Molecular Weight Determination Research Articles

Investigation of the chemical structure and analgesic and anti-inflammatory properties of polysaccharides that constitute the dietary fibers of soursop (Annona muricata) fruit

Soursop fruits are widely used in the folk medicine to treat a variety of health conditions. Once the chemical structure of dietary fibers from fruits is closely related to its biological functions in the human body, we aimed to explore structural features and biological activity of dietary fibers from soursop. Polysaccharides that constitute the soluble and insoluble fibers were extracted and further analyzed using monosaccharide composition, methylation, molecular weight determination and 13C NMR data. Soursop soluble fibers (SWa fraction) were characterized as having type II arabinogalactan and a highly methyl esterified homogalacturonan, while non-cellulosic insoluble fibers (SSKa fraction) were mainly composed by a pectic arabinan, a xylan-xyloglucan complex and a glucuronoxylan. The oral pre-treatment with SWa and SSKa promoted antinociception in mice writhing test, reducing the number of pain-like behaviors (in 84.2 % and 46.9 %, respectively, at 10 mg/kg) and peritoneal leucocyte migration (55.4 % and 59.1 %, at 10 mg/kg), effects possibly associated with the pectins present in fruit pulp extractions. SWa also significantly inhibited the plasmatic extravasation of Evans blue dye in 39.6 % at 10 mg/kg. This paper describes for the first time the structural features of soursop dietary fibers that may be of biological significance in future.

Preparation, Structural Characterisation, and Bioactivities of Fructans: A Review

Polysaccharides are important components of higher plants and have attracted increasing attention due to their many nutraceutical benefits in humans. Fructans, heterogeneous fructose polymers that serve as storage carbohydrates in various plants, represent one of the most important types of natural polysaccharides. Fructans have various physiological and therapeutic effects, which are beneficial to health, and have the ability to prevent or treat various diseases, allowing their wide use in the food, nutraceutical, and pharmaceutical industries. This article reviews the occurrence, metabolism, preparation, characterisation, analysis, and bioactivity of fructans. Further, their molecular weight, monosaccharide composition, linkages, and structural determination are described. Taken together, this review provides a theoretical foundation for further research into the structure-function relationships of fructans, as well as valuable new information and directions for further research and application of fructans in functional foods.

Effect of retting methods on molecular weight of Agave atroverance fibers

This study was undertaken to investigate the effect of retting method on the molecular weight of different portion of the Agave atroverance fiber (top, middle and bottom) extracted by different retting techniques. The raw fibers from Agave atroverance plant were retted by biological and chemical (degumming) retting methods. In biological retting method both the stagnant and boil water were utilized and in chemical retting method, the extracted fibres were treated with the 5% NaOH. Agave atroverance fiber is not purely cellulosic fiber. Percentage composition of different portion of the raw fiber was also determined. It contains α-cellulose, hemicellulose, nitrogenous matter, mineral matters and miscellaneous. The retted fibres were tested for determination of molecular weight. The percentage loss of molecular weight was found to be more in case of chemically retted fibres owing to the enhanced digestibility of lignocellulosic material by 4% sodium chlorite solution. Contrary to this, biological retting showed higher molecular weight due to the presence of higher cellulosic matter and removal of pectic substabces.

An innovative method for highly-efficient fabrication of carbon fiber precursors via acrylonitrile emulsion copolymerization coupled to a chemical oscillator

A new synthetic protocol to produce the carbon fiber precursor polyacrylonitrile (PAN) and its block copolymers with polyethylene glycol (PEG) is proposed here. The constant flux of radical species produced at low concentrations during the oscillating Belousov-Zhabotinsky (BZ) reaction was properly exploited to initiate the radical polymerization reaction. Compared with conventional methods, this oscillating initiation decreases the probability of chain termination, thus favouring the production of high molecular weight polymers, and it does not require an inert atmosphere and elevated temperatures to be produced. The solubility of the polymeric chains during the polymerization reaction was improved by adding the anionic micelle-forming surfactant sodium dodecyl sulphate (SDS). Following the initiation step, short oligomer chains are able to overcome the micellar interface, thereby reaching a favourable environment for the increase of the polymeric chains, thus strongly contributing to the increase of the molecular weight of the fibers’ precursors. The synthesis was conducted by adding the monomer acrylonitrile (AN) to the unperturbed and PEG-perturbed BZ system after the onset of the oscillations, in the absence and presence of increasing amounts of the SDS surfactant. The potentiometric technique was utilized to detect the dynamics of the oscillatory reaction. Preliminarily, the response of the BZ system to the monomer addition was investigated. Additional information was provided from the study of the effect of the SDS and PEG concentration on the dynamics of the BZ reaction during AN polymerization, thus obtaining a deepening in the understanding of the BZ mechanism. The characterization of the obtained polymers and copolymers, by melting point measurements, molecular weight determinations, Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) analyses, and thermal treatments, indicated that the proposed synthetic method produces carbon fiber precursors with high molecular weight and good thermal stability. The addition of the surfactant was revealed as a good method to improve and/or finely tune the precursor molecular weight. The proposed synthetic protocol represents a valuable alternative to conventional methods to produce high-performant precursors of carbon fibers.

Exo-polygalacturonase production enhancement by Piriformospora indica from sugar beet pulp under submerged fermentation using the response surface methodology.

This study proposed a novel and cost-effective approach to enhance and optimize the exo-polygalacturonase from P. indica, a root endophytic fungus. In the current investigation, the impact of ammonium sulfate, sugar beet pulp (SBP), and glucose as variables on induction of exo-polygalacturonase from P. indica was optimized using the central composite design (CCD) of response surface methodology (RSM) under submerged fermentation (SmF). Additionally, determination of the exo-polygalacturonase molecular weight and in situ analysis was performed. The optimal reaction conditions, which resulted in the highest enzyme activity, were observed in the following conditions: ammonium sulfate (4g/L), SBP (20g/L), and glucose (60g/L). Under the optimized condition, the maximum enzyme activity reached 19.4U/ml (127U/mg), which increased by 5.84 times compared to non-optimized conditions. The exo-polygalacturonase molecular weight was estimated at 60 KDa. In line with the bioinformatic analysis, the exo-polygalacturonase sequence of P. indica showed similarity with Rhizoctonia solani's and Thanateporus cucumeris. These results indicated that SBP acts as a cheap and suitable inducer of exo-polygalacturonase production by P. indica in submerged cultivation. The outcome of this study will be useful for industries to decrease environmental pollution with cost-effective approaches.

Production of Two Novel Polyketide Pigments by Fusarium chlamydosporum

Aim: The aim of the present study was to evaluate the pigment production by the fungus Fusarium chlamydosporum in Glucose Peptone Yeast Extract medium and further to assess its toxicity by in vitro methods. Materials and Methods: The coloured crude extract yielded 4 fractions when subjected to column chromatography, upon which Fraction 2 and 4 were subjected to characterization procedures by UV-Visible spectrophotometry, Fourier Transform Infrared Spectroscopy and Molecular weight determination by Liquid Chromatography Mass Spectroscopy (LCMS). The toxicity of the pigments was evaluated in vitro on L-929 Mouse Fibroblast cell lines by MTT Assay. Results: The fungus produced dark red pigment in Glucose Peptone Yeast Extract medium on extraction with ice cold chloroform. The results summarized Fraction 2 and 4 to be the polyketide derivatives, Rubrofusarin and 8-O-methyl fusarubin respectively wherein the IC50 values of rubrofusarin and 8-O-methyl fusarubin was 183.85 and 82.366 μg/ml respectively. Conclusion: The significance of the present study lies in the characterization of 2 novel polyketides, rubrofusarin and 8-O-methyl fusarubin from F. chlamydosporum and there have been no literature reviews on the production of these pigments from the fungus.

Biologically important 26-32-membered macrocyclic complexes of manganese (II): In situ one pot template synthesis (IOPTS), characterization and bio-efficacy

Twenty six to thirty two membered tetraazamacrocyclic complexes of manganese (II) have been synthesized by template condensation of MnCl2.4H2O with dicarboxylic acid (malonic, succinic, glutaric or adipic acid) and 1,8-diaminooctane in 1:2:2 molar ratios. The new products with octahedral geometry have been characterized by elemental analyses, molecular weight determinations, molar conductance, magnetic moment and spectral studies viz., infrared and electronic. On the basis of the spectral studies the binding sites are proposed as the nitrogen atom of the macrocycles. The formulation of the complexes as [Mn(Macn)Cl2] (where n = 1 - 4) has been established on the basis of chemical composition. To assess the growth inhibiting potential of the manganese (II) complexes biological screening has been undertaken.

Preparation process optimisation, structural characterisation and stability analysis of sika deer blood–selenium chelate

Context Selenium deficiency occurs all over the world. Therefore, the research and development of selenium supplements has been a focus for relevant scholars. Organic selenium is safer and more efficient than is inorganic selenium. In fact, China’s sika deer resources are of high quality, but the utilisation rate of deer blood is very low. Research has found that deer blood is a reasonable peptide source for the preparation of selenium-chelate supplements. The abundance of deer blood resources provided conditions for this study. Aim To provide new selenium supplements for humans, and further develop and utilise China’s sika deer industry, which to some extent also improves the utilisation rate of deer blood resources. Methods Peptides were hydrolysed by protease, and the best hydrolysates were screened. Single-factor experiments and response-surface methodology were used to study the effects of pH, temperature, time and peptide:selenium mass ratio on selenium-chelating activity. The sika deer blood polypeptide–selenium was characterised and analysed through ultraviolet spectrum, infrared spectrum, amino acid analysis, molecular-weight determination, scanning electron microscopy, and particle-size and potential analysis. Also, thermal-stability and acid–base-stability tests were conducted. Key results The chelating activity of alkaline protease hydrolysate was the highest, being 73.1 ± 0.16%. The pH value, temperature, time and peptide:selenium mass ratio had influence on selenium-chelating activity. Because of the cross-linking of selenium ions, the chelated selenium aggregates into larger particles with a more compact structure. The determination of amino acid and molecular weight showed that the metal-chelating activity of small-molecular peptides was very strong. Glutamic acid (Glu) and aspartic acid (Asp) play an important role in the binding of selenium ions. At the same time, the chelated SDBP–selenium had acid–base stability and thermal stability. Conclusion Studies depicted that SDBP–selenium is suitable as a new type of selenium supplement. Implications The preparation of deer blood polypeptide-chelated selenium provides a scientific basis for the development of new selenium supplements and the practical application of deer blood resources.

Fractionation and Absolute Molecular Weight Determination of Organosolv Lignin and Its Fractions: Analysis by a Novel Acetone-Based SEC─MALS Method

Accurate and reliable structural characterization of technical lignins is still challenging and inhibits industrial utilization as only poor understanding of structure–property relationship is available. Especially, molar mass analysis of technical lignins is of paramount interest; however, the usage of conventional size exclusion chromatography (SEC) and synthetic polymer standards as a consequence of inaccessible lignin standards is predominantly found in academia. This leads to a huge discrepancy in molecular weight analyses of lignins between different laboratories and consequently to fragile comparability. In this study, organosolv (OS) lignin from beech wood was exemplarily used to develop and evaluate a new acetone–water-based SEC method with the ability to be coupled to an electrospray ionization-mass spectrometer (ESI-MS) or to a multi-angle light scattering detector (MALLS or short MALS). The eluent system used shows very good solubility for the lignins investigated and hence lowers the probability for molecular aggregation of lignin molecules in solution. Solvent fractionation in acetone–water mixtures was conducted to acquire molecular weight classes. The starting lignin (parent lignin) was initially dissolved in 80 wt % acetone–water. Various fractions of the parent lignin were produced by a stepwise reduction of the acetone content. Molecular weights based on narrow polyethylene glycol (PEG)/polyethylene oxide (PEO) standards and absolute molar masses by coupling SEC with MALS were obtained, and the drawback of using polymer standards is discussed in detail. At a lower acetone content, low-molecular-weight fractions were found. Additionally, the specific refractive index increments (dn/dc) were determined for the parent lignin and its fractions. The impact of dn/dc on the final molecular weight (MW) was evaluated considering the chemical composition obtained by nuclear magnetic resonance spectroscopy (NMR) analysis. Furthermore, light scattering revealed that the absorption behavior for this OS lignin is low and neglectable. This article proposes a new acetone-based analytical method for direct determination of absolute molar masses of OS lignin molecules.

Molecular weight determination of low molecular weight hyaluronic acid and chondroitin sulfate by gel permeation chromatography

Low molecular weight (LWM) hyaluronic acid (HA) and chondroitin sulfate (CS) have a wide range of applications. To determine their molecular weight (MW), we developed a gel permeation chromatography (GPC) method, which is calibrated based on serrated peaks in the chromatograms. MW calibrants were obtained from the enzymolysis of HA and CS using hyaluronidase. The identical structure of calibrants and samples ensured the soundness of the method. The highest confidence MWs were up to 14,454 and 14,605 for HA and CS, respectively, and the standard curves showed very high correlation coefficients. Thanks to the changeless relationship between MW and its contribution to the GPC integral, the second calibration curves could be derived via one GPC column, also embodied correlation coefficients of >0.9999. The discrepancies of MW values were minuscule, and the measurement of a sample could be conducted in <30 min. The accuracy of the method was verified using LWM heparins, and the measured Mw values showed a 1.2 %–2.0 % error relative to pharmacopeia results. The MW results obtained for LWM-HA and LWM-CS samples were also consistent with the results obtained by multiangle laser light scattering. The method was also verified be able to measure the very low MWs.

Structural characteristic of polysaccharide isolated from Nostoc commune, and their potential as radical scavenging and antidiabetic activities

In this paper, Nostoc commune crude polysaccharide was extracted by heating and Ultrasonic-assisted methods separately, homogeneous polysaccharide HNCP3 and UNCP4 were obtained after purified by DEAE-52 cellulose column chromatography and Sephacryl G-100 gel column chromatography. The structures of HNCP3 and UNCP4 were characterized by molecular weight determination, infrared spectroscopy, DSC detection, sodium periodate oxidation, smith degradation reaction and methylation analysis. The conformation of the solution was studied by SEM and AFM. The results showed that the Ultrasonic-assisted extraction had effects on the molecular weight, monosaccharide composition, molar ratio and configuration of Nostoc commune. The main chain of HNCP3 and UNCP4 was → 6)-D-Glcp(1→ and → 2, 6)-D-Glcp, but UNCP4 contained 1, 2, 6-galactose and 2, 3-Me2-D-Ara branches, while HNCP3 did not. The results of the monosaccharides composition of indicated that mannose was presented in both HNCP3 and UNCP4. SEM and AFM showed that the structure of UNCP4 was helical, and the solution conformations of HNCP3 and UNCP4 were different in different solution environments. Studies on DPPH radicals, superoxide anions, and hydroxyl radicals scavenging abilities showed that UNCP4 had higher antioxidant activity, while studies on the antidiabetic activities showed that the hypoglycemic effect of UNCP4 was stronger than that of HNCP3. Therefore, Ultrasonic-assisted extraction (UAE) increases the bioactivity of Nostoc commune polysaccharide (NCP) as well as the extraction rate.

Kekerabatan merpati hias (Columba livia) dilihat dari profil protein darah

Objective: The purpose of this study was to predict the kinship of ornamental pigeons based on blood proteins. Methods: The research method used is exploratory descriptive with a laboratory observation-based approach. Research procedures include: Blood Sampling, Blood Protein Isolation, Purification, Measurement of concentration with a nanodrop spectrophotometer and Electrophoresis. Data analysis includes: Protein Band Profile and Determination of Protein Molecular Weight with RF formula and Relationship with MVSP version 3.22 program. Results : The protein profile in the plasma of ornamental pigeons is different from one type of pigeon to another. some of the protein appears in the ornamental pigeon species but does not appear in other breeds. Likewise with the target protein to be analyzed, some are expressed and some are not expressed in ornamental pigeons. Results based on the analysis of protein profiles and dendograms of the four specific proteins (hemoglobin, transferrin, posttransferrin, and immunoglobulin) contained in erythrocytes and blood plasma, it can be seen that there are two clusters. Cluster 1 is occupied by varieties of ornamental pigeons Moven and cluster 2 is occupied by varieties of ornamental pigeons Lahore, American fantail, Vienna, Indian Fantail, King, Capucine, Gondok and Modena. Conclusions: The results of the ornamental pigeon kinship prediction based on blood protein showed that each variety had different kinship relationships. King, Capucine, Gondok and Modena pigeons have the closest relationship, and Moven pigeons have the most distant relationship from the researched ornamental pigeons.

Calibration of high performance size exclusion chromatography (HPSEC) for molecular weight estimation of aquatic humic substances

Three high performance size exclusion chromatography (HPSEC) columns were compared, along with mobile phase chemistry and calibration standards, for the determination of apparent molecular weight (AMW) of aquatic humic substances using a UV absorbance detector (λ = 254 nm). The addition of 10 % organic solvent did not influence peak elution times of sodium polystyrene sulfonate (PSS) standards or chromatograms of Suwannee River humic acid (SRHA) or fulvic acid (SRFA) but did result in an additional peak being detected in a treated municipal wastewater sample (WWT). Mobile phase concentration was found to have a greater effect on peak position of PSS standards and SRHA than mobile phase pH or sample injection volume. Several chemicals of known molecular weight were tested alongside PSS standards, with salicylic acid (138.1 Da) and 4-chlorobenzoic acid (156.6 Da) resulting in retention times that aligned with the PSS MW standards. Of the three columns tested, the two with comparable pore sizes (i.e., 250 and 300 Å) were found to result in similar peak elution times and highly linear calibration curves over the range of 210–17,000 Da, while the column with the smaller pore size (i.e., 100 Å) gave better peak separation in the low AMW range (i.e., < 1000 Da). Estimations of AMW of SRHA using various sets of calibration standards on one of the three columns tested ranged from 1080 to 2799 Da using 0.02 M NH4CH3CO2 as eluent and 60-µL injections. AMW of SRFA ranged from 939 to 2434 Da for the same conditions.

Anisotropic swelling of rubber: extension of the Flory theory

The anisotropy of the swelling of rubber is examined both theoretically and experimentally. The Flory theory is extended to account for anisotropic swelling, allowing the determination of the average molecular weight between cross-links for rubber with swelling anisotropy for the first time. In addition, specimens from five commercial rubbers manufactured using either compression-moulding or sheet-rolling processes are swollen in appropriate organic solvents. Their linear dimensions and mass are carefully recorded before swelling, in the swollen state, and after drying, to obtain three linear swelling ratios which can differ by up to 10% within each specimen. Compression-moulded rubbers are shown to be transversely isotropic after moulding, whereas rolled rubbers exhibit full anisotropy, with different swelling ratios in all three directions. None of the rubbers examined were found to be truly isotropic. The new anisotropic swelling theory is applied to the experimental data to determine the average molecular weight between cross-links, which is determined as up to 0.5% larger than the value obtained using the Flory isotropic swelling theory.

Dual-Responsive Amphiphilic P(DMAEMA-co-LMA-co-OEGMA) Terpolymer Nano-Assemblies in Aqueous Media.

This work reports on the synthesis and self-assembly of a novel series of dual-responsive poly[2-(dimethylamino)ethylmethacrylate-co-laurylmethacrylate-co-(oligoethyleneglycol)methacrylate], P(DMAEMA-co-LMA-co-OEGMA)statistical terpolymers in aqueous solutions. Five P(DMAEMA-co-LMA-co-OEGMA) amphiphilic terpolymers, having different content of the three monomers, were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The success of the synthesis was confirmed by the molecular characterization of the terpolymers via size exclusion chromatography (SEC) for the determination of molecular weights and the molecular weight distributions. By using nuclear magnetic resonance (1H-NMR) and Fourier-transform infrared (FTIR) spectroscopy, it was possible to determine the exact composition of the terpolymers. Dynamic light scattering (DLS) and fluorescence spectroscopy (FS) indicated the formation of P(DMAEMA-co-LMA-co-OEGMA) unimolecular or multichain aggregates in aqueous solutions, as a response to pH, temperature and ionic strength changes, with their dimensions being largely affected. The amphiphilic terpolymers were able to encapsulate the hydrophobic drug curcumin (CUR) and demonstrate stability to fetal bovine serum (FBS) solutions. These terpolymer aggregates were studied by DLS, FS and UV-Vis, and it was found that they may have been used as potential nanocarriers for drug delivery and bio-imaging applications.

End Group Analysis of Polyisobutylene Succinic Anhydride (PIBSA) Carried Out with Pyrene Excimer Fluorescence

A procedure is established to determine the molar fraction (fdoubly) of doubly-maleated polyisobutylene (PIBSA2) in a PIBSA sample mainly constituted of mono-maleated polyisobutylene (PIBSA1), where the succinic anhydride (SA) groups are located at the end of the PIB chain. To this end, a PIBSA sample was labeled with 1-pyrenemethylamine (PyMA) to generate PIB-PySI, where the 1-pyrenemethyl group was linked to the PIB chain via a succinimide group. Depending on the procedure applied to purify the PIB-PySI samples, different regions of the molecular weight distribution (MWD) representing the PIBSA samples could be isolated and characterized by a combination of GPC, FTIR, and UV–vis absorption analysis to yield its MWD, number of isobutylene units per succinic anhydride (NIB/NSA), and pyrene content (λPy, in μmol of pyrene per gram of sample). These analyses were consistent with the expected size and chemical composition of the different PIB-PySI samples. fdoubly was calculated from the molar fraction (fagg) of pyrene labels attached onto the PIBSA2 species. fagg was determined through the global model free analysis (MFA) of the fluorescence decays of the pyrene monomer and excimer acquired for solutions of the PIB-PySI samples in THF. The different fractions of the MWD of the PIBSA sample yielded similar fdoubly values across the MWD, implying an even distribution of PIBSA2 species across a PIBSA MWD. The constancy of fdoubly across the MWD enabled the determination of the number average molecular weight (Mn) of the PIB-PySI samples from λPy. An analysis combining the GPC traces obtained with a differential refractive index and UV–vis absorption detector yielded the MWD of the original PIBSA sample. These experiments demonstrated that the proposed PEF-based methodology can be applied to characterize the SA end groups of PIBSA samples and could be further extended to characterize the end groups of other end-functionalized polymers.

Oligomerization of an ansa-ferrocene with pyrazabole bridge

ansa-Ferrocenes with pyrazabole bridges are chemically robust entities and therefore suitable building blocks for the synthesis of rigid-rod polymers that combine redox-active Fe(II) centers and beltene-like π faces. The specific monomers we developed bear OEt groups at both tetracoordinated boron atoms (for solubility reasons) and ethynyl substituents at the 4-positions of the two pyrazole rings. Polymerization was accomplished by a condensation reaction with 1,4-diiodobenzene using a Sonogashira–Hagihara-type protocol. As a result, oligomers with a number-average molecular weight of Mn = 7.6 kDa and dispersity of Ð = 1.55 were obtained, suggesting an average chain length of about 14 repeating units based on gel permeation chromatography analysis in THF relative to narrow polystyrene standards. The molecular weight determination was complemented by MALDI-TOF mass spectrometry and (heteronuclear) NMR spectroscopy to verify the intact pyrazabole monomer repeat units and the nature of the end groups. The oligomers were further characterized by UV–vis spectroscopy and cyclic voltammetry, which demonstrated the successful synthesis of a new class of redox-active materials.

Extraction and Purification of Lectin from Soybean Seeds (Glycine max)

In this study, the effectiveness of the ion exchange column packed with anionic resin DEAE-Sephadex®-A-50 in purifying lectin isolated by conventional saline buffer method was investigated. After the lectin extraction, the purification efficacy of ion exchange cationic and anionic resins was compared. The purified lectin was freeze-dried to a solid state to characterize its physiochemical properties. The characterization included the presence and content of protein, sulfur, and carbohydrate, hemagglutination test, gel electrophoresis for molecular weight determination, and metal photometry for sodium content determination. The physiochemical characterization was carried out by Fourier-transfer infrared spectroscopy and X-ray diffraction studies. The test results were compared with the standard sample of soybean lectin. The purified lectin was amorphous, basic in nature, tetramer, galactose binding/N-acetylgalactosamine molecule in its sodium salt form, with a molecular weight of 120 kiloDaltons. Based on the results, the anionic resin DEAE-Sephadex®-A-50 can effectively purify lectin isolated from soybean seeds.

Ring-Opening Polymerization (ROP) of Phenylalanine Derived O-Carboxyanhydride (OCA) Using Different Mono- and Bimolecular Conjugated Catalysts and Amino or Alcohol Initiators

In the present study, we investigated the activity of four groups of organocatalysts, initiators, and combined catalysts-initiators, through bimolecular reactions with linked catalysts-initiators operating during the polymerization, through a monomolecular pathway in ring-opening polymerization of O-carboxyanhydrides (OCAs) derived from phenylalanine, in the presence or absence of the cocatalyst 4-dimethyl aminopyridine (4-DMAP). The polymerization of the Phe-OCA process was measured by gel permeation chromatography and combined molecular weight determinations in different solvents and temperatures, at various concentrations of initiators and with/without the cooperative effect of cocatalysts. NMR estimated the rate constants of polymerization. Dimethylaminoethyl amine and dimethylaminopropyl amine, without 4-DMAP, were found as highly active catalysts for a more controlled polymerization reaction. 4-(Hydroxymethyl)-1H-imidazole, in the presence of 4-DMAP, was the most effective catalyst for the uncontrolled polymerization reaction of Phe-OCA. Phe-OCA polymers were found biocompatible in vitro proposing applicability for biomedical materials. The present study highlights different catalysts and has important implications for the synthesis of polymeric polyesters in translational medicine.

Polymeric Compounds of Lingonberry Waste: Characterization of Antioxidant and Hypolipidemic Polysaccharides and Polyphenol-Polysaccharide Conjugates from Vaccinium vitis-idaea Press Cake.

Lingonberry (Vaccinium vitis-idaea L.) fruits are important Ericaceous berries to include in a healthy diet of the Northern Hemisphere as a source of bioactive phenolics. The waste generated by the V. vitis-idaea processing industry is hard-skinned press cake that can be a potential source of dietary fiber and has not been studied thus far. In this study, water-soluble polysaccharides of V. vitis-idaea press cake were isolated, separated, and purified by ion-exchange and size-exclusion chromatography. The results of elemental composition, monosaccharide analysis, ultraviolet–visible and Fourier-transform infrared spectroscopy, molecular weight determination, linkage analysis, and alkaline destruction allowed us to characterize two polyphenol–polysaccharide conjugates (PPC) as neutral arabinogalactans cross-linked with monomeric and dimeric hydroxycinnamate residues with molecular weights of 108 and 157 kDa and two non-esterified galacturonans with molecular weights of 258 and 318 kDa. A combination of in vitro and in vivo assays confirmed that expressed antioxidant activity of PPC was due to phenolic-scavenged free radicals, nitrogen oxide, hydrogen peroxide, and chelate ferrous ions. Additionally, marked hypolipidemic potential of both PPC and acidic polymers bind bile acids, cholesterol, and fat, inhibit pancreatic lipase in the in vitro study, reduce body weight, serum level of cholesterol, triglycerides, low/high-density lipoprotein–cholesterol, and malondialdehyde, and increase the enzymatic activity of superoxide dismutase, glutathione peroxidase, and catalase in the livers of hamsters with a 1% cholesterol diet. Polysaccharides and PPC of V. vitis-idaea fruit press cake can be regarded as new antioxidants and hypolipidemic agents that can be potentially used to cure hyperlipidemic metabolic disorders.