Delphinidin Glycosides Research Articles

Characterization of Anthocyanins Including Acetylated Glycosides from Highbush Blueberry (Vaccinium corymbosum L.) Cultivated in Korea Based on UPLC-DAD-QToF/MS and UPLC-Qtrap-MS/MS

In this study, anthocyanin glycosides from nine cultivars of highbush blueberries grown in Korea were characterized using UPLC-DAD-QToF/MS and UPLC-Qtrap-MS/MS. A total of twenty-two derivatives were identified, consisting of mono-glycosides and acetyl-glycosides attached to aglycones, such as cyanidin, peonidin, delphinidin, petunidin, and malvidin. Among them, seven acetylated glycosides were tentatively determined by comparing the related authentic standards and previous reports and presented mass fragmentation, in which the acetyl group remained as the form attached to the sugar without de-esterification in positive ionization mode. The mid-season cultivar ‘New Hanover’ showed the highest total anthocyanin content (1011.7 mg/100 g dry weight) with predominant malvidin and delphinidin glycosides. Particularly, the ‘Patriot’ (early season) recorded the highest proportion of acetylated glycosides (19.7%). Multivariate analysis showed a distinct separation between early and mid-seasons with Draper. Especially, delphinidin 3-O-galactoside (VIP = 1.94) was identified as a marker for mid-season, and malvidin 3-O-glucoside (VIP = 1.79) was identified as a marker for early season. These comprehensive anthocyanin profiles of Korean blueberries will serve as fundamental data for breeding superior cultivars, evaluating and developing related products as well as clinical and metabolomic research.

Integrated Untargeted Metabolome, Full-Length Sequencing and Transcriptome Analyses Reveal the Mechanism of Flavonoid Biosynthesis in Blueberry (Vaccinium spp.) Fruit.

As a highly economic berry fruit crop, blueberry is enjoyed by most people and has various potential health benefits, many of which are attributed to the relatively high concentrations of flavonoids. To obtain more accurate and comprehensive transcripts, the full-length transcriptome of half-highbush blueberry (Vaccinium corymbosum/angustifolium cultivar Northland) obtained using single molecule real-time and next-generation sequencing technologies was reported for the first time. Overall, 147,569 consensus transcripts (average length, 2738 bp; N50, 3176 bp) were obtained. After quality control steps, 63,425 high-quality isoforms were obtained and 5030 novel genes, 3002 long non-coding RNAs, 3946 transcription factor genes (TFs), 30,540 alternative splicing events, and 2285 fusion gene pairs were identified. To better explore the molecular mechanism of flavonoid biosynthesis in mature blueberry fruit, an integrative analysis of the metabolome and transcriptome was performed on the exocarp, sarcocarp, and seed. A relatively complete biosynthesis pathway map of phenylpropanoids, flavonoids, and proanthocyanins in blueberry was constructed. The results of the joint analysis showed that the 228 functional genes and 42 TFs regulated 78 differentially expressed metabolites within the biosynthesis pathway of phenylpropanoids/flavonoids. O2PLS analysis results showed that the key metabolites differentially accumulated in blueberry fruit tissues were albireodelphin, delphinidin 3,5-diglucoside, delphinidin 3-O-rutinoside, and delphinidin 3-O-sophoroside, and 10 structural genes (4 Vc4CLs, 3 VcBZ1s, 1 VcUGT75C1, 1 VcAT, and 1 VcUGAT), 4 transporter genes (1 VcGSTF and 3 VcMATEs), and 10 TFs (1 VcMYB, 2 VcbHLHs, 4 VcWD40s, and 3 VcNACs) exhibited strong correlations with 4 delphinidin glycosides. These findings provide insights into the molecular mechanisms of flavonoid biosynthesis and accumulation in blueberry fruit.

Floral scents, specialized metabolites and stress-response activities in Heritiera fomes and Bruguiera gymnorrhiza from Sundarban mangrove ecosystem.

Floral biochemistry and stress physiology is an underexplored aspect of mangroves, which should be investigated as part of preservation and restoration efforts. A thriving true mangrove tree (Bruguiera gymnorrhiza (L.) Lamk.) and a threatened mangrove-associate species (Heritiera fomes Buch. Ham.) were studied in the Sundarban region of India for seasonal variations in floral odours, non-volatile phytochemicals, antioxidant enzyme activities, and surface water chemistry in surrounding habitat. Both species were found to exhibit significant differences in floral volatilomes, protein contents, antioxidant enzyme activities, total flavonoids, and total phenolic contents between spring and autumn blooms. The bird-pollinated flowers of B. gymnorrhiza also showed considerable seasonal differences in floral anthocyanin and proline contents, indicating vulnerability of the post-anthesis open flowers to environmental factors. Contrarily to previous findings, B. gymnorrhiza floral bouquet appeared to be enriched in various classes of volatiles - dominated by sulphurous compounds in bud stage and terpenoids in open stage. Floral anthocyanins, contributing to the striking colouration of the calyx, were found to comprise cyanidin and delphinidin derivatives. Other glycosides of cyanidin and delphinidin were detected in H. fomes flowers, contributing to visual guides to potential food rewards for pollinating insects. Floral tissue in H. fomes was found to be protected by densely overlapping layers of stellate trichomes containing sesquiterpenoids as phytoprotectants. Comparison of the two floral species suggested that H. fomes flowering is optimized to oligohaline (but not freshwater) vernal conditions; whereas B. gymnorrhiza blooms are adapted for biologically enriched (including abundant herbivores and microbial growth), mesohaline forest habitats.

Transcriptome analysis reveals the mechanism for blue-light-induced biosynthesis of delphinidin derivatives in harvested purple pepper fruit.

Anthocyanins are the main pigments that affect the color and quality of purple-fruited sweet pepper (Capsicum annuum). Our previous study indicated that blue light can induce anthocyanin accumulation in purple pepper. In view of its underlying mechanism that is unclear, here, anthocyanin content was determined, and transcriptome analysis was performed on pepper fruits harvested from different light treatments. As a result, among the identified anthocyanin metabolites, the levels of delphinidin (Dp) glycosides, including Dp-3-O-rhamnoside, Dp-3-O-rutinoside, and Dp-3-O-glucoside, were highly accumulated in blue-light-treated fruit, which are mainly responsible for the appearance color of purple pepper. Correlation between anthocyanin content and transcriptomic analysis indicated a total of 1,619 upregulated genes were found, of which six structural and 12 transcription factor (TF) genes were involved in the anthocyanin biosynthetic pathway. Structural gene, for instance, CaUFGT as well as TFs such as CaMYC2-like and CaERF113, which were highly expressed under blue light and presented similar expression patterns consistent with Dp glycoside accumulation, may be candidate genes for anthocyanin synthesis in response to blue-light signal.

The isolation of anthocyanin monomers from blueberry pomace and their radical-scavenging mechanisms in DFT study

This study explored the isolation of anthocyanin monomers using a medium- and high-pressure separation technique as a means to increase the added value of a by-product of the blueberry juice industry. Six anthocyanin monomers were isolated with a purity of 95% and identified as mono-galactoside, glucoside, and isomers of delphinidin, malvidin, and even malvidin-3-O-arabinoside, malvidin-3-(6″-acetyl)-O-glucoside by LC-MS and 1H NMR. Following the conformation search, the computer calculation manifested the active sites of six anthocyanins (C4′-OH) and their stabilities based on the structural and energy parameters. The DPPH tests demonstrated that delphinidin glycoside’s free radical scavenging ability (89.93 ± 2.03 % and 86.50 ± 3.16 %) was significantly higher than that of malvidin (80.39 ± 1.30 % and 81.02 ± 0.45 %), and that malvidin’s capacity was improved by conjugation arabinoside (87.48 ± 2.39 %) and acetylated glucoside (88.39 ± 1.37 %), which was compatible with the computer calculation.

Chemical Composition and Polyphenol Compounds of Vaccinium floribundum Kunth (Ericaceae) from the Volcano Chimborazo Paramo (Ecuador)

Mortiño (Vaccinium floribundum Kunth) is considered a “superfruit” due to its antioxidant capacity and possible health benefits. To date, there is no known study that addresses the biochemical characterization of mortiño berries from the paramo of the Chimborazo volcano (Ecuador). So, the aim of this research was to evaluate for the first time the effect of the stage of development of the mortiño berries (two stages) and environment of origin (three sampling areas) on fruit quality. Polyphenol compounds were identified by high-performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometric (ESI-MSn) and quantified by high-performance liquid chromatography with a diode array detector (HPLC-DAD). Moreover, antioxidant properties (ABTS•+, and DPPH), sugar and organic acids, and minerals were examined. The main organic acids were quinic and citric acid, while glucose, fructose, sucrose, mannose, and sorbitol were the main sugars determined in the mortiño fruits. The main constituents of the mortiño berries included hydroxycinnamic acids (5-O-caffeoylquinic acid), flavonols (quercetin 3-hexoside, quercetin 5-hexoside, quercetin 3-pentoside, and quercetin-3-O-rhamnoside) and anthocyanins. Seven anthocyanins were identified: glycosides of cyanidin, delphinidin, petunidin, peonidin, and pelargonidin. The research confirms that the mortiño berries produced in the Ecuadorian paramo area are a valuable source of polyphenolics, rich in sugars and organic acids, and can be classified as a good source of microelements.

Enhancement on antioxidant and antibacterial activities of Brightwell blueberry by extraction and purification

A blueberry anthocyanin extract was obtained from Brightwell blueberry fruits cultivated in eastern China and the extraction and purification conditions were optimized. The components of the anthocyanin extract were identified using ultra-performance liquid chromatography-electrospray ionization interface-mass spectrometer. The antioxidant and antibacterial activities of the blueberry fruit supernatant (BFS), blueberry anthocyanin crude extract (BCE), and blueberry anthocyanin rich extract (BRE) were evaluated. The extraction yield was 1.79 ± 0.0014 mg/g under the following optimal conditions: 1:20 solid-to-liquid ratio (v/w), 24 h, 34 °C, and 90% ethanol containing 0.21% (v/v) hydrochloric acid. With regard to purification, anthocyanin purity increased 19.1-fold. Nine fractions were identified as the glycosides of delphinidin, cyanidin, petunidin, and malvidin. The biological activities of the blueberry anthocyanin extract were improved through extraction and purification. Compared with BFS and BCE, BRE had a higher DPPH radical scavenging activity (EC50 = 0.51 mg/mL), ABTS antioxidant capacity (EC50 = 0.32 mg/mL), and oxygen radical absorbance capacity (0.43 mmol Trolox/g). Furthermore, BRE (2 mg/mL) showed a maximum of 84.64 ± 0.35% reduction in the biofilm biomass of Listeria monocytogenes and the inhibition zone given by BRE against Escherichia coli was 16.04 ± 0.38 mm. BRE showed the highest antioxidant capacities and obvious antibacterial effects against food-related microorganisms than the other samples. Therefore, BRE can be used as a natural antioxidant and antibacterial agent and has potential health advantages and food industry applications.

Transcriptomic, Proteomic and Metabolomic Analysis of Flavonoid Biosynthesis During Fruit Maturation in Rubus chingii Hu.

Rubus chingii HU, is a medicinal and nutritious fruit, which is very rich in flavonoids. However, the biosynthesis of its flavonoids is poorly understood. This study examined flavonoids and the genes/proteins at four fruit ripening phases using LC-MS/MS and qPCR. Six major kinds of anthocyanins, primarily consisted of flavanol-anthocyanins, which differed in form or concentration from other Rubus species. In contrast to other known raspberries species, R. chingii had a decline in flavonoids during fruit ripening, which was due to down-regulation of genes and proteins involved in phenylpropanoid and flavonoid biosynthesis. Unexpectedly, anthocyanin also continuously decreased during fruit maturation. This suggests that anthocyanins are not responsible for the fruit’s reddish coloration. Flavanol-anthocyanins were derived from the proanthocyanidin pathway, which consumed two flavonoid units both produced through the same upstream pathway. Their presence indicates a reduction in the potential biosynthesis of anthocyanin production. Also, the constantly low expression of RchANS gene resulted in low levels of anthocyanin biosynthesis. The lack of RchF3′5′H gene/protein hindered the production of delphinidin glycosides. Flavonoids primarily comprising of quercetin/kaempferol-glycosides were predominately located at fruit epidermal-hair and placentae. The proportion of receptacle/drupelets changes with the maturity of the fruit and may be related to a decrease in the content of flavonoids per unit mass as the fruit matures. The profile and biosynthesis of R. chingii flavonoids are unique to Rubus. The unique flavonol pathways of R. chingii could be used to broaden the genetic diversity of raspberry cultivars and to improve their fruit quality.

Liquid Chromatographic Quadrupole Time-of-Flight Mass Spectrometric Untargeted Profiling of (Poly)phenolic Compounds in Rubus idaeus L. and Rubus occidentalis L. Fruits and Their Comparative Evaluation.

This study provided a detailed profiling of the antioxidant and bioactive compounds occurring in three varieties of Rubus idaeus L. fruits (“Fall Gold”, “Glen Ample” and “Tulameen”) compared to Rubus occidentalis L. black raspberry (“Jewel” cultivar), adopting a comprehensive untargeted metabolomics approach developed with UHPLC analysis coupled with quadrupole/time-of-flight high resolution mass spectrometry, using the SWATH® acquisition protocol. The feature selection and annotation workflow, applied to the analysis of raspberry extracts in both polarities, allowed identifying 68 bioactive compounds mainly belonging to the classes of (poly)phenolic compounds. Interestingly, some of these identifications (e.g., ferulic acid glycosides and the ellagitannin-like nobotanin/malabathrin) represent the first report in raspberry fruits. Principal component analysis made possible highlighting the features more related to the expression of a genotype effect within the R. idaeus species or between the two raspberry species herein investigated. Overall, flavanols were the most discriminating features for the Fall Gold variety, whereas ellagitannins and flavonol glycosides represent more distinctive metabolic traits in Glen Ample and Tulameen fruits. Moreover, R. occidentalis Jewel variety was strongly characterized by the occurrence of anthocyanins, such as cyanidin, pelargonidin and delphinidin glycosides.

Phytochemical Profile, Antiradical Capacity and α-Glucosidase Inhibitory Potential of Wild Arbutus unedo L. Fruits from Central Italy: A Chemometric Approach.

Nowadays, there is a growing interest in botanicals for human nutrition and care. Arbutus unedo wild berries are edible and medicinal fruits that contain many healthy bioactive components, which can be considered a valuable resource for the food ingredient market and for nutraceutical and cosmetic sectors. In the present study, the polyphenols and in vitro antiradical and hypoglycemic activities of five wild Italian accessions of A. unedo were investigated, and their chemical profiles were treated by means of unsupervised chemometric techniques like the hierarchical and principal component analysis. Moreover, Fourier-transformed mid-infrared spectroscopy was used to provide a rapid assessment of the phytochemical composition of different accessions. Samples differed mainly in their anthocyanin content and overall nutraceutical potential. Anthocyanins were present mainly as glycosides of cyanidin and delphinidin, with delphinidin-3-O-glucoside being the most abundant one, ranging from 49 ± 1 to 111 ± 3 mg g−1 (for P1 and P2, respectively; p < 0.05). Extracts were screened for their in vitro biological activities by using the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), 2,2-diphenyl-1-picrylhydrazyl (DPPH•) antiradical tests, while their hypoglycemic activity was investigated by the α-glucosidase inhibition test. In both in vitro antiradical tests, the highest capacity was recorded for P2 (EC50: 1.17 and 0.064 mg mL−1, for DPPH• and ABTS•+, respectively), with values higher than those reported in the literature for A. unedo fruit extracts. P2 also showed the highest inhibition power towards α-glucosidase (about 70%). Moreover, the nonparametric correlation analysis pointed out a very high significant correlation between the percentage of α-glucosidase inhibition and cyanidin-3-O-rutinoside (r: 0.973; p < 0.01). Finally, the application of hierarchical analysis to samples analyzed provided three different clusters based on the average phytochemical content coded as low, medium and high. Moreover, principal component analysis made it possible to establish similarities among the accessions depending on their overall nutraceutical characteristics and on the relative anthocyanin content.

Thermal processing under oxygen–free condition of blueberry puree: Effect on anthocyanin, ascorbic acid, antioxidant activity, and enzyme activities

The effect of thermal treatment of blueberry was investigated using a designed grinding and continuous packaging system under oxygen–free conditions. The grinding, packaging, and heating at 90 °C for 30 min under anaerobic condition were compared to heating under aerobic conditions, showing complete inactivation of oxidative enzymes. Heating without oxygen retained anthocyanins and ascorbic acid whereas heating in atmospheric air does not. Delphinidin glycoside was mostly influenced by oxygen deficiency during heating, followed by petunidin and malvidin glycosides. The differences in oxygen sensitivity may be closely associated with the number of hydroxylation in the B ring. The result of anthocyanin led to higher antioxidant activity and redness values of purees heated without oxygen than purees heated with oxygen. Consequently, thermal processing under oxygen–free condition can prevent oxidation of anthocyanin, resulting in higher retention of color and nutritional values of blueberry products.

Effect of vacuum–grinding on the stability of anthocyanins, ascorbic acid, and oxidative enzyme activity of strawberry

In this study, strawberries were ground at vacuum levels of 2.67, 6.67, 13.33, 19.99, and 101.33 kPa (atmospheric pressure) using a specially designed vacuum grinding and continuous packaging device. The grinding at higher vacuum levels led to better maintenance of ascorbic acid and anthocyanins, resulting in a higher antioxidant activity and redness due to the low oxygen availability limiting oxidation. Vacuum-grinding below 2.67 kPa prevented the oxidation of pelargonidin glycosides to a greater degree than that of cyanidin and delphinidin glycoside, due to structural differences related to the number of hydroxyl groups in the B ring, revealing the faster oxidation rate of diphenolic anthocyanins. The model fits indicated a logarithmic rather than a linear degradation as the oxygen level increased, indicating that even small amount of oxygen may cause drastic quality deterioration during grinding. Overall, our results indicate that vacuum grinding at very low oxygen levels is an effective technology to prevent the oxidation of anthocyanins and ascorbic acid, resulting in higher redness and antioxidant activities in strawberries.

Effect of nitrate concentration on plant growth and anthocyanin accumulation in the ornamental bromeliad Alcantarea imperialis

Alcantarea imperialis (Carrière) Harms is a large bromeliad species with showy inflorescence widely used in landscape projects. When grown in vitro under different nitrogen (N) concentrations, its normally green leaves show red coloration. Thus, the aim of this study was to evaluate the in vitro growth of A. imperialis plants and identify the anthocyanins present on their leaves. Plants obtained from seeds were cultivated in vitro for six months in Murashige and Skoog (MS) medium with varying N concentrations (3.75, 7.5, and 15 mM NO3 −) and transferred to the greenhouse where they remained for 12 months. The number of leaves and roots, length of aerial parts and roots, mass of shoot and root parts, photosynthetic pigment contents (chlorophyll a, b, and carotenoids), and anthocyanin levels were determined. During in vitro cultivation, anthocyanin levels increased with increasing N concentrations. The presence of pelargonidin, cyanidin and delphinidin glycosides in A. imperialis leaves was identified by high-performance liquid chromatography (HPLC). Using NO3 − as N source enhanced plant growth and anthocyanin accumulation in A. imperialis.

Identification of Maple Anthocyanin and its Antiproliferative Activity against LLC, T47D and C3H10T1/2 Cells.

The genus Acer contains around 200 species, with more than 400 garden varieties. There is considerable diversity in these species and garden varieties, and each can be characterized by morphology and chemical composition. The red appearance of Acer leaves is due to anthocyanin compounds, including cyanidin glycosides, delphinidin glycosides, and galloylated anthocyanins. Few studies have investigated the diversity of anthocyanin compounds in garden varieties, and no studies have examined the pharmacological effects of these compounds. The purpose of this study was to identify the anthocyanins of Acer palmatum cv. 'Chishio', a garden variety of A. palmatum and evaluate their antiproliferative and antioxidant activities. A methanol extract of fresh leaves was partitioned with ethyl acetate. The extract was purified by column chromatography and compounds were subsequently identified by 1H and 13C NMR and ESI-HRMS. Antiproliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4- sulfophenyl)-2H-tetrazolium, inner salt (MTS) colorimetric assay. The antioxidant assay was evaluated by scavenging activity using the stable radical DPPH. The anthocyanins cyanidin-3-O-(6''-O-α-rhamnopyranosyl- β-glucopyranoside), cyanidin-3-O- β- glucopyranoside, cyanidin-3-O-[2''-O-(galloyl)-6''-O-(rhamnosyl)-β-glucoside], and cyanidin-3-O-[2''-O-(galloyl)- β-glucopyranoside] were isolated from A. palmatum cv. 'Chishio'. All four anthocyanin compounds showed antiproliferative activity against LLC and T47D cells, and galloylated anthocyanin showed antiproliferative activity against C3H10T1/2 cells. All four anthocyanins inhibited the activity of DPPH radicals in a dosedependent manner. Maple anthocyanins could be a new cancer therapeutic agent or prophylactic medicine.

Ameliorating Effects of Delphinol&amp;#174;, Anthocyanin Standardized Maqui Berry Extract, on Skin Brightness and Redness in Japanese Females: A Randomized Double-Blind Placebo-Controlled Pilot Study

Maqui berries are wildly grown or cultivated in the Patagonian region in Chile. The berries contain large amounts of anthocyanins, especially delphinidin glycosides, which are strong anti-oxidants. We previously reported that standardized maqui berry extract, which contained lots of anthocyanins, has ameliorative effects against dry eyes and visible light-induced photoreceptor cell damage. However, the influence of maqui berry extract on the human skin has not been evaluated even though many skin troubles are related to active oxygen species. Therefore, we conducted a randomized double-blind placebo-controlled pilot study with Delphinol®, a maqui berry extract standardized for anthocyanins, especially delphinidins and cyanidins, in healthy Japanese female subjects. Capsules containing Delphinol® (60 mg) or placebo were orally administered to subjects aged 27 to 57 years old for eight weeks. Skin conditions [pigmentation, redness, skin tone, wrinkles, texture, oil content, water content, trans epidermal water loss (TEWL), collagen score, dermal thickness, and elasticity] were measured before and after intervention. In the Delphinol® group, the saturation significantly increased after eight weeks and reddish spots significantly decreased after four weeks of intake. The collagen score, which decreases with age, slightly increased with age by Delphinol® ingestion for eight weeks. Thus, the anthocyanin-standardized maqui berry extract Delphinol® increased skin brightness and collagen content, and improved facial skin redness. This study suggests that the daily oral intake of maqui berry extract can help maintain a healthy facial condition.

Kinetic and Thermodynamic Characteristics of Thermal Degradation of Anthocyanins from Strawberry and Blueberry Commercial Juices

Thermal stabilities of anthocyanins in strawberry and blueberry commercial juices were studied over the temperatures 75, 85 and 95 oC. Results indicated that the thermal degradation of anthocyanins followed the first-order reaction kinetics. The temperature-dependent degradation was adequately modeled on the Arrhenius equation. During heating, anthocyanins in the strawberry juice degraded faster than in blueberry juice, with the activation energies of 74.16 kJ/mol and 65.75 kJ/mol, respectively. Cyanidin-3-glucoside (cyd-3-glu) was more susceptible to the thermal treatment than pelargonidin glycosides in strawberry juice. Delphinidin glycosides were more susceptible to the thermal treatment than cyanidin glycosides in blueberry juice. However, cyd-3-glu in strawberry juice was more sensitive to the thermal treatment than in blueberry juice. Obtained results for activation enthalpies indicated that the degradation process was endothermic and Gibbs free energy of activation indicated that they were not spontaneous.

Anthocyanins protect the gastrointestinal tract from high fat diet-induced alterations in redox signaling, barrier integrity and dysbiosis

The gastrointestinal (GI) tract can play a critical role in the development of pathologies associated with overeating, overweight and obesity. We previously observed that supplementation with anthocyanins (AC) (particularly glycosides of cyanidin and delphinidin) mitigated high fat diet (HFD)-induced development of obesity, dyslipidemia, insulin resistance and steatosis in C57BL/6J mice. This paper investigated whether these beneficial effects could be related to AC capacity to sustain intestinal monolayer integrity, prevent endotoxemia, and HFD-associated dysbiosis. The involvement of redox-related mechanisms were further investigated in Caco-2 cell monolayers. Consumption of a HFD for 14 weeks caused intestinal permeabilization and endotoxemia, which were associated with a decreased ileum expression of tight junction (TJ) proteins (occludin, ZO-1 and claudin-1), increased expression of NADPH oxidase (NOX1 and NOX4) and NOS2 and oxidative stress, and activation of redox sensitive signals (NF-κB and ERK1/2) that regulate TJ dynamics. AC supplementation mitigated all these events and increased GLP-2 levels, the intestinal hormone that upregulates TJ protein expression. AC also prevented, in vitro, tumor necrosis factor alpha-induced Caco-2 monolayer permeabilization, NOX1/4 upregulation, oxidative stress, and NF-κB and ERK activation. HFD-induced obesity in mice caused dysbiosis and affected the levels and secretion of MUC2, a mucin that participates in intestinal cell barrier protection and immune response. AC supplementation restored microbiota composition and MUC2 levels and distribution in HFD-fed mice. Thus, AC, particularly delphinidin and cyanidin, can preserve GI physiology in HFD-induced obesity in part through redox-regulated mechanisms. This can in part explain AC capacity to mitigate pathologies, i.e. insulin resistance and steatosis, associated with HFD-associated obesity.

Analysis of Young Shoots of 'Anji Baicha' (Camellia sinensis) at Three Developmental Stages Using Nontargeted LC-MS-Based Metabolomics.

'Anji Baicha' (Camellia sinensis) is a low-temperature-sensitive tea variety. During the development of young shoots, the leaves of 'Anji Baicha' exhibit periodic albinism. The quality of 'Anji Baicha' is closely related to the color of the fresh leaves, with whiter leaves affording a higher amino acid content and superior sensory quality after processing. However, the metabolic mechanism of its quality formation is still unclear. In this study, we analyzed the metabolomic changes of young shoots of 'Anji Baicha' and screened for metabolic markers that may be involved in the periodic albinism. Positive- and negative-mode UPLC-QTOF-MS was applied to the metabolomic analysis of young leaves of 'Anji Baicha' during three developmental stages (i.e., the pre-albescent, albescent, and regreening stages). The results revealed significant differences in the metabolic profiles of the young leaves at the three stages. The differential metabolites were mainly related to the pathways of flavonoid, phenylpropanoid, and amino acid biosynthesis. The concentrations of several amino acids (primarily l-theanine, l-glutamate, N2 -acetyl-l-ornithine, l-aspartic acid, d-proline, l-glutamine, l-leucine, and pyroglutamic acid) and 12-OPDA were significantly higher in the albescent stage. In contrast, during the albescent stages, the concentrations of several carbohydrates (d-fructose, β-d-galactopyranose, 3-O-fucopyranosyl-2-acetamido-2-deoxyglucopyranose, galactose-β-1, 4-xylose acetyl-maltose, and 2-fucosyllactose) were significantly lower. Moreover, catechins (mainly epigallocatechin and catechin derivatives), dimeric catechins (primarily proanthocyanidins), and flavonol and flavonol/flavone glycosides (mainly kaempferol, myricetin, quercetin, cyanidin, and delphinidin glycosides) were detected at the highest levels in the regreening or pre-albescent stages. The obtained results enhance the current understanding of the metabolic mechanisms of periodic albinism and quality development formation in 'Anji Baicha'. PRACTICAL APPLICATION: The obtained results not only provide information regarding differential metabolites but also advance the understanding of the mechanism of periodic albinism in 'Anji Baicha' at the metabolite level and open up new possibilities for the genetic improvement of tea cultivars.

Composition of Anthocyanins and Proanthocyanidins in Three Tropical Vaccinium Species from Costa Rica

Total polyphenol content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC), and proanthocyanidin (PAC) content were determined in fruit from three tropical Vaccinium species (Vaccinium consanguineum, Vaccinium floribundum, and Vaccinium poasanum) from Costa Rica sampled at three stages of fruit development. Results show that TAC increased as the fruit developed, while TPC, TFC, and PAC content decreased. Anthocyanin profiles were evaluated using electrospray ionization tandem mass spectrometry. Cyanidin and delphinidin glycosides were the predominant anthocyanins for the three tropical Vaccinium species. Proanthocyanidins were characterized using attenuated total reflection Fourier transform infrared spectroscopy, nuclear magnetic resonance, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The presence of procyanidin structures with B-type interflavan bonds were observed, but deconvolution of mass spectrometry isotope patterns indicated that PACs with one or more A-type interflavan bonds accounted for more than 74% of the oligomers at each degree of polymerization.

Variation of Anthocyanins, Proanthocyanidins, Flavonols, and Organic Acids in Cultivated and Wild Diploid Blueberry Species

The flavonoid and organic acid profiles of one cultivated tetraploid and six wild diploid blueberry species (Vaccinium spp.) were systematically investigated using high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (HPLC-ESI-MS-MS). Eighteen individual anthocyanins from five aglycone classes were characterized among species, with malvidin and delphinidin glycosides accounting for 31.4% and 29.1% of total anthocyanins. Twenty-three flavonol glycosides from six aglycone classes were identified, among which quercetin and myricetin glycosides accounted for more than 80% of total flavonols in most species. Both inter- and intraspecies differences in anthocyanin and flavonol composition were observed, as described by principal component analysis. Only B-type proanthocyanidins were found in blueberry species, and highly polymerized molecules with degree of polymerization greater than 10 appeared to be the most abundant fraction. Although overall proanthocyanidin levels varied from 27.7 to 146.3 mg/100 g fruit, all species exhibited similar proanthocyanidin composition. Citric, quinic, and shikimic acid were the major identified blueberry organic acids. However, their relative abundance varied across species. In certain species either citric acid (e.g., Vaccinium darrowii) or quinic acid (e.g., Vaccinium corymbosum) was lacking.