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Hye Ryung Park - One of the best experts on this subject based on the ideXlab platform.

  • structural elucidation of anti metastatic rhamnogalacturonan ii from the pectinase digest of Citrus Peels Citrus unshiu
    International Journal of Biological Macromolecules, 2017
    Co-Authors: Hye Ryung Park, Su Beom Park, Hee Do Hong, Kwang Soon Shin
    Abstract:

    Abstract The aim of this study was to characterize a polysaccharide found in Citrus Peels with an anti-metastatic property. CPE-II was purified by the pectinase digestion of Citrus Peels. During in vivo lung metastasis of Colon26-M3.1, administration of 10 μg of CPE-II per mouse showed 81.3% inhibition of metastasis. CPE-II consists of 15 different monosaccharides and 22 different glycosyl linkages, characteristic of rhamnogalacturonan II (RG-II). The primary structure was elucidated based on sugar composition, methylation analysis, oligosaccharide analysis, and sequencing using GC, GC–MS, LC–MS, and ESI–MS/MS analyses. Sequential degradation using partial acid hydrolysis indicated that CPE-II contained Rhap-(1 → 5)-Kdo, Araf-(1 → 5)-Dha, an AceA-containing nonasaccharide, and an uronic acid-rich oligosaccharide in addition to an α-(1 → 4)-galacturono-oligosaccharide main chain. The molecular weight of CPE-II was observed to decrease from 9 to 5 kDa at a pH value of

  • structural elucidation of anti metastatic rhamnogalacturonan ii from the pectinase digest of Citrus Peels Citrus unshiu
    International Journal of Biological Macromolecules, 2017
    Co-Authors: Hye Ryung Park, Su Beom Park, Hee Do Hong, Hyung Joo Suh, Kwang Soon Shin
    Abstract:

    The aim of this study was to characterize a polysaccharide found in Citrus Peels with an anti-metastatic property. CPE-II was purified by the pectinase digestion of Citrus Peels. During in vivo lung metastasis of Colon26-M3.1, administration of 10μg of CPE-II per mouse showed 81.3% inhibition of metastasis. CPE-II consists of 15 different monosaccharides and 22 different glycosyl linkages, characteristic of rhamnogalacturonan II (RG-II). The primary structure was elucidated based on sugar composition, methylation analysis, oligosaccharide analysis, and sequencing using GC, GC-MS, LC-MS, and ESI-MS/MS analyses. Sequential degradation using partial acid hydrolysis indicated that CPE-II contained Rhap-(1→5)-Kdo, Araf-(1→5)-Dha, an AceA-containing nonasaccharide, and an uronic acid-rich oligosaccharide in addition to an α-(1→4)-galacturono-oligosaccharide main chain. The molecular weight of CPE-II was observed to decrease from 9 to 5kDa at a pH value of <2.0, as observed by HPSEC. Thus, we propose that the anti-metastatic CPE-II is primarily present as an RG-II dimer.

Kwang Soon Shin - One of the best experts on this subject based on the ideXlab platform.

  • structural elucidation of anti metastatic rhamnogalacturonan ii from the pectinase digest of Citrus Peels Citrus unshiu
    International Journal of Biological Macromolecules, 2017
    Co-Authors: Hye Ryung Park, Su Beom Park, Hee Do Hong, Kwang Soon Shin
    Abstract:

    Abstract The aim of this study was to characterize a polysaccharide found in Citrus Peels with an anti-metastatic property. CPE-II was purified by the pectinase digestion of Citrus Peels. During in vivo lung metastasis of Colon26-M3.1, administration of 10 μg of CPE-II per mouse showed 81.3% inhibition of metastasis. CPE-II consists of 15 different monosaccharides and 22 different glycosyl linkages, characteristic of rhamnogalacturonan II (RG-II). The primary structure was elucidated based on sugar composition, methylation analysis, oligosaccharide analysis, and sequencing using GC, GC–MS, LC–MS, and ESI–MS/MS analyses. Sequential degradation using partial acid hydrolysis indicated that CPE-II contained Rhap-(1 → 5)-Kdo, Araf-(1 → 5)-Dha, an AceA-containing nonasaccharide, and an uronic acid-rich oligosaccharide in addition to an α-(1 → 4)-galacturono-oligosaccharide main chain. The molecular weight of CPE-II was observed to decrease from 9 to 5 kDa at a pH value of

  • structural elucidation of anti metastatic rhamnogalacturonan ii from the pectinase digest of Citrus Peels Citrus unshiu
    International Journal of Biological Macromolecules, 2017
    Co-Authors: Hye Ryung Park, Su Beom Park, Hee Do Hong, Hyung Joo Suh, Kwang Soon Shin
    Abstract:

    The aim of this study was to characterize a polysaccharide found in Citrus Peels with an anti-metastatic property. CPE-II was purified by the pectinase digestion of Citrus Peels. During in vivo lung metastasis of Colon26-M3.1, administration of 10μg of CPE-II per mouse showed 81.3% inhibition of metastasis. CPE-II consists of 15 different monosaccharides and 22 different glycosyl linkages, characteristic of rhamnogalacturonan II (RG-II). The primary structure was elucidated based on sugar composition, methylation analysis, oligosaccharide analysis, and sequencing using GC, GC-MS, LC-MS, and ESI-MS/MS analyses. Sequential degradation using partial acid hydrolysis indicated that CPE-II contained Rhap-(1→5)-Kdo, Araf-(1→5)-Dha, an AceA-containing nonasaccharide, and an uronic acid-rich oligosaccharide in addition to an α-(1→4)-galacturono-oligosaccharide main chain. The molecular weight of CPE-II was observed to decrease from 9 to 5kDa at a pH value of <2.0, as observed by HPSEC. Thus, we propose that the anti-metastatic CPE-II is primarily present as an RG-II dimer.

Silke Schiewer - One of the best experts on this subject based on the ideXlab platform.

  • Optimization and kinetic modeling of cadmium desorption from Citrus Peels: A process for biosorbent regeneration
    Journal of Hazardous Materials, 2012
    Co-Authors: Eloh Njikam, Silke Schiewer
    Abstract:

    Abstract Citrus peel biosorbents are efficient in removing heavy metals from wastewater. Heavy metal recovery and sorbent regeneration are important for the financial competitiveness of biosorption with other processes. The desorbing agents HNO 3 , NaNO 3 , Ca(NO 3 ) 2 , EDTA, S, S-EDDS, and Na-Citrate were studied at different concentrations to optimize cadmium elution from orange or grapefruit Peels. In most cases, desorption was fast, being over 90% complete within 50 min. However sodium nitrate and 0.001 M nitric acid were less efficient. Several new models for desorption kinetics were developed. While zero-, first- and second-order kinetics are commonly applied for modeling adsorption kinetics, the present study adapts these models to describe desorption kinetics. The proposed models relate to the number of metal-filled binding sites as the rate-determining reactant concentration. A model based on first order kinetics with respect to the remaining metal bound performed best. Cd bound in subsequent adsorption after desorption was similar to the original amount bound for desorption by nitric acid, but considerably lower for calcium nitrate as the desorbent. While complexing agents were effective desorbents, their cost is higher than that of common mineral acids. Thus 0.01–0.1 M acids are the most promising desorbing agents for efficient sorbent regeneration.

  • biosorption of cadmium ii ions by Citrus Peels in a packed bed column effect of process parameters and comparison of different breakthrough curve models
    Clean-soil Air Water, 2011
    Co-Authors: Abhijit Chatterjee, Silke Schiewer
    Abstract:

    The efficiency of low cost Citrus Peels as biosorbents for removal of cadmium ions from aqueous solution was investigated in a fixed bed column, a process that could be applied to treat industrial wastewaters similar to commonly used ion exchange columns. Effluent concentration versus time profiles (i.e., breakthrough curves) were experimentally determined in a laboratory-scale packed bed column for varying operational parameters such as flow rate (2, 9, and 15.5 mL/min), influent cadmium concentration (5, 10, and 15 mg/L), and bed height (24, 48, and 72 cm) at pH 5.5. Column operation was most efficient for empty bed contact times of at least 10 min, which were apparently necessary for mass transfer. While the sorption capacity was largely unaffected by operational variables, the Thomas (Th) rate constant increased with the flow rate, and slightly decreased with increasing column length. Three widely used semi-mechanistic models (Th, Bohart–Adams, and Yoon–Nelson) were shown to be equivalent and the generalized model was compared with a two-parameter empirical model (dose-response). The latter was found to be able to better simulate the breakthrough curve in the region of breakthrough and saturation.

  • the role of pectin in cd binding by orange peel biosorbents a comparison of Peels depectinated Peels and pectic acid
    Journal of Hazardous Materials, 2010
    Co-Authors: Silke Schiewer, Muhammad Iqbal
    Abstract:

    Abstract Biosorption by cheaply and abundantly available materials such as Citrus Peels can be a cost efficient method for removing heavy metals from wastewater. To investigate the role pectin plays in metal binding by Citrus Peels, native orange Peels, protonated Peels, depectinated Peels, and extracted pectic acid were compared. Kinetic experiments showed that equilibrium was achieved in 1 h. The 1st-order model was more effective in describing the kinetics than the 2nd-order model. Titrations showed two acidic sites with pKa values around 4 (carboxyl) and 10.5 (hydroxyl), respectively. The pH dependent surface charge was described well by a two-site model. Sorption isotherms were best modeled assuming a 1:2 binding stoichiometry, followed by the Langmuir and the Freundlich model. The binding capacity was highest for pectic acid (2.9 mequiv./g) followed by protonated Peels and native Peels, being lowest for depectinated Peels (1.7 mequiv./g). This showed the importance of pectin in metal binding by Citrus Peels. However, even depectinated Peels were still good sorbents which still provided carboxyl groups that were involved in metal binding. FTIR spectra confirmed the presence of carboxyl and hydroxyl groups in all materials and their involvement in metal binding.

  • pectin rich fruit wastes as biosorbents for heavy metal removal equilibrium and kinetics
    Bioresource Technology, 2008
    Co-Authors: Silke Schiewer, Santosh B Patil
    Abstract:

    Abstract Biosorption can be used as a cost effective and efficient technique for the removal of toxic heavy metals from wastewater. Waste materials from industries such as food processing and agriculture may act as biosorbents. This study investigates the removal of cadmium by fruit wastes (derived from several Citrus fruits, apples and grapes). Citrus Peels were identified as the most promising biosorbent due to high metal uptake in conjunction with physical stability. Uptake was rapid with equilibrium reached after 30–80 min depending on the particle size (0.18–0.9 mm). Sorption kinetics followed a second-order model. Sorption equilibrium isotherms could be described by the Langmuir model in some cases, whereas in others an S-shaped isotherm was observed, that did not follow the Langmuir isotherm model. The metal uptake increased with pH, with uptake capacities ranging between 0.5 and 0.9 meq/g of dry peel. Due to their low cost, good uptake capacity, and rapid kinetics, Citrus Peels are a promising biosorbent material warranting further study.

Inwook Choi - One of the best experts on this subject based on the ideXlab platform.

  • narirutin fraction from Citrus Peels attenuates alcoholic liver disease in mice
    Food and Chemical Toxicology, 2013
    Co-Authors: Hoyoung Park, Sang Keun Ha, Inwook Choi
    Abstract:

    Abstract This study aimed to demonstrate protective activities of the narirutin fraction from Peels of Citrus unshiu against ethanol-induced hepatic damage through an animal study. Citrus narirutin fraction (CNF), contained 75% of narirutin, was obtained by an ultra-sonicated extraction and further purification. ICR mice were divided into four groups; normaldiet control, ethanol control (6.5 g ethanol/kg), low-CNF (ethanol + 150 mg CNF/kg) and high-CNF (ethanol + 300 mg CNF/kg) groups. Consumption of alcohol for 8 weeks induced severe liver damage with increases in prognostic indicators such as aspartate transaminase, alanine transaminase in serum whereas co-administration of CNF suppressed their increases. Excessive accumulations in liver TG and TC in ethanol control group were also suppressed by co-administration of CNF. Co-administration of CNF maintained SOD activity, GSH and malondialdehyde levels close to those of the normal diet group. Chronic consumption of alcohol also stimulated abrupt increases in pro-inflammatory cytokines such as nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α and interleukin (IL)-1β in liver otherwise co-administration of CNF effectively suppressed production of these cytokines dose-dependently. These results indicate that co-administration of CNF with alcohol can alleviate alcohol induced liver damage through preventing lipid formation, protecting antioxidant system and suppressing productions of pro-inflammatory cytokines.

  • narirutin fraction from Citrus Peels attenuates lps stimulated inflammatory response through inhibition of nf κb and mapks activation
    Food and Chemical Toxicology, 2012
    Co-Authors: Sang Keun Ha, Hoyoung Park, Inwook Choi
    Abstract:

    In this study, we examined the regulatory activity of narirutin fraction from Citrus Peels on the production of inflammatory mediators managing acute or chronic inflammatory diseases in macrophages. Narirutin fraction inhibited the release, by lipopolysaccharide (LPS)-stimulated macrophages, of nitric oxide (NO) and prostaglandin E2 (PGE2) through suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively. The release, by LPS stimulated macrophages, of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) was also reduced by narirutin fraction in a dose-dependent manner. Furthermore, narirutin fraction inhibited the LPS-mediated activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs), which are signaling molecules involved in production of pro-inflammatory factors. As a result of these properties, narirutin fraction has the potential to be used as a functional dietary supplement and effective anti-inflammatory agent.

Claudette Berset - One of the best experts on this subject based on the ideXlab platform.

  • antioxidant activity and phenolic composition of Citrus peel and seed extracts
    Journal of Agricultural and Food Chemistry, 1998
    Co-Authors: Alexandra Bocco, Marie-elisabeth Cuvelier, Hubert Richard, Claudette Berset
    Abstract:

    A possible way to valorize Citrus Peels and seeds, which are byproducts of the juice extraction industry, is to use them as natural antioxidants. The antioxidant activity of several Citrus peel and seed extracts obtained either by methanol extraction (free phenolic compounds) or by alkaline hydrolysis (bound phenolic compounds) was tested in a model system based on accelerated citronellal oxidation. Generally, seeds possessed greater antioxidant activity than Peels. The composition of all tested samples was studied by HPLC:  methanol extracts are rich in flavones and glycosylated flavanones, whereas hydrolyzed extracts contain mainly phenolic acids and flavonols. The phenolic composition of some Citrus Peels and seeds was described for the first time. No clear relationship could be shown between the antioxidant activity and the phenolic composition of the extracts. Keywords: Citrus fruits; byproducts; antioxidant activity; flavanones; phenolic acids

  • antioxidant activity and phenolic composition of Citrus peel and seed extracts
    Journal of Agricultural and Food Chemistry, 1998
    Co-Authors: Alexandra Bocco, Marie-elisabeth Cuvelier, Hubert Richard, Claudette Berset
    Abstract:

    A possible way to valorize Citrus Peels and seeds, which are byproducts of the juice extraction industry, is to use them as natural antioxidants. The antioxidant activity of several Citrus peel and...