Delphinidin-3-glucoside Research Articles

Effect of light quality on polyphenol biosynthesis in three varieties of mung bean sprouts with different color seed coats.

We investigated the mechanism of the effect of different light qualities on the synthesis and regulation of mung bean sprouts. Light quality acts as a signal molecule, strongly enhancing polyphenol biosynthesis in sprouts. Mung bean (Vigna radiata) sprouts are a popular sprouting vegetable all over the world and are an excellent source of polyphenols with high antioxidant activity. This study investigated the effects of light qualities on the kinetic changes and metabolic regulation mechanism of light signal-mediating polyphenols in three mung bean sprout cultivars. Experimental results showed that three light qualities significantly enhanced the contents of caffeic acid, rutin, vitexin,genistin and delphinidin 3-glucoside. Interestingly, ferulic acid and vitexin responded selectively to blue light and red light, severally. Most genes involved in polyphenol biosynthesis were activated under different light quality conditions, resulting in an overaccumulation of phenylpropanoids. Pearson correlation analysis showed that PAL, F3H, F3'H and F3'5'H expression correlated highly with rutin, whereas ANS expression paralleled anthocyanin biosynthesis. Moreover, MYB111, MYB3, MYB4, MYB1 and MYC2 were critical regulators of polyphenol biosynthesis in mung bean sprouts. These changes were likely due to the changes in theexpression of the photoreceptor genes CRY-D, PHOT2, PHYE and light response genes (PIF3 and HY5). Our results provide insights into polyphenol biosynthesis in sprouts and microgreens.

Nontoxic and Naturally Occurring Active Compounds as Potential Inhibitors of Biological Targets in Liriomyza trifolii

In recent years, novel strategies to control insects have been based on protease inhibitors (PIs). In this regard, molecular docking and molecular dynamics simulations have been extensively used to investigate insect gut proteases and the interactions of PIs for the development of resistance against insects. We, herein, report an in silico study of (disodium 5'-inosinate and petunidin 3-glucoside), (calcium 5'-guanylate and chlorogenic acid), chlorogenic acid alone, (kaempferol-3,7-di-O-glucoside with hyperoside and delphinidin 3-glucoside), and (myricetin 3'-glucoside and hyperoside) as potential inhibitors of acetylcholinesterase receptors, actin, α-tubulin, arginine kinase, and histone receptor III subtypes, respectively. The study demonstrated that the inhibitors are capable of forming stable complexes with the corresponding proteins while also showing great potential for inhibitory activity in the proposed protein-inhibitor combinations.

Chemical and volatile composition, and microbial communities in edible purple flowers (Torenia fournieri F. Lind.) cultivated in different organic systems

Edible flowers have been widely consumed fresh in drinks, salads, desserts and salty dishes. This study evaluated the color parameters, chemical composition (phenolics, sugars, organic acids), volatiles compounds and microbiota (bacterial and fungal communities) in edible purple flowers (Torenia fournieri F. Lind.) cultivated in biocompost and traditional organic systems. Torenia flowers cultivated in biocompost had high (p < 0.05) contents of anthocyanins (cyanidin 3,5-diglucoside, delphinidin 3-glucoside), flavonols (quercitin 3-glycoside, myricetin and rutin), sugars (rhamnose and glucose), organic acids (citric and succinic), aldehydes (hexanal, cis-2-hexenal and trans-2-hexenal), and alcohols (trans-2-hexenol and 3-ethyl-4-methylpentan-1-ol). Flowers cultivated in biocompost showed higher (p < 0.05) abundance Cyanobacteria and Basidiomycota bacterial and fungal phyla, respectively, than flowers cultivated in traditional system. The high abundance of Oxyphotobacteria and Dothideomycetes classes, Acetobacterales and Cladosporiales orders, Oxyphotobacteriaceae and Cladosporiaceae families, and Raoultella and Cladosporium genera characterized torenia flowers cultivated in biocompost. The cultivation system influenced the torenia flowers microbiota and composition, primarily due to environmental response and enhanced uptake of nutrients. Our findings indicate that cultivation of torenia using the agroindustrial based-biocompost improves bioactive and volatiles contents in more purple and fruity flavored flowers, rendering flowers more attractive for consumption.

Identification of Seven Key Structural Genes in the Anthocyanin Biosynthesis Pathway in Sepals of Hydrangea macrophylla.

Under specific cultivation conditions, the sepal color of Hydrangea macrophylla (H. macrophylla) changes from red to blue due to the complexation of aluminum ions (Al3+), delphinidin 3-glucoside, and copigments. However, this phenomenon cannot occur in all cultivars despite the presence of sufficient Al3+ and copigments. To explore the mechanism of sepal bluing in H. macrophylla, there is an urgent need to study the molecular regulation of the anthocyanin biosynthesis pathway. However, the key structural genes, other than CHS, regulating anthocyanin biosynthesis in the sepals of H. macrophylla have not been identified. In this study, based on full-length transcriptome data from H. macrophylla ‘Bailmer’, the key structural genes regulating anthocyanin biosynthesis in the sepals of H. macrophylla were isolated and investigated. Ultimately, seven key structural genes, HmCHS1, HmCHI, HmF3H1, HmF3′H1, HmF3′5′H, HmDFR2, and HmANS3, were demonstrated to show high expression levels in colored sepals. The expression levels of these seven genes increased gradually with the development of sepals and were highest in the full-bloom stage. The trend of gene expression was consistent with the trend of anthocyanin contents. It was concluded that the seven selected genes were involved in anthocyanin biosynthesis in the sepals of H. macrophylla. The full-length sequence data have been deposited into the NCBI Sequence Read Archive (SRA) with accession number PRJNA849710. This study lays a good foundation for the further elucidation of the molecular mechanism of sepal coloration in H. macrophylla.

Genetic mapping of simply inherited categorical traits, including anthocyanin accumulation profiles and fruit appearance, in eggplant (Solanum melongena).

The appearance quality of the eggplant (Solanum melongena L.) fruit is an important trait that influences its commercial value. It is known that quality traits such as anthocyanin composition and fruit surface pattern are categorical and are inherited simply. However, research examples of gene mapping for the composition (anthocyanin accumulation profile) and the surface pattern in eggplant fruit are limited. To map loci for these traits including the accumulation profiles of two anthocyanins, a widely spreading anthocyanin, delphinidin 3-(p-coumaroyl) rutinoside-5-glucoside (nasunin), and the relatively rare delphinidin 3-glucoside (D3G), we used two F2 intracrossed populations (LWF2 and N28F2). For the LWF2 population, mapping was achieved by reconstructing the linkage map created by Fukuoka et al. [1]. In the case of the N28F2 population, we constructed a linkage map consisting of 13 linkage groups using 238 simple sequence repeats, 75 single-nucleotide polymorphisms. Using the two F2 populations, the nasunin accumulating profile, the striped pattern on the fruit surface, the colors of flowers, fruit, and calyxes, and the D3G accumulating profile were genetically mapped. Furthermore, by utilizing the eggplant reference genome information, mutations in the causative candidate genes for those loci were identified. Overall, the results of this study suggest that inactivation of key enzymes of anthocyanin metabolism and the gene orthologous to the tomato u gene are potential causes of observed variety in eggplant appearance traits.

Effect of Soybean Protein Isolate-7s on Delphinidin-3-O-Glucoside from Purple Corn Stability and Their Interactional Characterization.

Anthocyanins are abundant in purple corn and beneficial to human health. Soybean protein isolate-7s (SPI-7s) could enhance the stability of anthocyanins. The stable system of soybean protein isolate-7s and delphinidin-3-O-glucoside complex (SPI-7s-D3G) was optimized using the Box–Behnken design at pH 2.8 and pH 6.8. Under the condition of pH 2.8, SPI-7s effectively improved the sunlight-thermal stabilities of delphinidin-3-O-glucoside (D3G). The thermal degradation of D3G conformed to the first order kinetics within 100 min, the negative enthalpy value and positive entropy value indicated that interaction was caused by electrostatic interaction, and the negative Gibbs free energy value reflected a spontaneous interaction between SPI-7s and D3G. The interaction of SPI-7s-D3G was evaluated by ultraviolet visible spectroscopy, circular dichroism spectroscopy and fluorescence spectroscopy. The results showed that the maximum absorption peak was redshifted with increasing the α-helix content and decreasing the β-sheet contents, and D3G quenched the intrinsic fluorescence of SPI-7s by static quenching. There was one binding site in the SPI-7s and D3G stable system. The secondary structure of SPI-7s had changed and the complex was more stable. The stabilized SPI-7s-D3G will have broad application prospects in functional foods.

Delphinidin-3-O-glucoside, an active compound of Hibiscus sabdariffa calyces, inhibits oxidative stress and inflammation in rabbits with atherosclerosis

Context Delphinidin-3-O-glucoside (DP) is a bioactive compound of Hibiscus sabdariffa L. (Malvaceae) (Roselle) calyces and exerts endothelial protection and lipid-lowering activities, which provided a basis for the prevention and treatment of cardiovascular diseases. Objectives To investigate the therapeutic effects of DP against atherosclerosis. Materials and methods A rabbit model of atherosclerosis (AS) was established by 12 weeks of a high-fat diet (HFD). The rabbits were divided into five groups: control, AS, simvastatin (4 mg/kg), and two DP groups (10 and 20 mg/kg). After treatment with DP or simvastatin by oral gavage for 12 weeks, the lipid profiles were measured. Histopathological assessment of the aorta was performed by H&E staining. Oxidative stress and inflammation-related markers were analyzed by ELISA kit and real-time RT-PCR. Results DP (20 mg/kg) decreased serum TG (2.36 ± 0.66 vs. 4.33 ± 0.27 mmol/L for the AS group), TC, LDL-C, and HDL-C (all p < 0.05). DP (20 mg/kg) also reduced lipid levels in the liver and aorta. DP (20 mg/kg) down-regulated the mRNA levels of IL-6, VCAM-1, and NF-κB and up-regulated the mRNA levels of GSH-PX and SOD1. Conclusions This study proved that DP alleviated the HFD-induced oxidative stress and inflammation in atherosclerosis rabbits. These results provided the scientific basis for developing novel therapies.

The effects of different drying methods on the in vitro bioaccessibility of phenolics, antioxidant capacity, minerals and morphology of black ‘Isabel’ grape

The black Isabel grapes were dehydrated by hot-air drying (HAD), vacuum-drying (VD), ultrasound-assisted vacuum-drying (US-VD), freeze-drying (FD), and their physical properties, phenolic compounds, antioxidant capacities, and mineral content were determined before and after simulated in vitro digestion. Among drying methods, FD provided the highest retention of the phenolic compounds, whereas US-VD caused the highest loss. The changes of phenolics of grapes differed among the digestion phases depending on the state of grapes (fresh or dried) and the drying method. The chlorogenic acid was the major phenolic compound identified, followed by protocatechuic acid and catechin. The malvidin-3-O-glucoside was the major anthocyanin followed by 3-glucosides of petunidin, delphinidin, cyanidin, and peonidin in the fresh and FD samples. At the end of digestion, a significant decrease in the levels of phenolics, minerals and no presence of anthocyanins was observed. VD raisins exhibited a higher bioaccessibility index for most of the phenolic compounds. Potassium was the most bioaccessible mineral from grape samples. Our results together with the morphology of the grapes revealed that different microstructures created by drying and the disruption of the natural matrix would influence the release, transformation, and subsequent absorption of phenolics and minerals in the simulated digestion model.

Syzygium cumini (L.) Skeels extracts; in vivo anti-nociceptive, anti-inflammatory, acute and subacute toxicity assessment

Ethnopharmacological relevanceSyzygium cumini (L.) Skeels has been extensively used in the ancient medical system of Pakistan, India, Bangladesh, and Sri Lanka to combat diabetes, inflammation, and renal disorders. These health-promoting aspects of S. cumini are related to bioactive metabolites such as phenolic acids, anthocyanins, tannins, and flavonoids. Aim of the studyEarlier to this study, we have reported S. cumini extracts as potential sources of bioactive compounds bearing antioxidant and anti-inflammatory properties. However, prior further suggesting S. cumini fruit extracts for consumption against inflammatory disorders, it was mandatory to validate the claim and explore toxicity of the extracts. This study aims to determine the in vivo anti-nociceptive, anti-inflammatory, acute, and subacute toxicity properties of S. cumini crude extracts, followed by identifying and quantifying bioactive metabolites. Material and methodsIn the present study, the anti-nociceptive and anti-inflammatory potential of S. cumini sequential crude extracts were evaluated using formalin and glutamate-induced paw licking method in mice. The acute and sub-acute toxicity assessment of active extract was performed by oral administration in rats. An acute toxicity trial was performed with two different doses, i.e., 2000 mg/kg and 3000 mg/kg for consecutive 14 days, whereas a sub-acute toxicity study was conducted at doses of 750 mg/kg and 1500 mg/kg for the next 28 days. Identification of bioactive compounds was performed using HPLC, and at the end, in silico docking calculations of identified compounds were performed. ResultsThe 100% methanolic extract (SCME) protected the mice from painful stimulation of formalin and glutamate in a dose-dependent manner with the maximum effect of 49% and 67% at 200 mg/kg, respectively, followed by moderate and non-influential effects of 50% methanolic extract and dichloromethane (DCM) extracts when compared to control, i.e., normal saline. The results of acute toxicity recorded LD50 of SCME over 3000 mg/kg, and no antagonistic effects were recorded during the subacute study when SCME dispensed at the rate of 750 mg/kg and 1500 mg/kg. SCME was found to induce no adverse effects to kidney, heart, liver, spleen, and paired lungs examined by hematological, serum biochemical, histological analysis. HPLC analysis of S. cumini 100% methanolic extracts revealed the presence of delphinidin 3-glucoside, peonidin-3,5-diglucoside, scopoletin, and umbelliferone at the concentration of 127.4, 2104, 31.3, 10.4 μg/g whereas in 50% methanolic extract, the quinic acid, catechin, and myricetin were present at the concentration of 54.9, 63.7, 12.3 μg/g, respectively. Umbelliferone and scopoletin are newly reported compounds in the present study. In silico docking calculations of these compounds indicated the potential of anti-nociceptive and anti-inflammatory activities. ConclusionsThese findings validate that S. cumini fruit extracts are a rich source of bioactive compounds that needs to be considered to enhance biological activities with lesser side effects.

Comparative assessment of phenolics, antioxidant and antiproliferative activities between Hippophae rhamnoides ssp. sinensis and H. tibetana leaf in Qinghai-Tibet Plateau

Hippophae rhamnoides ssp. sinensis (Rha) and H. tibetana (Tib) are two species of sea buckthorn which distribute in Qinghai-Tibet Plateau. Our results showed that both sea buckthorn leaf exhibited high total phenolic and flavonoid content, and Rha leaf showed much higher level. In addition, 66 phenolic compounds were detected, belonging to classes of benzoic acid derivatives, flavonols, flavanols, flavanones, and so on. Classes of benzoic acid derivatives and flavonols were most abundant, among them ellagic acid and rutin were the most and second abundant phenols. Besides, methyl gallate, 2,6-dihydroxybenzoic acid, 4-hydroxybenzoic acid, gentisic acid, narcissin, astragalin, nicotiflorin, prunin, procyanidin B3, cyanidin 3-O-rutinoside chloride, delphinidin 3-glucoside, gallocatechin, taxifolin, aromadendrin and trans-3,3′,4′,5,5′,7-Hexahydroxyflavanone were the first time to be identified in SBT leaf. Furthermore, significant free radical scavenging effects of ABTS and DPPH, ferric reducing antioxidant ability, cellular antioxidant properties and anti-proliferation activity against HepG2 cells were observed in the aqueous ethanol extracts of sea buckthorn leaf. While Rha showed stronger inhibitory effects, which might due to the higher content of total phenolic and flavonoid profiles. Our finding clearly supported that Rha leaf as a wild and non-pollution plant could be a better choice as a healthy food resource.

Integration of Metabolome and Transcriptome Reveals the Relationship of Benzenoid-Phenylpropanoid Pigment and Aroma in Purple Tea Flowers.

Tea (Camellia sinensis) flowers are normally white, even though the leaves could be purple. We previously discovered a specific variety with purple leaves and flowers. In the face of such a phenomenon, researchers usually focus on the mechanism of color formation but ignore the change of aroma. The purple tea flowers contain more anthocyanins, which belong to flavonoids. Meanwhile, phenylalanine (Phe), derived from the shikimate pathway, is a precursor for both flavonoids and volatile benzenoid–phenylpropanoids (BPs). Thus, it is not clear whether the BP aroma was attenuated for the appearance of purple color. In this study, we integrated metabolome and transcriptome of petals of two tea varieties, namely, Zijuan (ZJ) with white flowers and Baitang (BT) with purple flowers, to reveal the relationship between color (anthocyanins) and aroma (volatile BPs). The results indicated that in purple petals, the upstream shikimate pathway promoted for 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS) was elevated. Among the increased anthocyanins, delphinidin-3-O-glucoside (DpG) was extremely higher; volatile BPs, including benzyl aldehyde, benzyl alcohol, acetophenone (AP), 1-phenylethanol, and 2-phenylethanol, were also enhanced, and AP was largely elevated. The structural genes related to the biosynthesis of volatile BPs were induced, while the whole flavonoid biosynthesis pathway was downregulated, except for the genes flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′,5′-hydroxylase (F3′5′H), which were highly expressed to shift the carbon flux to delphinidin, which was then conjugated to glucoside by increased bronze-1 (BZ1) (UDP-glucose: flavonoid 3-O-glucosyltransferase) to form DpG. Transcription factors (TFs) highly related to AP and DpG were selected to investigate their correlation with the differentially expressed structural genes. TFs, such as MYB, AP2/ERF, bZIP, TCP, and GATA, were dramatically expressed and focused on the regulation of genes in the upstream synthesis of Phe (DAHPS; arogenate dehydratase/prephenatedehydratase) and the synthesis of AP (phenylacetaldehyde reductase; short-chain dehydrogenase/reductase), Dp (F3′H; F3′5′H), and DpG (BZ1), but inhibited the formation of flavones (flavonol synthase) and catechins (leucoanthocyanidin reductase). These results discovered an unexpected promotion of volatile BPs in purple tea flowers and extended our understanding of the relationship between the BP-type color and aroma in the tea plant.

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.

Assessing the effects of a novel biostimulant to enhance leafminer resistance and plant growth on common bean

The leafminer Liriomyza trifolii is one of the major insects that affect Phaseolus vulgaris production worldwide. Novel and safe biobased stimulator compound (BSTC) with micronutrient-amino acid chelated compounds was developed from natural compounds and was used for foliar spray of P. vulgaris. Treated plants showed significantly increased in quality and productivity as well as significant reduction in leafminer infestation by close the tunnel end resulting in larvae suffocation and death. BSTC contains chemical composition that has important function in inducing immunity and resistance against insects, enhance plant growth and production. Also, HPLC showed that the assembled BSTC is rich in nucleobases than yeast extract (> 56 fold). Aminochelation zinc enhanced the rate of absorption of nutrient compounds and could participate in safe biofortification strategy. The expression of plant defense related genes under BSTC treatment revealed strong correlations between the transcription rates of defense related genes. Based on binding energies and interacting residues of six vital insect proteins, the best-docked complexes was obtained with disodium 5′-inosinate, delphinidin 3-glucoside and hyperoside. Obtained findings indicate that the foliar application of BSTC can enhance plant growth and productivity, uptake of important elements, expression of defense related genes and inhibit insect essential genes.

Effect of thermosonication treatment on blueberry juice quality: Total phenolics, flavonoids, anthocyanin, and antioxidant activity

To investigated the effects of thermosonication (TS) on blueberry juice quality. The raw juice (RJ), pasteurized juice (60 °C, 30 min, PJ), and TS treated juice (20 kHz, 200 W, 400 W, and 600 W at 60 °C for 15 min, TJ) were analysed for colour characteristics, total antioxidant contents, antioxidant capacity, and composition of anthocyanins. Results showed that TS treated juice had higher colour density (CD), L*, and ΔE values and lower values of chroma (C), hue angle (h), yellow index (YI). The content of total phenolics, flavonoids, and anthocyanins, were increased by 139.32%, 251.72%, and 94.12%, respectively, in TJ600 sample compared to the RJ samples. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical (▪OH) scavenging capacity were increased to 65.22%, 51.13%, significantly higher than PJ sample. The content of delphinidin-3-O-glucoside (Dp-G) and cyanidin-3-O-glucoside (Cy-G), were 54.40 mg/L, 28.75 mg/L in juice. Correlation analysis indicated that the antioxidant contents play an important role in CD, and Cy-G determines the brightness or darkness of the juice. Collectively, the findings suggested that TS could be a feasible alternative to pasteurization for improving the quality and antioxidant activity of blueberry juice.

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.

Counter-current fractionation-assisted and bioassay-guided separation of active compounds from cranberry and their interaction with α-glucosidase

An effective method for the selection of active compounds from cranberry based on counter-current fractionation and bioassay-guided separation was established. Cranberry extract showed potential α-glucosidase inhibitory activity. The active compounds were extracted by different solvents and enriched in water. The water extract was divided into eight fractions via high-speed counter-current chromatography to further track the active compounds. Results indicated that the α-glucosidase inhibitory activity of F7 was remarkable higher than the other fractions. Four compounds, including delphinidin-3-glucoside (D3G), cyanidin-3-glucoside, cyanidin-3-rutinoside, and pelargonidin-3-glucoside, were separated from F7 through column chromatography, and their structures were identified by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, 1H nuclear magnetic resonance (NMR), and 13C NMR. D3G showed the strongest α-glucosidase inhibitory activity among the compounds. Moreover, the interaction mechanism between α-glucosidase and D3G was clearly characterized and described by spectroscopic analyses and molecular docking. D3G could spontaneously bind with α-glucosidase to form complexes through hydrophobic interaction. The secondary structure of α-glucosidase changed in varying degrees after complexation with D3G. The α-helix and β-turn contents of α-glucosidase markedly decreased, whereas the irregular coil increased. These findings provide a new insight into the interaction between α-glucosidase and D3G.

Molecular stabilization and complexation: the secrets of making a nuclear-selective histological stain from naturally occurring anthocyanins without oxidation

ABSTRACT The natural colorant, roselle, found in Hibiscus sabdariffa, has been used as a histological dye since at least 1976. As a simple extract roselle acts as a general red counterstain, but when treated with an oxidant and metallic mordant it functions as a useful blue nuclear-selective stain. In the past 40 years it has been assumed that oxidation is necessary when preparing a stain from roselle, as of course it is for the related flavonoid dyes hematoxylin and brazilin. However, the chemistry of roselle argues against this. Roselle is a mixture of four closely related compounds: delphinidin 3-sambubioside and cyanidin 3-sambubioside, delphinidin 3-glucoside and cyanidin 3-glucoside. Each of these in turn can exist in 8 different configurations in a complex state of equilibrium largely dependent upon pH. Of these compounds, only three are colored. In plants, and in their complex extracts, formation of these colorless compounds is inhibited by the presence of other colorless aromatic molecules, a stabilizing process termed co-pigmentation. The color of such extracts may be red in the acid range and blue or violet above neutrality. Complexation (chelation) with metal cations occurs above pH 2.8 or 3.0, depending upon the concentration of the metal. Prior oxidation is not needed for such chelation to occur. With Al3+ the resulting metal complex, which we term rosalum, is violet or blue. Following spectrophotometric investigation of this complexation, we were able to formulate a nuclear-selective violet/blue stain without the use of an oxidant.

Syzygium cumini(L.),Skeels fruit extracts: In vitro and in vivo anti-inflammatory properties

Ethnopharmacological relevanceSyzygium cumini (L.) Skeels is an important medicinal plant utilized in the health care systems of Pakistan, India, Sri Lanka, and Bangladesh. S. cumini have been used to treat renal issues, indigestion, diabetes, dysentery, and employed in folk medicine to treat inflammations. It is known to anticipate antioxidant, anti-inflammatory, anticancer, anti-diabetic, anti-bacterial, antifungal, activities, and radioprotective activities. Material and methodsWe examined the in vitro anti-inflammatory activities of S. cumini fruit extracts, evaluated using membrane stabilization, egg albumin denaturation, and bovine serum albumin denaturation assays. In vivo anti-inflammatory activity was also assessed, using murine models of carrageenan, formaldehyde, and PGE2 induced paw edema. Fractionation of active extracts was performed using HPLC, followed by LC-ESI-MS/MS analysis to identify the bioactive compounds responsible for anti-inflammatory activity. ResultsThe crude methanolic extract showed stronger in vitro and in vivo anti-inflammatory activities compared to other extracts. The most potent effects were observed in the formaldehyde induced paw edema assay wherein methanolic extract and standard indomethacin induced 72% and 88% inhibition against paw edema volume in comparison to control (normal saline) respectively. In the bovine serum albumin denaturation assay the methanolic extract induced 82% inhibition against denaturation as compared to control (phosphate buffer) while standard diclofenac sodium induced 98% inhibition. In contrast, 50% v/v MeOH:H2O or 100% dichloromethane extracts displayed moderate to weak effects in the anti-inflammatory models. HPLC fractionation provided 6 active sub-fractions, four (MF2, MF3, MF6, MF7) from the 100% methanolic extract and two (HAF1, HAF3) from the 50% methanolic extract. The MF2, MF7, and HAF1 sub-fractions displayed potent activity in all studied in vitro assays. LC-ESI-MS-MS analysis tentatively identified delphinidin 3-glucoside, peonidin-3,5-diglucoside, gallic acid, liquitrigenin, scopoletin, umbelliferon, and rosmanol from the 100% methanolic fractions. Myricetin, catechin, quinic acid, chlorogenic acid, ellagic acid, gallic acid, and caffeic acid were identified in the 50% methanolic fractions. ConclusionsThese results demonstrate that S. cumini fruit extracts are a rich source of bioactive compounds that are worthy of further investigation as leads for anti-inflammatory drug discovery.

Quality matrix reveals the potential of Chak-hao as a nutritional supplement: a comparative study of matrix components, antioxidants and physicochemical attributes

In the current trend of increased health consciousness in response to increased incidence of lifestyle disorders, functional foods, and nutritional supplements got immense acceptance globally. Whole grain foods rich in functional bio-actives being a better substitute for supplements, there is an emerged interest in exploring potential candidates like pigmented rice. The present study thus aims to evaluate the natural variability in matrix composition owing nutritional and antioxidant potential of pigmented niche rice varieties like Matta (red) and Chak-hao (black) compared to non-pigmented (NJ 72 and PB 1509). Comprehensive NQM developed indicated that Chak-hao, geographical indication (GI) rice has stout nutritional makeup in terms of phenolics (2.5 mg/g GAE), anthocyanins (0.65 g/kg), proanthocyanidins (54 mg/100 g), antioxidant activity (36 µmol TE/g) and resistant starch (4.13%) compared to Matta. The content of high-quality fatty acids like oleic (38.8%), linoleic (29%), and anthocyanin forms like cyanidin-3-glucoside (C3G)- 304 mg/Kg, delphinidin-3-glucoside (D3G)- 220 mg/Kg and peonidin-3-glucoside (P3G)- 120 mg/Kg was also most expressive in the black pigmented rice Chak-hao. Highly significant (p < 0.05) antioxidant activity and positive correlation with total phenolics, anthocyanins and proanthocyanidins content were most evident in pigmented varieties. Physicochemical attributes endorsing cooking time, water uptake ratio, grain elongation ratio, gruel solid loss and swelling ratio varied between 15–35 min, 2.17–3.2, 1.5–2.3, 0.28–1.25 and 1.75–2.66 respectively. The correlation between nutritional attributes endorsing antioxidant potential being strongly positive and most significant for Chak-hao, it could be the stellar addition for functional food industry as a nutritional supplement for addressing the ever-increasing pandemics like diabetes, obesity and other chronic diseases.

Nondestructive measurement of anthocyanin in intact soybean seed using Fourier Transform Near-Infrared (FT-NIR) and Fourier Transform Infrared (FT-IR) spectroscopy

The content of phytochemical compounds such as anthocyanin in soybeans, yielded from agricultural practices is usually affected by the quality of the mother seed. Therefore, non-destructive technique for intact soybean seed selection based on anthocyanin content is highly demanded for breeding programs. The objective of this study was to evaluate the feasibility of Fourier-transform near-infrared (FT-NIR) and Fourier-transform infrared (FT-IR) spectroscopic techniques to determine the total anthocyanin content (TAC) and content of different types of anthocyanin, namely cyanidin-3-glucoside (C3G) and delphinidin-3-glucoside (D3G), in single seed state of soybean. FT-NIR and FT-IR spectra from 70 different varieties of soybean seeds were acquired and compared with the chemical components analyzed using high-performance liquid chromatography (HPLC). The prediction performance of the partial least squares regression (PLSR) models for the FT-NIR spectra indicated R2 of 0.88–0.90 and standard error of prediction (SEP) of 9.4–19.5% for the chemical components, which were slightly better than R2 of 0.86–0.88 and SEP of 9.7–21.8% of FT-IR. The number of variables could be reduced down to 50% using a variable importance in projection (VIP) method without noticeable decrements in prediction performance. The results demonstrated potential of FT-NIR and FT-IR spectroscopic techniques to predict anthocyanin contents in a single seed of soybean nondestructively.