Identification of anthocyanins in muscadine grapes with HPLC-ESI-MS

In vitro and in vivo biological activities of anthocyanins from Nitraria tangutorun Bobr. fruits

Anthocyanins are the main compounds in Nitraria tangutorun Bobr. The enrichment and purification of anthocyanins on macroporous resins were investigated. Regarding anthocyanin purification, static adsorption and desorption were studied. The optimal experimental conditions were the following: resin type: X-5; static adsorption time: 6h; desorption solution: ethanol-water-HCl (80:19:1, V/V/V; pH 1); desorption time: 40min. Furthermore, the in vitro and in vivo biological activities of the anthocyanins were evaluated. The anthocyanins showed ideal scavenging effects on free radicals in vitro, especially on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl free radical (OH). In the animal experiment, blood lipid metabolism of hyperlipidemia rats was regulated by anthocyanin contents. The superoxide dismutase (SOD) activity and the total antioxidant capacity (TAC) of hyperlipidemia rats were also improved by anthocyanins. These results showed that anthocyanins from N. tangutorun Bobr. fruits had potential biological activities in vivo as well as in vitro.

Multiple loss-of-function 5-O-glucosyltransferase alleles revealed in Vitis vinifera, but not in other Vitis species

Wild and loss-of-function alleles of the 5 - O - glucosyltransferase gene responsible for synthesis of diglucoside anthocyanins in Vitis were characterized. The information aids marker development for tracking this gene in grape breeding. Anthocyanins in red grapes are present in two glycosylation states: monoglucoside (3-O-glucoside) and diglucoside (3, 5-di-O-glucoside). While monoglucoside anthocyanins are present in all pigmented grapes, diglucoside anthocyanins are rarely found in the cultivated grape species Vitis vinifera. Biochemically 3-O-glucoside anthocyanins can be converted into 3,5-di-O-glucoside anthocyanins by a 5-O-glucosyltransferase. In this study, we surveyed allelic variation of the 5-O-glucosyltransferase gene (5GT) in 70 V. vinifera ssp. vinifera cultivars, 52 V. vinifera ssp. sylvestris accessions, 23 Vitis hybrid grapes, and 22 accessions of seven other Vitis species. Eighteen 5GT alleles with apparent loss-of-function mutations, including seven premature stop codon mutations and six frameshift indel mutations, were discovered in V. vinifera, but not in the other Vitis species. A total of 36 5GT alleles without apparent loss-of-function mutations (W-type) were identified. These W-type alleles were predominantly present in wild Vitis species, although a few of them were also found in some V. vinifera accessions. We further evaluated some of these 5GT alleles in producing diglucoside anthocyanins by analyzing the content of diglucoside anthocyanins in a set of representative V. vinifera cultivars. Through haplotype network analysis we revealed that V. vinifera ssp. vinifera and its wild progenitor V. vinifera ssp. sylvestris shared many loss-of-function 5GT alleles and extensive divergence of the 5GT alleles was evident within V. vinifera. This work advances our understanding of the genetic diversity of 5GT and provides a molecular basis for future marker-assisted selection for improving this important wine quality trait.

Unraveling the mechanism underlying the glycosylation and methylation of anthocyanins in peach

Modification of anthocyanin plays an important role in increasing its stability in plants. Here, six anthocyanins were identified in peach (Prunus persica), and their structural diversity is attributed to glycosylation and methylation. Interestingly, peach is quite similar to the wild species Prunus ferganensis but differs from both Prunus davidiana and Prunus kansueasis in terms of anthocyanin composition in flowers. This indicates that peach is probably domesticated from P. ferganensis. Subsequently, genes responsible for both methylation and glycosylation of anthocyanins were identified, and their spatiotemporal expression results in different patterns of anthocyanin accumulation in flowers, leaves, and fruits. Two tandem-duplicated genes encoding flavonoid 3-O-glycosyltransferase (F3GT) in peach, PpUGT78A1 and PpUGT78A2, showed different activity toward anthocyanin, providing an example of divergent evolution of F3GT genes in plants. Two genes encoding anthocyanin O-methyltransferase (AOMT), PpAOMT1 and PpAOMT2, are expressed in leaves and flowers, but only PpAOMT2 is responsible for the O-methylation of anthocyanins at the 3' position in peach. In addition, our study reveals a novel branch of UGT78 genes in plants that lack the highly conserved intron 2 of the UGT gene family, with a great variation of the amino acid residue at position 22 of the plant secondary product glycosyltransferase box. Our results not only provide insights into the mechanisms underlying anthocyanin glycosylation and methylation in peach but will also aid in future attempts to manipulate flavonoid biosynthesis in peach as well as in other plants.

Ameliorative effect of black rice anthocyanin on senescent mice induced byd-galactose

This study investigated the ameliorative effect of black rice anthocyanin (BACN) in senescent mice induced byd-galactose.

Anthocyanin phytochemical profiles and anti-oxidant activities of Vitis candicans and Vitis doaniana

INTRODUCTION

Grapes are one of the most important fruit crops in the world. The quality of red grape berries greatly depends on skin colour, mainly due to the anthocyanin profile. Today, the American Vitis species have the greatest potential for breeding work. They have multiple resistance properties in comparison with Vitis vinifera but little is known about their anthocyanin content.

OBJECTIVE

To determine the anti-oxidant properties and anthocyanin profile of two American species, Vitis candicans and Vitis doaniana, by using LC-MS(n) and LC-NMR.

METHODS

Grape extracts were prepared by extraction of berry skins with acidified methanol. The complete structure elucidation of the individual anthocyanins was performed with LC-MS(n) , LC-NMR and NMR experiments. Individual anthocyanins in the extracts were quantified by using malvidin glucoside as external standard. The anti-oxidant activities of grape skin extracts were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical scavenging and oxygen radical absorbance capacity (ORAC) assays.

RESULTS

By using LC-MS(n) and LC-NMR experiments, 30 anthocyanins were identified and quantified in the two Vitis species, including two new cis-p-coumaroyl derivatives. Vitis candicans and V. doaniana showed significant differences in their anthocyanin profile. These two Vitis species possess low-to-medium anti-oxidant activities in comparison with V. vinifera.

CONCLUSION

The profiles of 30 anthocyanins were established unambiguously in two American Vitis species.

Adsorption/desorption characteristics and separation of anthocyanins from muscadine (Vitis rotundifolia) juice pomace by use of macroporous adsorbent resins

In this study, the adsorption/desorption characteristics of anthocyanins on five Amberlite resins (FPX-66, XAD-7HP, XAD-16N, XAD-1180, and XAD-761) were evaluated. FPX-66 and XAD-16N showed the highest adsorption and desorption capacities and ratios for anthocyanins from muscadine pomace extract, while XAD-7HP had the lowest adsorption and desorption capacities and ratios. On the basis of static adsorption and desorption tests, three resins (FPX-66, XAD-16N, and XAD-1180) were selected for adsorption kinetics and isotherms. The adsorption mechanism was better explained by the pseudo-first-order kinetics for FPX-66 and XAD-16N; however, for XAD-1180, pseudo-second-order kinetics was the most suitable model. The experimental data fitted best to Langmuir isotherm model for all three resins. Dynamic testing was done on a column packed with FPX-66 resin and breakthrough volume was reached at 17 bed volumes of muscadine pomace water extract during adsorption. Three bed volumes of aqueous ethanol (70%) resulted in complete desorption. Resin adsorption resulted in a concentrated pomace extract that contained 13% (w/w) anthocyanins with no detectable sugars.

Evolution of phenolic compounds from color and flavor problems to health benefits

Early studies focused on the negative effects on color and flavor of foods, followed by exploration of the antioxidant properties and the associated health benefits. The growing body of evidence suggests that plant-based polyphenols may help prevent or delay the onset of a multiplicity of diseases. Newer work suggests that a variety of polyphenols can alter the expression of genes in the inflammatory pathway. Data also show that the absorption of the polyphenols is very limited. Insulin resistance and endothelial and mitochondrial dysfunction are hallmarks of the metabolic syndrome and aging and occur at the early stages of the disease. There is limited clinical evidence that certain polyphenolic metabolites by virtue of their anti-inflammatory activities can improve insulin sensitivity and endothelial and mitochondrial function, suggesting that polyphenols are good for disease prevention. The goal of this review is to summarize the evolution and emphasize the potential benefits of polyphenols.

Phenolic contents and compositions in skins of red wine grape cultivars among various genetic backgrounds and originations

In order to analyze and compare the phenolic characteristics of red wine grapes with diverse genetic backgrounds, skin phenolics among 21 different cultivars belonging to Vitis vinifera L., East Asian and North American Vitis species and hybrids, as well as 2 varieties of muscadine grapes were estimated by HPLC-MS/MS. There were 45 anthocyanins, 28 flavonols, 8 flavan-3-ols, 9 cinnamic acids, 5 benzoic acids, 5 ellagic acids and 2 stilbenes detected in all the samples. Total contents of each phenolic type varied significantly among the different grape cultivars investigated. There was also a large variability in the phenolic compositions of different grape groups. The differences in anthocyanin composition were obvious between V. vinifera and non-V. vinifera grapes and also between the grapes originating from Eurasia and North America. Quercetin-3-glucuronide and quercetin-3-glucoside were marker flavonol compounds for Euvitis grape skins. Flavan-3-ol monomers were dominant in the skins of muscadine and non-V. amurensis East Asian grapes, whereas polymers were more common in V. vinifera and North American grapes. The muscadine grapes were very rich in flavonols, flavan-3-ols and ellagic acids. Via principal component analysis, these grape cultivars were clustered into three groups according to their characteristic phenolic content and composition.

Optimization of Ultrasonic-Assisted Extraction of Flavonols and Anthocyanins from Blueberry Using RSM

Ultrasonic-assisted extraction (UAE) method was developed for continued extraction of flavonols and anthocyanins from Blueberry. Response surface methodology (RSM) was employed to optimize experimental conditions for extraction of flavonols and anthocyanins. Three major independent variables such as ultrasonic power (W), extraction time (min), liquid to solid ratio (mL/g) were studied. The optimal extraction conditions of flavonols and anthocyanins were determined as follows: ultrasonic power 512.7 W, extraction time 29.8 min, liquid to solid ratio 9.5:1 mL /g. Under a modified condition (ultrasonic power 510W, extraction time 30 min, liquid to solid ratio 10:1 mL /g), the experimental yields of flavonols and anthocyanins were 0.806mg/g and 2.903mg/g respectively, which were agreed closely with the predicted values (0.804mg/g and 2.899mg/g).

Inhibitory effects of muscadine anthocyanins on α-glucosidase and pancreatic lipase activities

Inhibitory effects of the Noble muscadine grape extracts and the representative phytochemicals for anthocyanins (i.e., cyanidin and cyanidin-3,5-diglucoside) on two enzymes, that is, α-glucosidase and pancreatic lipase, were investigated regarding their antidiabetic activities. The study demonstrated that the anthocyanin extracts and the selected chemicals obeyed the competitive mode against the enzymes. The methanolic extracts of whole fruit and skin of the muscadine showed inhibitory activities against the α-glucosidase with their IC(50) values at 1.50 and 2.73 mg/mL, and those against the lipase at 16.90 and 11.15 mg/mL, respectively, which indicated that the muscadine extracts possessed strong antidiabetic activities. Particularly, the ethyl acetate (EtoAc) extract and the butanol (BuOH) extract exhibited much higher inhibitory activities against both enzymes than the CHCl(3) and water extracts, while the majority of anthocyanins existed in the BuOH fractions. Moreover, cyanidin exhibited a much stronger antidiabetic activity than cyanidin-3,5-diglucoside, suggesting that anthocyanins may have higher inhibitory activities after being digested. Further chromatographic analysis by high-performance liquid chromatography-mass spectrometry identified five individual anthocyanins, including cyanidin, delphinidin, petunidin, peonidin, and malvidin glycosides.

Anthocyanins profile of grape berries of Vitis amurensis, its hybrids and their wines

Anthocyanins are responsible for the color of grapes and wine, an important attribute of their quality. Many authors have used anthocyanins profile to classify the grape cultivars and wine authenticity. The anthocyanin profiles of grape berries of Vitis amurensis, its hybrids and their wines were analyzed by HPLC-ESI-MS/MS. The results identified 17 anthocyanins in these grape cultivars, including 11 anthocyanin monoglucosides (five pyranoanthocyanin monoglucosides and one acylated pyranoanthocyanin monoglucoside) and six anthocyanin diglucosides. Likewise, 15 kinds of anthocyanins were detected in wines, including six diglucosides and nine monoglucosides of anthocyanidins, in which four pyranoanthocyanin monoglucosides (Petunidin-3-O-glucoside-4-acetaldehyde, Malvidin-3-O-glucoside-4-pyruvic acid, Malvidin-3-O-glucoside-acetaldehyde and Peonidin-3-O-glucoside-4-pyruvic acid) were detected. In addition, a total of 14 kinds of anthocyanins including six diglucosides and eight monoglucosides of anthocyanidins were identified in skins, in which two pyranoanthocyanin monoglucosides (Peonidin-3-O-glucoside-4-pyruvic acid, Malvidin-3-O-glucoside-4-vinylphenol) and one acylated pyranoanthocyanin monoglucoside (Malvidin-3-O-(6-O-acetyl)-glucoside-4-vinylphenol) were detected. The anthocyanins profile of grape skin of V. amurensis and its hybrids consist of the anthocyanin monoglucosides, diglucosides and pyranoanthocyanins. The wines produced resulted in a slightly different anthocyanin distribution. Pelargonidin-3,5-diglucosides was first found in the skins and wines, however, no acetyl was detected in wines. The principal component analysis results suggest that the anthocyanin profiles were helpful to classify these cultivars of V. amurensis.

Antioxidant capacity, phenolic content, and profiling of phenolic compounds in the seeds, skin, and pulp of Vitis rotundifolia (Muscadine Grapes) As determined by HPLC-DAD-ESI-MS(n)

The objective of this study was to determine and compare the total phenolic content and antioxidant capacity in the seeds, skin, and pulp of eight cultivars of Florida-grown muscadine grapes and to identify the phenolic compounds in these respective portions. Total phenolic contents were determined colorimetrically using Folin-Ciocalteu reagent, and antioxidant capacity was determined by oxygen radical absorbance capacity (ORAC). High-performance liquid chromatography equipped with diode array (HPLC-DAD) and electrospray ionization mass spectrometric detection (ESI-MS(n)) was used to identify the phenolic compounds in the seeds, skin, and pulp of muscadine grapes. The total phenolic content and antioxidant capacity, based on fresh weight, were highest in seeds followed by skin and pulp. On average, 87.1, 11.3, and 1.6% of phenolic compounds were present in seeds, skin, and pulp, respectively. A total of 88 phenolic compounds of diverse structures were tentatively identified in muscadines, which included 17 in the pulp, 28 in the skin, and 43 in the seeds. Seventeen compounds were identified for the first time in muscadine grapes. The compounds identified in seeds included hydrolyzable tannins, flavan-3-ols and condensed tannins, ellagic acid derivatives, and quercetin rhamnoside. The skin contained hydrolyzable tannins, flavonoids, including anthocyanin 3,5-diglucosides, quercetin, myricetin, and kaempferol glycosides.

Different anthocyanin profiles of the skin and the pulp of Yan7 (Muscat Hamburg x Alicante Bouschet) grape berries

Yan73 is a “teinturier” red wine variety cultivated in China and used in winemaking to strengthen red wine color. Here, the anthocyanin profile in both the skin and pulp of this grape variety was analyzed by HPLC-MS. The results showed that 18 anthocyanins were detected in both the skin and the pulp, and pelargonidin-3-O-glucoside, an anthocyanin compound hardly detected in most other Vitis vinifera berries, was found. However, the contents of individual anthocyanins in the skin and the pulp were significantly different. Compared with the skin, the pulp exhibited much lower ratio of 3’,5’-substituted to 3’-substituted anthocyanins and much higher ratio of methoxylation of anthocyanin B-ring to non methoxylation, and with regard to the aromatic acylated and aliphatic acylated anthocyanins, both their contents in the skin are higher than in the pulp. The findings will provide some new insight for the tissue-specific expression and regulation of the genes involving in anthocyanin biosynthesis in grape berries.

Advanced separation methods of food anthocyanins, isoflavones and flavanols

In recent years, increasing knowledge of the positive health effects of food polyphenols has prompted the need to develop new separation techniques for their extraction, fractionation and analysis. This article provides an updated and exhaustive review of the application of counter-current chromatography, high performance liquid chromatography, capillary electrophoresis, and their hyphenation with mass spectrometry to the study of food polyphenols. Flavonoids constitute the largest class of polyphenols, widely spread in the plant kingdom and common in human diet which has been the most widely studied with respect to their antioxidant and biological activities. The main subgroups are anthocyanins, catechins, isoflavones, flavonols and flavones. They are reported to exhibit antioxidant, anti-carcinogenic, anti-inflammatory, anti-atherogenic, anti-thrombotic, and immune modulating functions, among others. Since red fruit anthocyanins, soy isoflavones and flavanols from grapes and teas are currently the most used phenolic compounds for producing new nutraceuticals and functional foods, this review is focused on these three flavonoid groups.