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The cross-linked microspheres were prepared and loaded with Favipiravir SARS-CoV-2 antiviral drug, by copolymerization of chitosan (CS) with a polysaccharide extracted from fresh pomegranate peels. Moreover, glutaraldehyde (Glu) has been used as a chemical cross-linker and sodium hexametaphosphate (SHMP) as a physical cross-linker. The extracted polysaccharide was analyzed, and different techniques have been used. The analyses lead to the conclusion that it is pectin. The surface morphology of the prepared microspheres was studied using a scanning electron microscope, where the size and shape factor (S) of the Glu microspheres showed high values (74.27 μm) and (0.852), respectively, meaning their surfaces tend to be rough, whereas the SHMP microspheres showed a smaller size particle (20.47 μm) and a smaller shape factor (0.748), which gives an indication that the SHMP microspheres have smooth surfaces. The swelling studies have shown that Glu microspheres have a higher degree of swelling, which means SHMP microspheres are more compact. The prepared microspheres have shown a higher loading percentage of Favipiravir antiviral drug in SHMP microspheres (37% w/w) in comparison with Glu microspheres (35% w/w), where the electrostatic interaction between the Favipiravir ions and SHMP anions helps for more loading. The microspheres prepared under different types of cross-linking have shown initial burst release of Favipiravir, followed by a step of controlled release for a certain period of time, whose period depends on the pH of the release medium. Both Glu and SHMP cross-linked microspheres have shown high controlled release times in buffered release solutions at pH = 7.4 and for shorter periods at pH = 1.3 and pH = 9.4, which may be related to the type of electrostatic interactions between drug and polymer systems and their reactions with release solution ions. [ABSTRACT FROM AUTHOR]

The preparation, chemical properties and bio-activities of polysaccharides derived from halophytes have gained an increasing interest in the past few years. Phytochemical and pharmacological reports have shown that carbohydrates are important biologically active compounds of halophytes with numerous biological potentials. It is believed that the mechanisms involved in these bio-activities are due to the modulation of immune system. The main objective of this summary is to appraise available literature of a comparative study on the extraction, structural characterizations and biological potentials, particularly immunomodulatory effects, of carbohydrates isolated from halophytes (10 families). This review also attempts to discuss on bioactivities of polysaccharides related with their structure-activity relationship. Data indicated that the highest polysaccharides yield of around 35% was obtained under microwave irradiation. Structurally, results revealed that the most of extracted carbohydrates are pectic polysaccharides which mainly composed of arabinose (from 0.9 to 72%), accompanied by other monosaccharides (galactose, glucose, rhamnose, mannose and xylose), significant amounts of uronic acids (from 18.9 to 90.1%) and some proportions of fucose (from 0.2 to 8.3%). The molecular mass of these pectic polysaccharides was varied from 10 to 2650 kDa. Hence, the evaluation of these polysaccharides offers a great opportunity to discover novel therapeutic agents that presented especially beneficial immunomodulatory properties. Moreover, reports indicated that uronic acids, molecular weights, as well as the presence of sulfate and unmethylated acidic groups may play a significant role in biological activities of carbohydrates from halophyte species. Unlabelled Image • Polysaccharides from halophytes presented potent structural and biological feature. • Polysaccharides (PS) from different species of halophytes were firstly compared. • MAE extraction of PS from halophytes provides the higher extraction yield. • The most of PS from selected halophytes are mainly pectic polysaccharides. • Polysaccharides from halophytes possess promising immunomodulatory properties. [ABSTRACT FROM AUTHOR]

Although various methods have been reported for the analysis of hazardous Hg 2+ ions in aqueous medium, development of environment-friendly colorimetric assays and enhancing their performances still remain a great challenge. Here, we propose a fully eco-friendly colorimetric assay for Hg 2+ detection. The approach uses silver nanoparticles (Ag Nps) stabilized by carboxymethyl cellulose (CMC), obtained by carboxymethylation of cellulose waste isolated from Tunisian date palm petioles, as optical probe and NaCl as risk-free reagent. Preliminary investigations reveal high stability of the as-prepared colloidal suspension through ξ-potential measurements and UV–vis spectrophotometry as function of aging, pH, and ionic strength. The analytical applicability of CMC-stabilized Ag NPs to detect Hg 2+ ions, using the feedback titration method proves several weaknesses including high detection limit (LOD) and limit of quantification (LOQ) as well as poor selectivity. The proposed strategy indicates that the sensitivity of the colorimetric assay was greatly influenced by the final concentration of NaCl in the test medium. An optimal NaCl concentration of 300 mM improved all the colorimetric assay performances. Especially, the LOD and the LOQ values, commonly used as quality criterion for analytical method, were greatly enhanced and found to be around 5 nM and 16 nM, respectively, which are lower than the permissible authorized level (30 nM) by the World Health Organization (WHO). Toward the purpose of practical application, the current developed fully eco-friendly colorimetric assay was successfully applied for analytical determination of Hg 2+ ions and drinking-water safety. [ABSTRACT FROM AUTHOR]

Clay-polymer nanocomposites can be functionalized with natural bioactive compounds found in plants as a way to improve the physicochemical properties as well as the functional properties of the resulting films and coatings for potential application in food protection. The presence of clays as a component in food packaging can provide these systems with several advantages, acting as a container to stabilize the bioactive compounds, as well as a vehicle for their controlled release, affording barrier properties against moisture and enhancing the mechanical properties of the polymer matrix. In this review, we used a comprehensive literature search to provide an overview of the most recent and significant insights on the functionalization of clay-based nanocomposites with natural additives extracted from plants or active compounds isolated from those extracts. Special emphasis was dedicated to the scientific outcome rising from the physicochemical properties of such engineered materials and their applications to satisfy the need for food quality and safety. [Display omitted] • Incorporation of bioactive compounds in clay-polymer nanocomposites is reviewed. • Physicochemical and functional properties of these hybrid materials are disclosed. • Potential applications in the food packaging sector are discussed. • Development of optimized formulations is still a challenging task for the industry. [ABSTRACT FROM AUTHOR]

Abstract: Background: The polysaccharide of culture medium from Arthrospira platensis was extracted by ultrafiltration, partially characterized and assayed for anticoagulant activity. Methods: The crude polysaccharidic fraction was fractionated by anion exchange chromatography on DEAE-cellulose, subjected to acetate cellulose electrophoresis and characterized by physicochemical procedures. The anticoagulant effect of the ultrafiltrated polysaccharide was checked by several coagulation tests. Results: Anion exchange chromatography revealed in the whole ultrafiltrated polysaccharidic fraction the occurrence of a sulfated spirulan-like component designated PUF2. The average molecular weight of PUF2 was determined by size exclusion chromatography combined with multi-angle light scattering (SEC-MALS) and viscosimetry and was 199 kDa and the sulfate content was 20% weight/dry weight. The physicochemical characterization indicated the occurrence of rhamnose (49.7%), galacturonic and glucuronic acid (32% of total sugar). The anticoagulant effect of this sulfated polysaccharide was mainly due to the potentiation of thrombin inhibition by heparin cofactor II and was 4-times higher than that of the porcine dermatan sulfate whereas it had no effect on anti-Xa activity. Conclusions: An ultrafiltrated sulfated polysaccharide, likely a calcium spirulan was obtained from the culture medium of A. platensis and showed an anticoagulant activity mediated by heparin cofactor II. General significance: Old culture medium of A. platensis may represent an important source for the spirulan-like PUF2 which was endowed with potentially useful anticoagulant properties whereas its obtention by ultrafiltration may represent an extraction procedure of interest. [Copyright &y& Elsevier]

Abstract: Introduction: The polysaccharide fraction from the skin of the ray Raja radula was extracted, characterized and assayed for anticoagulant activity. Materials and methods: A whole polysaccharidic fraction was extracted from the skin of the ray Raja radula by papain digestion followed by cetylpyridinium chloride and ethanol precipitation and was subjected to gel chromatography and anion exchange chromatography, acetate cellulose electrophoresis and characterized by physicochemical procedures. APTT and anti Xa assays were performed to assess the anticoagulant activity of the polysaccharidic fractions in comparison with unfractionated heparin. Results: Gel and anion-exchange chromatography revealed two negatively charged polysaccharidic populations different in both molecular weight and charge. Infrared spectra suggested the occurrence of uronic acids and acetylated hexosamines. The second polysaccharide was highly sulfated, with a sulfate content of approximately 29%. These data suggested that dermatan sulfate (DS) is the sulfate rich polysaccharide whereas hyaluronic acid (HA) is the polysaccharide devoid of sulfate groups. Molecular mass characterization indicated that their average molecular masses were 22 kDa and 85 kDa, respectively. The sulfated polysaccharide, i.e. presumably DS, accounted alone for the observed concentration-dependent anticoagulant activity which was, as measured by APTT, 2 to 3-fold lower than that of heparin. In addition, it had a significant anti-Xa activity. Conclusion: A major-sulfated polysaccharide, likely a dermatan sulfate, was extracted from the ray Raja radula skin. The results indicated that it exhibited a high anticoagulant activity and suggested that it was mediated by both heparin cofactor II and antithrombin. [Copyright &y& Elsevier]

Abstract: Water and Chelator-soluble polymers were independently isolated from the alcoholic-insoluble substance (AIS) of Mesembryanthenum crystallinum leaves. After precipitation in ethanol and ultrafiltration (40kD cut-off) of recovered solids dissolved in water, the yield relative of the so-call Lw and LCh polymers to the AIS dry matter was 2.5±0.2 and 7±0.5%. The galacturonic acid contents were 67±3% and 63±5%. The degrees of methylesterification of ca. 45±3% and 50±3%, showed that Lw and LCh belonged to the fairly methylesterified pectin class. From sugar analysis, LCh was shown to contain at least two types of pectic blocks, homogalacturonan (HG: 58%) and rhamnogalacturonan-I (RG-I: 34%). Their structure were deduced after saponification, polygalacturonase treatments, size exclusion chromatography (SEC) onto Sephacryl S-200 and then sugar composition of the collected fractions. The main polymers were methylesterified HG (32%), some of them being linked to non-methylesterified HG (10%), and to polygalacturonase-resistant HG (17%). In addition, there were (1) a highly soluble RG-I with long galactan side chains (RG-I–gal accounting for 9%) and (2) a RG-I with short arabino-galactan side chains (25%), named RG-I–ara/gal that was almost totally lost during SEC analysis, due to its low solubility at room temperature and in absence of chelators. SEC coupled with differential refractive index and light scattering showed that highly methylesterified HG chains exhibited aggregate structures in solution due to intermolecular hydrophobic interactions. These interactions formed hydrophobic clusters, which have been characterized by surface tension measurements and with a polarity probe, the Coomassie Brilliant Blue dye. After alkaline treatment of LCh, the self-assembly of HG disappeared. [Copyright &y& Elsevier]

Polysaccharide-rich materials were extracted from the alcohol-insoluble solids of Olea europaea l. **leaves. Structural characteristics were determined by colorimetric techniques, FT-IR, GC–MS, SEC/MALS/VD/DRI, and NMR (1H,13C). The extract and its main macromolecular components were characterized to assess their ability toward antioxidant, α-amylase inhibition, and antiproliferative activities. Results revealed that the ultrasound olive leave extract comprises polysaccharides with uronic acid, galactose, arabinose, and glucose in molar percentages of 11.7%, 11.3%, 7.5%, and 4.9% respectively, constituting 41% of the total mass. In addition, polyphenols (21%) and proteins (9%) are associated with these polysaccharides. Further, the extract showed noticeable ORAC and free radical scavenging abilities, in addition to high in vitro antiproliferative activity against Caco-2 colon carcinoma cell lines. Similarly, the extract exhibited a strong, uncompetitive inhibition of α-amylase by 75% in the presence of the extract with 0.75 µg/mL of concentration. This research concludes that ultrasound extraction method can be used for the extraction of polysaccharide–polyphenol–protein complexes. These conjugates exhibit the potential for combined biological activities resulting from a synergistic effect of its compounds, making them promising ingredients for the development of functional food. [ABSTRACT FROM AUTHOR]

Natural insecticidal products, essentially essential oils and their bioactive compounds are available as an excellent alternative method to control insect pests as well as they are less toxic to human health. However, due to their volatile constituents, encapsulation could be considered as the most suitable solution for their practical application. Therefore, this study aims to explore the insecticidal toxicity of chitosan nanoparticles loaded with Rosmarinus officinalis essential oil against adults of Carpophilus hemipterus. Chitosan nanoparticles were prepared by ionic gelation method with an encapsulation efficiency 41.543.1% and loading capacity 5.24G0.28%. Results revealed that chitosan nanoparticles loaded rosemary oil exhibited interesting insecticidal toxicity towards C. hemipterus adults in stored dates with 50.73% mortality. Overall, this work pointed out that the innovative design method based on chitosan-nanoparticles loaded rosemary oil can be promoted in integrated pest management program for stored date pests. [ABSTRACT FROM AUTHOR]

Alginate nanocomposite films incorporating sepiolite (Sep) modified with myrtle berries extract (MBE) rich in polyphenols were prepared by solution casting method. The effects of different extract concentrations on the film properties were determined by measuring physicochemical, mechanical and antioxidant properties of the films. Fourier transform infrared (FTIR) spectra indicated that strong interactions between the polyphenols present in the MBE and sepiolite were involved in the films. The results suggested that incorporation of Sep-MBE hybrids into the films improved elongation at break, tensile strength, water vapor and UV barrier properties compared to the control film. The antioxidant activity of the films was significantly improved and raised with increasing content of MBE. The release kinetics results of MBE polyphenols from the active films into alcoholic food simulant indicated that the addition of Sep-MBE hybrids to alginate film is able to slow the release of MBE polyphenols. This study revealed the benefits of incorporation of Sep-MBE hybrids into the alginate films and their potential application as active packaging films or coating material. • Alginate films containing sepiolite-myrtle berries extract biohybrids were developed. • The bionanocomposite films showed improved mechanical, thermal, and UV barrier properties. • The water vapor permeability of alginate was reduced due to incorporation of sepiolite-extract hybrids. • Incorporation of myrtle berries extract provided the bionanocomposite films with antioxidant activity. • The developed films can be used potentially as an active packaging material. [ABSTRACT FROM AUTHOR]

Emulsifiers have been extracted from the alcohol-insoluble solids of olive (Olea europaea L.) stones. The extracts containing proteins and carbohydrates were characterized by dynamic light scattering, zeta potential measurements, Fourier transform infrared spectroscopy (FT–IR), Gas chromatography coupled with mass spectroscopy GC–MS, and size exclusion chromatography (SEC). The FT–IR and SEC data agree that the extracts have two macromolecular structural components: a polysaccharidic and a proteinic population. Experiments have been conducted as to evaluate the extracts' ability to emulsify oil-in-water emulsions, using confocal laser scanning microscopy for the examination of the microstructure, and static light scattering for the determination of droplets/flocs size distributions. The extracts are adequate emulsifiers for neutral model emulsions, providing stability against coalescence for 14 days. The interfacial characteristics of the extracts' components (interfacial composition/topology and dynamic interfacial tension) have been examined as to complement the composition, emulsification and emulsion stability data. This work concludes that olive stones, the main by-products of olive processing, have the potential to act as sources of high added-value emulsifiers. [Display omitted] • Emulsifiers are extracted from olive stones. • The emulsifying extracts are characterized for their polymeric populations. • The extracts have good emulsification capacity and give good emulsion stability. • Their emulsification capacity is linked to their interfacial properties. [ABSTRACT FROM AUTHOR]

Abstract The preparation of a new drug delivery system (DDS) based on the combination of two natural polymers chitosan (CS) and high-esterified pectin (HEP) and beidellite (Bd) was proposed. Diclofenac sodium was chosen as model drug and was loaded in the nanocomposite by means of intercalation solution technique. The samples were characterized by X-ray diffraction, Thermal analysis, Infrared spectroscopy and high resolution transmission electron microscopy coupled with energy dispersive X-Ray analysis. Drug loading capacity and encapsulation efficiency of the clay polymer nanocomposite was quantified. UV–Vis spectroscopy (276 nm) was used as the drug quantification technique throughout the whole study. In vitro drug release profile in simulated intestinal fluid was also evaluated. Results demonstrated the formation of diclofenac polymorph during the drug loading process, thus obtaining a new crystal form of the drug possessing different physico-chemical properties with respect to the diclofenac sodium salt form. Moreover, the in vitro release study showed that the bionanocomposite elaborated could form a network aiming for a modified release of diclofenac. Consequently, Na-Bd/CS/HEP nanocomposite proved to be a promising formulation to control anionic drug release process. Highlights • Chitosan, pectin and a natural clay mineral were used as nanocomposite ingredients. • The nanocomposite effectively encapsulated diclofenac sodium (DS). • After the intercalation, the formation of a DS polymorph was found. • The prepared nanocomposite demonstrated to control the amount of drug released. [ABSTRACT FROM AUTHOR]

Abstract Chitosan (CS) and purified sodium beidellite (Na-Bd) were used to obtain a nanocomposite able to carry anionic pharmaceutical ingredients. Diclofenac sodium (DS) was chosen as a model drug and was loaded by intercalation solution technique. Solid state characterization of the resultant hybrids was performed, including X-ray diffraction, Fourier transformed infrared spectroscopy, Thermal analysis and high resolution transmission electron microscopy coupled with energy dispersive X-Ray analysis. Drug loading capacity and encapsulation efficiency were quantified by measuring equilibrium concentration by UV–Vis spectroscopy at 276 nm. Solid-state characterization of the samples confirmed both chemical and physical interaction of DS with the nanocomposites. High drug loading along with a modified cumulative release of the drug in simulated intestinal fluid was obtained. The developed clay/polymer hybrids can act as potential candidates for the design of modified dosage forms of anionic drugs. Highlights • Chitosan/sodium-beidellite nanocomposite was prepared. • Diclofenac sodium was successfully loaded. • A partial exfoliation of the clay has been detected. • Significant drug encapsulation efficiency was found. • The release of Diclofenac was modified in comparison with the pure drug. [ABSTRACT FROM AUTHOR]

Gracilaria gracilis farming was conducted in the Bizerte lagoon (North of Tunisia) at two depths (0.5 and 2.5 m) using various initial fragment weights (5, 20, and 40 g) in order to investigate the alga growth, agar yield, and quality. IR spectra of agar were performed in comparison to the commercial one. Moreover, the proximate biochemical composition of seaweeds was investigated. The results showed that the highest daily growth rate and agar yield were recorded at 0.5 m, using 5 g as initial fragment weight (5.98 ± 1.98% day−1, 14.87 ± 1.91% dw, respectively). Maximum gel strength was 356.67 ± 15.25 g cm−2 at 2.5 m using an initial weight of 20 g. Gelling and melting temperatures varied from 34.33 ± 0.57 to 35.50 ± 0.57 °C and from 77.00 ± 1.00 to 85.00 ± 0.50 °C, respectively. IR analysis revealed that some spectra were similar, while others were different. The highest dry matter (22.68 ± 1.77%) and ash content (35.25 ± 0.02% of dw) were recorded at 2.5 m, using initial weights of 20 and 5 g, respectively. The maximum carbohydrate and the crude protein contents were obtained at 0.5 m, using 5 g as initial weight (9.52 ± 0.36 and 5.83 ± 0.7% dw, respectively). The highest R-phycoerythrin content was recorded at 0.5 m (0.050 ± 0.007 mg g−1 dw), while the maximum of total lipid content was recorded at 2.5 m with initial weight of 5 g (3.58 ± 0.63% dw). Our findings indicated that growth and biochemical composition of G. gracilis depend on the depth and initial fragment weights. [ABSTRACT FROM AUTHOR]

The production of cellulose nanofibrils (CNFs) with a high yield from Ammophila arenaria has been explored and the ensuing CNFs were characterized in terms of morphology, crystallinity and rheological properties. Ammophila arenaria (marram grass) is a perennial grass plant with high tolerance to drought, which is growing naturally in nutritionally poor sand with low organic matter. Fibers were extracted from the plant by conventional alkaline pulping and bleaching with a yield around 50% based on the dry weight of the plant. A TEMPO-mediated oxidation and a cationization with glycidyltrimethylammonium chloride were performed as a pretreament to facilitate the fibrillation process and produced stable CNF suspension with high yield and controlled surface charge. High pressure homogenization was used for the mechanical disintegration of the pretreated fibers and nanosized CNFs with width around 5–8 nm were produced with a yield exceeding 80%. [ABSTRACT FROM AUTHOR]

Cross flow ultrafiltration (UF) using a cellulose membrane (cut off of 5 kDa) was employed to separate phenolic compounds from carbohydrates of hydro-ethanolic extract obtained from Zizyphus lotus fruit. The performance of the UF membrane was evaluated in terms of permeate flux, fouling index and retention values of total phenolic compounds, carbohydrates and uronic acid contents. The results showed that at VRF of 4.5, the membrane gave the highest rejections towards carbohydrates (99.89 %) and uronic acids (82.8 %) and the lowest average rejection of total phenolic compounds (3.12 %). Moreover, the permeate fraction exhibited the highest 2,2-diphenyl-1-picrylhydrazyl free radical scavenging ability and total antioxidant capacity with 0.036 mg.mL-1 and 102.145(mgGAE.g-1DM), respectively. This result is due to the presence of phenolic compounds (gallic acid, syringic acid, catechin, quercetin and kaempferol) as identified by HPLC system. Besides, a low rejection values of the UF membrane concerning these compounds were confirmed by liquid chromatography analyses. [ABSTRACT FROM AUTHOR]

Due to the numerous side effects of conventional drugs against herpetic infections and the growing phenomenon of resistance, the researchers turned to natural compounds as a source of new drugs because they are less toxic than the synthetic molecules. This study aimed to analyse the activity of Pistacia vera L. male floral bud extracts, against the replication of herpes simplex virus type 2, as well as to investigate their mode of action, isolate, and identify the active compound. Cell viability and anti-herpes virus activity were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and the plaque reduction assay, respectively. Three extracts (ethanolic, aqueous and polysaccharide extracts) were tested, only aqueous and polysaccharide extracts had anti-herpetic activity with a selectivity index of 29.12 and 20.25, respectively. Investigation about the mechanism of action indicated that the two active extracts inhibited the virus replication by direct contact with virucidal selectivity indexes of 39.15 and 32.09, respectively. An active compound was isolated from the aqueous extract using TLC bio-guided assay: it was identified as gallic acid by high-performance liquid chromatography–diode array detection coupled with electrospray ionization mass spectrometry (HPLC–DAD–ESI-MSn). The antiviral activity of Pistacia vera L. has been previously shown. The selectivity index of gallic acid is much lower than that of the active extract from which it has been isolated. Therefore, we can consider the aqueous extract prepared from Pistacia vera L. male floral buds as a promising natural product for treating herpetic diseases. [ABSTRACT FROM AUTHOR]

The fishing and aquaculture industries generate a huge amount of waste during processing and preservation operations, especially those of tuna. Recovering these by-products is a major economic and environmental challenge for manufacturers seeking to produce new active biomolecules of interest. A new hyaluronic acid was extracted from bluefin tuna's vitreous humour to assess its antioxidant and pharmacological activities. The characterization by infrared spectroscopy (FT-IR), nuclear magnetic resonance ((1D 1H) and 2D (1H COSY, 1H/13C HSQC)) and size exclusion chromatography (SEC/MALS/DRI/VD) revealed that the extracted polysaccharide was a hyaluronic acid with high uronic acid content (55.8 %) and a weight average molecular weight of 888 kDa. This polymer possesses significant anti-radical activity and ferrous chelating capacity. In addition, pharmacological evaluation of its anti-inflammatory and analgesic potential, using preclinical models, in comparison with reference drugs (Dexamethasone, diclofenac, and acetylsalicylate of lysine), revealed promising anti-inflammatory activity as well as interesting peripheral and central antinociceptive activity. Therefore, our new hyaluronic acid compound may therefore serve as a potential drug candidate for the treatment of pain sensation and inflammation of various pathological origins. [Display omitted] • A novel hyaluronic acid was extracted from the vitreous humour of bluefin tuna. • The physicochemical properties of the isolated hyaluronic acid were studied. • The isolated hyaluronic acid demonstrated significant pharmacological properties. • The hyaluronic acid demonstrated promising potential as an anti-inflammatory agent. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate antimicrobial and antioxidant activities of different fractions obtained from edible Tunisian Ziziphus Lotus leaves of Tozeur region. Different organic extracts were tested: cyclohexane, dichloromethane, ethyl acetate, n-butanol and water. Bio-guided fractionation revealed that dichloromethane fraction is the most active against S. aureus and Methicillin-resistant S. aureus strains. Moreover, this fraction showed the highest antileishmanial activity with IC50 values of 20.55 ± 0.34 μg/mL and 15.37 ± 0.17 μg/mL against L. major and L. infantum, respectively. The potentialities of antibacterial and leishmanicidal activities found in dichloromethane could be explained by the presence of major flavonoids such as catechin, rutin and luteolin 7-O-glucoside as revealed by HPLC system. The observed moderate antifungal activity, which was only given by butanolic fraction against pathogen fungi, may be attributed to the presence of chlorogenic acid. Furthermore, dichloromethane and butanolic fraction showed a good DPPH (2,2-diphenyl-1-picryl hydrazyl) scavenging activity and Ferric reducing power. These results suggest that Ziziphus lotus leaf fractions might be used as antioxidant and antimicrobialagent. [ABSTRACT FROM AUTHOR]

The use of natural extracts in the field of cosmetics and pharmaceuticals is increasing due to the growing demand for sustainable and safe products, together with their potential therapeutic benefits. Bioextracts from the parenchyma of Opuntia ficus indica cladodes were characterized and evaluated as emulsifying agents. They contain pectin together with variable amounts of arabinogalactan-protein complex (AGP), as in many polysaccharides of natural origin. Their protein content varies according to the purification steps: 11.4 wt% for the raw mucilage (Mofi), 4.7 wt% for the pectin fraction (Pofi) and less than 0.5 wt% for the filtrated pectin fraction (FPofi). Part of the AGP contained in the Mofi and Pofi extracts precipitates as particles with a ∼5 µm diameter. Mofi at 1.5 wt% concentration is an efficient emulsifier of oil-in-water emulsions of medium-chain triglycerides or sunflower oil with stability against coalescence for more than three months. Pofi is less efficient and FPofi does not allow the stabilization of emulsions. The performance of emulsifiers is directly related to the protein content of the extracts and the role of the insoluble particles is essential. The insoluble particles of AGP are responsible for the stabilization through a Pickering effect. The emulsions have the characteristic properties of Pickering emulsions. [Display omitted] • Mucilage from Opuntia ficus indica allows the stabilization of o/w emulsions. • The insoluble part of the mucilage is the actual stabilizing agent. • The soluble part made of purified pectin cannot stabilize emulsions. • A Pickering effect stabilizes the emulsions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pectin was extracted from Arthrocnemum indicum leaves for GCE modification. • A wide linear range between 9.10 −5 mM to 2.10−2 mM is obtained. • A detection limit of 0.09 µM is found. • A good selectivity versus amino acids, uric acid and ascorbic acid is observed. • The detection of l -tryptophan in urine samples was successful. Pectin from Arthrocnemum indicum leaves (PAI) extracted from plants, harvested in the Tunisian Sahel, was used for the first time as a sensitive matrix for the design of an electrochemical sensor of l -tryptophan via differential pulse voltammetry (DPV). A glassy carbon electrode (GCE) was modified by a PAI layer through simple adsorption, leading to a DPV signal of l -tryptophan that was increased by a factor of 15. The PAI-modified electrode exhibited a good analytical performance towards the detection of l -tryptophan with a wide linear range between 9.10−5 mM to 2.10−2 mM, a detection limit of 0.09 µM, and a sensitivity of 90.15 µA. mM−1. Compared to other reported electrochemical sensors, PAI/GCE presents a lower detection limit, even without the use of nanomaterials. In addition, the PAI/GCE showed good reproducibility and good selectivity towards the determination of l -tryptophan versus other amino acids, uric acid, and ascorbic acid, making it suitable for the determination of l -tryptophan in biological fluids. [ABSTRACT FROM AUTHOR]

A Box-Behnken design was used to optimize extraction temperature, extraction time and concentration of the salicylic acid to obtain a maximum polysaccharide yield from Citrus sinensis peels. The optimal settings were: extraction time 3 h, extraction temperature 80 °C and concentration of the salicylic acid 1.5%. Under these conditions, the experimental yield and uronic acid content were 11.74% and 66.9% respectively. Preliminary characterization was performed via FT-IR, SEC/MALS/VD/DRI and GC–MS after hydrolysis. SEC analysis showed that the extracted polysaccharide had a weight average molar mass of 350 kDa and an intrinsic viscosity of 640 mL/g. The GC–MS results revealed that the extracted polysaccharide was composed of arabinose 56.7%, galactose 17.8%, xylose 13.8%, rhamnose 5.1%, mannose 2.5% and glucose 1.5% suggested a rhamnogalacturonan pectin type I with a degree of esterification of 50.9% (IRTF). The flow curve and the dynamic frequency sweep were obtained at 10, 20, 30 and 40 g/L in water and at 30 g/L in presence of CaCl 2 or NaCl at 1 mol/L. The solutions showed shear-thinning behavior fitted with Ostwald-De Waele model, except 10 g/L with a Newtonian behavior. The apparent viscosity and, the G' and G" moduli increase with PACO concentration in agreement with a slow-down of the dynamic chain. In the presence of CaCl 2 or NaCl the reduction of electrostatic repulsions between pectin chains decreases the rheological parameters. The effect is less sensitive with CaCl 2 due to intermolecular interactions. The antiproliferative activity of the extracted pectin on human Caco-2 and Hep-2 cells was very interesting with an IC 50 1.4 and 1.8 μg/mL respectively. [ABSTRACT FROM AUTHOR]

The necessity to increase the efficiency of organ preservation has pushed physicians to consider the use of pharmacological additives in preservation solutions to minimize ischemia reperfusion injury. Here, we evaluated the effect of fucoidan, sulfated polysaccharide from brown seaweed, as an additive to IGL-1 (Institut Georges Lopez) preservation solution. Livers from Wistar rats were preserved for 24 h at 4 °C in IGL-1 solution, enriched or not with fucoidan (100 mg/L). Thereafter, they were subjected to reperfusion (2 h, at 37 °C) using an isolated perfused rat liver model. The addition of fucoidan to IGL-1 solution reduced hepatic injury (AST, ALT) and improved liver function compared to IGL-1 solution without fucoidan. In addition, we noted a significant increase in the phosphorylation of AMPK, AKT protein kinase and GSK3-β, leading to a reduction in VDAC phosphorylation, as well as a reduction in apoptosis (caspase 3), mitochondrial damage, oxidative stress and endoplasmic reticulum (ER) stress markers. Furthermore, ERK1/2 and P38 MAPKs phosphorylation significantly decreased after supplementation of IGL-1 solution with fucoidan. In conclusion, the supplementation of IGL-1 solution with fucoidan maintained liver graft integrity and function through the prevention of the ER stress, oxidative stress and mitochondrial dysfunction. Fucoidan could be considered as potential natural therapeutic agent to alleviate graft injury. • Fucoidan maintains cell survival. • Fucoidan modulates the phosphorylation of AKT and AMPK and ER stress. • Fucoidan protects mitochondria and reduced oxidative stress and apoptosis. • Fucoidan improves the preservation of hepatic grafts. [ABSTRACT FROM AUTHOR]

Brown seaweeds produce useful bioactive substances with high cosmetic and pharmacological values due to the presence of antioxidant derivatives, mainly phlorotannins (PHT), which are of particular interest. A central composite rotatable design (CCRD) with three variables (extraction time, dry material-to-solvent ratio and ethanol concentration) and two responses was performed to optimize the microwave-assisted extraction (MAE) of phlorotannins from Cystoseira sedoides using response surface methodology (RSM). Results showed that the independent variables significantly affected both phlorotannin content and the scavenging capacity. The optimum operating conditions were extraction time, 101.74 sec; dry material-to-solvent ratio, 1:10 g/mL; and ethanol extraction, 50%. Under these conditions, the predicted values of PHT content and radical scavenging activity-IC50 were close to the observed values and were 383.887 µg PGE/g Dm and 18.353 µg/mL, respectively. Characterization of the phlorotannin-rich fraction was conducted by high-performance liquid chromatography and Fourier transform infrared spectroscopy. The evaluation of the anticancer activity against MCF-7 breast cancer cell line showed a potent activity to trigger apoptotic death in more than a half of the MCF-7 cells, with an estimated IC50 value of 78 μg/mL. In addition, this fraction induced a notable growth regression effect on 3D spheroids model in a concentration-dependent manner, with a growth rate of about 1.17, at 200 µg/mL. Abbreviations: CCRD: Central composite rotatable design; Dm: Dry material; DMBA: 2,4-dimethoxy benzaldehyde; DMSO: Dimethyl sulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EDTA: Ethylene diamine tetraacetic acid; FBS: Fetal bovine serum; FT-IR: Fourier transform infrared; HPLC: High-performance liquid chromatography; IC50: Half-maximal inhibitory concentration; MAE: Microwave-assisted extraction; Min: minutes; PBS: Phosphate buffered saline; PGE: Phloroglucinol equivalent; PHT: Phlorotannins; PHT-SED: phlorotannins derived from Cystoseira sedoides; PI: Propidium iodide; RSA: Radical scavenging activity; RSM: Response surface methodology; Sec: seconds [ABSTRACT FROM AUTHOR]

Spinacia is an interesting medicinal halophyte plant that is employed as a food and therapeutic agent in traditional medicine. In this work, water-soluble polysaccharides from Spinacia oleracea were extracted and preliminary characterization was established via FT-IR, UV–vis, 1H NMR and SEC/MALS DRI technics. The extracted polysaccharide, with an average molecular mass of 408 kDa, was composed of arabinose, galactose, mannose, glucose, rhamnose and xylose in the molar percentage of 49.3%, 28.1%, 4.9%, 7.8%, 8.2% and 1.7%, respectively. The polysaccharide showed significant antioxidant activity. Moreover, Spinacia polysaccharide, significantly prevented oxidation-induced Cd damage and exhibited a protective effect against Cd cytotoxicity on HEK293 and HCT116 cells, with an important cell viability decrease, an important reduction of MDA production and ROS levels. The outcomes obtained suggest that the Spinacia polysaccharides may be used as an accessible source of natural antioxidants and as potential phytochemicals against kidney and colon cancer. Unlabelled Image • Polysaccharides from Spinach (Spinacia oleracea) were carefully extracted. • Preliminary physico-chemical characterizations were investigated. • Extracted carbohydrates have been found to possess antioxidant properties in vitro. • Cadmium causes oxidative stress mediated damages to HEK293 and HCT116 cells. • Extracted polysaccharides provided significant protection against these damages. [ABSTRACT FROM AUTHOR]

As a health-beneficial fruit, watermelon is widely consumed by people around the world. However, components responsible for the health benefits are not yet determined. As watermelon contains a large amount of polysaccharides, these carbohydrates might play an important role in the health benefits. In this work, polysaccharide from watermelon rinds (PWR) was extracted by papain digestion, purified and characterized by GC–MS, SEC/MALS/VD/DRI, FTIR and 1D and 2D NMR which revealed the glycosidic linkages, their locations in branches and backbone. The monosaccharide composition revealed that the extracted polysaccharide was composed of galactose (38.26%), arabinose (26.12%), rhamnose (17.86%), mannose (9.94%), xylose (5.10%) and glucose (2.70%) with a percentage of uronic acid of 45%. A combination of CPG and NMR analysis showed that the extracted polysaccharide is arabinogalactan linked to type I rhamnogalacturonan. we notice that the arabinogalactan was formed by →6)-β-D-Gal p -(1→ as backbone with short branching of arabinose linked in α 1 → 3, rhamnose linked in α 1 → 4, mannose linked in β 1 → 6 and galactose branches linked in β 1 → 3. Furthermore, PWR exhibited obvious cytotoxicity ability to human laryngeal carcinoma Hep-2 cells in a dose-and time-dependant manner. • Extraction of arabinogalactan from quince peels by Papain was performed. • Characterization of the extracted polysaccharide was achieved. • Antiproliferative activity on Hep-2 cells was evaluated. [ABSTRACT FROM AUTHOR]

• Small amounts of PPUN effectively prevent corrosion, highlighting its potential as a corrosion inhibitor. • Quantum chemical studies provide detailed insights into the donor–acceptor interaction mode of PPUN. • PPUN's Galacturonic acid and Glucose are highly effective inhibitors against XC38 corrosion in acidic media. • This study pioneers the use of PPUN extracted from Opuntia ficus-indica's nopales Pulp for corrosion inhibition. Corrosion causes massive damage to our equipment and buildings, wasting billions of dollars every year. Identifying a workable answer to this problem is a priority. Scientists have begun using inhibitors derived from renewable resources and natural ingredients to have a minor possible detrimental impact on the environment. Though many synthetic structures exist to prevent corrosion during the acid pickling process, the persistence of the problem has prompted modern corrosion scientists to investigate this field further by studying natural products with increasingly intriguing moieties for practical applications and their applied capabilities against corrosion. Electrochemical studies have been used to fully explore the inhibitory effects of Pulp (PPUN) from prickly pear nopales of Opuntia ficus-indica (OFI) on mild steel corrosion in 1 M HCl solution. Scanning electron microscopy (SEM) and atomic force microscopy were used to investigate the surface of mild steel (AFM). The XPS method was used to learn about the mechanism of inhibition happening on mild steel. Through its absorption on the metal surface and its inhibition of the active corrosion site, the inhibitor is shown by a potentiodynamic polarization study to slow down both cathodic and anodic processes. The adsorption of PPUN on metal was demonstrated by a shift in impedance characteristics (charge transfer resistance R t and double layer capacitance C dl). The PPUN and product film have been analyzed using SEM and AFM. The computed values correspond well with those from the experiments. Based on MDS results, Galacturonic acid and Glucose constituents adsorb tightly on the carbon steel cluster surface. [ABSTRACT FROM AUTHOR]

Abstract Nutritional, soluble carbohydrates and aroma volatile profiles of Tunisian wild Swiss chard leaves (Beta vulgaris L. var. cicla) have been characterized. The chemical composition of an ethanol chard leaves extract, as well as its in vitro antioxidant, α-amylase and α-glucosidase inhibition activities were carefully evaluated. The results of the proximate composition showed that total carbohydrate fraction, mainly as dietary fiber were the major macronutrient (2.43 g/100 g fw), being the insoluble dietary fiber the predominant fraction (2.30 g/100 g). In addition, leaves of Beta vulgaris L. were especially rich in Mg, Fe and Ca (4.54, 2.94 and 2.28 mg/100 g fw) and very poor in Na (0.09 mg/100 g fw). Volatile profile revealed that non-terpene derivatives and sesquiterpene hydrocarbons were the essential classes of volatiles in the chard leaves. Myricitrin, p-cumaric acid and rosmarinic acid were characterized. Moreover, the ethanol extract of wild Swiss chard leaves revealed significant antioxidant capacity. Furthermore, a good enzyme inhibitory effects on α-glucosidase and α-amylase activities were observed. These findings highlighted the potential health benefits of wild Swiss Chard as a source of nutritional and bioactive compounds. Graphical abstract Nutritional, phytochemical composition and bioactivity (antioxidant, hypoglycemic and antimicrobial activity) of Edible Swiss chard (Beta vulgaris L. var. cicla) were investigated. Unlabelled Image Highlights • Studied halophyte leaves present nutritional profile adequate for human consumption. • Swiss chard leaves exhibit high contents of Mg, Ca, K and Fe. • Swiss Chard leaves is a source of phytochemical compounds to elaborate healthful foods. • Swiss chard leaves is a good source of pigments and other phenolic compounds. • Chard leaves extract has significant biological activities. [ABSTRACT FROM AUTHOR]

Abstract This study was designed to characterize the physico-chemical properties of the sulfated polysaccharide (SP) isolated from the red alga Laurencia obtusa and to evaluate its apoptotic, gastroprotective and antioxidant activities. The different macromolecular characteristics of SP were determined by size exclusion chromatography combined with multi-angle laser light-scattering detection (SEC-MALLS), Fourier transform infrared spectroscopy (FTIR) analysis and nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR). The native molecular weight of the extracted polysaccharide is high (≥336,900 g·mol−1). It showed high amounts of sulfated groups (28.2%) and low levels of proteins. It was found to be a potent inducer of apoptosis on acute monocytic leukaemia THP-1cell lines with EC 50 value of 53 μg·mL−1. Furthermore, a significant gastroprotective effect (p < 0.01) was also observed with a gastric ulcer inhibition of 63.44%, 78.42% and 82.15% at the doses 25, 50 and 100 mg·kg−1, respectively. In addition, SP significantly increased glutathione levels (GSH) and decreased the concentration of thiobarbituric acid-reactive substances (TBARS) in EtOH/HCl-damaged gastric mucosa in rats; it also exhibited an important antioxidant activity in vitro. Therefore, SP, derived from the red alga Laurencia obtusa, may have a potential therapeutic effect against acute myeloid leukaemia and a beneficial potential as gastroprotective and antioxidant natural product. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract In this work, a new design of voltammetric glucose biosensor, based on the encapsulation of glucose oxidase (GOx) in a chitosan/κ‑carrageenan (CHIT/CAR) polyelectrolyte complex (PEC) using a simple coacervation process is presented. A conductometric monitoring of this is performed. Spectroscopic and morphological characterization of the PEC film encapsulating GOx is carried out. Compared to biosensors based on a chitosan film, a more sensitive voltammetric detection of glucose is obtained. Using square wave voltammetry (SWV), the CHIT/CAR PEC based biosensor exhibits a wide linearity range from 5 μM to 7 mM glucose with a detection limit of 5 μM. Excellent selectivity against ascorbic acid, uric acid and urea is observed and the applicability of the biosensor for glucose detection in spiked saliva samples was demonstrated. Graphical abstract Unlabelled Image Highlights • Glucose oxidase is encapsulated in a chitosan/κ‑carrageenan polyelectrolyte complex. • A more sensitive voltammetric detection of glucose is obtained compared to that based on chitosan film. • The biosensor exhibits a wide linearity range from 5 μM to 7 mM glucose. • The biosensor exhibits a detection limit of 5 μM glucose. • Excellent selectivity against ascorbic acid, uric acid and urea is observed. [ABSTRACT FROM AUTHOR]

Abstract In order to develop new and low cost anticoagulants as potential heparin alternatives, sulfation of a pectin-like polysaccharide from Opuntia ficus indica cladodes using SO 3 -DMF complex was performed with a significant sulfate content (7%). FTIR and NMR assays indicated that the sulfation reaction had occurred. In addition, GC–MS analyses demonstrated that sulfation was carried out on the arabinose units of native polysaccharide. Moreover, Physico-chemical characterization indicated an evident decrease of the average molecular weight (M w) and sugar rates after sulfation. Finally, anticoagulant assays demonstrated that the anticoagulant activity was significantly enhanced by the addition of sulfate groups. Thus, sulfated polysaccharides exhibited the most potent anticoagulant activity by prolonging activated partial thromboplastin time (APTT) and thrombin time (TT). Highlights • Pectin was isolated from Opuntia ficus indica (OFI) cladodes with yield of 24.50% from dry matter. • Chemical sulfation of extracted pectin was performed using SO 3 -DMF complex. • FTIR, NMR and GC–MS indicated that the sulfation reaction had occurred with a highest sulfate content of 7.04%. • Sulfated polysaccharides showed significant anticoagulant potential depending on the sulfate content. [ABSTRACT FROM AUTHOR]

Abstract The overuse of antibiotics and biofilm formation ability has led to the emergence of bacterial resistant strains. The combined use of several antibiotics has been found as an efficient strategy to overcome this resistance. In this study, two exopolysaccharides (EPS) obtained from Lactobacillus plantarum (EPS-Lp) and Bacillus spp. (EPS-B), isolated from a traditional Tunisian food "ricotta cheese" and hypersaline environment respectively, were used to counteract the biofilm formation and efflux pumps activities in Escherichia coli ATCC35218. The obtained results revealed that the tested EPSs can be effective against E. coli at a concentration > 1 mg/ml and were able to modulate biofilm formation by 50%. Moreover, at a concentration of 512 μg/ml, the tested EPSs inhibit the EtBr efflux in the tested bacteria and no significant difference was shown compared to cells treated with reserpine (P > 0.05). The positive effect of the tested EPSs may be due to the decrease of Indole production level proposed as a signal involved in quorum sensing and through the significant reduction of the hydrophobicity percentage between the treated and untreated cells. Overall, EPS-Lp and EPS-B, when used at appropriate concentration, may inhibit biofilm formation and reduce efflux pumps implicated in bacterial adhesion and antimicrobial resistance. These results make them an interesting candidate in the design of a new strategies to control bacterial biofilm-associated infections. Highlights • EPSs were extracted from Lactobacillus plantarum and halophilic Bacillus spp. • Both EPS-LP and EPS-b showed antibacterial activity. • Both EPS-LP and EPS-b induced the inhibition of biofilm and efflux pumps Escherichia coli ATCC35218. • The tested EPSs inhibit the indole production. [ABSTRACT FROM AUTHOR]

Abstract Prunus amygdalus is used in the folk medicine that proved the interest of this plant which cures many diseases. Many researchers are interested to valorize almond waste (hull and shell) and to evaluate their biological and pharmacological activities. In this work, polysaccharides from Prunus amygdalus shell were extracted sequentially by water, ammonium oxalate and hydrochloric acid. The monosaccharide composition of polysaccharides fractions was performed by GC–MS. Water-soluble polysaccharide was found to be the most effective extracting agent with an extracted yield of 9%. The acid Soluble Polysaccharides (ASP) exhibited the highest galacturonic acid content (31.95%), the highest polysaccharides extractability (88.57%) and the lowest degree of esterification (31.76%). The different polysaccharides fractions were characterized by FTIR, 1H NMR and SEC/MALS/VD/DRI. The antioxidant tests (DPPH, ABTS and FRAP) indicated that ASP showed even better antioxidant activities. Moreover, the result of the antiproliferative activity against Caco-2 and B-16 cells showed that ASP exhibited strong cytotoxicity ability which confirmed that the Prunus amygdalus peels may comprise the natural raw materials for new drug and functional food. Highlights • Extraction of polysaccharides from Prunus amygdalus peels in three mediums was performed • Physico-chemical characterization and preliminary spectroscopic analyses revealed that the polysaccharides were pectin-like • The extracted polysaccharides exhibited significant antiproliferative activity against B-16 and Caco-2 cells [ABSTRACT FROM AUTHOR]

Abstract Some oxysterols resulting either from enzymatic oxidation or autoxidation of cholesterol are associated with age-related diseases including neurodegenerative diseases. Among these oxysterols, 7β-hydroxycholesterol (7β-OHC) is often found at increased levels in patients. It is therefore important to identify molecules or mixtures of molecules to prevent 7β-OHC-induced side effects. Consequently, murine oligodendrocytes (158N) were cultured in the absence or presence of 7β-OHC (20 μg/mL, 24 h) with or without a natural oil extracted from sea urchin (Paracentrotus lividus) eggs known for its biological activity. Firstly, the chemical composition of this oil was determined using 31P NMR and GC-MS. Secondly, this oil was used to reduce 7β-OHC-induced side effects. To this end, the oil (160 μg/mL) was added to the culture medium of 158N cells 2 h before 7β-OHC. The effects of 7β-OHC with or without the oil on cell viability were studied with the MTT test. Photometric methods were used to analyze antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPx), as well as the generation of lipid peroxidation products (malondialdehyde (MDA), conjugated dienes (CDs)) and protein oxidation product (carbonylated proteins (CPs)). Gas chromatography was used to determine the fatty acid profile. With 7β-OHC, an induction of cell death associated with oxidative stress (alteration of GPx and SOD activities) was observed; an overproduction of lipid peroxidation products (MDA and CDs) and CPs was also revealed. Sea urchin egg oil attenuated 7β-OHC-induced cytotoxicity: 7β-OHC-induced cell death was reduced, GPx and SOD activities were normalized, and lower levels of MDA, CDs and CPs were produced. In addition, whereas a disturbed fatty acid profile was observed with 7β-OHC, similar fatty acid profiles were found in control cells and in cells cultured with 7β-OHC associated with sea urchin egg oil. These data demonstrate the protective activities of sea urchin egg oil against 7β-OHC-induced side effects on 158N cells, supporting the concept that this oil may have benefits in the prevention of neurodegenerative diseases. Highlights • 7β-hydroxycholesterol (7β-OHC) induces 158N cell death associated with cellular fatty acid profile alteration. • 7β-OHC induces an enhancement of Gluthation peroxidase (GPx) and superoxide dismutase (SOD) activities. • 7β-OHC induces an overproduction of lipid peroxidation products (MDA and CD) and carbonylated proteins (CP). • Sea urchin egg oil attenuates 7β-OHC induced side effects: it reduces cell death, and normalize the fatty acid profile. • Sea urchin egg oil modulates the antioxidant enzymes activities and attenuates the production of MDA and CD. [ABSTRACT FROM AUTHOR]

Central composite design was performed to optimize uronic acid rate, esterification degree, total antioxidant ability and antiglycation capacity of carbohydrates from Arthrocnemum indicum leaves. Three independent variables were opted: extraction temperature, time and ratio (solvent/material). The optimal settings were: extraction temperature of 80 °C, time of 288 min and (solvent/solid) ratio of 40 mL/g. Under these settings, uronic acid rate and esterification degree were 49.29%, 30.24%, respectively, whereas total antioxidant activity and antiglycation capacity was 35.81 mg ascorbic acid equivalents/g matter and 69.81%, respectively. Colorimetric assays showed that total sugar and uronic acid contents for polysaccharide were 71.78% and 49.24%, respectively. Furthermore, Preliminary structure study was performed via various methods including FT-IR, NMR and UV–vis analysis. SEC analyzes revealed that polysaccharide had an average molecular weight of 2179 kDa. Moreover, GC–MS analyzes showed that extracted polysaccharide was a pectic polysaccharide which formed of arabinose, mannose, galactose, rhamnose, glucose and xylose in the molar percentage of 66.68%, 3.93%, 12.71%, 6.31%, 6.08% and 4.29%, respectively. This results revealed that extracted polysaccharide can be employed as source of natural antioxidants and as possible antiglycated agents. [ABSTRACT FROM AUTHOR]

Two new inorganic-organic hybrid materials based on heteropolyoxometalates (POMs): (C 4 H 10 N) 6 [P 2 Mo 18 O 62 ]·4H 2 O (P 2 Mo 18 ) and (C 6 H 8 NO) 4 [H 2 P 2 W 18 O 62 ]·6H 2 O (P 2 W 18 ) are reported as mediators for electron transfer between FAD-dependent glucose dehydrogenase (FAD-GDH) and a multiwalled carbon nanotube (MWCNT) matrix for glucose biofuel cell and biosensor applications. These polyoxometalates were chosen due to their promising redox behavior in a potential range for mediated electron transfer with the glucose oxidizing enzyme, FAD-GDH. P 2 Mo 18 and P 2 W 18 were immobilized on 1-pyrenemethylamine (PMA) functionalized MWCNT deposits. After immobilization of FAD-GDH, the P 2 W 18 -modified MWCNT electrode demonstrated mediated electron transfer and provided a catalytic current density of 0.34 mA cm −2 at 0.2 V vs SCE with an open circuit potential (OCP) of −0.08 V vs SCE. A 10-fold increase in catalytic current to 4.7 mA cm −2 at 0.2 V vs SCE and a slightly lower OCP of −0.10 V vs SCE was observed for an equivalent electrode modified with P 2 Mo 18 .The apparent superiority of P 2 Mo 18 is related, at least in part, to its improved incorporation in the MWCNT matrix compared to P 2 W 18 . Both POM-modified bioanodes showed exceptional stabilities with 45% of their initial performances remaining after 15 days. The mediated electron transfer capacities of the POMs were also evaluated in a glucose sensor setup and showed very satisfying performances for glucose detection, including a sensitivity of 0.198 mA mol L −1 cm −2 , a satisfying linear range between 1 mmol L −1 and 20 mmol L −1 , and good reproducibility for the P 2 Mo 18 electrode. [ABSTRACT FROM AUTHOR]

Nowadays, it has been an increasing demand for health-oriented products such as high fiber and low calories products. The aim of this work is to try to substitute these additives with a natural extract from Opuntia macrorhiza Engelm. which is a good source of dietary fibre and mineral compounds. Physicochemical and functional properties of seeds and cladodes powders were investigated and indicated the possibility of incorporating them into the manufacture of cakes. The study demonstrated that cakes having good sensory qualities can be produced by the replacement of wheat flour with 15% of cladodes and 5% of seeds powder. The consumption of a cake enriched with O. macrorhiza cladodes and seeds is also proposed for health reasons. Thus, the flour obtained from O. macrorhiza cladodes and seeds can be suggested as an ingredient in food products. [ABSTRACT FROM AUTHOR]

Box-Behnken design (BBD) was performed via ultrasound-assisted system to optimize extraction yield and total antioxidant ability of polysaccharides from Suaeda fruticosa . Three independent variables were studied: temperature, time and pH with optimal settings 90 °C, 37 min and 2.9, respectively. Under these settings, isolation yield and total antioxidant activity were 34.0% and 31.8 mg ascorbic acid equivalent/g material, respectively. Furthermore, preliminary structure study was carried out using UV–vis analysis, Fourier transform infrared spectroscopy (FT-IR) and Nuclear magnetic resonance (1D ( 1 H, 13 C NMR) and 2D ( 1 H, 1 H COSY, 1 H/ 13 C HSQC)) methods Size exclusion chromatography (SEC) determination revealed that polysaccharide extracted had an average molecular weight of 240 kDa. Chemical composition analyses showed that extracted polysaccharide was a pectin-like polysaccharide with uronic acid content (47.5%) and neutral monosaccharides (52.5%) constituted mainly of arabinose, mannose, galactose, rhamnose, glucose and xylose in the molar percentage of 48.63%, 5.85%, 29.42%, 7.96%, 6.54% and 1.60%, respectively. This sugar composition was typical of that of a galactoarabinan. Importantly, the optimum polysaccharide possesses significant potentials in antioxidant activity effect. Moreover, pharmacological investigation of extracted polysaccharide revealed a good anti-inflammatory effect and interesting peripheral as well as central antinociceptive activities. [ABSTRACT FROM AUTHOR]

In this work, polyethylene terephthalate (PET) was chemically modified by covalent co-immobilization of two separate layers of bioactive polymers composed of chitosan and a new dermatan sulfate isolated fromRaja montaguiskin. The new materials obtained were characterized by determination of carboxyl groups, ATR-FTIR spectroscopy, drop water contact angle, SEM, and TGA measurements. The different immobilizations modified the surface characteristics; especially when the first layer was dermatan sulfate (PET–DS–Chito) which presented the best surface wettability (71 ± 3°). It also reduced the ability ofStaphylococcus epidermidisto form biofilm on PET surfaces which could decrease the virulence of vascular prosthesis infections. [ABSTRACT FROM AUTHOR]

In this study, Box-Behnken design was used to optimize the ultrasonic extraction of Carpobrotus edulis polysaccharides (CEP), and the effect of time, extraction temperature and water to material ratio was evaluated. Optimum conditions were 1.77 h, 78.0 °C and 33.04 mL/g to improved CEP yield (7.84%), which is in good agreement with the predicted yield 7.77%. Then, the physico-chemical, antioxidant and antiglycation properties of optimized CEP were studied, and the total sugar and galacturonic acid content were 89.7 and 63.2%, respectively. The composition of neutral monosaccharide was arabinose, xylose, rhamnose and mannose in the molar percentage of 71.84, 14.80, 8.57, and 4.79%, respectively. In addition, ( 1 H, and 13 C) NMR and FTIR analyses confirmed the presence of uronic acids in the free and methyl ester forms with a degree of esterification of 31.27%. Therefore, this finding showed that CEP is a low methoxyl pectic polysaccharide, with an average molecular weight about 65,000 g/mol. Finally, the results indicated that CEP presents strong antioxidant activities in vitro (DPPH, chelating ability and reducing power), and significantly inhibits lipid peroxidation and the formation of fluorescent advanced glycation end products in glucose-BSA system model. [ABSTRACT FROM AUTHOR]

The aim of this study is to isolate pectin from peel (WNPE) and pulp (WNPU) of Opuntia microdasys var. rufida ’s ( OMR ) cladodes and to characterize these polysaccharides by size exclusion (SEC/MALS/VD/DRI), gas chromatography coupled to mass spectrometer (GC–MS), nuclear magnetic resonance ( 1 H NMR), and Fourier transform infrared spectroscopy (FTIR) analysis. The polysaccharides were extracted in neutral aqueous media followed by ethanol precipitation and dialysis. Both WNPE and WNPU are mainly composed of uronic acids and some neutral sugars such as arabinose, galactose, rhamnose and mannose. Their molecular weight range from 2,180,000 and 4,920,000 g/mol. The in-vivo pharmacological activities (anti-inflammatory, analgesic and gastroprotective activities) have been performed. The extracted pectin (50–100 mg/kg, i.p. (intraperitoneal)) inhibited, in a dose-related manner, both carrageenan-induced paw edema in rats and Xylene-induced ear edema in mice. A dose-dependent action was obtained against chemical (writhing test) and thermic (hot plate test) stimuli, respectively, with doses of 50 and 100 mg/kg. Moreover, a considerable gastroprotective effect was observed with these two biopolymers, the gastric ulcer was attenuated until 67.67% for WNPE and 81.93% for WNPU, at the dose of 100 mg/kg. [ABSTRACT FROM AUTHOR]

Alginates from three genus of Tunisian brown algae were isolated and characterized by size exclusion chromatography and Solid-state NMR spectroscopy. Alginate from Padina pavonica (APP) had the highest molecular weight (Mw) with 147,000 g/mol while it was 85,000 g/mol for alginate from Cystoseira compressa (ACC) and 58,000 g/mol for alginate from Dictyopteris membranaceae (ADM). The mannuronate (M) to guluronate (G) ratios were estimated from spectral deconvolution of the 13 C CP/MAS spectra and the results has shown that all the extracts are mannuronic acid-rich alginates with M/G ratio increased in the order ADM – ACC – APP. An interesting gastroprotective effect was observed for the extracts; ADM and ACC exhibited the highest inhibition of gastric lesions, at 50 mg/kg, with 83.41% and 75.39% respectively. Otherwise, it has been shown that the gastroprotective effect of alginates depends mainly on their uronic acid composition. [ABSTRACT FROM AUTHOR]

Content:Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements. Objective:In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities. Materials and methods:Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed. Results:The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090–181 kDa) and intrinsic viscosity (1550–473 mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC50value of HA and LWMHA was 1.43, 0.76 and 0.36 mg/mL and 1.20, 0.89 and 0.17 mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA. Discussion and conclusion:The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity. [ABSTRACT FROM AUTHOR]

The isolation, purification and ozone depolymerization of polysaccharides from Arthrocnemum indicum as well as the evaluation of their antiproliferative capacities were investigated. The ozone treatment for various reaction times (0, 15, 30, 45 and 60 min) was employed as degradation method in order to attain lower molecular weight product with stronger antiproliferative property. According to FTIR, 1 H NMR and UV-vis analysis, the main chain of ozonolytic degraded polysaccharides could be preserved. The monosaccharide composition, which was determined via GC/MS analysis, showed that extracted polysaccharides were of type of arabinan-rich pectic polysaccharides. Macromolecular characteristics as well as intrinsic viscosity of the degraded polysaccharides were performed by size exclusion chromatography before and after ozone treatment. These experiments showed that intrinsic viscosity and molecular weight (Mn and Mw) of degraded samples decreased with increase in reaction time. Furthermore, preliminary antiproliferative tests indicated that degraded polysaccharide for 1 h showed even better antiproliferative capacity. [ABSTRACT FROM AUTHOR]

Microwave-assisted extraction was employed for the isolation of polysaccharides fromPosidonia oceanica(PPO). The extracting parameters were optimized adopting response surface methodology. The highest polysaccharide yield (2.55 ± 0.09%), which is in concordance with the predicted value (2.76%), was obtained under the following conditions: extraction time 60 s, liquid–solid ratio of 50:1 (mL/g) and power of 800 W. This polysaccharide, with molecular weight of 524 KDa, characterized by gas chromatography–mass spectrometry showed that PPO was mainly composed of galactose, glucose, and arabinose with molar percentages 25.38, 24.37, and 21.64%, respectively. The pharmacological evaluation of PPO using animal models at the dose of 100 mg/kg indicated a significant anti-inflammatory activity with a percentage of inhibition of edema of 54.65% and a significant antinociceptive activity with 78.91% inhibition of writhing for peripheral analgesic activity and an increase in the hot plate reaction time for central analgesic activity. Microwave-assisted extraction and pharmacological activities of polysaccharides fromPosidonia oceanica [ABSTRACT FROM PUBLISHER]

The purpose of this investigation was to develop a new method for extracting polysaccharides from Aloe vera , considering their inhibitory effectiveness. Acemannan, the major functional Aloe vera gel polysaccharide, was gently deacetylated, in presence of sodium borohydride, in order to obtain water-soluble polysaccharides. Varying deacetylation time leads to different deacetylation degrees, which were determined via potentiometric titration. Physical and structural properties of different polymers were assessed. Fourier Transform Infrared spectroscopy confirmed acemannan deacetylation. The molecular weights were examined via Size Exclusion Chromatography analysis. Neutral sugars and uronic acid contents were also determined. Furthermore, the antibacterial activity was evaluated using counting assays. AVB5, the less deacetylated polymer, exhibited the highest antibacterial activity against four different bacteria stains, with an inhibition greater than 98%. Moreover, the strongest inhibition of E. Coli and E. faecalis biofilms formation was observed with AVB5 through BIC50 ≤ 7.6 ± 0.7 and BIC90 ≤ 68.2 ± 4.5. It was also found to be the most efficient to eradicate the biomass, via the assessment of BEC50 ≤ 10.9 ± 0.6 and BEC90 ≤ 75.5 ± 4. Collectively, deacetylation treatment of Aloe vera acemannan reduces considerably antibacterial and antibiofilm potential. [ABSTRACT FROM AUTHOR]

This work is devoted to investigate the available agricultural Tunisian waste: the date pits as reinforcing filler for thermoplastic matrix. The chemical composition of this reinforcing filler is found to be comparable to nonwood plants: its content comprises of 13% of extractibles, 22% of lignin, and 61% of holocellulose. Then, the lignocellulosic filler was used to prepare different composites films using Brabender mixing device. A series of composite film was established by different loadings of the date pits waste with 10–50% of the filler in 10% as an interval. The ensuing composites materials were then characterized by several techniques such as the morphology of the composites, which was investigated using scanning electron microscopy. The thermal properties of prepared materials were studied using differential scanning calorimetry and thermogravimetric analysis. Finally, the mechanical and water absorption properties were involved. The obtained results indicated that date pits–based particles enhanced the thermomechanical properties of the thermoplastic matrix and demonstrated that this available lignocellulosic biomass can be considered to be a promising filler material. [ABSTRACT FROM AUTHOR]

Because of their functional diversity, bioactive compounds are becoming a new biocontrol agent to limit biofilm formation by pathogens. In this study, the physico-chemical characterization of an exopolysaccharide (EPS) isolated from Lactobacillus plantarum (EPLB) was characterized and its in vitro effect on biofilm formation was studied. The EPS had a molecular weight of 36 kDa and polydispersity index estimated to be 1.2. The tested EPLB had an antibacterial activity, with a Minimal Inhibition Concentration (MIC) values ranging between 1 mg/ml and 10 mg/ml, displayed an antibiofilm effect concentration dependent on Gram positive and negative strains. Among the pathogenic strains, 2 out of 4 appeared to be more than 50% inhibited in their biofilm development by the EPS. The antibiofilm activity can be due to the ability of the EPS to influence the function of biological membranes like hydrophobicity that decreased (P < 0.05) when the EPS was used at a concentration of 512 μg/ml. This EPS without cytotoxic effect, showed an antioxidant effect on the quenching of DPPH radicals and the inhibition of lipid peroxidation with a percentage of 64% and 66%, respectively. Taken together these biological properties, EPLB can be considered as a potential prebiotic agent in the design of new therapeutic strategies for bacterial biofilm-associated infections. [ABSTRACT FROM AUTHOR]

Sulfated polysaccharide (SP) from the eggs of sea urchin Paracentrotus lividus, extracted by papain digestion, was characterized by size exclusion chromatography coupling on-line with light scattering and viscosity detectors (SEC/MALS/VD/DRI), gas chromatography coupled to mass spectrometer (GC–MS), and Fourier transform infrared spectroscopy (FTIR) analysis. The native molecular mass of the extracted polysaccharide is high (≥22 000 KDa) and it is composed mainly of arabinose, accompanied by other monosaccharides (mostly galactose, glucose and fucose), significant amounts of uronic acids (18.4%) and relatively high proportions of sulfate (22.4%). The pharmacological evaluation of SP showed a significant in vivo anti-inflammatory activity ( p < 0.001), 3 h after injection, the edema inhibition was 75.8% at the dose of 100 mg/Kg; a significant peripheral analgesic activity ( p < 0.001), with 64.9% of writhing inhibition, and a significant increase in the hot plate reaction time in mice indicating central analgesic activity. In addition, an interesting gastroprotective effect was observed with this polysaccharide; the gastric ulcer inhibition was 69.7%, at the dose of 100 mg/Kg. [ABSTRACT FROM AUTHOR]

Carpobrotus edulis is an important South African medicinal plants used as a food and therapeutic agent in traditional medicine. The aim of this study was to determine the phytochemical content, antioxidant, antiglycation and cytotoxic effect against Human Colon Cancer Cell Line (HCT-116) of aqueous and ethanol-water (1:1 v/v) extracts of Carpobrotus edulis. The content of total phenolics and flavonoids in aqueous and ethanol–water extract were 151.99 μg and 66.35 μg gallic acid equivalents/mg of dry extract, and 38.84 μg and 21.96 μg quercetin/mg of dry extract, respectively. Furthermore, phenolic compositions analysis indicated the presence of seven majority compounds including sinapic acid, ferulic acid, luteolin7- o -glucoside, hyperoside, isoquercitrin, ellagic acid and isorhamnetin 3- O -rutinoside. The ethanol-water extract (100–1000 μg/mL) showed better antioxidant activity than aqueous extract. Furthermore, Carpobrotus edulis extracts, especially ethanol-water extract significantly inhibited the formation of fluorescent advanced glycation end products, prevented oxidation-induced protein damage and exhibited a cytotoxic effect against HCT116 cells, with a significant decrease in cell viability after 24 h of incubation. The results obtained suggest that the Carpobrotus edulis extracts could be used as an easily accessible source of natural antioxidants and as potential phytochemicals against protein glycation and colon cancer. [ABSTRACT FROM AUTHOR]