Pelargonidin-3-glucoside Research Articles

Unraveling the color evolution and metabolic pathways of pelargonidin-3-O-glucoside during lactic acid fermentation of the strawberry juice color simulation system: A novel perspective through untargeted metabolomics

This study aimed to unraveling the color evolution and metabolic pathways of pelargonidin-3-O-glucoside (P3G) during lactic acid fermentation of the strawberry juice color simulation system. The results revealed that fermentation with both Lactobacillus plantarum and Lactobacillus acidophilus caused a decline in pH of the strawberry juice color simulation system and significantly accelerated the decrease in P3G content. The CIELAB space model pointed out that parameters a⁎ and b⁎ of the group treated with both lactic acid bacteria and P3G initially increased to a peak level and then gradually decreased, shifting the overall color towards orange and then gradually fading. Furthermore, untargeted metabolomics results revealed that P3G was progressively degraded and converted to pyruvate, methylparaben, 3,4-dihydroxybenzoic acid, p-anisic acid, and terephthalic acid, affecting the metabolic pathways of glycolysis, d-amino acids, benzoate degradation, aromatic compounds degradation, and aminobenzoate degradation in lactic acid bacteria.

A multiscale approach to understanding the shared blue-orange flower color polymorphism in two Lysimachia species

BackgroundPolymorphisms are common in nature, but they are rarely shared among closely related species. Polymorphisms could originate through convergence, ancestral polymorphism, or introgression. Although shared neutral genomic variation across species is commonplace, few examples of shared functional traits exist. The blue-orange petal color polymorphisms in two closely related species, Lysimachia monelli and L. arvensis were investigated with UV-vis reflectance spectra, flavonoid biochemistry, and transcriptome comparisons followed by climate niche analysis.ResultsSimilar color morphs between species have nearly identical reflectance spectra, flavonoid biochemistry, and ABP gene expression patterns. Transcriptome comparisons reveal two orange-specific genes directly involved in both blue-orange color polymorphisms: DFR-2 specificity redirects flux from the malvidin to the pelargonidin while BZ1-2 stabilizes the pelargonidin with glucose, producing the orange pelargonidin 3-glucoside. Moreover, a reduction of F3’5’H expression in orange petals also favors pelargonidin production. The climate niches for each color morph are the same between the two species for three temperature characteristics but differ for four precipitation variables.ConclusionsThe similarities in reflectance spectra, biochemistry, and ABP genes suggest that a single shift from blue-to-orange shared by both lineages is the most plausible explanation. Our evidence suggests that this persistent flower color polymorphism may represent an ancestrally polymorphic trait that has transcended speciation, yet future analyses are necessary to confidently reject the alternative hypotheses.

MM/GB(PB)SA integrated with molecular docking and ADMET approach to inhibit the fat-mass-and-obesity-associated protein using bioactive compounds derived from food plants used in traditional Chinese medicine

IntroductionObesity is currently a major global concern, requiring the development of effective therapeutics. This study determines the inhibitory activity against FTO (fat mass and obesity-associated protein) of food plant-derived bioactive compounds of TCM (traditional Chinese medicine) importance, by in silico approaches. MethodsFood plant-derived phytochemicals, such as curcumin (CCMN), cajaisoflavone (CJIF), cyanidin-3-O-glucoside (C3OG) and pelargonidin-3-glucoside (P3GS), were selected as ligands, and docked to FTO. The reference FTO-inhibitor used was meclofenmic acid (MCFA). MDS (molecular dynamic simulations) was accomplished with 10 ns run for the docked complex of FTO with the most potential phytocompound. The phytochemicals were subjected to bioactivity scoring, Lipinski's rule of five screening, and ADMET prediction. Law ResultsMolecular docking demonstrated binding energies of -9.4, -8.8, -8.7 and -8.2 kcal/mol for CCMN, CJIF, C3OG and P3GS, respectively. The reference inhibitor MCFA had binding energy of -7.8 kcal/mol, and therefore, the FTO inhibition capacity of the ligands were in order of CCMN > C3OG > P3GS > CJIF > MCFA. The FTO residues His231, Ser229, Val228, Leu109, Tyr108 and Pro93 played crucial role in protein-ligands interaction displaying hydrogen bonds and hydrophobic contacts. MDS-based MM/GB(PB)SA binding free energies authenticated CCMN (-6.67/-8.77 kcal/mol) as a stronger FTO inhibitor than MCFA (0.19/-0.02 kcal/mol). Pharmacological properties of the phytochemicals predicted were comparable to MCFA standard. DiscussionTCM compounds of botanical origin are important for the effective management of obesity. In the current study, all the phytochemicals, the potential TCM ingredients, with acceptable pharmacological properties displayed excellent binding affinity and stronger inhibitory activity against FTO, compared to MCFA. FTO_CCMN displayed more energetic stability compared to FTO_MCFA using MM/GB(PB)SA approaches. Overall, this study paved the basis of FTO-associated obesity management with food plant-based therapeutics of TCM importance in the globe.

Structural characterization of strawberry pomace

Strawberries are a nutrient dense food rich in vitamins, minerals, non-nutrient antioxidant phenolics, and fibers. Strawberry fiber bioactive structures are not well characterized and limited information is available about the interaction between strawberry fiber and phenolics. Therefore, we analyzed commercial strawberry pomace in order to provide a detailed carbohydrate structural characterization, and to associate structures with functions. The pomace fraction, which remained after strawberry commercial juice extraction, contained mostly insoluble (49.1 % vs. 5.6 % soluble dietary fiber) dietary fiber, with pectin, xyloglucan, xylan, β-glucan and glucomannan polysaccharides; glucose, fructose, xylose, arabinose, galactose, fucose and galacturonic acid free carbohydrates; protein (15.6 %), fat (8.34 %), and pelargonidin 3-glucoside (562 μg/g). Oligosaccharides from fucogalacto-xyloglucan, methyl-esterified rhamnogalacturonan I with branched arabinogalacto-side chains, rhamnogalacturonan II, homogalacturonan and β-glucan were detected by MALDI-TOF MS, NMR and glycosyl-linkage analysis. Previous reports suggest that these oligosaccharide and polysaccharide structures have prebiotic, bacterial pathogen anti-adhesion, and cholesterol-lowering activity, while anthocyanins are well-known antioxidants. A strawberry pomace microwave acid-extracted (10 min, 80 °C) fraction had high molar mass (2376 kDa) and viscosity (3.75 dL/g), with an extended rod shape. A random coil shape, that was reported previously to bind to phenolic compounds, was observed for other strawberry microwave-extracted fractions. These strawberry fiber structural details suggest that they can thicken foods, while the polysaccharide and polyphenol interaction indicates great potential as a multiple-function bioactive food ingredient important for gut and metabolic health.

Unveiling cervical cancer therapeutics from Abrus precatorius and Aphanamixis polystachya: Insights from molecular docking, dynamics simulation, MM/GBSA and DFT analyses

Cervical cancer is the fourth most prevalent form of cancer affecting women, which poses a significant concern, especially in middle- and lower-income countries with an approximately 85 % fatality rate. As conventional drugs used to treat cervical cancer are expensive and expose severe side effects, there is a growing demand to search for novel medications. Therefore, in the current investigation employing bioinformatic approach, we explored bioactive phytoconstituents of two indigenous species of Bangladesh, namely Abrus precatorius L. and Aphanamixis polystachya (Wall.) R.N. Parker, for their anticancer efficacy targeting cervical cancer E6 oncoprotein. The study utilized molecular docking, ADMET assay, molecular dynamics simulation, MM/GBSA and DFT calculation that unveiled four lead compounds, such as Abruslactone A (-8.4 kcal/mol), Vitexin (-8.2 kcal/mol), 5-Betacholanic acid (-7.5 kcal/mol) and Pelargonidin 3-glucoside (-7.2 kcal/mol) from Abrus precatorius, and three lead compounds, namely Rohituka 5 (-7.5 kcal/mol), Polystachin (-7.5 kcal/mol) and Aphanamixinin (-7.3 kcal/mol) from Aphanamixis polystachya. All the lead candidates exhibited favorable pharmacokinetic, pharmacodynamic and toxicity properties. Molecular dynamics simulation revealed noteworthy structural stability and compactness of the lead candidates. MM/GBSA analysis unraveled Polystachin to have the highest free binding energy (-72.45 kcal/mol) and Abruslactone A having the lowest binding energy (-50.92 kcal/mol). DFT analysis revealed higher molecular reactivity of Aphanamixis polystachya phytocompounds than Abrus precatorius. Among the lead compounds, 5-Betacholanic acid showed the highest kinetic stability (ΔE = 7.217 eV), and Pelargonidin 3-glucoside demonstrated highest molecular reactivity (ΔE = 3.086 eV). The optimization of the lead compounds, assessment of safety profiles, and progression towards clinical trials could transform the current findings into promising drug candidates for cervical cancer. Finally, the results obtained from this study may lay the foundation for the development of novel anticancer therapeutics.

In Vitro Antioxidant Activity, Bioaccessibility, and Thermal Stability of Encapsulated Strawberry Fruit (Fragaria × ananassa) Polyphenols.

Bioactive compounds in red fruits, such as strawberries, are vulnerable to digestion, and encapsulation has become an alternative for their protection. This study aims at encapsulating strawberry juice (SJ) by freeze-drying with pea protein and okra mucilage (SJPO), pea protein and psyllium mucilage (SJPP), and pea protein, psyllium mucilage, and okra mucilage (SJPPO) and investigating the in vitro release. The highest encapsulation efficiency was observed in capsule SJPPO (95.38%) and the lowest efficiency in SJPO (82.45%). Scanning electron microscopy revealed an amorphous glassy structure for the structure of the strawberry microcapsules, and X-ray diffraction confirmed that observation. However, X-ray diffraction further showed that SJPPO was crystalline, indicating a tighter crosslinking density than the other microcapsules. Fourier transform infrared spectroscopy showed peaks at 3390 and 1650 cm-1, confirming the presence of polyphenols and polysaccharides in the strawberry microcapsules. Thermal stability was higher for SJPPO, and the observed thermal transitions were due to the bonds formed between the polymers and polyphenols. Pelargonidin 3-glucoside, cyanidin 3-glucoside, cyanidin, delphinidin, malvidin 3-glucoside, ellagic acid, chlorogenic acid, catechin, and kaempferol were identified in the strawberry microcapsules. Digestion affected the compounds' content; the bioaccessibility for SJ was 39.26% and 45.43% for TPC and TAC, respectively. However, encapsulation improved the bioaccessibility of both TPC (SJPP, 51.54%; SJPO, 48.52%; and SJPPO, 54.39%) and TAC (SJPP, 61.08%; SJPO, 55.03%; and SJPPO, 71.93%). Thus, encapsulating pea protein isolate, psyllium mucilage, and okra mucilage is an effective method to facilitate targeted release and preserve the biological activities of fruits.

Effect of nanopesticides (azoxystrobin and bifenthrin) on the phenolic content and metabolic profiles of strawberries (Fragaria × ananassa).

Nanoencapsulation has opened promising fields of innovation for pesticides. Conventional pesticides can cause side effects on plant metabolism. To date, the effect of nanoencapsulated pesticides on plant phenolic contents has not been reported. In this study, a comparative evaluation of the phenolic contents and metabolic profiles of strawberries was performed for plants grown under controlled field conditions and treated with two separate active ingredients, azoxystrobin and bifenthrin, loaded into two different types of nanocarriers (Allosperse® polymeric nanoparticles and SiO2 nanoparticles). There were small but significant decreases of the total phenolic content (9%) and pelargonidin 3-glucoside content (6%) in strawberries treated with the nanopesticides. An increase of 31% to 125% was observed in the levels of gallic acid, quercetin, and kaempferol in the strawberries treated with the nanoencapsulated pesticides compared with the conventional treatments. The effects of the nanocarriers on the metabolite and phenolic profiles was identified by principal component analysis. Overall, even though the effects of nanopesticides on the phenological parameters of strawberry plants were not obvious, there were significant changes to the plants at a molecular level. In particular, nanocarriers had some subtle effects on plant health and fruit quality through variations in total and individual phenolics in the fruits. Further research will be needed to assess the impact of diverse nanopesticides on other groups of plant metabolites. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genome-Wide Identification and Comparative Transcriptome Methods Reveal FaMDHAR50 Regulating Ascorbic Acid Regeneration and Quality Formation of Strawberry Fruits.

Ascorbic acid (AsA) is a crucial water-soluble antioxidant in strawberry fruit, but limited research is currently available on the identification and functional validation of key genes involved in AsA metabolism in strawberries. This study analyzed the FaMDHAR gene family identification, which includes 168 genes. Most of the products of these genes are predicted to exist in the chloroplast and cytoplasm. The promoter region is rich in cis-acting elements related to plant growth and development, stress and light response. Meanwhile, the key gene FaMDHAR50 that positively regulates AsA regeneration was identified through comparative transcriptome analysis of 'Benihoppe' strawberry (WT) and its natural mutant (MT) with high AsA content (83 mg/100 g FW). The transient overexpression experiment further showed that overexpression of FaMDHAR50 significantly enhanced the AsA content by 38% in strawberry fruit, with the upregulated expression of structural genes involved in AsA biosynthesis (FaGalUR and FaGalLDH) and recycling and degradation (FaAPX, FaAO and FaDHAR) compared with that of the control. Moreover, increased sugar (sucrose, glucose and fructose) contents and decreased firmness and citric acid contents were observed in the overexpressed fruit, which were accompanied by the upregulation of FaSNS, FaSPS, FaCEL1 and FaACL, as well as the downregulation of FaCS. Additionally, the content of pelargonidin 3-glucoside markedly decreased, while cyanidin chloride increased significantly. In summary, FaMDHAR50 is a key positive regulatory gene involved in AsA regeneration in strawberry fruit, which also plays an important role in the formation of fruit flavor, apperance and texture during strawberry fruit ripening.

Integrated metabolome and transcriptome analysis of anthocyanin accumulation during the color formation of bicolor flowers in Eustoma grandiflorum

The bicolor flowers of Eustoma grandiflorum have a special phenotype and high ornamental value. However, the coloration mechanism of these flowers has not been reported. We used metabolomics and transcriptomics to analyze the accumulation of secondary metabolites and the expression of differential genes in bicolor petals at different developmental stages, to elucidate the molecular mechanism underlying anthocyanin accumulation in these bicolor flowers of E. grandiflorum. The metabolomics analysis revealed that five kinds of anthocyanins in the upper pigmented petals at different developmental stages, and three kinds of anthocyanins were identified in the comparison between the pink upper tepals and the white bases at stage 3, with pelargonidin 3-glucoside 5-(6-coumaroyl) glucoside showing the most significant difference. The differentially expressed genes (DEGs) related to flavonoid biosynthesis in bicolor flowers were further analyzed by transcriptomics, and 25 structural genes and 5 MYB transcription factors (TFs) were screened, among which EgCHS1 showed significantly higher expression (approximately 21.5 times) in the upper tepals than in the tepal bases. Transcriptomic and metabolomic association analysis showed that the EgFLS2 and EgFLS3 genes were related to the largest quantity differentially accumulated metabolites (DAMs), and ferulate was associated with the largest quantity of DEGs. This study provides a basis for anthocyanin accumulation and coloration mechanism during the development of E. grandiflorum bicolor flowers. The results will be conducive for promoting artificial regulation of flower color and breeding new cultivars of E. grandiflorum.

Functional identification of anthocyanin glucosyltransferase genes: a Ps3GT catalyzes pelargonidin to pelargonidin 3-O-glucoside painting the vivid red flower color of Paeonia.

Glycosylation from an anthocyanidin 3-O-glucosyltransferase Ps3GT (PsUGT78A27) facilitates the accumulation of pelargonidin 3-O-glucoside, which defines the vivid red flower color and occurs only in specific peony tree cultivars. Although tree peony cultivars of Chinese and Japanese both originated from China, vivid red color is only found in flowers of Japanese cultivars but not of Chinese cultivar groups. In this study, a Japanese tree peony cultivar 'Taiyoh' with vivid red petals and a Chinese tree peony cultivar 'Hu Hong' with reddish pink petals were chosen as the experimental materials. Flavonoids profiling indicated that pelargonidin 3-O-glucoside (Pg3G) detected only in Japanese cultivar contributed to vivid red color of tree peony petals, while pelargonidin 3,5-di-O-glucoside (Pg3G5G) found in both of Japanese and Chinese cultivars was responsible for pink flower color. Through the integration of full-length transcriptome sequencing and in vitro enzymatic activity analysis, two anthocyanin glucosyltransferase genes PsUGT78A27 and PsUGT75L45 were isolated from the petals of tree peony, and their encoding products exhibited enzymatic activities of pelargonidin 3-O-glucosyltransferase and anthocyanin 5-O-glucosyltransferase, respectively. Further quantitative real-time PCR revealed that PsUGT78A27 displayed high expression in petals of both cultivars and PsUGT75L45 was expressed at high levels in cultivar 'Hu Hong' only. Using a gene gun technique, the GFP fusion proteins of PsUGT78A27 and PsUGT75L45 were visualized to be cytoplasmic and nuclear localization in the epidermal cells of tree peony petals, and the glucosylation function of PsUGT78A27 and PsUGT75L45 to alter petal color of tree peony and herbaceous peony had been directly validated in vivo. These results demonstrated that PsUGT78A27 and PsUGT75L45 are key players for the presence or absence of vivid red flower color in tree peony cultivars. Our findings further elucidated the chemical and molecular mechanism of petal pigmentation of Paeonia and could help breed the Paeonia cultivars possessing novel flower colors.

Determination of Phenolic Compounds in Blue Corn Flour (Zea mays L.) Produced and/or Metabolized by Colletotrichum gloeosporioides in a Fermentation Process

Phenolic compounds are secondary metabolites produced by plants, and their study has been increased in recent years due to their ability to improve human health. The aim of this work was the determination of phenolic compounds presents in blue corn flour before and after a fermentation process, where different proportions were used of blue corn (Zea mays L.) flour and Czapek Dox culture medium (90 mL of culture medium with 10 g of blue corn flour, 80 mL of culture medium with 20 g of blue corn flour and 70 mL of culture medium with 30 g of blue corn flour) and were fermented at 3 different times (20, 25 and 30 days) with the Colletotrichum gloeosporioides fungus. A determination of the phenolic compounds was carried out with five standard solutions, which were cyanidin 3-glucoside (CYA), pelargonidin 3-glucoside (PEL), chlorogenic acid (CLA), quercetin (QRC) and cinnamic acid (CA). The obtained results showed the presence of CA and PEL. The most abundant phenolic compound in the fermented samples was CLA over the naturally occurring compounds in blue corn, which are CYA and PEL. QRC was the phenolic compound with the lowest concentration in blue corn flour samples fermented with Colletotrichum gloeosporioides.

Improvement of stability and lipophilicity of pelargonidin-3-glucoside by enzymatic acylation with aliphatic dicarboxylic acid

Dicarboxylic acids derived acylated-anthocyanins are common in nature, which can also be obtained by enzymatic acylation of anthocyanins. However, little research have focused on the properties of anthocyanins with dicarboxylic acid derivatives due to the complexity of isolation, detection, and identification. In this work, pelargonidin-3-glucoside (Pg3G) was acylated with various dicarboxylic acids. The conversion yields of acylated Pg3G were positively associated with carbon chain lengths of dicarboxylic acids. The primary acylated products were identified as pelargonidin-3-(6″-malonyl) glucoside, pelargonidin-3-(6″-succinyl) glucoside, and pelargonidin-3-(6″-glutaryl) glucoside using LC-MS and NMR. Furthermore, the three acylated Pg3G derivatives exhibited improved thermostability and enhanced lipophilicity compared with Pg3G. The improved thermostability was attributed to the influence of dicarboxylic acids substituent on the distribution of flavylium cation, quinoidal base, hemiketal, cis-chalcone, and trans-chalcone at the equilibrium condition. Overall, our research provided insights about the improved stability and lipophilicity of pelargonidin-3-glucoside following enzymatic acylation with aliphatic dicarboxylic acids.

In-silico drug-likeness analysis, ADME properties, and molecular docking studies of cyanidin-3-arabinoside, pelargonidin-3-glucoside, and peonidin-3-arabinoside as natural anticancer compounds against acting receptor-like kinase 5 receptor.

The aim of the study was in-silico drug-likeness analysis, absorption, distribution, metabolism, and excretion (ADME) properties, and molecular docking studies of anthocyanins as natural anticancer compounds against acting receptor-like kinase 5 (ALK5) receptor. Transforming growth factor-β (TGF-β) plays an essential role in various cellular processes. Increased expression of TGF-β and its receptor TGFβR-I (i.e. ALK5) have been associated with poor prognosis in cancer patients. The drug-likeness activity of anthocyanins was performed using SwissADME tool. Molecular docking studies were carried out by using the Autodock Vina 1.5.6 tool. The results revealed that cyanidin-3-arabinoside (C3A), pelargonidin-3-glucoside (P3G), and peonidin-3-arabinoside (P3A) were able to use both Lipinski's rule of five and Ghose variations. The binding energies of C3A, P3G, and P3A against ALK5 were found as -8.0, -8.3, and -8.4 kcal mol-1, respectively. These selected anthocyanins have shown higher binding energies than known inhibitors to the ALK5 receptor. Further in-vitro and in-vivo studies were strongly recommended to clarify the whole mechanism.

Comparison of superior bred strawberry genotypes with popular cultivars in terms of fruit bioactive compounds over the full range of harvest dates

Secondary compounds of fruit are among the essential concerns due to their positive effects on human health. Many studies have attempted to improve these compounds by applying different genotype or cultivation practices such as irrigation and fertilization. This study aimed to find out the effect of different harvest dates on strawberry genotypes in terms of total phenolic (TP), total antioxidant activity (TAA), total monomeric anthocyanin (TMA), and some crucial individual phenolic compounds during the five-month growing season (January - May periods) with one month intervals. Besides, superior bred lines ('33′, '36′ and '61′) were compared with widely grown cultivars ('Rubygem', 'Festival' and 'Fortuna') under the Mediterranean climate conditions. Regarding the genotypes, it was observed that TMA, TP, TAA, (−) epicatechin, (−) epicatechin gallate, pelargonidin 3- glucoside (P3G), and pelargonidin 3- rutinoside (P3R) values were the highest values in the 33-bred line, while the 36-bred line stood out in terms of ferulic acid and cyanidin 3- glucoside (C3G). This study also has shown that the chlorogenic acid and sinapic acid contents of the 61-bred line were found in the highest level compared with the others. Regarding the harvest date, fruit antioxidant activity, total phenolic compounds, and individual phenols such as gallic, syringic, ferulic, (−) epicatechin and ellagic acid were measured the highest in May-harvested fruits, whereas these values were observed at the lowest level in March, except for syringic and (−) epicatechin. On the other hand, rutin, quercetin, sinapic acid, chlorogenic and caffeic acids, and P3G and P3R levels of fruits were the highest in April, when it was the most intense harvest period in Mediterranean climate conditions. These observations indicated that these compounds could be increased by choosing the right genotype and suitable environmental conditions.

Maturation Process, Nutritional Profile, Bioactivities and Utilisation in Food Products of Red Pitaya Fruits: A Review

Red pitaya (Hylocereus polyrhizus, red pulp with pink peel), also known as dragon fruit, is a well-known species of pitaya fruit. Pitaya seeds and peels have been reported to exhibit higher concentrations of total polyphenols, beta-cyanins and amino acid than pulp, while anthocyanins (i.e., cyanidin 3-glucoside, delphinidin 3-glucoside and pelargonidin 3-glucoside) were only detected in the pulp extracts. Beta-cyanins, phenolics and flavonoids were found to increase gradually during fruit maturation and pigmentation appeared earlier in the pulp than peel. The phytochemicals were extracted and purified by various techniques and broadly used as natural, low-cost, and beneficial healthy compounds in foods, including bakery, wine, dairy, meat and confectionery products. These bioactive components also exhibit regulative influences on the human gut microbiota, glycaemic response, lipid accumulation, inflammation, growth of microbials and mutagenicity, but the mechanisms are yet to be understood. The objective of this study was to systematically summarise the effect of red pitaya’s maturation process on the nutritional profile and techno-functionality in a variety of food products. The findings of this review provide valuable suggestions for the red pitaya fruit processing industry, leading to novel formulations supported by molecular research.

Bioavailability, Absorption, and Metabolism of Pelargonidin-Based Anthocyanins Using Sprague-Dawley Rats and Caco-2 Cell Monolayers.

The present study is aimed to clarify the absorption and metabolism properties of pelargonidin-based anthocyanins. Results showed that pelargonidin-3-O-rutinoside (Pg3R) was absorbed in its intact form after oral administration and reached a maximum plasma concentration of 175.38 ± 55.95 nM at 60 min. Three main metabolites were identified in plasma, including Pg3R-monoglucuronide (m/z 755.2046), Pg3R-hydroxylated (m/z 595.1644), and Pg3R-demethylated (m/z 565.1569) metabolites. The plasma concentration of the Pg3R-demethylated metabolite (57.04 ± 23.15 nM) was much higher than that of other two metabolites, indicating that demethylation was the main metabolic pathway for Pg3R, while the glucuronide conjugate was detected as the dominant metabolic form of pelargonidin-3-O-glucoside (Pg3G). The bioavailability of Pg3R (1.13%) was fourfold higher than that of Pg3G (0.28%), demonstrating that anthocyanins linked to the rutinoside may exhibit higher bioavailability than that of glucoside. In vitro transport study unveiled that passive diffusion and active efflux were involved in the absorption of Pg3R and Pg3G.

Antioxidative and Anti-Inflammatory Phytochemicals and Related Stable Paramagnetic Species in Different Parts of Dragon Fruit.

In this study, we investigated the antioxidant and anti-inflammatory phytochemicals and paramagnetic species in dragon fruit using high-performance liquid chromatography (HPLC) and electron paramagnetic resonance (EPR). HPLC analysis demonstrated that dragon fruit is enriched with bioactive phytochemicals, with significant variations between each part of the fruit. Anthocyanins namely, cyanidin 3-glucoside, delphinidin 3-glucoside, and pelargonidin 3-glucoside were detected in the dragon fruit peel and fresh red pulp. Epicatechin gallate, epigallocatechin, caffeine, and gallic acid were found in the dragon fruit seed. Additionally, 25–100 mg × L−1 of dragon fruit pulp and peel extracts containing enrichment of cyanidin 3-glucoside were found to inhibit the production of reactive oxygen species (ROS), reactive nitrogen species (RNS), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in cell-based studies without exerted cytotoxicity. EPR primarily detected two paramagnetic species in the red samples. These two different radical species were assigned as stable radicals and Mn2+ (paramagnetic species) based on the g-values and hyperfine components. In addition, the broad EPR line width of the white peel can be correlated to a unique moiety in dragon fruit. Our EPR and HPLC results provide new insight regarding the phytochemicals and related stable intermediates found in various parts of dragon fruit. Thus, we suggest here that there is the potential to use dragon fruit peel, which contains anthocyanins, as a natural active pharmaceutical ingredient.

Glycosides changed the stability and antioxidant activity of pelargonidin

Pelargonidin glucosides represent important pigments in the food industry. We compared the pH, metal-ionic, and thermal stability of pelargonidin (Pg), pelargonidin-3-O-glucoside (P3G), pelargonidin-3-O-rutinoside (P3R), and pelargonidin-3,5-O-diglucoside (P35DG) using visible spectrum analysis at 400–700 nm. The results showed that the pH stability of P3G and P3R exceeded Pg and P35DG. Ferrous ion (Fe2+) enhanced the stability of P3G and P3R, while thermal processing-induced degradation was evident in Pg and pelargonidin glycosides, according to the 1.5-order kinetic equation. Moreover, Pg and P35DG displayed higher temperature sensitivity than P3G and P3R. Then, 2,2-diphenyl-1-picrylhydrazyl (DPPH)-scavenging activity and ferric reducing antioxidant power (FRAP) analysis of the chemical models, and cell activity and reactive oxygen species assays of Caco2 and human umbilical vein endothelial cells (HUVECs) were used to identify the relationship between the pelargonidin structure and antioxidant activity. The DPPH-scavenging activity and FRAP values increased when the number and molecular weight of the pelargonidin glycosides were reduced, increasing the pro-oxidant properties in the Caco2 cells and the antioxidant activity in the HUVECs. Accordingly, this study suggested that glycosides might enhance the stability while decreasing the antioxidant activity of pelargonidin since glycosides increase the steric hindrance during reactions.

Down-Regulation of Claudin-2 Expression by Cyanidin-3-Glucoside Enhances Sensitivity to Anticancer Drugs in the Spheroid of Human Lung Adenocarcinoma A549 Cells.

Claudin-2 (CLDN2), an integral membrane protein located at tight junctions, is abnormally expressed in human lung adenocarcinoma tissues, and is linked to drug resistance in human lung adenocarcinoma A549 cells. CLDN2 may be a target for the prevention of lung adenocarcinoma, but there are few compounds which can reduce CLDN2 expression. We found that cyanidin-3-glucoside (C3G), the anthocyanin with two hydroxyl groups on the B-ring, and cyanidin significantly reduce the protein level of CLDN2 in A549 cells. In contrast, pelargonidin-3-glucoside (P3G), the anthocyanin with one hydroxyl group on the B-ring, had no effect. These results suggest that cyanidin and the hydroxyl group at the 3-position on the B-ring play an important role in the reduction of CLDN2 expression. The phosphorylation of Akt, an activator of CLDN2 expression at the transcriptional level, was inhibited by C3G, but not by P3G. The endocytosis and lysosomal degradation are suggested to be involved in the C3G-induced decrease in CLDN2 protein expression. C3G increased the phosphorylation of p38 and the p38 inhibitor SB203580 rescued the C3G-induced decrease in CLDN2 expression. In addition, SB203580 rescued the protein stability of CLDN2. C3G may reduce CLDN2 expression at the transcriptional and post-translational steps mediated by inhibiting Akt and activating p38, respectively. C3G enhanced the accumulation and cytotoxicity of doxorubicin (DXR) in the spheroid models. The percentages of apoptotic and necrotic cells induced by DXR were increased by C3G. Our data suggest that C3G-rich foods can prevent the chemoresistance of lung adenocarcinoma A549 cells through the reduction of CLDN2 expression.

Avocado Creole Peel Ameliorates Metabolic Alterations Caused by a High Sucrose Fat Diet in a Wistar Rats Model

High-sucrose high-fat diets are one of the causes of malnutrition, and may induce metabolic alterations such as dyslipidemia, insulin resistance, and adipogenesis. The objective of this work was to investigate the possible protective effect of traditionally edible avocado creole peel (Persea americana Mill var. drymifolia) when consuming a high-sucrose and fat diet (HSFD). The experimental animal model included 21 male Wistar rats divided in three groups: the control group received a standard diet of purina®, the HSFD group received a high fat diet plus 30% sucrose in drinking water, and finally the HSFD + AP group received the HSFD diet supplemented with 200mg/kg of avocado peel for 14 weeks. It was observed that alterations included higher cholesterol, glucose, insulin, fatty acids and TNF-α levels as well as lower HDL, and adiponectin. The addition of avocado peel reverted some of these effects, resulting in normal values of triglicerides, insulin and adiponectin, while attenuated the levels of total cholesterol. Liver weight of the group added with avocado peel was similar to the control group. The neuronal density in the hippocampal areas CA1 and dentate gyrus DC were lower in the high glucose fat group, while the ingestion of the avocado peel showed a neuroprotective effect. The avocado creole ingestion reverted or attenuated most of the metabolic effects caused by a high-sucrose fat diet which was attributed to the compounds detected by HPLC-MS and GC-MS that included bioactive polyphenols such as flavanol quercetin, flavanone naringenin, flavan 3-ol catechin, cyanidin 3-glucoside, pelargonidin 3-glucoside, pelargonidin 3-rhamnoside, hydroxydelphinidin, eugenol and estragole.