Complex Polyphenols Research Articles

Unraveling the performance of dispersion-corrected functionals for the accurate description of weakly bound natural polyphenols.

Long-range non-covalent interactions play a key role in the chemistry of natural polyphenols. We have previously proposed a description of supramolecular polyphenol complexes by the B3P86 density functional coupled with some corrections for dispersion. We couple here the B3P86 functional with the D3 correction for dispersion, assessing systematically the accuracy of the new B3P86-D3 model using for that the well-known S66, HB23, NCCE31, and S12L datasets for non-covalent interactions. Furthermore, the association energies of these complexes were carefully compared to those obtained by other dispersion-corrected functionals, such as B(3)LYP-D3, BP86-D3 or B3P86-NL. Finally, this set of models were also applied to a database composed of seven non-covalent polyphenol complexes of the most interest. Graphical abstract Weakly bound natural polyphenolsᅟ.

Abstract B29: Improving the efficacy of dendritic cell-based human papillomavirus vaccines in mice using a natural lignin-carbohydrate complex and/or synthetic lignin-like polyphenol polymers

Abstract Immunization with dendritic cell (DC)-based vaccines is a promising vaccination strategy to provide an effective personalized immunotherapy against cancer and other diseases. However, the results of clinical cancer immunotherapy trials carried out using DC-based vaccines to date have shown only modest clinical outcomes. We have previously demonstrated that a polyphenylpropenoid-polysaccharide complex (PPC), a lignin-carbohydrate complex derived from the cones of Pinus sylvestris, induces in vitro the differentiation and maturation of human mononuclear cell-derived DCs (Bradley et al., Int Immunopharmacol 2003;3) and murine bone marrow-derived DCs (BMDCs) (An et al., Anticancer Res 2010;30). Furthermore, oral administration of PPC enhanced a DC vaccine-induced melanoma antigen-specific CD8+ T-cell response (Burrows et al., BMC Complement Altern Med 2009;9) and the proliferative phase of a primary T cell response (Bradley et al., BMC Complement Altern Med 2014;14). In the present study, using a human papillomavirus (HPV)-induced mouse tumor model, we investigated whether ex vivo treatment of BMDCs with the synthetic lignin-like polyphenol polymers poly-caffeic acid (pCA) and poly-coumaric acid (pCoA), as well as PPC, improves the efficacy of DC-based vaccines. Polymerization of the phenylpropenoic acids caffeic acid (CA) and poly-coumaric acid (CoA) was performed by horseradish peroxidase/hydrogen peroxide-mediated enzymatic reactions. BMDCs were prepared by culturing murine bone marrow cells in the presence of GM-CSF for 8-10 days. These BMDCs were pulsed with synthetic tumor antigen peptides HPV16 E743-62 or HPV16 E743-77 that contain both a cytotoxic T lymphocyte (CTL) and a helper T cell epitope. Peptide-pulsed DCs were treated further ex vivo with synthetic polyphenol polymers or PPC and then injected twice into C57BL/6 mice. In addition, splenocytes obtained from immunized mice were restimulated with HPV16 E749-57 peptide (E7 CTL epitope) for 5 days. Tumor antigen-specific CD8+ T cell responses were assessed by HPV16 E749-57/H-2Db pentamer staining. We observed that immunization with PPC-treated HPV16 E743-77 peptide-loaded BMDCs significantly enhanced the induction of pentamer-positive CD8 positive cells in splenocytes (2- to 3-fold increase). Moreover, ex vivo restimulation with E7 CTL epitope peptide dramatically increased the number of pentamer-positive CD8 positive cells in splenocytes obtained from mice immunized with PPC-treated, peptide-loaded DCs (6- to 7-fold increase) when compared to splenocytes from mice immunized with PPC-nontreated, peptide-loaded DCs. Experiments using pCA and pCoA are in progress. We conclude that 1) ex vivo treatment with the natural PPC complex significantly potentiates the in vivo efficacy of DC-based HPV vaccines and 2) tumor antigen-specific CD8+ T cells are significantly expanded ex vivo by restimulating splenocytes from mice primed in vivo with PPC-treated, peptide-loaded BMDCs. In addition, our preliminary studies show that PPC, pCA and pCoA significantly increase the expression levels of CD8α, XCR1 and/or CLEC9A on murine BMDCs that have been demonstrated to be essential for the induction of CTL responses. Our approaches will provide innovative strategies for the design of more effective DC-based vaccines and adaptive T-cell therapies for the treatment of patients with cancer and other immune disorders. Citation Format: Soichi Haraguchi, Tina Pastoor, William Guy Bradley, Akiko Tanaka. Improving the efficacy of dendritic cell-based human papillomavirus vaccines in mice using a natural lignin-carbohydrate complex and/or synthetic lignin-like polyphenol polymers. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr B29.

Colloidal complexation of zein hydrolysate with tannic acid: Constructing peptides-based nanoemulsions for alga oil delivery

Colloidal complexation of zein hydrolysate (ZH) with tannic acid (TA) and the possibility of using the ZH-TA complex to construct a nanoemulsion system for alga oil delivery were investigated. Turbidity and fluorescence titration measurements demonstrated the complexation of ZH with TA, which leads to the formation of ZH-TA complex. Isothermal titration calorimetry further confirmed the complexation between ZH and TA was driven by the non-covalent interaction (e.g. hydrophobic interaction and hydrogen bonding). The emulsifying activity of ZH was considerably improved after the complexation with TA, which was responsible for the fabrication of alga oil nanoemulsions (d = 120 nm). The emulsions stabilized by the ZH-TA complex showed a remarkable physical stability and high alga oil encapsulation efficiency. More importantly, the complexation of ZH with TA also endowed ZH-TA complex with high antioxidative properties. The alga oil nanoemulsions stabilized by ZH-TA complex showed an increased oxidative stability with reduced lipid hydroperoxides and volatile hexanal compared with that of stabilized by ZH alone. This study demonstrated that ZH-TA complex could be employed as an emulsifier in constructing a physical stable nanoemulsion delivery system, and opens up the possibility of utilizing peptides–polyphenol complex as efficient emulsifiers to improve the oxidative stability of O/W nanoemulsions.

Locating the binding sites of antioxidants resveratrol, genistein and curcumin with tRNA

We located the binding sites of antioxidants resveratrol, genistein and curcumin on tRNA in aqueous solution at physiological conditions using constant tRNA concentration and various polyphenol contents. FTIR, UV–visible, CD spectroscopic methods and molecular modeling were used to determine polyphenol binding sites, the binding constant and the effects of polyphenol complexation on tRNA conformation and particle formation. Structural analysis showed that polyphenols bind tRNA via G-C and A-U base pairs through hydrophilic, hydrophobic and H-bonding contacts with overall binding constants of Kres–tRNA=8.95(±0.80)×103M−1, Kgen–tRNA=3.07(±0.5)×103M−1 and Kcur–tRNA=1.55(±0.3)×104M−1. Molecular modeling showed the participation of several nucleobases in polyphenol–tRNA adduct formation with free binding energy of −4.43 for resveratrol, −4.26kcal/mol for genistein and −4.84kcal/mol for curcumin, indicating that the interaction process is spontaneous at room temperature. While tRNA remains in A-family structure, major biopolymer aggregation and particle formation occurred at high polyphenol contents.

Low flammability foam-like materials based on epoxy, tannic acid, and sodium montmorillonite clay

Aerogels based on sodium montmorillonite clay, epoxy polymer, and tannic acid as a flame retardant additive were fabricated through a simple, environmentally friendly freeze-drying process in which water is used as solvent. A one-step coating method using a coordination complex of natural polyphenols and Fe(III) ions was examined. Both the blended and the coated aerogels exhibit low flammabilities (the parameters measured are the time to ignition, the critical heat flux for ignition, and the heat release rate); the effects of tannic acid upon the aerogel compressive mechanical properties are reported.

Characterization of iron–polyphenol complex nanoparticles synthesized by Sage (Salvia officinalis) leaves

Abstract In this paper iron–polyphenol complex nanoparticles (Fe–P NPs) were synthesized by Sage ( Salvia officinalis ) leaf extract, which have excellent adsorptive-flocculation capacity for water treatment. They were characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) so that their surface properties could be understood. It was found that synthesized Fe–P NPs were cross-linked in colloid with spherical particles ranged from 5 to 25 nm. Their surfaces were capped with O–H groups. Dried powder derived from Fe–P NPs colloid can remain stable after several hours and then be partially oxidized to iron oxide on exposure to air. Removal of cationic dye ethyl violet with Fe–P NPs was tested to confirm that the surface charge on Fe–P NPs is positive.

Fate of humic acids isolated from natural humic substances

Composition of humic acids (HA) is a function of plant-derived inputs, degradation processes regulated by microorganisms, organo-mineral interactions and age. Characterization of different origin humic substances is important for evaluation of their contribution to stabile and labile carbon pool in the environment. The relative abundance of chemical components in HA isolated from soils, compost, commercial lignohumates, alginite, acadiane and lignite was studied with aim to quantify content of important biomarkers such as amino acid, lipids and polyphenols. HA were considered as a heterogeneous complex and high concentration of peptides, polyphenols and lipids was determined in acadian-HA to compare with soil-HA. Compost-HA contained much more amino acids to compare with soil-HA samples. Alginite-HA and lignite-HA were similar in biomarkers content to soil-HA. Fourier transform infrared spectroscopy confirmed that chemical composition and functional groups content differs with the origin, humification degree and the age of studied samples. Soil-HA are typically composed of a variety of −OH, COOH−, C–O, C–H2, (aliphatic and aromatic) groups, quinines, lignin fragments, polysaccharide, monosaccharide and proteins fragments, which are linked together by −O−, −NH−, −H=, >C=O, metal ions and –S− groups. 13C NMR spectroscopy showed that aromatic carbon content was the highest in lignite-HA and soil-HA.

Fabrication of a Superhydrophobic, Fire-Resistant, and Mechanical Robust Sponge upon Polyphenol Chemistry for Efficiently Absorbing Oils/Organic Solvents

In this study, a superhydrophobic, fire-resistant, and mechanical robust sponge was fabricated through a two-step polyphenol chemistry strategy for efficiently absorbing oils/organic solvents (rapidness in absorption rate and large quantity in absorption capacity). Specifically, the Fe(III)–polyphenol complex is formed upon the metal–organic coordination between tannic acid (TA, a typical polyphenol) and Fe(III) ions, which is spontaneously coated on the surface of the pristine melamine sponge. Then, free catechol groups in the polyphenol are applied for grafting 1-dodecanethiol, thus generating the superhydrophobic sponge. Several characterizations have confirmed the chemical/topological structures, superhydrophobicity, fire-resistant merits, and mechanical robust property of the sponge. As a result, this sponge exhibits excellent absorption capacities of oils/organic solvents up to 69–176 times its own weight, indicating promising sorbents for removing oily pollutants from water. Meanwhile, owing to the facile fabrication process and inexpensive/easy available raw materials, the large-scale production of this sponge will be convenient and cost-effective.

Improving oxidative stability of peanut oil under microwave treatment and deep fat frying by stearic acid–surfacant–tea polyphenols complex

In this work we present a study of the influence of a stearic acid–surfactant–tea polyphenols complex (SSTC) on the oxidative and thermal stability of peanut oil under microwave heating and simulated deep fat frying. Changes of the quality parameters of all oil samples containing different SSTCs were very obvious, compared with those of pure peanut oil. Especially for the oil sample containing SSTC‐P, the p‐anisidine value decreased 48.89% and 14.90% after microwave heating and simulated deep fat frying. For K232, it decreased 36.90% and 33.18%, respectively. By GS–MS analysis, the content of unsaturated fatty acids in peanut oil containing SSTC‐P was 8.7 times more than that in pure peanut oil after microwave treatment. As an efficient food antioxidant, the self‐assembled complex of tea polyphenols in edible oil prepared by this novel method may have great market potential.Practical applications: Oxidation processes are one of the major problems encountered in oil consumption and storage. The addition of natural antioxidants is a major way to inhibit oxidation processes in edible oils. Tea polyphenols are excellent source of phenolic compounds, which have been reported to show good antioxidant activity. The results of this study suggest that oil‐soluble tea polyphenols can be prepared based on a stearic acid–surfactant–tea polyphenols complex. The dispersion of SSTC into peanut oil can improve oxidative and thermal stability of edible oil. Therefore, the complex of tea polyphenols in edible oil may have great market potential of food antioxidant.Tea polyphenols solution was used as the aqueous phase. Stearic acid containing appropriate amount of surfactant were poured into a 50 mL centrifuge tube, and kept in a water bath maintained at 80°C and stirred at 500 rpm until a homogeneous clear solution was obtained. Then, the aqueous phase and the oil phase were mixed using a homogenizer at 26 000 rpm for 2 min to form a stable W/O emulsion. The resulting emulsion was frozen rapidly in liquid nitrogen, and lyophilized using a freeze‐drying machine for 48 h. Finally, all of the stearic acid–surfactant–tea polyphenols complexes (SSTC) were obtained. The SSTC was dispersed in peanut oil. Oxidation products of the oil sample were analyzed by GC–MS under microwave heating.

Phenolic sulfates as new and highly abundant metabolites in human plasma after ingestion of a mixed berry fruit purée.

Bioavailability studies are vital to assess the potential impact of bioactive compounds on human health. Although conjugated phenolic metabolites derived from colonic metabolism have been identified in the urine, the quantification and appearance of these compounds in plasma is less well studied. In this regard, it is important to further assess their potential biological activity in vivo. To address this gap, a cross-over intervention study with a mixed fruit purée (blueberry, blackberry, raspberry, strawberry tree fruit and Portuguese crowberry) and a standard polyphenol-free meal was conducted in thirteen volunteers (ten females and three males), who received each test meal once, and plasma metabolites were identified by HPLC-MS/MS. Sulfated compounds were chemically synthesised and used as standards to facilitate quantification. Gallic and caffeic acid conjugates were absorbed rapidly, reaching a maximum concentration between 1 and 2h. The concentrations of sulfated metabolites resulting from the colonic degradation of more complex polyphenols increased in plasma from 4h, and pyrogallol sulfate and catechol sulfate reached concentrations ranging from 5 to 20μm at 6h. In conclusion, phenolic sulfates reached high concentrations in plasma, as opposed to their undetected parent compounds. These compounds have potential use as biomarkers of polyphenol intake, and their biological activities need to be considered.

Stability and immunogenicity of hypoallergenic peanut protein-polyphenol complexes during in vitro pepsin digestion.

Allergenic peanut proteins are relatively resistant to digestion, and if digested, metabolized peptides tend to remain large and immunoreactive, triggering allergic reactions in sensitive individuals. In this study, the stability of hypoallergenic peanut protein-polyphenol complexes was evaluated during simulated in vitro gastric digestion. When digested with pepsin, the basic subunit of the peanut allergen Ara h 3 was more rapidly hydrolyzed in peanut protein-cranberry or green tea polyphenol complexes compared to uncomplexed peanut flour. Ara h 2 was also hydrolyzed more quickly in the peanut protein-cranberry polyphenol complex than in uncomplexed peanut flour. Peptides from peanut protein-cranberry polyphenol complexes and peanut protein-green tea polyphenol complexes were substantially less immunoreactive (based on their capacity to bind to peanut-specific IgE from patient plasma) compared to peptides from uncomplexed peanut flour. These results suggest that peanut protein-polyphenol complexes may be less immunoreactive passing through the digestive tract in vivo, contributing to their attenuated allergenicity.

Protocatechuic Acid Prevents oxLDL-Induced Apoptosis by Activating JNK/Nrf2 Survival Signals in Macrophages.

Protocatechuic acid (PCA), one of the main metabolites of complex polyphenols, exerts numerous biological activities including antiapoptotic, anti-inflammatory, and antiatherosclerotic effects. Oxidised LDL have atherogenic properties by damaging arterial wall cells and inducing p53-dependent apoptosis in macrophages. This study was aimed at defining the molecular mechanism responsible for the protective effects of PCA against oxidative and proapoptotic damage exerted by oxLDL in J774 A.1 macrophages. We found that the presence of PCA in cells treated with oxLDL completely inhibited the p53-dependent apoptosis induced by oxLDL. PCA decreased oxLDL-induced ROS overproduction and in particular prevented the early increase of ROS. This decrease seemed to be the main signal responsible for maintaining the intracellular redox homeostasis hindering the activation of p53 induced by ROS, p38MAPK, and PKCδ. Consequently the overexpression of the proapoptotic p53-target genes such as p66Shc protein did not occur. Finally, we demonstrated that PCA induced the activation of JNK, which, in turn, determined the increase of nuclear Nrf2, leading to inhibition of the early ROS overproduction. We concluded that the antiapoptotic mechanism of PCA was most likely related to the activation of the JNK-mediated survival signals that strengthen the cellular antioxidant defences rather than to the PCA antioxidant power.

Chemical composition and biological activity of Rubus idaeus shoots--a traditional herbal remedy of Eastern Europe.

BackgroundThe young shoots of Rubus idaeus are traditionally used as a herbal remedy in common cold, fever and flu-like infections yet there is no research concerning this plant material. The aim of the study was to evaluate the chemical composition and biological properties of raspberry shoots from 11 cultivar varieties.MethodsThe methanol extracts were subjected to chromatographic analysis using HPLC-DAD-ESI-MS, and two-dimensional ‘comprehensive’ LCxLC techniques. The biological activity of the shoot extract from the ‘Willamette’ cultivar variety was evaluated. Antioxidant activity was tested using DPPH and phosphomolybdenum assay. Antimicrobial activity was estimated towards 15 strains of human pathogenic bacteria using broth microdilution method. Cytotoxic activity was tested using MTT cell viability assay.ResultsThe dominating compounds identified in the shoots of R. idaeus were ellagic acid (26.1 - 106.8 mg/100 g) and sanguiin H-6 (139.2 - 633.1 mg/100 g). The best separation of compounds present in the analysed polyphenol complex, was achieved by ‘comprehensive’ LCxLC method using Nucleodur Sphinx RP column in the first dimension and Chromolith Performance column in the second dimension. The shoot extract was found to be a strong antioxidant (EC50 19.4 μg/ml, AAE 427.94 mg/g) and displayed the strongest bactericidal properties towards Corynebacterium diphtheriae. The extract revealed higher cytotoxic activity towards the HL-60 cells (IC50 110 μg/ml) than HeLa (IC50 300 μg/ml).ConclusionsThe shoots of R. idaeus stand out as a valuable source of sanguiin H-6 and ellagic acid and possess a number of biological properties including antioxidative, antimicrobial and cytotoxic.

Computer-aided discovery of biological activity spectra for anti-aging and anti-cancer olive oil oleuropeins.

Aging is associated with common conditions, including cancer, diabetes, cardiovascular disease, and Alzheimer's disease. The type of multi-targeted pharmacological approach necessary to address a complex multifaceted disease such as aging might take advantage of pleiotropic natural polyphenols affecting a wide variety of biological processes. We have recently postulated that the secoiridoids oleuropein aglycone (OA) and decarboxymethyl oleuropein aglycone (DOA), two complex polyphenols present in health-promoting extra virgin olive oil (EVOO), might constitute a new family of plant-produced gerosuppressant agents. This paper describes an analysis of the biological activity spectra (BAS) of OA and DOA using PASS (Prediction of Activity Spectra for Substances) software. PASS can predict thousands of biological activities, as the BAS of a compound is an intrinsic property that is largely dependent on the compound's structure and reflects pharmacological effects, physiological and biochemical mechanisms of action, and specific toxicities. Using Pharmaexpert, a tool that analyzes the PASS-predicted BAS of substances based on thousands of "mechanism-effect" and "effect-mechanism" relationships, we illuminate hypothesis-generating pharmacological effects, mechanisms of action, and targets that might underlie the anti-aging/anti-cancer activities of the gerosuppressant EVOO oleuropeins.

1H-NMR as a structural and analytical tool of intra- and intermolecular hydrogen bonds of phenol-containing natural products and model compounds.

Experimental parameters that influence the resolution of 1H-NMR phenol OH signals are critically evaluated with emphasis on the effects of pH, temperature and nature of the solvents. Extremely sharp peaks (Δν1/2 ≤ 2 Hz) can be obtained under optimized experimental conditions which allow the application of 1H-13C HMBC-NMR experiments to reveal long range coupling constants of hydroxyl protons and, thus, to provide unequivocal assignment of the OH signals even in cases of complex polyphenol natural products. Intramolecular and intermolecular hydrogen bonds have a very significant effect on 1H OH chemical shifts which cover a region from 4.5 up to 19 ppm. Solvent effects on –OH proton chemical shifts, temperature coefficients (Δδ/ΔT), OH diffusion coefficients, and nJ(13C, O1H) coupling constants are evaluated as indicators of hydrogen bonding and solvation state of phenol –OH groups. Accurate 1H chemical shifts of the OH groups can be calculated using a combination of DFT and discrete solute-solvent hydrogen bond interaction at relatively inexpensive levels of theory, namely, DFT/B3LYP/6-311++G (2d,p). Excellent correlations between experimental 1H chemical shifts and those calculated at the ab initio level can provide a method of primary interest in order to obtain structural and conformational description of solute-solvent interactions at a molecular level. The use of the high resolution phenol hydroxyl group 1H-NMR spectral region provides a general method for the analysis of complex plant extracts without the need for the isolation of the individual components.

Migration of phenolic compounds from different cork stoppers to wine model solutions: antioxidant and biological relevance

Considering the enological interest of cork, this study aimed to identify and quantify the phenolic compounds able to migrate from different classes (natural cork stoppers “Flor” and “Third” quality and microagglomerate cork stopper) of cork stoppers into bottled wine model solutions. Another aim was to evaluate some antioxidant and biological features of cork phenolics that migrated into the wine model solutions. The main phenolic acids and aldehydes detected were as follows: gallic and protocatechuic acid detected both around 3.5 mg/L and vanillin and protocatechuic aldehyde detected around 2.5 and 1.5 mg/L after 27 months of bottling, respectively. Trace amounts of more complex polyphenols, namely hydrolysable tannins (castalagin/vescalagin and mongolicain A/B), were also detected. Two antioxidant features of the wine model solutions bottled with different wine cork stoppers were studied, namely the antiradical capacity and the reducing capacity, being the natural cork stoppers the ones with the higher activities. The intestinal absorption of the compounds in each wine model solution after 27 months in bottled was evaluated. The simpler phenolic compounds were able to cross Caco-2 cell model. The antiproliferative activity of the same wine model solutions was also evaluated against gastric and breast cancer cells. All samples were active against the two cell lines, which highlight the possible health outcomes of wine sealed with cork stoppers.

The protective effects of a polyphenol-enriched protein powder on exercise-induced susceptibility to virus infection.

Prolonged and intensive exercise induces transient immunosuppression and is associated with an increased risk and severity of infections. The goal of this study was to characterize the antiviral and antibacterial properties of the bioactive metabolites of a blueberry-green tea-polyphenol soy protein complex (PSPC) in the serum of supplemented subjects during a 3-day intensified training period. Long-distance runners, randomly divided into two groups, ingested 40 g/day PSPC or placebo (soy protein and colorings) for 17 days, with a 3-day running period inserted at day 14. Blood serum samples were collected pre-14 days and post-14 days supplementation, and immediately and 14 h after the third day of running. The post-exercise serum from both groups significantly promoted the growth of Escherichia coli and Staphylococcus aureus in culture by 20-70%, but returned to normal levels following recovery. Furthermore, the serum from subjects ingesting PSPC did not display antibacterial properties at any time point. In contrast, there was a significant difference in the ability of serum from PSPC-supplemented versus placebo-supplemented athletes to protect cells in culture from killing by vesicular stomatitis virus following strenuous exercise. In addition, the serum of subjects who ingested PSPC significantly delayed an exercise-induced increase in virus replication. These results indicate that polyphenol complexes containing blueberry and green tea have the potential to protect athletes from virus infections following rigorous exercise.

Lipid Composition of the Birch Mushroom Inonotus obliquus

Inonotus obliquus (birch mushroom or chaga) is the sterile conk of the fungus. Preparations of chaga have been used in both folk and official medicine. Thus, the chaga preparation Befungin is described in the Russian pharmacopoeia. The basic composition of chaga preparations and characteristic water-soluble (pigment and polyphenol) complexes in addition to directions for the use of chaga preparations for oncological diseases were reported. Information on the chemical composition of I. obliquus, in particular its lipid composition, are exceedingly limited. A broad spectrum of activity was demonstrated for I. obliquus and its preparations [1–4]. Many researchers relate the effects of I. obliquus with compounds such as phenol complexes, polysaccharides, and melanin [4, 5]. We investigated the lipid composition of chaga because several of them also exhibit antitumor activities. They include glyceryl ethers (GE) [6, 7] and prostaglandins (PG) [8, 9]. There is also information that fungi, including I. obliquus, contain oxylipins [10]. The I. obliquus studied by us contained 1.25% total lipids. We found that the PG and lipid contents were subject to seasonal oscillations (depending on the collection time). Whereas the lipid content in autumn was 0.5%, it tripled in January and was 1.5%. Seasonal variations were also noted in the PG content. In October, PG was 0.9%; in January, 0.3%. The dependence was reverse of that of the lipids. Lipids from I. obliquus were analyzed by oneand two-dimensional TLC. The lipid extract contained neutral lipids such as diand triglycerides, phytosterols, fatty alcohols, free fatty acids (FA), and FA esters. Phosphoand glycolipids were not observed. According to the literature, I. obliquus exhibited antitumor activity [1, 5] that was related to a polysaccharide complex. The antitumor activity in the lipids was associated with GE [11]. The -GE were hydrocarbon derivatives of glycerin with an ether bond in the glycerin 1-position and were remarkable because one representative of this class, batyl alcohol, was described in the Russian pharmacopoeia as a radioprotective agent. Therefore, we determined the -GE content in the lipid extract of I. obliquus using the method proposed by us earlier [12]. The -GE made up 0.6% of the total lipids. The FA composition and content of I. obliquus are given below.

Stability and biological activity of wild blueberry (Vaccinium angustifolium) polyphenols during simulated in vitro gastrointestinal digestion

Wild blueberries are rich in polyphenols and have several potential health benefits. Understanding the factors that affect the bioaccessibility and bioavailability of polyphenols is important for evaluating their biological significance and efficacy as functional food ingredients. Since the bioavailability of polyphenols such as anthocyanins is generally low, it has been proposed that metabolites resulting during colonic fermentation may be the components that exert health benefits. In this study, an in vitro gastrointestinal model comprising sequential chemostat fermentation steps that simulate digestive conditions in the stomach, small intestine and colon was used to investigate the breakdown of blueberry polyphenols. The catabolic products were isolated and biological effects tested using a normal human colonic epithelial cell line (CRL 1790) and a human colorectal cancer cell line (HT 29). The results showed a high stability of total polyphenols and anthocyanins during simulated gastric digestion step with approximately 93% and 99% of recovery, respectively. Intestinal digestion decreased polyphenol- and anthocyanin- contents by 49% and 15%, respectively, by comparison to the non-digested samples. During chemostat fermentation that simulates colonic digestion, the complex polyphenol mixture was degraded to a limited number of phenolic compounds such as syringic, cinnamic, caffeic, and protocatechuic acids. Only acetylated anthocyanins were detected in low amounts after chemostat fermentation. The catabolites showed lowered antioxidant activity and cell growth inhibition potential. Results suggest that colonic fermentation may alter the biological activity of blueberry polyphenols.

Dye removal using iron–polyphenol complex nanoparticles synthesized by plant leaves

This paper examined the ability of iron–polyphenol complex nanoparticles (Fe–P NPs) synthesized by eucalyptus leaf extracts as a novel adsorptive flocculant to remove acid black 194 from aqueous solution. The influential parameters such as ratios of reagents, doses of Fe–P NPs, pH, temperatures and initial dye concentration were tested. The kinetics, experimental equilibrium and thermodynamic data for acid black 194 and Fe–P NPs systems were collected. The adsorption of dye on Fe–P NPs appears to be a physical process. This study confirms that removal of dye utilizing Fe–P NPs is more efficient than using traditional inorganic flocculant FeCl3. The Fe–P NPs could be employed as inexpensive and low-toxic adsorptive flocculant for removing dye from water.