Sephadex G-100 Column Research Articles

Preparation, Preliminary Characterization and Antiangiogenic Activities of Polysaccharides from Pomegranate Peels

In the present study, the crude polysaccharides from pomegranate peels (CPP) were prepared by compound enzyme-extraction technology, and the response surface methodology was used to optimize the extraction parameters. Box–Behnken design (BBD) was applied to estimate the effects of extraction temperature, extraction pH, and dosage of compound enzyme on the yield of CPP. A mathematical model with high fitness was obtained. Extraction temperature, extraction pH, and dosage of compound enzyme exhibited independent and interactive effects on CPP yield. CPP were purified by macroporous resin HP-20 and Sephadex G-100 column chromatography to afford purified fraction of CPP-2. The relative molecular weight of CPP-2 was 93.5 kDa. In CPP-2, and FT-IR spectra showed that the main components among CPP-2 may be pectic polysaccharides.The effect of CPP-2 on angiogenesis was measured in vivo by using the chick embryo chorioallantoic membrane (CAM) assay. The results demonstrated that CPP-2 suppressed angiogenesis in chicken embryos.

Purification, characterization and antioxidant activity of polysaccharides from Porphyra haitanensis

In order to study the antioxidant activity of Porphyra haitanensis polysaccharides and the effect of their structure on the antioxidant activity, the Porphyra haitanensis polysaccharide (PHP), prepared by hot water extraction and alcohol precipitation, was separated and purified by Cellulose DEAE-52 ion exchange and Sephadex G-100 column chromatography. Three purified components including PHP1, PHP2 and PHP3 were obtained, and chemical composition analysis and structural characterization were performed. The in vitro free radical scavenging activity of the purified polysaccharide fractions and their ability to relieve oxidative stress in macrophage RAW264.7 were investigated. The results indicated that all the three fractions possessed appreciable DPPH radical, superoxide anion radical, and hydroxyl radical scavenging ability and reducing power. They were also found to effectively reduce the MDA content and ROS level, and to improve the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) in H2O2-treated RAW264.7 cells. Among the three polysaccharides, PHP3 possessed the most potent activity. Porphyra haitanensis polysaccharides have potential to develop as natural non-toxic antioxidants and may find application as the ingredients of functional foods.

Investigating the thermodynamic and kinetics properties of acid phosphatase extracted and purified from seedlings of Chenopodium murale

Herein acid phosphatase isoenzyme was extracted from the C. murale seedlings. The purification was accomplished by chromatographic techniques and passing through DEAE-cellulose and Sephadex G-100 column. The specific activity of acid phosphatase 5.75 U/mg of protein was obtained with 66 purification fold 15.8% yield and molecular mass was 29 kDa with very faint bands corresponding to 18 kDa and 14 kDa. The maximal activity at pH 5.0 and 50 °C best illustrated by first order kinetics. When temperature was raised (55 °C to 75 °C), the deactivation rate constant was increased from 0.001 to 0.014 min−1, while half-life was decreased from 693 to 49 min−1. The results of activity collected at different temperature were then used to estimate, activation energy of hydrolysis reaction (Ea = 47.59 kJmol−1). A high Z-value (18.86 °C min−1) was obtained indicating a less sensitivity towards temperatures. The residual activity examinations were carried out from 55 °C to 75 °C and assessing the Deactivation Energy (Ed 116.39 kJmol−1), Enthalpy change (ΔH° 113.55kJmol−1), Entropy change (ΔS° 110.33kJmol−1) and change in Gibbs free energy (ΔG° 10.02 kJmol−1). Taken together, thermodynamic parameters confirm the high stability of enzyme and show potential commercial applicability.

Extraction and Purification of Lipases Enzyme from Germinating Seeds of Four Crops

Lipase enzyme has attracted a lot of attention in recent years because of its diverse biotechnological applications. The present study was conducted to screen germinated seeds of four crops, namely sunflower (Helianthus annuus), flaxor linseed (Linum usitatissimum ), peanut (Arachis hypogaea ) and castor bean (Ricinus communis), for the activity of their lipases. to the study also included the extraction and purification of lipase from the seeds of the most promising crop using different solvents.
 The results indicated that the maximum enzymatic activity (0.669 U/ml) was obtained when 0.1 M Tris-HCl buffer extract was used after 3 days of seed germination of all the tested species, as compared to the other test solvents (acetone and water). Sunflower germinated seeds showed the highest lipase activity, which was higher by 159.67, 185.32, and 285.90 % over the activities of castor bean, flax, and peanut seeds, respectively. Among the used ranges of saturation of ammonium sulfate, the ratio of 70% was the best in precipitating the crude enzyme, showing a highest specific activity of 2.576 U/ mg protein.
 The first stage of gel filtration chromatography column by Sephadex G-200 indicated the presence of two non-identical peaks, one for protein and another for lipase activity, between the fractions of 18 to 23. The active fractions were pooled and loaded again in the Sephadex G-200 column and the eluted fractions showed two identical peaks, one for protein and another for lipase activity, between the fractions of 19 to 23. The final purification step by gel filtration showed a specific activity of 6.482 U/mg proteins with a yield of 38.75 % and 11.33 folds of time of purification. The study revealed that sunflower seeds are a better source of lipase as compared to the other used plant seeds, which can be used in different industries.

Immunomodulatory and Antioxidant Effects of Polysaccharides from the Parasitic Fungus Cordyceps kyushuensis.

The ascomycete Cordyceps genus has been used as valued traditional Chinese medicine. Cordyceps kyushuensis is a unique species of Cordyceps, which parasitizes on the larvae of Clanis bilineata Walker, and its major component cordycepin and aqueous extract are known to have many pharmacological effects. However, the physiological function of water-soluble polysaccharides has not been explored in detail. In this study, to resolve these doubts, we extracted and separated Cordyceps-derived polysaccharides and then evaluated the immunomodulatory and antioxidant activities. Four polysaccharide fractions were purified from Cordyceps-cultured stroma by DEAE-cellulose 23 and Sephadex G-150 column chromatography. Basic structural information was elucidated on the basis of physicochemical property and spectroscopic evidences. The antioxidant activities were evaluated by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method and protective effect of DNA damage. The qualified immunologic activities were also determined in vivo and in vitro. The polysaccharides could stimulate the proliferation of mouse splenocytes whether concanavalin A (ConA) and lipopolysaccharide (LPS) existed or not, strengthen peritoneal macrophages to devour neutral red, and increase the content of interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-α) in serum. The research provides the corresponding evidence for Cordyceps polysaccharides as a potential candidate for functional foods and therapeutic agents.

Optimization, Purification and Antitumor Activity of Kodamaea ohmeri ANOMY L-Asparaginase Isolated from Banana Peel.

L-Asparaginase is an important enzyme that converts L-asparagine to L-aspartate and ammonia. Microbial L-asparaginase has important applications as anticancer and food processing agents. This study reported the isolation, screening of a local yeast isolate from banana peel for L-asparaginase production using submerged fermentation, optimization of the production, purification, and anticancer assay of L-asparaginase. The yeast isolate was identified as Kodamaea ohmeri ANOMY based on the analysis of nuclear large subunit (26S) rDNA partial sequences. It was a promising L-asparaginase producer with a specific activity of 3059±193 U/mg in a non-optimized medium. The classical one-variable-at-a-time method was used to optimize the production medium components, and it was found that the elimination of K2HPO4 from the medium increased L-asparaginase specific activity (3100.90±180 U/mg). Statistical optimization of L-asparaginase production was done using Plackett-Burman and Box-Behnken designs. The production medium for the maximum L-asparaginase specific activity (8500±578U/mg) was as follows (g/L): L-asparagine (7.50), NaNO3 (0.50), MgSO4.7H2O (0.80), KCl (0.80) associated with an incubation period of 5 days, inoculum size of 5.60 %, and pH (7.0). The optimization process increased L-asparaginase production by 2.78-fold compared to the non-optimized medium. L-Asparaginase was purified using ammonium sulphate precipitation followed by gel filtration on a Sephadex G-100 column. Its molecular weight was 66 KDa by SDS-PAGE analysis. The cell morphology technique was used to evaluate the anticancer activity of L-asparaginase against three different cell lines. L-Asparaginase inhibited the growth of HepG-2, MCF-7, and HCT-116 cells at a concentration of 20, 50, and 60 μL, respectively.

Purification and characterization of non-enzymatic glycoprotein (NEGp) from flax seed buffer extract that exhibits anticoagulant and antiplatelet activity

The current study deals with the purification and characterization of non-enzymatic glycoprotein (NEGp) from flax seed buffer extract. Sephadex G-100 and DEAE-A25 column chromatography techniques were employed to isolate NEGp. NEGp showed single sharp band at 29 kDa region on 10% SDS-PAGE, and under reduced and non-reduced conditions revealed its monomeric nature. Besides, NEGp taken up the PAS stain at 29 kDa region reveals the presence of carbohydrate moiety. Purity of NEGp was adjudged by RP-HPLC, as it revealed a single sharp peak at the retention time of 3.4 min. The exact molecular mass of NEGp was found to be 26 kDa which was confirmed by MALDI-TOF. Circular di-chromism spectra of NEGp showed 12.0% α-helix, 24.3% α-helix turn and 63.7% random coils without beta pleated sheets. NEGp was found to exhibit anticoagulant activity by extending clotting time of both platelet rich plasma and platelet poor plasma from control 240 s to 1800 s and 280 s to 2100 s respectively at the concentration of 8 μg. NEGp inhibited the agonists such as ADP, epinephrine and arachidonic acid induced platelet aggregation in washed platelets. The percentage of inhibition was found to be 70%, 80% and 60% respectively. While, it did not interfere in thrombin, PAF and collagen induced platelet aggregation. NEGp did not hydrolyse RBC membrane, devoid of haemorrhagic and edema inducing properties in experimental mice.

Characterization and inhibitory activities on α-amylase and α-glucosidase of the polysaccharide from blue honeysuckle berries

An acidic heteropolysaccharide HEP-2 was obtained from blue honeysuckle berry extracts after purification using Sepharose 6B and Sephadex G-200 column chromatography. The molecular weight of HEP-2, determined with high-performance gel permeation chromatography, was 3.01 × 106 Da. Fourier transform infrared spectroscopy, gas chromatography and nuclear magnetic resonance analyses revealed the presence of α-, β-pyranose ring and six sugar residues in HEP-2. Amorphous aggregates of HEP-2 with irregular shape and lacking the triple helical structure were detected using the Congo red test, scanning electron and atomic force microscopy, and X-ray diffraction studies. Rheological characterization showed typical shear-thinning behavior and viscoelastic property of the polysaccharide. HEP-2 exerted significant inhibitory effects on α-amylase and α-glucosidase and displayed competitive inhibition kinetics. The collective results support the potential utility of HEP-2 as a hypoglycemic agent for enzyme-targeted treatment of diabetes or functional food.

Tree bark scrape fungus: A potential source of laccase for application in bioremediation of non-textile dyes.

Although laccase has been recognized as a wonder molecule and green enzyme, the use of low yielding fungal strains, poor production, purification, and low enzyme kinetics have hampered its large-scale application. Thus,this study aims to select high yielding fungal strains and optimize the production, purification, and kinetics of laccase of Aspergillus sp. HB_RZ4. The results obtained indicated that Aspergillus sp. HB_RZ4 produced a significantly large amount of laccase under meso-acidophilic shaking conditions in a medium containing glucose and yeast extract. A 25 μM CuSO4 was observed to enhance the enzyme yield. The enzyme was best purified on a Sephadex G-100 column. The purified enzyme resembled laccase of A. flavus. The kinetics of the purified enzyme revealed high substrate specificity and good velocity of reaction,using ABTS as a substrate. The enzyme was observed to be stable over various pH values and temperatures. The peptide structure of the purified enzyme was found to resemble laccase of A. kawachii IFO 4308. The fungus was observed to decolorize various dyes independent of the requirement of a laccase mediator system.Aspergillus sp. HB_RZ4 was observed to be a potent natural producer of laccase, and it decolorized the dyes even in the absence of a laccase mediator system. Thus, it can be used for bioremediation of effluent that contains non-textile dyes.

Production of fungal enzymes in Macaúba coconut and enzymatic degradation of textile dye

Abstract The reduction of environmental pollutants has been important for the sustainability (environmental, economic, and social) of the manufacturing companies. The agro-industry annually produces tons of vegetable residues that is discarded in the environment. Textile industries have a high rate of dye discharges in water resources. Fungal enzymes produced in plant residues can degrade recalcitrant organic compounds. Thus, the aim of the study was the production, purification, characterization, and use of dye discoloration of enzymes produced by Pleurotus ostreatus (PLO 02 and PLO 06) and Pleurotus eryngii (PLE 05) in Macauba coconut (Acrocomia aculeate) residue. The initial time of colonization of the substrate was of 18 (P. eryngii) and 22 days (P. ostreratus). After this period, 50 g of substrate were collected every five days to evaluate the enzymatic activity before and after the purification in sephadex G-100 column. All fungal strains had activity of laccase, lignin peroxidase (LiP), manganese peroxidase (MnP), xylanase, cellulase, and lipase in crude protein extract. The enzymes kept the activities from 4 to 60 °C for about 16 h and these activities were higher in acidic than alkaline pH. Furthermore, the enzymes of P. eryngii degraded about 100% of Carmine indigo dye after 24 h of incubation. Therefore, the Macauba coconut residue is a good substrate for the enzyme production and these enzymes have high degradation capacity of the indigo dye.

Antiviral activity against porcine epidemic diarrhea virus of Pogostemon cablin polysaccharide

Ethnopharmacological relevanceThe dry overground parts of Pogostemon cablin (Blanco) Benth. is widely used in China as a traditional Chinese medicine for the treatment of diarrhea, vomiting, nausea and fever. Polysaccharide is an important component of Pogostemon cablin (Blanco) Benth. but has not been studied. Pogostemon cablin (Blanco) Benth. is used to treat porcine epidemic diarrhea. But it is not known whether Pogostemon cablin polysaccharides (PCPs) has the antiviral activities against porcine epidemic diarrhea virus (PEDV). Aim of the studyThe purpose of present study is to investigate the structural characterization and the anti-PEDV activities of PCPs. Materials and methodsPCPs were prepared by water extraction and alcohol precipitation method and purified with DEAE-52 cellulose column and Sephadex G-100 column. Then, the structural characterization of the polysaccharides including the infrared spectrum, molecular weight and monosaccharide composition were analyzed. Afterwards, the antiviral effect of PCPs against PEDV on IPEC-J2 cells was studied by MTT method and real-time PCR method. Additionally, the effects of PCPs on PEDV adsorption, penetration and replication were analyzed by real-time PCR method. Furthermore, we also investigate whether the anti-oxidative effects of PCPs were important to the anti-PEDV activities. ResultsFour polysaccharides were obtained and named as PCP1.1 (31.3 kDa), PCP1.2 (3.5 kDa), PCP2.1 (9.1 kDa) and PCP2.2 (8.3 kDa). PCP1.1, PCP1.2 and PCP2.1 were composed of fucose, arabinose, galactose, glucose, mannose, galacturonic acid and glucuronic acid; and PCP2.2 was composed of arabinose, galactose, glucose, galacturonic acid and glucuronic acid. All PCPs showed anti-PEDV activities. PCP1.1 and PCP1.2 inhibited PEDV replication, while PCP2.1 and PCP2.2 inhibited PEDV penetration and replication. All PCPs showed anti-oxidative effects, which were important to the anti-PEDV activities. ConclusionsThe treatment effect of Pogostemon cablin (Blanco) Benth. on porcine epidemic diarrhea might be related to the anti-PEDV effect of PCPs. Furthermore, the anti-oxidative effects of PCPs play important roles in their antiviral activities against PEDV.

Sulfated modification, characterization and monosaccharide composition analysis of Undaria pinnatifida polysaccharides and anti-tumor activity.

Undaria pinnatifida (U. pinnatifida) polysaccharides (UPPS) are considered to be the major bioactive components of U. pinnatifida. The aim of the present study was to investigate the separation, sulfated modification, characterization and monosaccharide composition of UPPS. The optimal processing conditions were as follows: Distilled water-to-solid ratio, 50 ml/g; extraction time, 300 min; and extraction temperature, 90˚C. The major polysaccharide fraction of U. pinnatifida (UPPS-B1) was purified via DEAE-52 and Sephadex G-200 column chromatography. The chlorosulfonic acid-pyridine method was applied for sulfation modification. UPPS-B1 and sulfated (S)-UPPS-B1 were characterized via chemical analysis, ultraviolet-visible and Fourier-transformed infrared spectroscopy, gas chromatography and high-performance liquid chromatography. The total sugar content of UPPS-B1 and S-UPPS-B1 was 79.78 and 77.28%, respectively. The sulfate radical content of UPPS-B1 and S-UPPS-B1 was 8.53 and 29.12%, whilst the content of uronic acid was 9.29 and 7.98%, respectively. The average molecular weight of UPPS-B1 and S-UPPS-B1 was determined to be 37 and 110 kD, respectively. UPPS-B1 was considered to be a heteropolysaccharide composed of xylose, mannose, glucose and galactose at a ratio of 7.9:8.7:12.0:9.8. In addition, S-UPPS-B1 was a heteropolysaccharide composed of xylose, mannose, glucose and galactose at a ratio of 1.0:9.7:6.4:1.6. The results of the tumor growth inhibition experiment demonstrated that UPPS-B1 exhibited anti-tumor activity in vivo, which was improved following sulfation to yield S-UPPS-B1.

Isolation of an anti-entomopathogenic fungal protein secreted from Pseudomonas aeruginosa BGf-2: An intestinal bacteriam of Blattella germanica (L.)

A bacterial strain (BGf-2) with anti-Beauveria bassiana activity was obtained from the feces of Blattella germanica (L.) and identified as Pseudomonas aeruginosa based on biochemical tests and 16S rRNA sequence analysis. An antifungal protein (A0A0H2ZK06) was purified with Sephadex G-100 column and DEAE-sepharose Fast Flowanion exchange from sterile BGf-2 fermentation liquid. Based on MALDI-TOF MS analysis and protein model building, A0A0H2ZK06 showed homology with Pyrrolidone carboxyl peptidases (pcps). Fermentation liquid and antifungal proteins not only reduced the B. bassiana conidial germination rate but also inhibited hyphal growth. A per os test showed that the mortality of cockroaches decreased after treatment with BGf-2 suspension compared with control. We hypothesized that gut microbes with antifungal activity might play an important role in protect cockroaches from pathogenic fungi.

A biological study of chitinase produced by clinical isolates of Pseudomonas aeruginosa and detection of ChiA responsible gene

All isolates in this study were diagnosed as P. aeroginosa according to the 16srRNA gene. Only two isolates were produced chitinase on chitin agar medium and were positive to the chiA gene. Most of the isolates exhibited high sensitivity (95%) and (90%) to Imipenem and Carbenicillin, respectively, and the resistance to Amoxicillin +Clavulanic acid was shown (80%), while revealed a variable degree in their response to others antibiotics. The crude extract activity and specific activity for extracted chitinase enzymes were 33 U/ml and 18.644U/mg, respectively. The enzyme was purified by different steps include: precipitating with saturation 70% of ammonium sulfate and then applied on ion-exchange chromatography using DEAE- cellulose column and then employ the Sephadex G-200 column for gel filtration chromatography. The purification fold and yield was 28.5%. The molecular weight of the purified enzyme was determined by SDS-PAGE method, and it appeared at 50 kDa. The results of the MTT assay showed that the chitinase has a cytotoxic effect on cancer liver cell lines at a concentration of 100 µg /ml and increased gradually at a concentration of 600 µg /ml, while it showed no or less cytotoxic effect on normal embryonic liver cell line (WRL-68). Chitinase enzyme appeared a higher antibacterial activity at concentration 600 µg/ml and a lower activity at concentration 400 towards clinical isolates of S. aurous and E. coli. The study of histopathological effects was exhibited little morphological changes on cells of liver tissues.

Cytotoxic and antioxidant activity of the polysaccharide isolated from the seeds of Strychnos potatorum

Abstract Nonconventional natural treatments have gained wide acceptance due to their promise of a cure with minimal or no side effects in cancer, but little scientific evidence exists. The polysaccharides were extracted from the seeds of Strychnos potatorum and were successively purified by chromatography on DEAE cellulose and Sephadex G-100 column. The purified polysaccharide was identified to be a heteropolysaccharide 1,4 β-D- galactomannan characterized using FTIR, NMR. The molecular weight was determined to be ∼ 1.28 X 10 4 Da through MALDI-TOF analysis. Presented, here is the first use of the polysaccharide isolated from the seeds of Strychnos potatorum exhibiting promising cytotoxic activity with IC50 of 365 μg/mL against human breast cancer cell line MCF-7. The antioxidant property of the polysaccharide was also evaluated and they possess potential scavenging activity for DPPH assay and hydroxy radical scavenging assay with increase in concentration.

Purification and characterization of chitinase from Paenibacillus sp. .

The chitinase-producing bacteria Paenibacillus sp. was isolated from soil samples. The chitinase was purified successively by ammonia sulfate fractional precipitation followed by chromatography on DEAE 52-cellulose column and then on SephadexG-75 column. The chitinase has a molecular weight of ca. 30 kDa as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis. Its optimum pH is 4.5, and its optimum temperature is 50°C with colloidal chitin as a substrate. The enzyme is stable below 45°C and in pH ranges between 4.5 and 5.5. It is activated by glucosamine, glucose, N-acetylglucosamine, and metal ions including Ca2+ , Fe2+ , Fe3+ , and Ni2+ . It is inhibited by SDS, H2 O2 , ascorbic acid, Cu2+ , Mg2+ , Ba2+ , Sn2+ , Cr3+ , and K+ . With colloidal chitin as substrate, the Km and the Vmax of the chitinase are 4.28 mg/mL and 14.29 μg/(Min·mL), respectively, whereas the end products of the enzymatic hydrolysis are 14.33% monomer and 85.67% dimer of N-acetylglucosamine. The viscosity of carboxymethylchitin decreased rapidly at the initial stages when subjected to chitinase hydrolysis, which indicates that the chitinase acts in an endosplitting pattern.

Isolation and Molecular Identification of Two Chitinase Producing Bacteria from Marine Shrimp Shell Wastes.

Chitinase enzymes have a various application in the field of environmental, biotechnology and medical aspects. This study aimed to the production of the chitinolytic enzymes from different species of bacteria. Bacterial isolation from different habitats was carried out on agar medium containing chitin as carbon and nitrogen sources. The obtained bacteria (20) were characterized and screened again in chitin broth medium. Out of 20 bacterial isolate, 2 new isolates, belonged to Streptomyces laurentii SN5 and Cellulosimicrobium funkei SN20, were the most active in chitin degradation compared to the other isolates. They have been characterized for the first time for their chitinase activity. They were identified using 16S rRNA gene analysis and in the liquid medium, the 2 isolates have enzyme activities of 0.533 and 0.537 U mL-1, respectively. The maximum chitinase production was obtained when those bacterial strains were grown in Luria-Bertani (LB) broth amended with 1% colloidal chitin, for 1 day and at temperature of 30°C. The optimum pH value for chitinase production was pH 7 for both S. laurentii and C. funkei. The enzyme has been purified using Sephadex G-100 and DEAE-Cellulose chromatography column and found to have a similar molecular size of ~50 kDa. Those two bacterial species could be used in chitinase production and in the environmental recycling of disposable chitin wastes such as chitin from shrimp shell waste.

Polysaccharides from Pleurotus eryngii var. elaeoselini (Agaricomycetes), a New Potential Culinary-Medicinal Oyster Mushroom from Italy.

Three water-soluble glucans (PELPS-A1, PELPS-A2, and PELPS-A3) purified from the hot water extract of the basidiomata of an edible mushroom Pleurotus eryngii var. elaeoselini by chromatography on DEAE-cellulose 32 and Sephadex G-100 column were found to consist of only D-glucose as monosaccharide constituent. Structural investigation was carried out by acid hydrolysis, periodate oxidation, and NMR experiments (1H-NMR, 13C-NMR, DQF-COSY, TOCSY, ROESY, HMQC, and HMBC). On the basis of these experiments, the structures of the repeating unit of the three isolated polysaccharides were established as follows: (1) PELPS-A1: {[→3)-α-D-Glcp-(1→]3→4)-α-D-Glcp-(1→2)-α-D-Glcp-(1→6)-α-D-Glcp-(1[→6)-β-D-Glcp-(1→]2}n 6 ↑ 1 α-D-Glcp (2) PELPS-A2: [→6)-β-D-Glcp-(1→6)-β-D-Glcp-(1→6)-β-D-Glcp-(1→]n 3 ↑ 1 β-D-Glcp (3) PELPS-A3: [→6)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glcp-(1→]n The dried basidiomata of P. eryngii var. elaoselini were tested for their antioxidant activity by DPPH and hydroxyl radical scavenging assays. The crude extract has shown a SC50 of 1.4 mg/mL for DPPH test while a SC50 of 5.7 mg/mL was observed for hydroxyl radical scavenging activity test. The antioxidant activity of PELPS-A1, PELPS-A2, and PELPS-A3, evaluated as hydroxyl radical scavenging activity, was similar and significant, suggesting their use as antioxidants.

Isolation, purification, structural characteristic and antioxidative property of polysaccharides from A. cepa L. var. agrogatum Don

Allium cepa L. var. agrogatum Don (ALAP) is commonly consumed in China as well as other regions and has various beneficial health effects. A novel acidic polysaccharide (named ALAP-21) was obtained from ALAP by ultrasonic and microwave-assisted extraction and purification using DEAE-52 anion exchange and Sephadex G-100 columns. The monosaccharide composition, structural and antioxidative properties of ALAP-21 were investigated by GC–MS chromatography, FT-IR and NMR spectroscopies and three antioxidative activity tests in vitro. The results showed that ALAP-21 was a heteropolysaccharide composed of glucose, galacturonic acid, mannose, galactose, arabinose, rhamnose, xylose, fructose and glucuronic acid with a relative molar ratio of 26.282: 27.546: 11.400: 4.781: 2.467: 2.445: 3.622: 1.106: 1.753, owning (1→4)-α-d-Glcp, (1→4)-α-d-GalAp6Me3OA, (1→4)-β-d-Galp6OMe, (1→2)-α-l-Rhap, (1→4)-β-d-Manp glycosidic linkages. (1→4)-α-d-Glcp and (1→4)-α-d-GalAp6Me3OA residues might be the main components of the sugar chain backbone of ALAP-21. Furthermore, ALAP-21 exhibited high potential for DPPH radicals (82.02%), hydroxyl radicals (53.33%) and superoxide anion radicals (50.28%). These results provide a reference for further research and rational development of ALAP polysaccharides.

Neuroprotective Effect of β-secretase Inhibitory Peptide from Pacific Hake (Merluccius productus) Fish Protein Hydrolysate.

Various methodologies have been employed for the therapeutic interpolation of the progressive brain disorder Alzheimer's disease. Thus, β-secretase inhibition is significant to prevent disease progression in the early stages. This study seeks to purify and characterize a novel β-secretase inhibitory peptide from Pacific hake enzymatic hydrolysate. A potent β-secretase inhibitory peptide was isolated by sequential purifications using Sephadex G-25 column chromatography and octadecylsilane (ODS) C18 reversed-phase HPLC. A total of seven peptides were synthesized using the isolated peptide sequences. SH-SY5Y cells stably transfected with the human ''Swedish'' amyloid precursor protein (APP) mutation APP695 (SH-SY5YAPP695swe) were used as an in-vitro model system to investigate the effect of Leu-Asn peptide on APP processing. The β-secretase inhibitory activity (IC50) of the purified peptide (Ser-Leu-Ala-Phe-Val-Asp- Asp-Val-Leu-Asn) from fish protein hydrolysate was 18.65 μM and dipeptide Leu-Asn was the most potent β-secretase inhibitor (IC50 value = 8.82 µM). When comparing all the seven peptides, the inhibition pattern of Leu-Asn dipeptide was found to be competitive by Lineweaver-Burk plot and Dixon plot (Ki value = 4.24 µM). The 24 h treatment with Leu-Asn peptide in SH-SY5Y cells resulted in reducing the β-amyloid (Aβ) production in a dose-dependent manner. Therefore, the results of this study suggest that β-secretase inhibitory peptides derived from marine organisms could be potential candidates to develop nutraceuticals or pharmaceuticals as antidementia agents.