red cabbage Cy-derivatives and to evaluate their spectral behaviors in acidified methanol (MeOH) and buffers pH 1-9. Major red cabbage anthocyanins were isolated using a semi-preparatory HPLC, dried and weighed. Pigments were dissolved in MeOH and diluted with either MeOH (0.1% HCl) or buffers to obtain final concentrations between 5×10(-5) and 1×10(-3)mol/L. Spectra were recorded and ε calculated using Lambert-Beer's law. The ε in acidified MeOH and buffer pH 1 ranged between ~16,000-30,000 and ~13,000-26,000L/molcm, respectively. Most pigments showed higher ε in pH 8 than pH 2, and lowest ε between pH 4 and 6. There were bathochromic shifts (81-105nm) from pH 1 to 8 and hypsochromic shifts from pH 8 to 9 (2-19nm). Anthocyanins molecular structures and the media were important variables which greatly influenced their ε and spectral behaviors.

Spectroscopic screening of assorted pigmented vegetables and fruits for anthocyanins

Anthocyanins is a ubiquitous water-soluble, vacuolar class of pigments that depending on their pH confers red, blue, purple and black color to tissues of higher plants such as leaves, stems, roots, flowers, fruits and bracts [32,33]. They accumulate in the vacuoles of epidermal or sub epidermal cells as an aqueous solution. More so, these pigments have gained wide acceptance because humans and animals have consumed pigmented plants (fruits and vegetables) from the beginning of time without any reported detrimental results and thus their widely adopted use as substitutes for synthetic colors which obviously cannot be subjected to such extensive consumption. This study screened for the presence of anthocyanins in five selected pigmented vegetables and fruits: beetroot (Beta vulgaris), red onions (Allium cepa), red cabbage (Brassica oleracea var. capitata f. rubra), eggplant (Solanum melongena) and red dodo (Amaranthaceae). Beet root, red dodo, red cabbage, egg plants, red onions were ...