Complex Polyphenols Research Articles

Toxicity of vegetable tannin extract from Acacia mearnsii in Saccharomyces cerevisiae

Vegetable tannins are complex polyphenols, which occur widely in nature. Traditionally, natural tannins have been used for tanning leather. In Brazil, the main tannin-based products are obtained from Acacia mearnsii, which is a leguminous tree native to Southeastern of Australia, and the first seeds were brought to Brazil in 1928. The main cultivation of acacia was established in Rio Grande do Sul state due to the possibility of raw material for charcoal, adhesives to fuel and for tanning leather. The leather tanning processes based on plant tannins are thought to be less harmful than chromium-based tanning, and it has been used as a sustainable alternative. However, there is scarce information about the environmental impact of the leather tanning processes, with most studies reporting inhibitory effects against microorganisms at high doses and stimulatory and positive health effects at low concentrations. The aim of this study was to evaluate the toxicity of tannin preparations extracted from A. mearnsii in Saccharomyces cerevisiae. Vegetable tannin toxicity in yeast was tested using two tannin treatments in different concentrations. In general, the results showed toxicity of vegetable in yeast, BY4741 and gsh1Δ strains.

Impact of storage on phytochemicals and milk proteins in peach yoghurt

Yoghurt supplemented with peach is a dairy product consumed around the world with a shelf-life of ca. 30 days. During this period protein–polyphenol complexes can be formed and have a detrimental effect on the in vivo solubility of both phenolic and proteins. Yoghurt enriched with peach preparate were produced and stored up to 28 days at 2 °C. Total antioxidant activity decreased 24%, total carotenoids increased 66%, while total phenolics remained unchanged during the yoghurt shelf-life. Carotenoids presented significant differences between peach enriched yoghurt and peach preparate stored under the same conditions. After 28 days the zeaxantin + lutein, β-cryptoxanthin and β-carotene increased 133, 122, and 84% respectively, for peach preparate, while in peach yoghurt they increased 68, 40, and 15%, indicating interactions of carotenoids with matrix components mainly proteins and fat present in yoghurt. Polyphenols presented higher stability when added to yoghurt with slight variations in their content of ca. 10% for (+)-catechin and 12% for p-coumaric acid, and no variations were recorded in neochlorogenic and chlorogenic acids and in rutin. The α-lactalbumin content decreased 22% after 24 h of peach addition while β-lactoglobulin content did not change. Peach polyphenols were very stable during yoghurt shelf-life while carotenoids were the compounds that presented higher interactions with the matrix.

Effects of Polyphenolic Extract from Pine Bark on the Improvement of Attention Deficit/Hyperactivity Disorder in Children and Adolescent

Purpose: To examine the hypothesis that intervention with the polyphenolic complex (PE) from pine bark improves the symptoms of ADHD and reduces oxidative stress in children and adolescent. Methods: It was a randomized, double-blind, crossover and placebo-controlled 10-weeks period study, including two interventional periods (4weeks/period) and one washout period (2 weeks). Data were from 8 participants with attention deficit hyperactivity disorder (ADHD) at ages 7~16 years (seven boys and one girl). During the first interventional period, participants were received a capsule of PE from pine bark, which contain 25mg Oligopin® per capsule, or a capsule of placebo, which contains 25mg cellulose. Then, participants entered the washout period for 2 weeks. After 2 weeks of washout, the participants entered the second interventional period and crossed over to receive an Oligopin® or placebo capsule. Neuropsychological assessment, routine blood biochemical parameter and antioxidative status were carried out in this study. Results: All blood biochemical parameters were normal in the interventional periods. However, the lipid peroxidation was significantly decreased when participants received the PE capsules. Moreover, the participants had a significant higher hit accuracy, inhibition, sustainability in CPT-II performanceduring the PE interventional period. Conclusions: The administration of the polyphenolic extract from pine bark (25 mg/day) for one month might improve the inattention and impulsivity and reduce plasma lipid peroxidation levels in children and adolescent with ADHD.

Galloyl moieties enhance the binding of (−)-epigallocatechin-3-gallate to β-lactoglobulin: A spectroscopic analysis

The current study was designed to examine the role of galloyl moieties in the interaction of β-lactoglobulin (β-Lg) with (−)-epigallocatechin-3-gallate (EGCG) using fluorescence and CD spectroscopic methods. The interactions with β-Lg were investigated for EGCG, (−)-epigallocatechin (EGC), and the phenolic compound methyl gallate (MeG) at pH values 3.0, 5.0 and 7.4. The spectroscopic data indicated the binding constants for polyphenol complexes with β-Lg in phosphate buffer pH 7.4 to be in the order of MeG>EGCG>EGC. MeG exhibited the strongest quenching efficiency compared to EGCG and EGC, and EGC exhibited the weakest quenching efficiency. The quenching efficiency of EGCG on β-Lg fluorescence decreased with increasing pH. Polyphenols binding results in a slight secondary structural change of β-Lg, consistent with the fluorescence analysis. This study confirmed that the high binding affinity of EGCG to β-Lg is due to the galloyl functional group.

Effect of fermentation parameters and their optimization on the phytochemical properties of lactic-acid-fermented mulberry juice

Morus nigra is an excellent source of polyphenols which, are associated with its functional properties. Lactic acid bacteria have been reported to hydrolyse complex polyphenols into simpler and more bioactive compounds during fermentation. Fermentation process depends on multiple parameters to obtain a desired product. The study evaluated the effects of fermentation parameters [temperature (TF), pH, inoculum concentration (IC) and brix (°Bx) on the phytochemical properties of lactic-acid-fermented mulberry juice (LFMJ)]. Correlation analysis showed that quadratic polynomial model could be used to illustrate the influence of fermentation parameters on phytochemical properties of LFMJ. Response surface plots showed that these independent variables significantly influenced the phytochemical content of LFMJ. The outcome of the study demonstrated that lactic acid fermentation significantly impacted on the total phenolic, anthocyanin and flavonoid contents of the beverage. The optimum fermentation conditions to obtain the highest phenolic, anthocyanin and flavonoid contents were TF (40 °C), pH (4.0), IC (3.90% v/v) and °Bx 14. Under the above-mentioned conditions, the experimental results obtained [total phenolic content (928.12 ± 3.05 mg/100 ml), total anthocyanin content (131.85 ± 1.03 mg/100 ml) and total flavonoid content (440.50 ± 2.00 mg/100 ml)] were in line with the predicted values—total phenolic content (879.25 mg/100 ml), total anthocyanin content (128.99 mg/100 ml) and total flavonoid content (436.63 mg/100 ml)) and an overall desirability of 0.911. The LFMJ was found to have a significant (P < 0.05) better colour, aroma, flavour, taste and overall acceptability compared to the non-fermented mulberry (NFMJ).

Antioxidative capacity and binding affinity of the complex of green tea catechin and beta-lactoglobulin glycated by the Maillard reaction

Major green tea catechin, epigallocatechin-3-gallate (EGCG), binds non-covalently to numerous dietary proteins, including beta-lactoglobulin of cow’s milk. The effects of glycation of proteins via Maillard reaction on the binding capacity for polyphenols and the antiradical properties of the formed complexes have not been studied previously.Binding constant of BLG glycated by milk sugar lactose to EGCG was measured by the method of fluorophore quenching. Binding of EGCG was confirmed by CD and FTIR. The antioxidative properties of the complexes were examined by measuring ABTS radical scavenging capacity, superoxide anion scavenging capacity and total reducing power assay.Glycation of BLG does not significantly influence the binding constant of EGCG for the protein. Conformational changes were observed for both native and glycated BLG upon complexation with EGCG. Masking effect of polyphenol complexation on the antioxidative potential of the protein was of the similar degree for both glycated BLG and native BLG.

Main constituents of polyphenol complex from seagrasses of the genus Zostera, their antidiabetic properties and mechanisms of action.

The present review analyzed the recent experimental studies of the alleviating activity of main constituents of the polyphenol complex from seagrasses of the genus Zostera, namely rosmarinic acid, luteolin and its sulfated derivatives, on carbohydrate and lipid metabolism disorders. A number of studies by our group and others, in which various experimental models of diabetes and hyperlipidemia were used, show a therapeutic action of the polyphenol complex and the abovementioned phenolic constituents, when applied separately and in combination. Based on the analysis of the results of these studies, the probable mechanisms of the therapeutic action of these compounds in diabetes and hyperlipidemia were proposed.

Quantum chemical calculation of NIR spectra of practical materials

In the third issue of the series on modern quantum chemical methods in the support role of NIR spectroscopy we continue to introduce the researchers from the field of experimental spectroscopy to practical aspects and applications of modern anharmonic theoretical approaches. The first two issues focused on explaining the necessary theoretical and practical background, allowing readers to get more familiar with the topic. An overview of recent literature reports highlighted the advantages stemming from using quantum chemical calculation in the support role to NIR spectroscopy. These deliberations were based on several cases of small- to medium-sized molecules. This part overviews the topic of applications of quantum theoretical methods to complex molecules with practical significance, which typically prove to be challenging objects for theoretical studies. An exemplary application of presented methodology to the case of Rosmarini folium biological samples is also examined here. The rosemary specific active compound, rosmarinic acid, is a relatively complex polyphenol with growing phytopharmaceutical importance, and therefore provides an excellent object of applied studies. The possibilities of combining the information stemming from quantum chemical calculation with the methods of advanced spectral data analysis, which are commonly used in experimental NIR spectroscopy (chemometrics, two-dimensional (2D) correlation spectra) are also overviewed. Again, these deliberations are based directly on the most recent reports published in the field.

Antioxidant defense during desiccation of the resurrection plant Haberlea rhodopensis

Maintaining a strong antioxidant system is essential for preventing drought-induced oxidative stress. Thus, in the present study we investigated the role of some non-enzymic and enzymic antioxidants in desiccation tolerance of Haberlea rhodopensis. The effects of high light upon desiccation on antioxidant capacity was estimated by comparing the response of shade and sun plants. The significant enhancement of the antioxidant capacity at 8% RWC corresponded to an enormous increase in flavonoid content. The important role of ascorbate-glutathione cycle in overcoming oxidative stress during drying of H. rhodopensis was established. The antioxidant capacity increased upon dehydration of both shade and sun plants but some differences in non-enzymatic and enzymatic antioxidants were observed.Investigations on the role of polyphenols in desiccation tolerance are scarce. In the present study the polyphenol profiles (fingerprints) of the resurrection plant Haberlea rhodopensis, including all components of the complex are obtained for the first time. It was clarified that the polyphenol complex of H. rhodopensis includes only two types of glycosides - phenylethanoid glucosides and hispidulin 8-C-glucosides. Upon desiccation the polyphenol content increase and the main role of phenylethanoid glucosides in the protection of H. rhodopensis was revealed.

New insight into the flavonoid composition of Chenopodium botrys

Due to their beneficial medicinal effects, in recent years there has been an increasing interest in the research of flavonoids in plant sources.In the conducted research the flavonoid composition of Chenopodium botrys was defined by applying an approach which included different extraction procedures and methods of detection. Primary extraction of polyphenols with two different solvents, HPLC-PDA fingerprint profiling and an Orbitrap UHPLC-MS/MS detection were used. The fingerprint profile of polyphenols showed that the major constituents were the methoxylated flavones nepetin, hispidulin and jaceosidin, while the quercetin glycosides represented a minor part. In order to elucidate their structure, the fragmentation of the compounds was examined by means of ESI-MS/MS analysis. A novel explanation of the fragmentation pathways of the methoxylated flavones was introduced. Nepetin, nobiletin, eupatilin, rutin and quercetin-3-O-galactoside were identified in the polyphenol complex of C. botrys for the first time.

Iron oxide nanoparticles coated with green tea extract as a novel magnetite reductant and stabilizer sorbent for silver ions: Synthetic application of Fe3O4@green tea/Ag nanoparticles as magnetically separable and reusable nanocatalyst for reduction of 4‐nitrophenol

Green tea extract having many phenolic hydroxyl and carbonyl functional groups in its molecular framework can be used in the modification of Fe3O4 nanoparticles. Moreover, the feasibility of complexation of polyphenols with silver ions in aqueous solution can improve the surface properties and capacity of the Fe3O4@green tea extract nanoparticles (Fe3O4@GTE NPs) for sorption and reduction of silver ions. Therefore, the novel Fe3O4@GTE NPs nano‐sorbent has potential ability as both reducing and stabilizing agent for immobilization of silver nanoparticles to make a novel magnetic silver nanocatalyst (Fe3O4@GTE/Ag NPs). Inductively coupled plasma analysis, transmission and scanning electron microscopies, energy‐dispersive X‐ray and Fourier transform infrared spectroscopies, and vibrating sample magnetometry were used to characterize the catalyst. Fe3O4@GTE/Ag NPs shows high catalytic activity as a recyclable nanocatalyst for the reduction of 4‐nitrophenol at room temperature.

Multicomponent, fragment-based synthesis of polyphenol-containing peptidomimetics and their inhibiting activity on beta-amyloid oligomerization.

A new and short fragment-based approach towards artificial (but "natural-based") complex polyphenols has been developed, exploiting the Ugi multicomponent reaction of phenol-containing simple substrates. The resulting library of compounds has been tested for its capacity to inhibit β-amyloid protein aggregation, as a possible strategy to develop new chemical entities to be used as prevention or therapy for Alzheimer's disease. Some of the members of this library have demonstrated, in thioflavin assays, a highly promising activity in inhibiting aggregation for two β-amyloid peptides: Aβ1-42 and the truncated AβpE3-42.

Phenolic compounds of ethanol extracts of Lemna minor L., Lemna trisulca L. and Lemna polyrrhiza L. Schleid and their immunomodulating activity

The purpose of the study is to determine the composition of the phenolic compounds of ethanol extracts isolated from three species of duckweed: Lemna minor L., Lemna trisulca L. and Lemna polyrrhiza L. (the synonym is Spirodella polyrrhiza Schleid.) and to study its effect on immune system activation. Materials and methods. The objects of the study are: air-dried grass samples of Lemna minor L., Lemna trisuica L. and Lemna polyrrhiza L. collected during their growing season in 2010–2011 in low-flow and stagnant ponds of Kozhevnikovsky and Tomsk districts of Tomsk region. Isolation of polyphenolic complexes (PFC) was carried out by extraction of air-dried raw material with ethyl alcohol. In qualitative and quantitative analysis of the samples studied the method of reversed-phase high-performance liquid chromatography on an Agilent 1100 Series instrument (USA) was used in isocratic mode. In the experiments, 200 male C57BL / 6 and BALB / C mice aged 8–12 weeks were used to determine immunomodulatory activity. Cell proliferation was assessed by a colorimetric method. The absorption of the obtained solutions was measured with a multi-channel spectrophotometer at the wavelength of 540 nm. The determination of antibody-forming cells in the spleen was performed by local hemolysis. The titer of antibodies in serum was evaluated in the hemagglutination reaction. The local hypersensitivity reaction of immediate type was assessed by the author’s modification. Results. For the first time the study of the qualitative composition and quantitative content of PFC of Lemna minor L. (LM) , Lemna trisulca L. (LT) trisulkas, and Lemna polyrrhiza L. (LP) : (4,7 ± 0,4)%, (3,3 ± 0,3)%, (12,8 ± 0,7)% was carried out. The highest content of phenolic acids (10,76%) and the sum of flavonoids, isoflavonoids and coumarins (14,7%) were found in the LP sample. The content of chlorogenic and 3,5-dihydroxybenzoic acids was 2–9 times higher in LP than in other species of duckweed. In LM and LT with concentrations of 5 μg/ml and LP in the range of 0,5–160 μg/ml did not have a toxic effect on antigen presenting cells. When incubated with LT (20 μg/ml), the proliferation of macrophages was reduced by 1,2 times, and when incubated with LM and LT (80 μg/ml), by 1,2 and 1,8 times, respectively. PFC duckweed (LP) did not have a similar effect. LM and LP had a stimulating effect on the production of nitrites in the concentrations of 5 and 20 μg/ml, increasing it by 1,3–1,6 times. Course introduction of LT and LP led to a significant decrease in the number of antibody-forming cells by 1,5 and 2,3 times and a decrease in the local hypersensitivity reaction by 1,9 and 1,5 times, respectively.

웅포산 홍차의 미백 활성 효과

Black tea is one of the most popular fancy drinks in the world. Black tea commonly referred to as oxidative fermented tea . In the oxidative fermented phase, simple phenolics converse into more complex polyphenols such as theaflavins and thearubigins. Recently, the consumption of black tea has increased in Korea. Even though, various compositions and biological effects have been researched about black teas produced in Korea, there have not been evaluated about black tea of Ungpo region, Korea.&#x0D; In this study, to evaluate the whitening effect black tea of Ungpo region, tyrosinase activities, melanin contents assay and the mRNA expression of microphthalmia-associated transcription factor(MIFF), tyrosinase-related protein(TRP)-1, and TRP-2 in B16F10 melanoma cells were performed with 50% ethanol extract of Black tea(BTE). BTE showed inhibitory effects of melanin contents and tyrosinase activity in α-MSH stimulated-B16F10 melanoma cells. The effects of BTE increased in a dose-dependent manner. BTE also suppressed the MITF, TRP-1 and TRP-2 mRNA levels which were associated with tyrosin synthesis in a dose-dependent manner. Especially, the protein levels of MITF and TRP-2 by 250 μ g/mL of BTE were lower than them by Kokic acid(100 μg/mL).&#x0D; These results indicate that the whitening effects of BTE is due to suppression of tyrosinase activities, melanogenesis, mRNA, and protein levels associated with melanin synthesis. In the conclusion, BTE could be used as an important material for the cosmeceutical industry and inner beauty fields utilizing the property of whitening.

Effect of chromium(III) gallate complex on stabilization of collagen

To improve the stability of the collagen, here we studied the interaction of chromium(III) polyphenolic complex, [Cr(GA)2] (GA: Gallic acid) with collagen using various spectroscopic techniques. Circular dichroism studies show that the [Cr(GA)2] and gallic acid did not induce any structural perturbations on the triple helix of the collagen. Both differential scanning calorimetric(DSC) data and micro-shrinkage temperature studies showed that [Cr(GA)2] stabilized the collagen by 6±1°C compared to gallic acid. Hydrodynamic studies revealed that the viscosity of collagen drastically reduced in the presence of [Cr(GA)2] while gallic acid did not. Fibrillation assay displayed a significant delay in fibril formation with Cr(III) complex compared to gallic acid treated collagen. The inhibition of fibril formation was further confirmed by microscopic data in which collagen fibres are seen with GA while [Cr(GA)2] treated collagen exhibit a thin microfibrils. From AFM studies, the d-periodicity of collagen was found to be decreased with [Cr(GA)2] while increased with gallic acid. The present study deliberate the advantage of metal complex containing polyphenolic ligand as crosslinking agent due to its synergistic effect of both metal center as well as polyphenolic groups in the stabilization of collagen structure.

Radical route to resveratrol oligomers

Resveratrol—made famous by its presence in red wine—has been touted for its health benefits. Oligomers of the compound may have even more promising medicinal properties, as they exhibit anti-inflammatory, immunomodulatory, and cytotoxic activities in cell studies. But getting enough of these complex polyphenols to study their mechanisms of action has been challenging. Chemists led by the University of Michigan’s Corey Stephenson and the University of Ottawa’s Derek Pratt now report a stereoconvergent synthesis of the resveratrol tetramers nepalensinol B and vateriaphenol C in 13 steps (Science 2016, DOI: 10.1126/science.aaj1597). Their strategy makes use of a persistent radical (shown) that’s derived from the resveratrol dimer, e-viniferin. “Persistent free radicals have become indispensable in the synthesis of organic materials through living radical polymerization,” the chemists point out in the report. “However, examples of their use in the synthesis of small molecules are rare.” Stephenson and Pratt n...

Extraction of cocoa proanthocyanidins and their fractionation by sequential centrifugal partition chromatography and gel permeation chromatography.

Cocoa beans contain secondary metabolites ranging from simple alkaloids to complex polyphenols with most of them believed to possess significant health benefits. The increasing interest in these health effects has prompted the need to develop techniques for their extraction, fractionation, separation, and analysis. This work provides an update on analytical procedures with a focus on establishing a gentle extraction technique. Cocoa beans were finely ground to an average particle size of <100μm, defatted at 20°C using n-hexane, and extracted three times with 50% aqueous acetone at 50°C. Determination of the total phenolic content was done using the Folin-Ciocalteu assay, the concentration of individual polyphenols was analyzed by electrospray ionization high performance liquid chromatography-mass spectrometry (ESI-HPLC/MS). Fractions of bioactive compounds were separated by combining sequential centrifugal partition chromatography (SCPC) and gel permeation column chromatography using Sephadex LH-20. For SCPC, a two-phase solvent system consisting of ethyl acetate/n-butanol/water (4:1:5, v/v/v) was successfully applied for the separation of theobromine, caffeine, and representatives of the two main phenolic compound classes flavan-3-ols and flavonols. Gel permeation chromatography on Sephadex LH-20 using a stepwise elution sequence with aqueous acetone has been shown for effectively separating individual flavan-3-ols. Separation was obtained for (-)-epicatechin, proanthocyanidin dimer B2, trimer C1, and tetramer cinnamtannin A2. The purity of alkaloids and phenolic compounds was determined by HPLC analysis and their chemical identity was confirmed by mass spectrometry.

Strategies to limit colour changes when fortifying food products with iron

Iron, vitamin A, zinc and iodine have been recognized to be the micronutrients with the largest deficiencies worldwide. Among these, iron is highly reactive and may lead to negatively perceived organoleptic changes in products such as dull colour and off-taste. The colour change originated in fortified fruit-containing food products was confirmed to be the result of the complexation of iron and polyphenols. Phenolic compounds with two or more vicinal hydroxy benzyl moieties in their structure, such as catechols and pyrogallols were investigated for their ability to give bathochromic shift phenomena when mixed with iron salts. Furthermore, strategies for limiting colour development were based on: 1) pH adjustment; 2) saturation of polyphenols with unreactive divalent metal ions; 3) suppression of iron reactivity through complexation. Some of these strategies showed a significant improvement in colour stability, with the best results achieved by the latter. The findings in model systems gave a good insight of the mechanisms involved in colour changes, and results were transferable to iron fortified banana puree.

Reduction of radiation-induced nitrative stress in leucocytes and kidney cells of rats upon administration of polyphenolic complex concentrates from red wine

The research has shown that exposure to ionizing radiation at the dose of 30 cGy leads to the activation of NO-synthase way of nitrogen oxide synthesis, as well as to the accumulation of its stable metabolites and 3’-nitrotyrosine modified proteins in rat peripheral blood leucocytes and the renal cortical layer. NO-synthase activity was preserved at the control value through the consumption of red wine natural polyphenolic complex concentrates by the irradiated animals. The content of proteins modified by tyrosine nitration decreased in the early period of post-radiation exposure due to the influence of the investigated concentrate. Thus the ability of red wine natural polyphenolic complex concentrates to prevent adverse changes in L-arginine/NO system and, therefore, inhibit the development of nitrative stress induced by low doses of ionizing radiation has been proved experimentally.

Heterogeneous photodegradation of methylene blue with iron and tea or coffee polyphenols in aqueous solutions.

Recently, we developed two new Fenton catalysts using iron (Fe) and spent tea leaves or coffee grounds as raw material. In this study, Fe-to-tea or Fe-to-coffee polyphenol complexes were successfully tested as heterogeneous photo-Fenton catalysts. The photodegradation efficiency of methylene blue solutions with Fe-to-polyphenol complexes was higher than that of homogeneous iron salts in the photo-Fenton process. Furthermore, the tested Fe-to-polyphenol complexes could be reused by simply adding H2O2 to the solutions. After three sequential additions of H2O2, the conventional catalysts FeCl2·4H2O and FeCl3 removed only 16.6% and 53.6% of the dye, while the catalysts made using spent coffee grounds and tea leaves removed 94.4% and 96.0% of the dye, respectively. These results showed that the complexes formed between Fe and chlorogenic acid, caffeic acid, gallic acid and catechin, which are the main polyphenols in tea and coffee, can be used to improve the photo-Fenton process.