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Sample records for barbadensis leaf polysaccharides

  1. Final report on the safety assessment of AloeAndongensis Extract, Aloe Andongensis Leaf Juice,aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice,aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract.

    PubMed

    2007-01-01

    Plant materials derived from the Aloe plant are used as cosmetic ingredients, including Aloe Andongensis Extract, Aloe Andongensis Leaf Juice, Aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice, Aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract. These ingredients function primarily as skin-conditioning agents and are included in cosmetics only at low concentrations. The Aloe leaf consists of the pericyclic cells, found just below the plant's skin, and the inner central area of the leaf, i.e., the gel, which is used for cosmetic products. The pericyclic cells produce a bitter, yellow latex containing a number of anthraquinones, phototoxic compounds that are also gastrointestinal irritants responsible for cathartic effects. The gel contains polysaccharides, which can be acetylated, partially acetylated, or not acetylated. An industry established limit for anthraquinones in aloe-derived material for nonmedicinal use is 50 ppm or lower. Aloe-derived ingredients are used in a wide variety of cosmetic product types at concentrations of raw material that are 0.1% or less, although can be as high as 20%. The concentration of Aloe in the raw material also may vary from 100% to a low of 0.0005%. Oral administration of various anthraquinone components results in a rise in their blood concentrations, wide systemic distribution, accumulation in the liver and kidneys, and excretion in urine and feces; polysaccharide components are distributed systemically and metabolized into smaller molecules. aloe-derived material has fungicidal, antimicrobial, and antiviral activities, and has been effective in wound healing and infection treatment in animals. Aloe barbadensis (also known as Aloe vera)-derived ingredients were not toxic

  2. Proteomic identification of a basic peroxidase stabilized within acetylated polymannan polysaccharide of Aloe barbadensis.

    PubMed

    Vittori, Natale; Martín, Mercedes; Sabater, Bartolomé

    2012-01-01

    Acetylated polymannan polysaccharide (ApmP) isolated from Aloe barbadensis Miller contains a stable peroxidase that was solubilized to investigate its biochemical, electrophoretic, immunological, and proteomic properties. In the electrophoretic band corresponding to the solubilized peroxidase, proteomic analysis detected seven tryptic peptides that matched homologous peptides covering one third of the ATP22a peroxidase of Arabidopsis thaliana. All the characteristics tested indicated that the activity stabilized within the ApmP pertains to the basic secretory peroxidase family, which includes members that have several biotechnological uses. Hence ApmP might yield a widely used peroxidase in stabilized form.

  3. Evaluation of in vitro and in vivo antioxidant potential of polysaccharides from Aloe vera (Aloe barbadensis Miller) gel.

    PubMed

    Kaithwas, Gaurav; Singh, Prashant; Bhatia, Daksh

    2014-04-01

    In the present study, the antioxidant activity of the polysaccharides from aloe vera (Aloe barbadensis Miller) gel was evaluated, in vitro by five established methods, 1,1-diphenyl-2-picrylhydrazyl (DPPH(-)) radical scavenging, nitric oxide (NO) scavenging, hydrogen peroxide scavenging, superoxide radical (O(-2)) scavenging and reducing power assay, and in vivo against doxorubicin (DOX)-induced myocardial oxidative stress (OS) in albino wistar rats. The polysaccharides exhibited significant inhibitory activity against DPPH(-), superoxide, NO and hydrogen peroxide scavenging assay with significant reducing activity at all concentrations used. DOX-induced (7.5 mg/kg, intravenously) cardiotoxicity manifested biochemically by a significant decrease in blood and tissue glutathione (GSH) along with elevated levels of serum lactate dehydrogenase and creatine phosphokinase. In addition, cardiotoxicity was further confirmed by the significant increase in lipid peroxidation expressed as thiobarbituric acid reactive substances (TBARS), catalase (CAT) and superoxide dismutase (SOD). Administration of aloe vera polysaccharides for 14 days produced a marked protection against cardiotoxicity induced by DOX evidenced by significant reductions in serum lactate dehydrogenase, serum creatine phosphokinase, cardiac TBARS, CAT and SOD along with increased levels of blood and tissue GSH in a dose-dependent manner. The present investigation is the first to establish the antioxidant potency of the polysaccharides from aloe vera against DOX-induced myocardial OS.

  4. In vitro and in vivo antioxidant activities of polysaccharide purified from aloe vera (Aloe barbadensis) gel.

    PubMed

    Kang, Min-Cheol; Kim, Seo Young; Kim, Yoon Taek; Kim, Eun-A; Lee, Seung-Hong; Ko, Seok-Chun; Wijesinghe, W A J P; Samarakoon, Kalpa W; Kim, Young-Sun; Cho, Jin Hun; Jang, Hyeang-Su; Jeon, You-Jin

    2014-01-01

    The in vitro and in vivo antioxidant potentials of a polysaccharide isolated from aloe vera gel were investigated. Enzymatic extracts were prepared from aloe vera gel by using ten digestive enzymes including five carbohydrases and five proteases. Among them, the highest yield was obtained with the Viscozyme extract and the same extract showed the best radical scavenging activity. An active polysaccharide was purified from the Viscozyme extract using ethanol-added separation and anion exchange chromatography. Purified aloe vera polysaccharide (APS) strongly scavenged radicals including DPPH, hydroxyl and alkyl radicals. In addition, APS showed a protective effect against AAPH-induced oxidative stress and cell death in Vero cells as well as in the in vivo zebrafish model. In this study, it is proved that both the in vitro and in vivo antioxidant potentials of APS could be further utilized in relevant industrial applications.

  5. Clear Evidence of Carcinogenic Activity by a Whole-Leaf Extract of Aloe barbadensis Miller (Aloe vera) in F344/N Rats

    PubMed Central

    Boudreau, Mary D.

    2013-01-01

    Aloe barbadensis Miller (Aloe vera) is an herbal remedy promoted to treat a variety of illnesses; however, only limited data are available on the safety of this dietary supplement. Drinking water exposure of F344/N rats and B6C3F1 mice to an Aloe vera whole-leaf extract (1, 2, and 3%) for 13 weeks resulted in goblet cell hyperplasia of the large intestine in both species. Based upon this observation, 2-year drinking water studies were conducted to assess the carcinogenic potential of an Aloe vera whole-leaf extract when administered to F344/N rats (48 per sex per group) at 0.5, 1, and 1.5%, and B6C3F1 mice (48 per sex per group) at 1, 2, and 3%. Compared with controls, survival was decreased in the 1.5% dose group of female rats. Treatment-related neoplasms and nonneoplastic lesions in both species were confined primarily to the large intestine. Incidences of adenomas and/or carcinomas of the ileo-cecal and cecal-colic junction, cecum, and ascending and transverse colon were significantly higher than controls in male and female rats in the 1 and 1.5% dose groups. There were no neoplasms of the large intestine in mice or in the 0 or 0.5% dose groups of rats. Increased incidences of mucosa hyperplasia of the large intestine were observed in F344/N rats, and increased incidences of goblet cell hyperplasia of the large intestine occurred in B6C3F1 mice. These results indicate that Aloe vera whole-leaf extract is an intestinal irritant in F344/N rats and B6C3F1 mice and a carcinogen of the large intestine in F344/N rats. PMID:22968693

  6. Clear evidence of carcinogenic activity by a whole-leaf extract of Aloe barbadensis miller (aloe vera) in F344/N rats.

    PubMed

    Boudreau, Mary D; Mellick, Paul W; Olson, Greg R; Felton, Robert P; Thorn, Brett T; Beland, Frederick A

    2013-01-01

    Aloe barbadensis Miller (Aloe vera) is an herbal remedy promoted to treat a variety of illnesses; however, only limited data are available on the safety of this dietary supplement. Drinking water exposure of F344/N rats and B6C3F1 mice to an Aloe vera whole-leaf extract (1, 2, and 3%) for 13 weeks resulted in goblet cell hyperplasia of the large intestine in both species. Based upon this observation, 2-year drinking water studies were conducted to assess the carcinogenic potential of an Aloe vera whole-leaf extract when administered to F344/N rats (48 per sex per group) at 0.5, 1, and 1.5%, and B6C3F1 mice (48 per sex per group) at 1, 2, and 3%. Compared with controls, survival was decreased in the 1.5% dose group of female rats. Treatment-related neoplasms and nonneoplastic lesions in both species were confined primarily to the large intestine. Incidences of adenomas and/or carcinomas of the ileo-cecal and cecal-colic junction, cecum, and ascending and transverse colon were significantly higher than controls in male and female rats in the 1 and 1.5% dose groups. There were no neoplasms of the large intestine in mice or in the 0 or 0.5% dose groups of rats. Increased incidences of mucosa hyperplasia of the large intestine were observed in F344/N rats, and increased incidences of goblet cell hyperplasia of the large intestine occurred in B6C3F1 mice. These results indicate that Aloe vera whole-leaf extract is an intestinal irritant in F344/N rats and B6C3F1 mice and a carcinogen of the large intestine in F344/N rats.

  7. Structural Characterization of Arabidopsis Leaf Arabinogalactan Polysaccharides1[W

    PubMed Central

    Tryfona, Theodora; Liang, Hui-Chung; Kotake, Toshihisa; Tsumuraya, Yoichi; Stephens, Elaine; Dupree, Paul

    2012-01-01

    Proteins decorated with arabinogalactan (AG) have important roles in cell wall structure and plant development, yet the structure and biosynthesis of this polysaccharide are poorly understood. To facilitate the analysis of biosynthetic mutants, water-extractable arabinogalactan proteins (AGPs) were isolated from the leaves of Arabidopsis (Arabidopsis thaliana) plants and the structure of the AG carbohydrate component was studied. Enzymes able to hydrolyze specifically AG were utilized to release AG oligosaccharides. The released oligosaccharides were characterized by high-energy matrix-assisted laser desorption ionization-collision-induced dissociation mass spectrometry and polysaccharide analysis by carbohydrate gel electrophoresis. The Arabidopsis AG is composed of a β-(1→3)-galactan backbone with β-(1→6)-d-galactan side chains. The β-(1→6)-galactan side chains vary in length from one to over 20 galactosyl residues, and they are partly substituted with single α-(1→3)-l-arabinofuranosyl residues. Additionally, a substantial proportion of the β-(1→6)-galactan side chain oligosaccharides are substituted at the nonreducing termini with single 4-O-methyl-glucuronosyl residues via β-(1→6)-linkages. The β-(1→6)-galactan side chains are occasionally substituted with α-l-fucosyl. In the fucose-deficient murus1 mutant, AGPs lack these fucose modifications. This work demonstrates that Arabidopsis mutants in AGP structure can be identified and characterized. The detailed structural elucidation of the AG polysaccharides from the leaves of Arabidopsis is essential for insights into the structure-function relationships of these molecules and will assist studies on their biosynthesis. PMID:22891237

  8. Green synthesis and characterization of silver nanoparticle using Aloe barbadensis

    SciTech Connect

    Thappily, Praveen E-mail: shiiuvenus@gmail.com; Shiju, K. E-mail: shiiuvenus@gmail.com

    2014-10-15

    Green synthesis of silver nanoparticles was achieved by simple visible light irradiation using aloe barbadensis leaf extract as reducing agent. UV-Vis spectroscopic analysis was used for confirmation of the successful formation of nanoparticles. Investigated the effect of light irradiation time on the light absorption of the nanoparticles. It is observed that upto 25 minutes of light irradiation, the absorption is linearly increasing with time and after that it becomes saturated. Finally, theoretically fitted the time-absorption graph and modeled a relation between them with the help of simulation software.

  9. Green synthesis and characterization of silver nanoparticle using Aloe barbadensis

    NASA Astrophysics Data System (ADS)

    Thappily, Praveen; Shiju, K.

    2014-10-01

    Green synthesis of silver nanoparticles was achieved by simple visible light irradiation using aloe barbadensis leaf extract as reducing agent. UV-Vis spectroscopic analysis was used for confirmation of the successful formation of nanoparticles. Investigated the effect of light irradiation time on the light absorption of the nanoparticles. It is observed that upto 25 minutes of light irradiation, the absorption is linearly increasing with time and after that it becomes saturated. Finally, theoretically fitted the time-absorption graph and modeled a relation between them with the help of simulation software.

  10. Optimum extraction of polysaccharides from motherwort leaf and its antioxidant and antimicrobial activities.

    PubMed

    Tahmouzi, Saeed; Ghodsi, Mitra

    2014-11-01

    Box-Behnken design was employed to optimize the extraction conditions for polysaccharides from the leaves of motherwort (Leonurus cardiaca L.). Three independent variables including extraction temperature (60-100 °C), extraction time (60-120 min), and the ratio of water to raw material (20-60) were investigated. The results revealed that the quadratic and linear terms of three factors had strong effects on the extraction yield of polysaccharides from motherwort leaf. The best extraction conditions for the yield of polysaccharide (LCLP) was extraction temperature of 81.4 °C, time of 106.6 min and the ratio of water to raw material of 45.2. Under the optimal conditions, the extraction yield of LCLP was 9.17 ± 0.39%, which was well matched with value predicted by the model 9.26%. The results indicated that the purified LCLP exerted obvious scavenging effects on free radicals in vitro. Furthermore, motherwort polysaccharides could be used as a novel antimicrobial additive.

  11. The Dynamics of Plant Cell-Wall Polysaccharide Decomposition in Leaf-Cutting Ant Fungus Gardens

    PubMed Central

    Harholt, Jesper; Willats, William G. T.; Boomsma, Jacobus J.

    2011-01-01

    The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants. PMID:21423735

  12. A sycamore cell wall polysaccharide and a chemically related tomato leaf polysaccharide possess similar proteinase inhibitor-inducing activities.

    PubMed

    Ryan, C A; Bishop, P; Pearce, G

    1981-09-01

    A large pectic polysaccharide, called rhamnogalacturonan I, that is solubilized by a fungal endo-alpha-1,4-polygalacturonase from the purified walls of suspension-cultured sycamore cells possesses proteinase inhibitor-inducing activity similar to that of the proteinase inhibitor-inducing factor, a pectic-like oligosaccharide fraction isolated from tomato leaves. This suggests that the proteinase inhibitor-inducing activity resides in particular polysaccharide fragments which can be released when plant cell walls are exposed to appropriate enzyme degradation as a result of either wounding or pest attack.

  13. Protective effects of Ginkgo biloba leaf polysaccharide on nonalcoholic fatty liver disease and its mechanisms.

    PubMed

    Yan, Zhengui; Fan, Ruifeng; Yin, Shaojie; Zhao, Xiaona; Liu, Jianzhu; Li, Liuhui; Zhang, Wenqi; Ge, Lijiang

    2015-09-01

    A water-soluble polysaccharide fraction extracted from the leaf of Ginkgo biloba was named GBLP. The protective effect of GBLP on nonalcoholic fatty liver disease (NAFLD) was observed and underlying mechanism was explored. Wistar male rats were randomly divided into five groups, namely, normal control group, model control group and GBLP groups (100, 200 and 400 mg/kg/d). A rat model of NAFLD was established in male Wistar rats by feeding with high-fat diet (HFD) for 8 weeks. On day 57, the intragastric administration of GBLP started once daily for 4 weeks. The results showed that GBLP supplementation significantly and dose-dependently lowered the weight gain of body, liver index and serum lipid parameters in HFD-fed rat. Meanwhile, GBLP attenuated HFD-induced liver injury through reducing hepatic steatosis, TG accumulation, serum ALT, AST and ALP levels. GBLP had a positive effect on obesity-associated insulin resistance (IR) via reducing serum glucose and insulin levels. Furthermore, GBLP enhanced the activities of antioxidant enzymes and reduced MDA levels in serum and liver. These results indicate that GBLP can play a certain protective role against HFD-induced NAFLD, and the protective effects may be associated with attenuating IR, preserving liver function, enhancing antioxidant defense system, and reducing lipid peroxidation.

  14. Leaf biomechanical properties in Arabidopsis thaliana polysaccharide mutants affect drought survival.

    PubMed

    Balsamo, Ronald; Boak, Merewyn; Nagle, Kayla; Peethambaran, Bela; Layton, Bradley

    2015-11-26

    Individual sugars are the building blocks of cell wall polysaccharides, which in turn comprise a plant׳s overall architectural structure. But which sugars play the most prominent role in maintaining a plant׳s mechanical stability during large cellular deformations induced by drought? We investigated the individual contributions of several genes that are involved in the synthesis of monosaccharides which are important for cell wall structure. We then measured drought tolerance and mechanical integrity during simulated drought in Arabidopsis thaliana. To assess mechanical properties, we designed a small-scale tensile tester for measuring failure strain, ultimate tensile stress, work to failure, toughness, and elastic modulus of 6-week-old leaves in both hydrated and drought-simulated states. Col-0 mutants used in this study include those deficient in lignin, cellulose, components of hemicellulose such as xylose and fucose, the pectic components arabinose and rhamnose, as well as mutants with enhanced arabinose and total pectin content. We found that drought tolerance is correlated to the mechanical and architectural stability of leaves as they experience dehydration. Of the mutants, S096418 with mutations for reduced xylose and galactose was the least drought tolerant, while the arabinose-altered CS8578 mutants were the least affected by water loss. There were also notable correlations between drought tolerance and mechanical properties in the diminished rhamnose mutant, CS8575 and the dehydrogenase-disrupted S120106. Our findings suggest that components of hemicellulose and pectins affect leaf biomechanical properties and may play an important role in the ability of this model system to survive drought.

  15. Leaf biomechanical properties in Arabidopsis thaliana polysaccharide mutants affect drought survival.

    PubMed

    Balsamo, Ronald; Boak, Merewyn; Nagle, Kayla; Peethambaran, Bela; Layton, Bradley

    2015-11-26

    Individual sugars are the building blocks of cell wall polysaccharides, which in turn comprise a plant׳s overall architectural structure. But which sugars play the most prominent role in maintaining a plant׳s mechanical stability during large cellular deformations induced by drought? We investigated the individual contributions of several genes that are involved in the synthesis of monosaccharides which are important for cell wall structure. We then measured drought tolerance and mechanical integrity during simulated drought in Arabidopsis thaliana. To assess mechanical properties, we designed a small-scale tensile tester for measuring failure strain, ultimate tensile stress, work to failure, toughness, and elastic modulus of 6-week-old leaves in both hydrated and drought-simulated states. Col-0 mutants used in this study include those deficient in lignin, cellulose, components of hemicellulose such as xylose and fucose, the pectic components arabinose and rhamnose, as well as mutants with enhanced arabinose and total pectin content. We found that drought tolerance is correlated to the mechanical and architectural stability of leaves as they experience dehydration. Of the mutants, S096418 with mutations for reduced xylose and galactose was the least drought tolerant, while the arabinose-altered CS8578 mutants were the least affected by water loss. There were also notable correlations between drought tolerance and mechanical properties in the diminished rhamnose mutant, CS8575 and the dehydrogenase-disrupted S120106. Our findings suggest that components of hemicellulose and pectins affect leaf biomechanical properties and may play an important role in the ability of this model system to survive drought. PMID:26520913

  16. Constituents of Agave americana and Agave barbadensis.

    PubMed

    Tinto, W F; Simmons-Boyce, J L; McLean, S; Reynolds, W F

    2005-09-01

    An investigation of Agave americana and Agave barbadensis resulted in the isolation of a new homoisoflavanoid, 7-hydroxy-3-(4-methoxybenzyl)-chroman (3), together with known compounds 7-hydroxy-3-(4-methoxybenzyl)-chroman-4-one (1), 5,7-dihydroxy-3-(4-methoxybenzyl)-chroman-4-one (2), cantalasaponin-1 (4), and 2-hydroxy-butanedioic acid-1-methyl ester (5).

  17. Mushroom tyrosinase inhibitors from Aloe barbadensis Miller.

    PubMed

    Wu, Xiaofang; Yin, Sheng; Zhong, Jiasheng; Ding, Wenjing; Wan, Jinzhi; Xie, Zhiyong

    2012-12-01

    Two new chromones, 5-((S)-2'-oxo-4'-hydroxypentyl)-2-(β-glucopyranosyl-oxy-methyl)chromone (1) and 5-((S)-2'-oxo-4'-hydroxypentyl)-2-methoxychromone (2), together with four known analogues, 8-C-glucosyl-7-O-methyl-(S)-aloesol (3), isoaloeresin D (4), 8-C-glucosyl-(R)-aloesol (5), and aloesin (6) were isolated from the aqueous extract of Aloe barbadensis Miller. Their structures were determined on the basis of spectroscopic evidences (1-D and 2-D NMR, HRMS, UV, and IR data), chemical methods and the literature data. The Mosher's method was applied to establish the absolute configuration of compounds 1 and 2. The inhibitory effects of these chromones on the activity of mushroom tyrosinase were examined, and compound 6 was identified as a noncompetitive tyrosinase inhibitor with an IC(50) value of 108.62μg·mL(-1).

  18. Advances on Bioactive Polysaccharides from Medicinal Plants.

    PubMed

    Xie, Jian-Hua; Jin, Ming-Liang; Morris, Gordon A; Zha, Xue-Qiang; Chen, Han-Qing; Yi, Yang; Li, Jing-En; Wang, Zhi-Jun; Gao, Jie; Nie, Shao-Ping; Shang, Peng; Xie, Ming-Yong

    2016-07-29

    In recent decades, the polysaccharides from the medicinal plants have attracted a lot of attention due to their significant bioactivities, such as anti-tumor activity, antioxidant activity, anticoagulant activity, antidiabetic activity, radioprotection effect, anti-viral activity, hypolipidemic and immunomodulatory activities, which make them suitable for medicinal applications. Previous studies have also shown that medicinal plant polysaccharides are non-toxic and show no side effects. Based on these encouraging observations, most researches have been focusing on the isolation and identification of polysaccharides, as well as their bioactivities. A large number of bioactive polysaccharides with different structural features and biological effects from medicinal plants have been purified and characterized. This review provides a comprehensive summary of the most recent developments in physiochemical, structural features and biological activities of bioactive polysaccharides from a number of important medicinal plants, such as polysaccharides from Astragalus membranaceus, Dendrobium plants, Bupleurum, Cactus fruits, Acanthopanax senticosus, Angelica sinensis (Oliv.) Diels, Aloe barbadensis Miller, and Dimocarpus longan Lour. Moreover, the paper has also been focused on the applications of bioactive polysaccharides for medicinal applications. Recent studies have provided evidence that polysaccharides from medicinal plants can play a vital role in bioactivities. The contents and data will serve as a useful reference material for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents.

  19. Advances on Bioactive Polysaccharides from Medicinal Plants.

    PubMed

    Xie, Jian-Hua; Jin, Ming-Liang; Morris, Gordon A; Zha, Xue-Qiang; Chen, Han-Qing; Yi, Yang; Li, Jing-En; Wang, Zhi-Jun; Gao, Jie; Nie, Shao-Ping; Shang, Peng; Xie, Ming-Yong

    2016-07-29

    In recent decades, the polysaccharides from the medicinal plants have attracted a lot of attention due to their significant bioactivities, such as anti-tumor activity, antioxidant activity, anticoagulant activity, antidiabetic activity, radioprotection effect, anti-viral activity, hypolipidemic and immunomodulatory activities, which make them suitable for medicinal applications. Previous studies have also shown that medicinal plant polysaccharides are non-toxic and show no side effects. Based on these encouraging observations, most researches have been focusing on the isolation and identification of polysaccharides, as well as their bioactivities. A large number of bioactive polysaccharides with different structural features and biological effects from medicinal plants have been purified and characterized. This review provides a comprehensive summary of the most recent developments in physiochemical, structural features and biological activities of bioactive polysaccharides from a number of important medicinal plants, such as polysaccharides from Astragalus membranaceus, Dendrobium plants, Bupleurum, Cactus fruits, Acanthopanax senticosus, Angelica sinensis (Oliv.) Diels, Aloe barbadensis Miller, and Dimocarpus longan Lour. Moreover, the paper has also been focused on the applications of bioactive polysaccharides for medicinal applications. Recent studies have provided evidence that polysaccharides from medicinal plants can play a vital role in bioactivities. The contents and data will serve as a useful reference material for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents. PMID:26463231

  20. Structural Modifications of Fructans in Aloe barbadensis Miller (Aloe Vera) Grown under Water Stress.

    PubMed

    Salinas, Carlos; Handford, Michael; Pauly, Markus; Dupree, Paul; Cardemil, Liliana

    2016-01-01

    Aloe barbadensis Miller (Aloe vera) has a Crassulaceae acid metabolism which grants the plant great tolerance to water restrictions. Carbohydrates such as acemannans and fructans are among the molecules responsible for tolerating water deficit in other plant species. Nevertheless, fructans, which are prebiotic compounds, have not been described nor studied in Aloe vera, whose leaf gel is known to possess beneficial pharmaceutical, nutritional and cosmetic properties. As Aloe vera is frequently cultivated in semi-arid conditions, like those found in northern Chile, we investigated the effect of water deficit on fructan composition and structure. For this, plants were subjected to different irrigation regimes of 100%, 75%, 50% and 25% field capacity (FC). There was a significant increase in the total sugars, soluble sugars and oligo and polyfructans in plants subjected to water deficit, compared to the control condition (100% FC) in both leaf tips and bases. The amounts of fructans were also greater in the bases compared to the leaf tips in all water treatments. Fructans also increase in degree of polymerization with increasing water deficit. Glycosidic linkage analyses by GC-MS, led to the conclusion that there are structural differences between the fructans present in the leaves of control plants with respect to plants irrigated with 50% and 25% FC. Therefore, in non-stressed plants, the inulin, neo-inulin and neo-levan type of fructans predominate, while in the most stressful conditions for the plant, Aloe vera also synthesizes fructans with a more branched structure, the neofructans. To our knowledge, the synthesis and the protective role of neo-fructans under extreme water deficit has not been previously reported.

  1. Structural Modifications of Fructans in Aloe barbadensis Miller (Aloe Vera) Grown under Water Stress

    PubMed Central

    Salinas, Carlos; Cardemil, Liliana

    2016-01-01

    Aloe barbadensis Miller (Aloe vera) has a Crassulaceae acid metabolism which grants the plant great tolerance to water restrictions. Carbohydrates such as acemannans and fructans are among the molecules responsible for tolerating water deficit in other plant species. Nevertheless, fructans, which are prebiotic compounds, have not been described nor studied in Aloe vera, whose leaf gel is known to possess beneficial pharmaceutical, nutritional and cosmetic properties. As Aloe vera is frequently cultivated in semi-arid conditions, like those found in northern Chile, we investigated the effect of water deficit on fructan composition and structure. For this, plants were subjected to different irrigation regimes of 100%, 75%, 50% and 25% field capacity (FC). There was a significant increase in the total sugars, soluble sugars and oligo and polyfructans in plants subjected to water deficit, compared to the control condition (100% FC) in both leaf tips and bases. The amounts of fructans were also greater in the bases compared to the leaf tips in all water treatments. Fructans also increase in degree of polymerization with increasing water deficit. Glycosidic linkage analyses by GC-MS, led to the conclusion that there are structural differences between the fructans present in the leaves of control plants with respect to plants irrigated with 50% and 25% FC. Therefore, in non-stressed plants, the inulin, neo-inulin and neo-levan type of fructans predominate, while in the most stressful conditions for the plant, Aloe vera also synthesizes fructans with a more branched structure, the neofructans. To our knowledge, the synthesis and the protective role of neo-fructans under extreme water deficit has not been previously reported. PMID:27454873

  2. Structural Modifications of Fructans in Aloe barbadensis Miller (Aloe Vera) Grown under Water Stress.

    PubMed

    Salinas, Carlos; Handford, Michael; Pauly, Markus; Dupree, Paul; Cardemil, Liliana

    2016-01-01

    Aloe barbadensis Miller (Aloe vera) has a Crassulaceae acid metabolism which grants the plant great tolerance to water restrictions. Carbohydrates such as acemannans and fructans are among the molecules responsible for tolerating water deficit in other plant species. Nevertheless, fructans, which are prebiotic compounds, have not been described nor studied in Aloe vera, whose leaf gel is known to possess beneficial pharmaceutical, nutritional and cosmetic properties. As Aloe vera is frequently cultivated in semi-arid conditions, like those found in northern Chile, we investigated the effect of water deficit on fructan composition and structure. For this, plants were subjected to different irrigation regimes of 100%, 75%, 50% and 25% field capacity (FC). There was a significant increase in the total sugars, soluble sugars and oligo and polyfructans in plants subjected to water deficit, compared to the control condition (100% FC) in both leaf tips and bases. The amounts of fructans were also greater in the bases compared to the leaf tips in all water treatments. Fructans also increase in degree of polymerization with increasing water deficit. Glycosidic linkage analyses by GC-MS, led to the conclusion that there are structural differences between the fructans present in the leaves of control plants with respect to plants irrigated with 50% and 25% FC. Therefore, in non-stressed plants, the inulin, neo-inulin and neo-levan type of fructans predominate, while in the most stressful conditions for the plant, Aloe vera also synthesizes fructans with a more branched structure, the neofructans. To our knowledge, the synthesis and the protective role of neo-fructans under extreme water deficit has not been previously reported. PMID:27454873

  3. The fungal symbiont of Acromyrmex leaf-cutting ants expresses the full spectrum of genes to degrade cellulose and other plant cell wall polysaccharides

    PubMed Central

    2013-01-01

    Background The fungus gardens of leaf-cutting ants are natural biomass conversion systems that turn fresh plant forage into fungal biomass to feed the farming ants. However, the decomposition potential of the symbiont Leucocoprinus gongylophorus for processing polysaccharides has remained controversial. We therefore used quantifiable DeepSAGE technology to obtain mRNA expression patterns of genes coding for secreted enzymes from top, middle, and bottom sections of a laboratory fungus-garden of Acromyrmex echinatior leaf-cutting ants. Results A broad spectrum of biomass-conversion-relevant enzyme genes was found to be expressed in situ: cellulases (GH3, GH5, GH6, GH7, AA9 [formerly GH61]), hemicellulases (GH5, GH10, CE1, GH12, GH74), pectinolytic enzymes (CE8, GH28, GH43, PL1, PL3, PL4), glucoamylase (GH15), α-galactosidase (GH27), and various cutinases, esterases, and lipases. In general, expression of these genes reached maximal values in the bottom section of the garden, particularly for an AA9 lytic polysaccharide monooxygenase and for a GH5 (endocellulase), a GH7 (reducing end-acting cellobiohydrolase), and a GH10 (xylanase), all containing a carbohydrate binding module that specifically binds cellulose (CBM1). Although we did not directly quantify enzyme abundance, the profile of expressed cellulase genes indicates that both hydrolytic and oxidative degradation is taking place. Conclusions The fungal symbiont of Acromyrmex leaf-cutting ants can degrade a large range of plant polymers, but the conversion of cellulose, hemicellulose, and part of the pectin occurs primarily towards the end of the decomposition process, i.e. in the bottom section of the fungus garden. These conversions are likely to provide nutrients for the fungus itself rather than for the ants, whose colony growth and reproductive success are limited by proteins obtained from ingesting fungal gongylidia. These specialized hyphal tips are hardly produced in the bottom section of fungus gardens

  4. Fat body in some genera of leaf-cutting ants (Hymenoptera: Formicidae). Proteins, lipids and polysaccharides detection.

    PubMed

    Roma, Gislaine Cristina; Mathias, Maria Izabel Camargo; Bueno, Odair Corrêa

    2006-01-01

    The comparative histochemical analysis of the fat body of workers belonging to the basal species Cyphomyrmex rimosus and Mycetarotes parallelus and to derived species Acromyrmex disciger and Atta laevigata revealed that this tissue is constituted mainly by cells denominated trophocytes and oenocytes. The trophocytes of all species studied here were characterized mainly by the proteins and lipids synthesis and storage, being the derived species the ones who have presented higher quantity of lipids in the trophocytes when compared to the trophocytes of basal species. In workers M. parallelus and A. laevigata, besides proteins and lipids, there has being observed the presence of polysaccharides, however, in C. rimosus and A. disciger these elements were detected in lower quantities. The histochemical studies of the oenocytes of basal and derived species revealed significant presence of proteins as well as lipids in these cells. In the oenocytes of derived species A. disciger and A. laevigata a higher quantity of lipidic inclusions has being observed, when compared to the basal species.

  5. Comparative evaluation of the effect of chlorhexidine and Aloe barbadensis Miller (Aloe vera) on dentin stabilization using shear bond testing

    PubMed Central

    Sinha, Dakshita Joy; Jaiswal, Natasha; Vasudeva, Agrima; Garg, Paridhi; Tyagi, Shashi Prabha; Chandra, Priyanka

    2016-01-01

    Introduction: The main objective of adhesive dentistry is to create an effective, durable union between the tooth structure and restorative material. However, degradation of adhesive dentine interface remains largely responsible for the relatively short lifetime of tooth colored resin restoration. Aim: The aim of the study is to compare the dentin collagen stabilization property of Chlorhexidine (CHX) and Aloe barbadensis Miller using shear bond strength testing. Materials and Methods: Occlusal reduction was done in sixty extracted human mandibular molars to expose the mid coronal dentin and divided into three groups n = 20. Following the surface pretreatment (Group 1 = control, Group 2 = CHX, Group 3 = Aloevera), dentine bonding agent and composite resin were applied and cured. The specimens were then subjected to shear bond strength testing. Results: From the results analyzed, it was noted that there was statistically significant difference between the groups Control and CHX and Control and A. barbadensis Miller (P < 0.05), specifically the values of Control < CHX and Control < A. barbadensis Miller (P < 0.05). However, there was no statistically significant difference between CHX and A. barbadensis Miller (P > 0.05). Hence, the following result for the shear bond strengths to dentin was obtained: Control < CHX ≈ A. barbadensis Miller. Conclusion: CHX and A. barbadensis Miller, as pretreatment agents of acid demineralized dentin collagen, has no adverse effect on the immediate shear bond strength of a two-step etch and rinse adhesive to dentin.

  6. Comparative evaluation of the effect of chlorhexidine and Aloe barbadensis Miller (Aloe vera) on dentin stabilization using shear bond testing

    PubMed Central

    Sinha, Dakshita Joy; Jaiswal, Natasha; Vasudeva, Agrima; Garg, Paridhi; Tyagi, Shashi Prabha; Chandra, Priyanka

    2016-01-01

    Introduction: The main objective of adhesive dentistry is to create an effective, durable union between the tooth structure and restorative material. However, degradation of adhesive dentine interface remains largely responsible for the relatively short lifetime of tooth colored resin restoration. Aim: The aim of the study is to compare the dentin collagen stabilization property of Chlorhexidine (CHX) and Aloe barbadensis Miller using shear bond strength testing. Materials and Methods: Occlusal reduction was done in sixty extracted human mandibular molars to expose the mid coronal dentin and divided into three groups n = 20. Following the surface pretreatment (Group 1 = control, Group 2 = CHX, Group 3 = Aloevera), dentine bonding agent and composite resin were applied and cured. The specimens were then subjected to shear bond strength testing. Results: From the results analyzed, it was noted that there was statistically significant difference between the groups Control and CHX and Control and A. barbadensis Miller (P < 0.05), specifically the values of Control < CHX and Control < A. barbadensis Miller (P < 0.05). However, there was no statistically significant difference between CHX and A. barbadensis Miller (P > 0.05). Hence, the following result for the shear bond strengths to dentin was obtained: Control < CHX ≈ A. barbadensis Miller. Conclusion: CHX and A. barbadensis Miller, as pretreatment agents of acid demineralized dentin collagen, has no adverse effect on the immediate shear bond strength of a two-step etch and rinse adhesive to dentin. PMID:27656056

  7. Hepatoprotective potential of Aloe barbadensis Mill. against carbon tetrachloride induced hepatotoxicity.

    PubMed

    Chandan, B K; Saxena, A K; Shukla, Sangeeta; Sharma, Neelam; Gupta, D K; Suri, K A; Suri, Jyotsna; Bhadauria, M; Singh, B

    2007-05-22

    Aloe barbadensis Mill. Syn. Aloe vera Tourn. ex Linn.(Liliaceae) has been used in variety of diseases in traditional Indian system of medicine in India and its use for hepatic ailments is also documented. In the present study an attempt has been made to validate its hepatoprotective activity. The shade dried aerial parts of Aloe barbadensis were extracted with petroleum ether (AB-1), chloroform (AB-2) and methanol (AB-3). The plant marc was extracted with distilled water (AB-4). All the extracts were evaluated for hepatoprotective activity on limited test models as hexobarbitone sleep time, zoxazolamine paralysis time and marker biochemical parameters. AB-1 and AB-2 were observed to be devoid of any hepatoprotective activity. Out of two active extracts (AB-3 and AB-4), the most active AB-4 was studied in detail. AB-4 showed significant hepatoprotective activity against CCl4 induced hepatotoxicity as evident by restoration of serum transaminases, alkaline phosphatase, bilirubin and triglycerides. Hepatoprotective potential was confirmed by the restoration of lipid peroxidation, glutathione, glucose-6-phosphatase and microsomal aniline hydroxylase and amidopyrine N-demethylase towards near normal. Histopathology of the liver tissue further supports the biochemical findings confirming the hepatoprotective potential of AB-4. The present study shows that the aqueous extract of Aloe barbadensis is significantly capable of restoring integrity of hepatocytes indicated by improvement in physiological parameters, excretory capacity (BSP retention) of hepatocytes and also by stimulation of bile flow secretion. AB-4 did not show any sign of toxicity up to oral dose of 2 g/kg in mice.

  8. Polysaccharide Degradation

    NASA Astrophysics Data System (ADS)

    Stone, Bruce A.; Svensson, Birte; Collins, Michelle E.; Rastall, Robert A.

    An overview of current and potential enzymes used to degrade polysaccharides is presented. Such depolymerases are comprised of glycoside hydrolases, glycosyl transferases, phosphorylases and lyases, and their classification, active sites and action patterns are discussed. Additionally, the mechanisms that these enzymes use to cleave glycosidic linkages is reviewed as are inhibitors of depolymerase activity; reagents which react with amino acid residues, glycoside derivatives, transition state inhibitors and proteinaceous inhibitors. The characterization of various enzymes of microbial, animal or plant origin has led to their widespread use in the production of important oligosaccharides which can be incorporated into food stuffs. Sources of polysaccharides of particular interest in this chapter are those from plants and include inulin, dextran, xylan and pectin, as their hydrolysis products are purported to be functional foods in the context of gastrointestinal health. An alternative use of degraded polysaccharides is in the treatment of disease. The possibility exists to treat bacterial exopolysaccharide with lyases from bacteriophage to produce oligosaccharides exhibiting bioactive sequences. Although this area is currently in its infancy the knowledge is available to investigate further.

  9. Bioactivities and extraction optimization of crude polysaccharides from the fruits and leaves of Rubus chingii Hu.

    PubMed

    Zhang, Tian-Tian; Lu, Chuan-Li; Jiang, Jian-Guo; Wang, Min; Wang, Dong-Mei; Zhu, Wei

    2015-10-01

    Polysaccharides of Rubus chingii Hu fruit and leaf were extracted to compare their antioxidant, anti-inflammatory, and anticancer activities against breast cancer cells MCF-7 and liver cancer cells Bel-7402. Results showed that all the tested bioactivities of polysaccharides from leaf (L-Ps) were better than those of polysaccharides from fruit (F-Ps). Response surface methodology was then used to optimize the extraction conditions of polysaccharides from leaf. Additionally, polysaccharides from fruit and leaf were characterized and their contents of total sugars, proteins and uronic acid were compared. It was found that polysaccharides from fruit and leaf were similar in IR and UV absorption, but significantly different in contents of total sugars, protein and uronic acid. Their elution profiles of DEAE-Sepharose fast flow column were different too. The main peak of polysaccharides from fruit was eluted with 0.3 mol/l NaCl solution and the main peak of polysaccharides from leaf was eluted with deionized water. The differences between the two polysaccharides may be responsible for their differences in bioactivities. Further studies are required to explore their complete structural characteristics, structure-activity relationship and the mechanism of their activities.

  10. In vivo tracing of organophosphorus pesticides in cabbage (Brassica parachinensis) and aloe (Barbadensis).

    PubMed

    Qiu, Junlang; Chen, Guosheng; Zhou, Hong; Xu, Jianqiao; Wang, Fuxin; Zhu, Fang; Ouyang, Gangfeng

    2016-04-15

    In vivo solid-phase microextraction (SPME) sampling method coupled with gas chromatography-mass spectrometry (GC-MS) analysis was employed to trace the uptake and elimination of organophosphorus pesticides (OPPs) in two kinds of edible plants, cabbage (Brassica parachinensis) and aloe (Barbadensis). The metabolism of fenthion in aloe was also investigated by the liquid chromatography tandem mass spectrometry analysis (LC-MS/MS) to understand the fate of OPPs in living plants better. Transpiration stream concentration factor (TSCF) and depuration rate constants of the OPPs in living plants were obtained therein. The health risk of the OPPs treated aloe was estimated by the maximum residue limit (MRL) approach, and it revealed that the OPPs were rather safe for their fast degradable property. However, peak concentration of fenthion-sulfoxide was found to exceed the MRL and was higher than that of the parent fenthion, which indicated the potential risk of pesticide metabolites. This study highlighted the application of in vivo SPME for contaminant tracing in different living edible plants. The in vivo tracing method is very convenient and can provide more data to evaluate the risk of different pesticides, which are very important for the safety of agriculture production. PMID:26878720

  11. In vivo tracing of organophosphorus pesticides in cabbage (Brassica parachinensis) and aloe (Barbadensis).

    PubMed

    Qiu, Junlang; Chen, Guosheng; Zhou, Hong; Xu, Jianqiao; Wang, Fuxin; Zhu, Fang; Ouyang, Gangfeng

    2016-04-15

    In vivo solid-phase microextraction (SPME) sampling method coupled with gas chromatography-mass spectrometry (GC-MS) analysis was employed to trace the uptake and elimination of organophosphorus pesticides (OPPs) in two kinds of edible plants, cabbage (Brassica parachinensis) and aloe (Barbadensis). The metabolism of fenthion in aloe was also investigated by the liquid chromatography tandem mass spectrometry analysis (LC-MS/MS) to understand the fate of OPPs in living plants better. Transpiration stream concentration factor (TSCF) and depuration rate constants of the OPPs in living plants were obtained therein. The health risk of the OPPs treated aloe was estimated by the maximum residue limit (MRL) approach, and it revealed that the OPPs were rather safe for their fast degradable property. However, peak concentration of fenthion-sulfoxide was found to exceed the MRL and was higher than that of the parent fenthion, which indicated the potential risk of pesticide metabolites. This study highlighted the application of in vivo SPME for contaminant tracing in different living edible plants. The in vivo tracing method is very convenient and can provide more data to evaluate the risk of different pesticides, which are very important for the safety of agriculture production.

  12. Topical Aloe Vera (Aloe barbadensis Miller) Extract Does Not Accelerate the Oral Wound Healing in Rats.

    PubMed

    Coelho, Fernanda Hack; Salvadori, Gabriela; Rados, Pantelis Varvaki; Magnusson, Alessandra; Danilevicz, Chris Krebs; Meurer, Luise; Martins, Manoela Domingues

    2015-07-01

    The effect of topical application of Aloe Vera (Aloe barbadensis Miller) extract was assessed on the healing of rat oral wounds in an in vivo model using 72 male Wistar rats divided into three groups (n = 24): control, placebo and Aloe Vera (0.5% extract hydroalcoholic). Traumatic ulcers were caused in the dorsum of the tongue using a 3-mm punch tool. The Aloe Vera and placebo group received two daily applications. The animals were sacrificed after 1, 5, 10 and 14 days. Clinical analysis (ulcer area and percentage of repair) and histopathological analysis (degree of re-epithelialization and inflammation) were performed. The comparison of the differences between scores based on group and experimental period, both in quantitative and semi-quantitative analyses, was performed using the Kruskal-Wallis test. The significance level was 5%. On day 1, all groups showed predominantly acute inflammatory infiltrate. On day 5, there was partial epithelialization and chronic inflammatory infiltrate. On the days 10 and 14 total repair of ulcers was observed. There was no significant difference between groups in the repair of mouth ulcers. It is concluded that treatment using Aloe Vera as an herbal formulation did not accelerate oral wound healing in rats.

  13. Method for producing capsular polysaccharides

    NASA Technical Reports Server (NTRS)

    Kern, Roger G. (Inventor); Petersen, Gene R. (Inventor); Richards, Gil F. (Inventor)

    1994-01-01

    Structurally altered capsular polysaccharides are produced by mutant bacteria. These polysaccharides are isolated by selecting a wild type bacterial strain and a phage producing degradative enzymes that have substrate specificity for the capsular polysaccharides produced by the wild type bacteria. Phage-resistant mutants producing capsular polysaccharides are selected and the structurally altered capsular polysaccharide is isolated therefrom.

  14. Chemical Modification of Polysaccharides

    PubMed Central

    Cumpstey, Ian

    2013-01-01

    This review covers methods for modifying the structures of polysaccharides. The introduction of hydrophobic, acidic, basic, or other functionality into polysaccharide structures can alter the properties of materials based on these substances. The development of chemical methods to achieve this aim is an ongoing area of research that is expected to become more important as the emphasis on using renewable starting materials and sustainable processes increases in the future. The methods covered in this review include ester and ether formation using saccharide oxygen nucleophiles, including enzymatic reactions and aspects of regioselectivity; the introduction of heteroatomic nucleophiles into polysaccharide chains; the oxidation of polysaccharides, including oxidative glycol cleavage, chemical oxidation of primary alcohols to carboxylic acids, and enzymatic oxidation of primary alcohols to aldehydes; reactions of uronic-acid-based polysaccharides; nucleophilic reactions of the amines of chitosan; and the formation of unsaturated polysaccharide derivatives. PMID:24151557

  15. Leukocyte phagocytosis and lysozyme activity in Nile tilapia fed supplemented diet with natural extracts of propolis and Aloe barbadensis.

    PubMed

    Dotta, Geovana; de Andrade, Jaqueline Inês Alves; Tavares Gonçalves, Eduardo Luiz; Brum, Aline; Mattos, Jacó Joaquim; Maraschin, Marcelo; Martins, Maurício Laterça

    2014-08-01

    Although there is evidence on the benefits in the use of immunostimulants in aquaculture, there are few commercial products being used. This study evaluated the use of natural substances as potential sources for the production of immunostimulants. Propolis and Aloe barbadensis have been widely studied and its extracts have different chemical constituents responsible for antimicrobial, anti-inflammatory and immunostimulant. Tilapia juveniles were fed for two weeks with diets supplemented mix of propolis extracts and aloe (1:1) in different concentrations: 0.5, 1 e 2%. After the experimental period, fish blood was collected for hematoimmunological as follows : hematocrit, total plasma protein, erythrocytes (RBC), leukocytes (WBC), differential leukocyte count, phagocytic activity, serum lysozyme activity, and serum antimicrobial activity, serum antimicrobial activity (evaluated against Aeromonas hydrophila, Enterococcus durans and Escherichia coli). Except for higher number of thrombocytes in 1%-supplemented fish, the rest did not show significant difference.

  16. Phylogeny of Amazona barbadensis and the Yellow-Headed Amazon Complex (Aves: Psittacidae): A New Look at South American Parrot Evolution

    PubMed Central

    Strzała, Tomasz

    2014-01-01

    The Yellow-shouldered Amazon (Amazona barbadensis) is the sole parrot of the genus Amazona that inhabits only dry forests. Its population has been dropping; therefore it has been the topic of many studies and conservation efforts. However, the phylogenetic relationship of this species to potential relatives classified within the Yellow-Headed Amazon (YHA) complex are still not clear. Therefore, we used more extensive data sets, including the newly sequenced mitochondrial genome of A. barbadensis, to conduct phylogenetic analyses. Various combinations of genes and many phylogenetic approaches showed that A. barbadensis clustered significantly with A. ochrocephala ochrocephala from Colombia and Venezuela, which created the Northern South American (NSA) lineage, clearly separated from two other lineages within the YHA complex, the Central (CA) and South American (SA). Tree topology tests and exclusion of rapidly evolving sites provided support for a NSA+SA grouping. We propose an evolutionary scenario for the YHA complex and its colonization of the American mainland. The NSA lineage likely represents the most ancestral lineage, which derived from Lesser Antillean Amazons and colonized the northern coast of Venezuela about a million years ago. Then, Central America was colonized through the Isthmus of Panama, which led to the emergence of the CA lineage. The southward expansion to South America and the origin of the SA lineage happened almost simultaneously. However, more intensive or prolonged gene flow or migrations have led to much weaker geographic differentiation of genetic markers in the SA than in the CA lineage. PMID:24823658

  17. Phylogeny of Amazona barbadensis and the Yellow-headed Amazon complex (Aves: Psittacidae): a new look at South American parrot evolution.

    PubMed

    Urantówka, Adam Dawid; Mackiewicz, Paweł; Strzała, Tomasz

    2014-01-01

    The Yellow-shouldered Amazon (Amazona barbadensis) is the sole parrot of the genus Amazona that inhabits only dry forests. Its population has been dropping; therefore it has been the topic of many studies and conservation efforts. However, the phylogenetic relationship of this species to potential relatives classified within the Yellow-Headed Amazon (YHA) complex are still not clear. Therefore, we used more extensive data sets, including the newly sequenced mitochondrial genome of A. barbadensis, to conduct phylogenetic analyses. Various combinations of genes and many phylogenetic approaches showed that A. barbadensis clustered significantly with A. ochrocephala ochrocephala from Colombia and Venezuela, which created the Northern South American (NSA) lineage, clearly separated from two other lineages within the YHA complex, the Central (CA) and South American (SA). Tree topology tests and exclusion of rapidly evolving sites provided support for a NSA+SA grouping. We propose an evolutionary scenario for the YHA complex and its colonization of the American mainland. The NSA lineage likely represents the most ancestral lineage, which derived from Lesser Antillean Amazons and colonized the northern coast of Venezuela about a million years ago. Then, Central America was colonized through the Isthmus of Panama, which led to the emergence of the CA lineage. The southward expansion to South America and the origin of the SA lineage happened almost simultaneously. However, more intensive or prolonged gene flow or migrations have led to much weaker geographic differentiation of genetic markers in the SA than in the CA lineage.

  18. POLYSACCHARIDE OF COCCIDIOIDES IMMITIS

    PubMed Central

    Pappagianis, D.; Putman, E. W.; Kobayashi, G. S.

    1961-01-01

    Pappagianis, D. (University of California, Berkeley), E. W. Putman, and G. S. Kobayashi. Polysaccharide of Coccidioides immitis. J. Bacteriol. 82:714–723. 1961.—Soluble polysaccharide from mycelia or culture filtrates of Coccidioides immitis was found to consist mainly of mannose, but also included small quantities of galactose and another reducing sugar. Isolation of the polysaccharide by ethanol precipitation provided accompanying nitrogenous material. There was 3 to 4% nitrogen, present in amino acids, but in a nondialyzable (possibly protein or peptide) form. The average molecular weight of the complex was 31,700. Attempts to separate the nitrogenous and polysaccharide materials by chemical methods or by moving boundary electrophoresis were unsuccessful; ultracentrifugation showed a single peak. Despite these findings, there appeared to be several antigenic species present, as indicated by multiple lines of precipitation in double diffusion and quantitative precipitin tests. In the latter, polysaccharide-containing fractions gave precipitates without measurable carbohydrate, suggesting separability of nitrogenous and polysaccharide components. Images PMID:14483753

  19. Acute inflammation and hematological response in Nile tilapia fed supplemented diet with natural extracts of propolis and Aloe barbadensis.

    PubMed

    Dotta, G; Ledic-Neto, J; Gonçalves, E L T; Brum, A; Maraschin, M; Martins, M L

    2015-05-01

    This study evaluated the acute inflammatory response induced by carrageenin in the swim bladder of Nile tilapia supplemented with the mixture of natural extracts of propolis and Aloe barbadensis (1:1) at a concentration of 0.5%, 1% and 2% in diet during 15 days. Thirty-six fish were distributed into four treatments with three replicates: fish supplemented with 0.5% of admix of extracts of propolis and Aloe (1:1) injected with 500 µg carrageenin; fish supplemented with 1% of admix of extracts of propolis and Aloe (1:1) injected with 500 µg carrageenin; fish supplemented with 2% of admix of extracts of propolis and Aloe (1:1), injected with 500 µg carrageenin and unsupplemented fish injected with 500 µg carrageenin. Six hours after injection, samples of blood and exudate from the swim bladder of fish were collected. It was observed an increase in the leukocyte count in the swim bladder exudate of fish supplemented with extracts of propolis and Aloe injected with carrageenin. The most frequent cells were macrophages followed by granular leukocytes, thrombocytes and lymphocytes. Supplementation with propolis and Aloe to 0.5% caused a significant increase in the number of cells on the inflammatory focus mainly macrophages, cells responsible for the phagocytic activity in tissues, agent of innate fish immune response.

  20. Effect of Aloe barbadensis Miller juice on oxidative stress biomarkers in aerobic cells using Artemia franciscana as a model.

    PubMed

    Sirdaarta, J; Cock, I E

    2010-03-01

    This study reports on the induction of oxidative stress in aerobic cell systems by Aloe barbadensis Miller (Aloe vera) juice using the salt water crustacean Artemia franciscana as a model. A consistent pattern was observed in which Artemia franciscana nauplii responded to Aloe vera juice exposure with a decrease in the overall activity of redox related enzymes. Exposure of Artemia franciscana to sub-lethal levels of Aloe vera juice resulted in a decreased activity of thioredoxin reductase, glutathione reductase and glutathione peroxidase by 34% (66% enzymatic activity), 79% (21% enzymatic activity) and 90% (10% enzymatic activity), respectively. Similarly apparent was the trend whereby the co-exposure of the nauplii to vitamin E counteracted this effect. For each of the biomarker enzymes tested, vitamin E co-exposure resulted in enzyme activities closer to the control value (78%, 56% and 32% of control enzymatic activities for thioredoxin reductase, glutathione reductase and glutathione peroxidase activity, respectively). These results indicate that exposure to sub-lethal doses of Aloe vera juice induces alterations in the cellular redox status of Artemia franciscana and that the addition of vitamin E helps the Artemia franciscana nauplii to overcome/block the juice induced oxidative stress.

  1. Hepatoprotective Activity of Herbal Composition SAL, a Standardize Blend Comprised of Schisandra chinensis, Artemisia capillaris, and Aloe barbadensis

    PubMed Central

    Yimam, Mesfin; Jiao, Ping; Moore, Breanna; Hong, Mei; Cleveland, Sabrina; Chu, Min; Jia, Qi; Lee, Young-Chul; Kim, Hyun-Jin; Nam, Jeong-Bum; Kim, Mi-Ran; Hyun, Eu-Jin; Jung, Gayoung; Do, Seon Gil

    2016-01-01

    Some botanicals have been reported to possess antioxidative activities acting as scavengers of free radicals rendering their usage in herbal medicine. Here we describe the potential use of “SAL,” a standardized blend comprised of three extracts from Schisandra chinensis, Artemisia capillaris, and Aloe barbadensis, in mitigating chemically induced acute liver toxicities. Acetaminophen and carbon tetrachloride induced acute liver toxicity models in mice were utilized. Hepatic functional tests from serum collected at T24 and hepatic glutathione and superoxide dismutases from liver homogenates were evaluated. Histopathology analysis and merit of blending 3 standardized extracts were also confirmed. Statistically significant and dose-correlated inhibitions in serum ALT ranging from 52.5% (p = 0.004) to 34.6% (p = 0.05) in the APAP and 46.3% (p < 0.001) to 29.9% (p = 0.02) in the CCl4 models were observed for SAL administered at doses of 400–250 mg/kg. Moreover, SAL resulted in up to 60.6% and 80.2% reductions in serums AST and bile acid, respectively. The composition replenished depleted hepatic glutathione in association with an increase of hepatic superoxide dismutase. Unexpected synergistic protection from liver damage was also observed. Therefore, the composition SAL could be potentially utilized as an effective hepatic-detoxification agent for the protection from liver damage. PMID:27066270

  2. Hepatoprotective Activity of Herbal Composition SAL, a Standardize Blend Comprised of Schisandra chinensis, Artemisia capillaris, and Aloe barbadensis.

    PubMed

    Yimam, Mesfin; Jiao, Ping; Moore, Breanna; Hong, Mei; Cleveland, Sabrina; Chu, Min; Jia, Qi; Lee, Young-Chul; Kim, Hyun-Jin; Nam, Jeong-Bum; Kim, Mi-Ran; Hyun, Eu-Jin; Jung, Gayoung; Do, Seon Gil

    2016-01-01

    Some botanicals have been reported to possess antioxidative activities acting as scavengers of free radicals rendering their usage in herbal medicine. Here we describe the potential use of "SAL," a standardized blend comprised of three extracts from Schisandra chinensis, Artemisia capillaris, and Aloe barbadensis, in mitigating chemically induced acute liver toxicities. Acetaminophen and carbon tetrachloride induced acute liver toxicity models in mice were utilized. Hepatic functional tests from serum collected at T24 and hepatic glutathione and superoxide dismutases from liver homogenates were evaluated. Histopathology analysis and merit of blending 3 standardized extracts were also confirmed. Statistically significant and dose-correlated inhibitions in serum ALT ranging from 52.5% (p = 0.004) to 34.6% (p = 0.05) in the APAP and 46.3% (p < 0.001) to 29.9% (p = 0.02) in the CCl4 models were observed for SAL administered at doses of 400-250 mg/kg. Moreover, SAL resulted in up to 60.6% and 80.2% reductions in serums AST and bile acid, respectively. The composition replenished depleted hepatic glutathione in association with an increase of hepatic superoxide dismutase. Unexpected synergistic protection from liver damage was also observed. Therefore, the composition SAL could be potentially utilized as an effective hepatic-detoxification agent for the protection from liver damage. PMID:27066270

  3. Leaf Activities.

    ERIC Educational Resources Information Center

    Mingie, Walter

    Leaf activities can provide a means of using basic concepts of outdoor education to learn in elementary level subject areas. Equipment needed includes leaves, a clipboard with paper, and a pencil. A bag of leaves may be brought into the classroom if weather conditions or time do not permit going outdoors. Each student should pick a leaf, examine…

  4. [Comparison on polysaccharide content and PMP-HPLC fingerprints of polysaccharide in stems and leaves of Dendrobium officinale].

    PubMed

    Zhou, Gui-Fen; Pang, Min-Xia; Chen, Su-Hong; Lv, Gui-Yuan; Yan, Mei-Qiu

    2014-03-01

    In order to provide scientific basics for exploitation and sufficient application of Dendrobium officinale leaves resources, the phenol-sulfuric acid method was applied to determine the polysaccharide content. The monosaccharides were derivated by PMP and the derivatives were identified by HPLC-DAD-ESI-MS(n) and the contents of mannose and glucose were determined simultaneously. Similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine (2004A) was employed to generate the mean chromatogram and similarity analysis of the samples was carried out. The results demonstrated that polysaccharide content, monosaccharide compositions and composition ratio had an obvious difference between stems and leaves. The polysaccharide content of stems was higher than that of leaves. Monosaccharide composition in leaf was significantly different from that in stem. The polysaccharide from stems was composed of mannose and glucose, however the polysaccharide of leaves was acid heteropolysaccharide and was mainly composed of five monosaccharides, including mannose, galacturonic acid, glucose, galactose and arabinose. The similarity value of the 14 batches was above 0.9, indicating that similarity of fingerprints among different samples was high. The study can provide evidence for expanding the medicinal parts of D. officinale.

  5. Leaf Development

    PubMed Central

    2013-01-01

    Leaves are the most important organs for plants. Without leaves, plants cannot capture light energy or synthesize organic compounds via photosynthesis. Without leaves, plants would be unable perceive diverse environmental conditions, particularly those relating to light quality/quantity. Without leaves, plants would not be able to flower because all floral organs are modified leaves. Arabidopsis thaliana is a good model system for analyzing mechanisms of eudicotyledonous, simple-leaf development. The first section of this review provides a brief history of studies on development in Arabidopsis leaves. This history largely coincides with a general history of advancement in understanding of the genetic mechanisms operating during simple-leaf development in angiosperms. In the second section, I outline events in Arabidopsis leaf development, with emphasis on genetic controls. Current knowledge of six important components in these developmental events is summarized in detail, followed by concluding remarks and perspectives. PMID:23864837

  6. Polysaccharides: Occurrence, Significance, and Properties

    NASA Astrophysics Data System (ADS)

    Bemiller, James N.

    Polysaccharides are properties present significance in all living organisms where they carry out one or more of their diverse functions. While there is no specific category or definition of a complex polysaccharide, most are structurally complex. Polysaccharides contain 1-5 different monosaccharide (sugar) units. The different sugar units may have different anomeric configurations and/or be joined by different glycosidic linkages. Polysaccharides may be linear or branched. Branches may be short saccharide units on a linear backbone or the molecule may have a branch-on-branch structure; in either case, the branches may be isolated or clustered. Polysaccharides may contain non-carbohydrate groups. Esters or cyclic acetal groups, when present, can be removed by appropriate treatments. All polysaccharides are polydisperse, i. e., are present in a range of molecular weights rather than having a single molecular weight. Most are polymolecular, i. e., differ in fine structure from molecule to molecule. So most polysaccharides can be said to be structurally complex. They may be attached to protein molecules or to other polysaccharide molecules. They are solvated by water. Most dissolve in aqueous systems, especially if they are alkaline. Polysaccharides can be depolymerized by acids and heat, specific enzymes, and high pH systems following oxidation. Their hydroxyl groups can be esterified (acylated), etherified (alkylated), and oxidized. Amino groups can be acylated (and deacylated). Carboxyl groups can be converted into esters, amides, and amines. Structural modification makes the molecules even more complex and polymolecular and, perhaps, polydisperse.

  7. Iodine-Catalyzed Polysaccharide Esterification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A review is provided of the recent reports to use iodine-catalyzed esterification reaction to produce esters from polysaccharides. The process entails reaction of the polysaccharide with an acid anhydride in the presence of a catalytic level of iodine, and in the absence of additional solvents. T...

  8. Polysaccharides of the red algae.

    PubMed

    Usov, Anatolii I

    2011-01-01

    Red algae (Rhodophyta) are known as the source of unique sulfated galactans, such as agar, agarose, and carrageenans. The wide practical uses of these polysaccharides are based on their ability to form strong gels in aqueous solutions. Gelling polysaccharides usually have molecules built up of repeating disaccharide units with a regular distribution of sulfate groups, but most of the red algal species contain more complex galactans devoid of gelling ability because of various deviations from the regular structure. Moreover, several red algae may contain sulfated mannans or neutral xylans instead of sulfated galactans as the main structural polysaccharides. This chapter is devoted to a description of the structural diversity of polysaccharides found in the red algae, with special emphasis on the methods of structural analysis of sulfated galactans. In addition to the structural information, some data on the possible use of red algal polysaccharides as biologically active polymers or as taxonomic markers are briefly discussed.

  9. Complete mitochondrial genome of endangered Yellow-shouldered Amazon (Amazona barbadensis): two control region copies in parrot species of the Amazona genus.

    PubMed

    Urantowka, Adam Dawid; Hajduk, Kacper; Kosowska, Barbara

    2013-08-01

    Amazona barbadensis is an endangered species of parrot living in northern coastal Venezuela and in several Caribbean islands. In this study, we sequenced full mitochondrial genome of the considered species. The total length of the mitogenome was 18,983 bp and contained 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, duplicated control region, and degenerate copies of ND6 and tRNA (Glu) genes. High degree of identity between two copies of control region suggests their coincident evolution and functionality. Comparative analysis of both the control region sequences from four Amazona species revealed their 89.1% identity over a region of 1300 bp and indicates the presence of distinctive parts of two control region copies.

  10. Polysaccharides and bacterial plugging

    SciTech Connect

    Fogler, H.S.

    1991-11-01

    Before any successful application of Microbial Enhanced Oil Recovery process can be realized, an understanding of the cells' transport and retentive mechanisms in porous media is needed. Cell transport differs from particle transport in their ability to produce polysaccharides, which are used by cells to adhere to surfaces. Cell injection experiments have been conducted using Leuconostoc cells to illustrate the importance of cellular polysaccharide production as a transport mechanism that hinders cell movement and plugs porous media. Kinetic studies of the Leuconostoc cells, carried out to further understand the plugging rates of porous media, have shown that the cells' growth rates are approximately equal when provided with monosaccharide (glucose and fructose) or sucrose. The only difference in cell metabolism is the production of dextran when sucrose is supplied as a carbon source. Experimentally it has also been shown that the cells' growth rate is weakly dependent upon the sucrose concentration in the media, and strongly dependent upon the concentration of yeast extract. The synthesis of cellular dextran has been found to lag behind cell generation, thus indicating that the cells need to reach maturity before they are capable of expressing the detransucrase enzyme and synthesizing insoluble dextran. Dextran yields were found to be dependent upon the sucrose concentration in the media. 10 refs., 9 figs., 9 tabs.

  11. Characterization of Aloeride, a new high-molecular-weight polysaccharide from Aloe vera with potent immunostimulatory activity.

    PubMed

    Pugh, N; Ross, S A; ElSohly, M A; Pasco, D S

    2001-02-01

    We have characterized a new immunostimulatory polysaccharide called Aloeride from commercial aloe vera (Aloe barbadensis) juice. Aloeride is between 4 and 7 million Da, and its glycosyl components include glucose (37.2%), galactose (23.9%), mannose (19.5%), and arabinose (10.3%). At 0.5 microg/mL Aloeride increased NF-kappa B directed luciferase expression in THP-1 human monocytic cells to levels 50% of those achieved by maximal concentrations (10 microg/mL) of LPS. Aloeride induced the expression of the mRNAs encoding IL-1beta and TNF-alpha to levels equal to those observed in cells maximally activated by LPS. Acemannan, the major carbohydrate component from aloe, used at 200 microg/mL in the macrophage assay resulted in negligible NF-kappa B activation. Analysis of acemannan and Aloeride using size-exclusion chromatography suggests that the low activity of acemannan is due to trace amounts of Aloeride. Although Aloeride comprises only 0.015% of the aloe juice dry weight, its potency for macrophage activation accounts fully for the activity of the crude juice.

  12. The molecular basis of polysaccharide cleavage by lytic polysaccharide monooxygenases

    PubMed Central

    Frandsen, Kristian E. H.; Simmons, Thomas J.; Dupree, Paul; Poulsen, Jens-Christian N.; Hemsworth, Glyn R.; Ciano, Luisa; Johnston, Esther M.; Tovborg, Morten; Johansen, Katja S.; von Freiesleben, Pernille; Marmuse, Laurence; Fort, Sébastien; Cottaz, Sylvain; Driguez, Hugues; Henrissat, Bernard; Lenfant, Nicolas; Tuna, Floriana; Baldansuren, Amgalanbaatar; Davies, Gideon J.; Leggio, Leila Lo; Walton, Paul H.

    2016-01-01

    Lytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes which oxidatively break down recalcitrant polysaccharides such as cellulose and chitin. Since their discovery LPMOs have become integral factors in the industrial utilization of biomass, especially in the sustainable generation of cellulosic bioethanol. We report here the first structural determination of an LPMO–oligosaccharide complex, yielding detailed insights into the mechanism of action of these enzymes. Using a combination of structure and electron paramagnetic resonance spectroscopy, we reveal the means by which LPMOs interact with saccharide substrates. We further uncover electronic and structural features of the enzyme active site, showing how LPMOs orchestrate the reaction of oxygen with polysaccharide chains. PMID:26928935

  13. The molecular basis of polysaccharide cleavage by lytic polysaccharide monooxygenases.

    PubMed

    Frandsen, Kristian E H; Simmons, Thomas J; Dupree, Paul; Poulsen, Jens-Christian N; Hemsworth, Glyn R; Ciano, Luisa; Johnston, Esther M; Tovborg, Morten; Johansen, Katja S; von Freiesleben, Pernille; Marmuse, Laurence; Fort, Sébastien; Cottaz, Sylvain; Driguez, Hugues; Henrissat, Bernard; Lenfant, Nicolas; Tuna, Floriana; Baldansuren, Amgalanbaatar; Davies, Gideon J; Lo Leggio, Leila; Walton, Paul H

    2016-04-01

    Lytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes that oxidatively break down recalcitrant polysaccharides such as cellulose and chitin. Since their discovery, LPMOs have become integral factors in the industrial utilization of biomass, especially in the sustainable generation of cellulosic bioethanol. We report here a structural determination of an LPMO-oligosaccharide complex, yielding detailed insights into the mechanism of action of these enzymes. Using a combination of structure and electron paramagnetic resonance spectroscopy, we reveal the means by which LPMOs interact with saccharide substrates. We further uncover electronic and structural features of the enzyme active site, showing how LPMOs orchestrate the reaction of oxygen with polysaccharide chains.

  14. Mediating chemical reactions using polysaccharides

    NASA Astrophysics Data System (ADS)

    Tyler, Lauren E.

    We have studied the NaBH4-mediated hydrogenation of select alkenes catalyzed by polysaccharide-stabilized nanoparticles. We compared the catalytic properties of Ni-based nanoparticles or Au/Co-based nanoparticles on the hydrogenation of cinnamic acid, cinnamide, cinnamyl alcohol, and ethyl cinnamate. We evaluated the possibility that the type of stabilizing polysaccharide surrounding the nanoparticle may affect the selectivity towards the alkene compounds that undergo the hydrogenation reaction. We found that the hydrogenation of cinnamide or ethyl cinnamate proceeded readily to 100% completion independent of the type of polysaccharide stabilizing the nanoparticle. However, the extent of the hydrogenation of cinnamyl alcohol and cinnamic acid varied greatly depending on the type of polysaccharide stabilizing the nanoparticle. In the course of these studies, we observed that some polysaccharides by themselves promoted the hydrolysis of ethyl cinnamate. Thus, we have raised the hypothesis that some polysaccharides may act as "esterases" and explored the interaction between select polysaccharides and a variety of ester compounds.

  15. Computer simulation and experimental study of the polysaccharide-polysaccharide interaction in the bacteria Azospirillum brasilense Sp245

    NASA Astrophysics Data System (ADS)

    Arefeva, Oksana A.; Kuznetsov, Pavel E.; Tolmachev, Sergey A.; Kupadze, Machammad S.; Khlebtsov, Boris N.; Rogacheva, Svetlana M.

    2003-09-01

    We have studied the conformational properties and molecular dynamics of polysaccharides by using molecular modeling methods. Theoretical and experimental results of polysaccharide-polysaccharide interactions are described.

  16. Cedar leaf oil poisoning

    MedlinePlus

    Cedar leaf oil is made from some types of cedar trees. Cedar leaf oil poisoning occurs when someone swallows this substance. ... The substance in cedar leaf oil that can be harmful is thujone (a hydrocarbon).

  17. Biochemical And Genetic Modification Of Polysaccharides

    NASA Technical Reports Server (NTRS)

    Kern, Roger G.; Petersen, Gene R.; Richards, Gil F.

    1993-01-01

    Bacteriophages producing endopolysaccharase-type enzymes used to produce, isolate, and purify high yields of modified polysaccharides from polysaccharides produced by, and incorporated into capsules of, certain bacteria. Bacteriophages used in conversion of native polysaccharide materials into polymers of nearly uniform high molecular weight or, alternatively, into highly pure oligosaccharides. Also used in genetic selection of families of polysaccharides structurally related to native polysaccharide materials, but having altered properties. Resulting new polysaccharides and oligosaccharides prove useful in variety of products, including pharmaceutical chemicals, coating materials, biologically active carbohydrates, and drag-reducing additives for fluids.

  18. Influence of high hydrostatic pressure on quality parameters and structural properties of aloe vera gel (Aloe barbadensis Miller).

    PubMed

    Vega-Gálvez, Antonio; Miranda, Margarita; Nuñez-Mancilla, Yissleen; Garcia-Segovia, Purificación; Ah-Hen, Kong; Tabilo-Munizaga, Gipsy; Pérez-Won, Mario

    2014-10-01

    The aim of this work was to study the effect of high hydrostatic pressure (HHP) on colour, dietary fibre, vitamin C content, polysaccharides content, physico-chemical and structural properties of aloe vera gel at three pressure levels (300, 400 and 500 MPa for 3 min) after 35 days of storage at 4 ± 1 °C. The results showed that HHP exerted a clear influence on most of the quality parameters studied. Moisture, protein and fat contents did not show changes with an increasing pressure. Ash, crude fibre and carbohydrates content increased with increasing pressure. Vitamin C content did not show significant differences after 35 days of storage. The variation of colour in the samples increased at 500 MPa. Total dietary fibre, water holding capacity and firmness increased with pressure. However, all HHP-treated samples presented a decrease in hydration ratio and polysaccharides content; and also minor alterations in the structural properties were produced at HHP of 300-500 MPa, resulting in a high quality gel. PMID:25328187

  19. Rheologically interesting polysaccharides from yeasts

    NASA Technical Reports Server (NTRS)

    Petersen, G. R.; Nelson, G. A.; Cathey, C. A.; Fuller, G. G.

    1989-01-01

    We have examined the relationships between primary, secondary, and tertiary structures of polysaccharides exhibiting the rheological property of friction (drag) reduction in turbulent flows. We found an example of an exopolysaccharide from the yeast Cryptococcus laurentii that possessed high molecular weight but exhibited lower than expected drag reducing activity. Earlier correlations by Hoyt showing that beta 1 --> 3, beta 2 --> 4, and alpha 1 --> 3 linkages in polysaccharides favored drag reduction were expanded to include correlations to secondary structure. The effect of sidechains in a series of gellan gums was shown to be related to sidechain length and position. Disruption of secondary structure in drag reducing polysaccharides reduced drag reducing activity for some but not all exopolysaccharides. The polymer from C. laurentii was shown to be more stable than xanthan gum and other exopolysaccharides under the most vigorous of denaturing conditions. We also showed a direct relationship between extensional viscosity measurements and the drag reducing coefficient for four exopolysaccharides.

  20. Polysaccharide-Modified Synthetic Polymeric Biomaterials

    PubMed Central

    Baldwin, Aaron D.; Kiick, Kristi L.

    2010-01-01

    This review presents an overview of polysaccharide-conjugated synthetic polymers and their use in tissue-engineered scaffolds and drug-delivery applications. This topic will be divided into four categories: (1) polymeric materials modified with non-mammalian polysaccharides such as alginate, chitin, and dextran; (2) polymers modified with mammalian polysaccharides such as hyaluronan, chondroitin sulfate, and heparin; (3) multi-polysaccharide-derivatized polymer conjugate systems; and (4) polymers containing polysaccharide-mimetic molecules. Each section will discuss relevant conjugation techniques, analysis, and the impact of these materials as micelles, particles, or hydrogels used in in-vitro and in-vivo biomaterial applications. PMID:20091875

  1. Polysaccharide-modified synthetic polymeric biomaterials.

    PubMed

    Baldwin, Aaron D; Kiick, Kristi L

    2010-01-01

    This review presents an overview of polysaccharide-conjugated synthetic polymers and their use in tissue-engineered scaffolds and drug-delivery applications. This topic will be divided into four categories: (1) polymeric materials modified with non-mammalian polysaccharides such as alginate, chitin, and dextran; (2) polymers modified with mammalian polysaccharides such as hyaluronan, chondroitin sulfate, and heparin; (3) multi-polysaccharide-derivatized polymer conjugate systems; and (4) polymers containing polysaccharide-mimetic molecules. Each section will discuss relevant conjugation techniques, analysis, and the impact of these materials as micelles, particles, or hydrogels used in in-vitro and in-vivo biomaterial applications. PMID:20091875

  2. Polysaccharides templates for assembly of nanosilver.

    PubMed

    Emam, Hossam E; Ahmed, Hanan B

    2016-01-01

    Polysaccharides are particularly attractive in biomedical applications due to its biodegradability and biocompatibility. In addition to its ecofriendly effects and easy processing into different hydrogel shapes, made polysaccharides used on a large scale as suitable media for preparation of silver nanoparticles (AgNPs). In spite of, most of polysaccharides are water insoluble, but it has shown to be quite efficient capping agents and/or nanoreactor matrices for production of AgNPs. Several methods have been developed to get the benefit of multi-functionality for polysaccharides' macromolecules in preparation of AgNPs. Therefore, recently, preparation of nanosilver using different polysaccharides have been the focus of an exponentially increasing number of works devoted to develop nanocomposites by blending AgNPs with different polysaccharides matrices. The current review represents a wide survey for the published studies which interested in using of polysaccharides in nanosilver preparations.

  3. Chitosan effects on physiochemical indicators of drought-induced leaf stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water deficit stress in crops is associated with leaf senescence, a damaging oxidative process that is irreversible once it is initiated. This study was conducted to assess the effect of chitosan, a marine polysaccharide with unique bioactive properties that scavenges for reactive oxygen species; h...

  4. Localization of polysaccharides in isolated and intact cuticles of eucalypt, poplar and pear leaves by enzyme-gold labelling.

    PubMed

    Guzmán, Paula; Fernández, Victoria; García, María Luisa; Khayet, Mohamed; Fernández, Agustín; Gil, Luis

    2014-03-01

    The presence and characteristics of cuticle polysaccharides have been demonstrated by staining and spectroscopic methods, but their location in the cuticle remains unclear. Furthermore, according to the prevailing model, polysaccharides are believed to be restricted to the cuticular layer and absent in the cuticle proper. With the aim of gaining insight into cuticular ultra-structure focussing on polysaccharides, cellulose and pectins have been identified and located in the transversal sections of isolated and intact adaxial leaf cuticles of Eucalyptus globulus, Populus × canescens and Pyrus communis by means of enzyme gold-labelling (Au-cellulase, EC 3.2.1.4, and -pectinase, EC 3.2.1.15) and transmission electron microscopy (TEM). The structure of the interface between the cuticle and the cell wall underneath was observed to influence the process of enzymatic isolation of leaf cuticles. Cellulose and pectins were detected for the first time in enzymatically isolated cuticles, sometimes appearing closely underneath the epicuticular wax layer. The location and presence of polysaccharides in intact and isolated leaf cuticles may have multiple implications, such as when estimating the bi-directional transport of substances between plant organs and the surrounding environment, or when interpreting organ ontogeny. The results are discussed within a plant ontological and ecophysiological context.

  5. Structurally altered capsular polysaccharides produced by mutant bacteria

    NASA Technical Reports Server (NTRS)

    Kern, Roger G. (Inventor); Petersen, Gene R. (Inventor); Richards, Gil F. (Inventor)

    1995-01-01

    Structurally altered capsular polysaccharides are produced by mutant bacteria. These polysaccharides are isolated by selecting a wild type bacterial strain and a phage producing degradative enzymes that have substrate specificity for the capsular polysaccharides produced by the wild type bacteria. Phage-resistant mutants producing capsular polysaccharides are selected and the structurally altered capsular polysaccharide is isolated therefrom.

  6. Sucrose release from polysaccharide gels.

    PubMed

    Nishinari, Katsuyoshi; Fang, Yapeng

    2016-05-18

    Sucrose release from polysaccharide gels has been studied extensively because it is expected to be useful in understanding flavour release from solid foods and to find a new processing method which produces more palatable and healthier foods. We provide an overview of the release of sucrose and other sugars from gels of agar and related polysaccharides. The addition of sucrose to agar solutions leads to the increase in transparency of the resulting gels and the decrease in syneresis, which is attributed to the decrease in mesh size in gels. The syneresis occurring in the quiescent condition and fluid release induced by compression is discussed. The relationship between the sugar release and the structural, rheological and thermal properties of gels is also discussed. Finally, the future research direction is proposed.

  7. Cellulose degradation by polysaccharide monooxygenases.

    PubMed

    Beeson, William T; Vu, Van V; Span, Elise A; Phillips, Christopher M; Marletta, Michael A

    2015-01-01

    Polysaccharide monooxygenases (PMOs), also known as lytic PMOs (LPMOs), enhance the depolymerization of recalcitrant polysaccharides by hydrolytic enzymes and are found in the majority of cellulolytic fungi and actinomycete bacteria. For more than a decade, PMOs were incorrectly annotated as family 61 glycoside hydrolases (GH61s) or family 33 carbohydrate-binding modules (CBM33s). PMOs have an unusual surface-exposed active site with a tightly bound Cu(II) ion that catalyzes the regioselective hydroxylation of crystalline cellulose, leading to glycosidic bond cleavage. The genomes of some cellulolytic fungi contain more than 20 genes encoding cellulose-active PMOs, suggesting a diversity of biological activities. PMOs show great promise in reducing the cost of conversion of lignocellulosic biomass to fermentable sugars; however, many questions remain about their reaction mechanism and biological function. This review addresses, in depth, the structural and mechanistic aspects of oxidative depolymerization of cellulose by PMOs and considers their biological function and phylogenetic diversity.

  8. Sucrose release from polysaccharide gels.

    PubMed

    Nishinari, Katsuyoshi; Fang, Yapeng

    2016-05-18

    Sucrose release from polysaccharide gels has been studied extensively because it is expected to be useful in understanding flavour release from solid foods and to find a new processing method which produces more palatable and healthier foods. We provide an overview of the release of sucrose and other sugars from gels of agar and related polysaccharides. The addition of sucrose to agar solutions leads to the increase in transparency of the resulting gels and the decrease in syneresis, which is attributed to the decrease in mesh size in gels. The syneresis occurring in the quiescent condition and fluid release induced by compression is discussed. The relationship between the sugar release and the structural, rheological and thermal properties of gels is also discussed. Finally, the future research direction is proposed. PMID:26952168

  9. Cellulose degradation by polysaccharide monooxygenases.

    PubMed

    Beeson, William T; Vu, Van V; Span, Elise A; Phillips, Christopher M; Marletta, Michael A

    2015-01-01

    Polysaccharide monooxygenases (PMOs), also known as lytic PMOs (LPMOs), enhance the depolymerization of recalcitrant polysaccharides by hydrolytic enzymes and are found in the majority of cellulolytic fungi and actinomycete bacteria. For more than a decade, PMOs were incorrectly annotated as family 61 glycoside hydrolases (GH61s) or family 33 carbohydrate-binding modules (CBM33s). PMOs have an unusual surface-exposed active site with a tightly bound Cu(II) ion that catalyzes the regioselective hydroxylation of crystalline cellulose, leading to glycosidic bond cleavage. The genomes of some cellulolytic fungi contain more than 20 genes encoding cellulose-active PMOs, suggesting a diversity of biological activities. PMOs show great promise in reducing the cost of conversion of lignocellulosic biomass to fermentable sugars; however, many questions remain about their reaction mechanism and biological function. This review addresses, in depth, the structural and mechanistic aspects of oxidative depolymerization of cellulose by PMOs and considers their biological function and phylogenetic diversity. PMID:25784051

  10. Polysaccharide-Based Micelles for Drug Delivery

    PubMed Central

    Zhang, Nan; Wardwell, Patricia R.; Bader, Rebecca A.

    2013-01-01

    Delivery of hydrophobic molecules and proteins has been an issue due to poor bioavailability following administration. Thus, micelle carrier systems are being investigated to improve drug solubility and stability. Due to problems with toxicity and immunogenicity, natural polysaccharides are being explored as substitutes for synthetic polymers in the development of new micelle systems. By grafting hydrophobic moieties to the polysaccharide backbone, self-assembled micelles can be readily formed in aqueous solution. Many polysaccharides also possess inherent bioactivity that can facilitate mucoadhesion, enhanced targeting of specific tissues, and a reduction in the inflammatory response. Furthermore, the hydrophilic nature of some polysaccharides can be exploited to enhance circulatory stability. This review will highlight the advantages of polysaccharide use in the development of drug delivery systems and will provide an overview of the polysaccharide-based micelles that have been developed to date. PMID:24300453

  11. Marine Polysaccharides in Pharmaceutical Applications: An Overview

    PubMed Central

    Laurienzo, Paola

    2010-01-01

    The enormous variety of polysaccharides that can be extracted from marine plants and animal organisms or produced by marine bacteria means that the field of marine polysaccharides is constantly evolving. Recent advances in biological techniques allow high levels of polysaccharides of interest to be produced in vitro. Biotechnology is a powerful tool to obtain polysaccharides from a variety of micro-organisms, by controlling the growth conditions in a bioreactor while tailoring the production of biologically active compounds. Following an overview of the current knowledge on marine polysaccharides, with special attention to potential pharmaceutical applications and to more recent progress on the discovering of new polysaccharides with biological appealing characteristics, this review will focus on possible strategies for chemical or physical modification aimed to tailor the final properties of interest. PMID:20948899

  12. Polysaccharide-based nanocomposites and their applications

    PubMed Central

    Zheng, Yingying; Monty, Jonathan; Linhardt, Robert J.

    2014-01-01

    Polysaccharide nanocomposites have become increasingly important materials over the past decade. Polysaccharides offer a green alternative to synthetic polymers in the preparation of soft nanomaterials. They have also been used in composites with hard nanomaterials, such as metal nanoparticles and carbon-based nanomaterials. This mini review describes methods for polysaccharide nanocomposite preparation and reviews the various types and diverse applications for these novel materials. PMID:25498200

  13. Starch-degrading polysaccharide monooxygenases.

    PubMed

    Vu, Van V; Marletta, Michael A

    2016-07-01

    Polysaccharide degradation by hydrolytic enzymes glycoside hydrolases (GHs) is well known. More recently, polysaccharide monooxygenases (PMOs, also known as lytic PMOs or LPMOs) were found to oxidatively degrade various polysaccharides via a copper-dependent hydroxylation. PMOs were previously thought to be either GHs or carbohydrate binding modules (CBMs), and have been re-classified in carbohydrate active enzymes (CAZY) database as auxiliary activity (AA) families. These enzymes include cellulose-active fungal PMOs (AA9, formerly GH61), chitin- and cellulose-active bacterial PMOs (AA10, formerly CBM33), and chitin-active fungal PMOs (AA11). These PMOs significantly boost the activity of GHs under industrially relevant conditions, and thus have great potential in the biomass-based biofuel industry. PMOs that act on starch are the latest PMOs discovered (AA13), which has expanded our perspectives in PMOs studies and starch degradation. Starch-active PMOs have many common structural features and biochemical properties of the PMO superfamily, yet differ from other PMO families in several important aspects. These differences likely correlate, at least in part, to the differences in primary and higher order structures of starch and cellulose, and chitin. In this review we will discuss the discovery, structural features, biochemical and biophysical properties, and possible biological functions of starch-active PMOs, as well as their potential application in the biofuel, food, and other starch-based industries. Important questions regarding various aspects of starch-active PMOs and possible economical driving force for their future studies will also be highlighted. PMID:27170366

  14. Solution NMR spectroscopy of food polysaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many polysaccharides are allowed for direct food use, where they serve a number of useful functions. In addition to possibly being a source of calories, a food polysaccharide may be a dietary fiber, bulking agent, crystallization inhibitor, thickener, encapsulant, gelling agent, foam and emulsion s...

  15. Bioactive polysaccharides and gut microbiome (abstract)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many polysaccharides have shown the ability to reduce plasma cholesterol or postprandial glycemia. Viscosity in the small intestine seems to be required to slow glucose uptake. Cereal mixed linkage beta-glucans, psyllium, glucomannans, and other polysaccharides also seem to require higher molecula...

  16. Applications of Important Polysaccharides in Drug Delivery.

    PubMed

    Huang, Gangliang; Mei, Xinya; Xiao, Feng; Chen, Xin; Tang, Qilin; Peng, Daquan

    2015-01-01

    Polysaccharide is a kind of biological material, which has good biocompatibility, non-toxicity, and non-immunogenicity. So, the polysaccharide has widely been applied in drug delivery system. The applications of chitosan, hyaluronic acid and dextran in drug delivery have been summarized herein. PMID:25578889

  17. Structural features, antioxidant and immunological activity of a new polysaccharide (SP1) from sisal residue.

    PubMed

    Zhang, Xuehong; Liu, Lina; Lin, Cuiwu

    2013-08-01

    A new water-soluble polysaccharide (SP1) with molecular weight of 9192Da was isolated from the residue after extracting fiber from sisal leaf and its structure was investigated. Monosaccharide composition analysis showed that SP1 was composed of Rha, GalA, Gal, Ara and Glc in a molar ratio of 1.82:1.69:1.00:0.23:0.15. The structure analysis indicated that the SP1 was comprised of a backbone of alternating 1,2-linked-α-l-Rhap and 1,4-linked-α-d-GalpA units, and the neutral polysaccharide side chains composed of Galp, Ara and Glcp residues were attached to the O-4 position of 1,2-linked-α-l-Rhap residues. SP1 could stimulate ConA-induced T lymphocyte proliferation and had noticeable DPPH radical-scavenging ability. PMID:23624283

  18. Enzymatic method for improving the injectability of polysaccharides

    DOEpatents

    Griffith, William L.; Compere, Alicia L.; Holleman, James W.

    1982-01-01

    A method for enhancing the ability of polysaccharides in aqueous solution to flow through a porous medium comprises contacting the polysaccharides with an endoenzyme capable of hydrolyzing at least one of the linkages of the sugar units of the polysaccharides and maintaining the polysaccharides in contact with the enzyme under hydrolysis conditions for a time sufficient to decrease the tendency of the polysaccharides to plug the porous medium yet insufficient to decrease the viscosity of the aqueous polysaccharides by more than 25%. The partially hydrolyzed polysaccharides are useful as thickening agents for flooding water used to recover oil from oil-containing subterranean formations.

  19. Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study.

    PubMed

    Corbin, Kendall R; Byrt, Caitlin S; Bauer, Stefan; DeBolt, Seth; Chambers, Don; Holtum, Joseph A M; Karem, Ghazwan; Henderson, Marilyn; Lahnstein, Jelle; Beahan, Cherie T; Bacic, Antony; Fincher, Geoffrey B; Betts, Natalie S; Burton, Rachel A

    2015-01-01

    Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like--rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47-50% w/w) and non-cellulosic polysaccharides (16-22% w/w), and whole leaves were low in lignin (9-13% w/w). Of the dry mass of whole Agave leaves, 85-95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41-48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition. PMID:26305101

  20. Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study

    PubMed Central

    Corbin, Kendall R.; Byrt, Caitlin S.; Bauer, Stefan; DeBolt, Seth; Chambers, Don; Holtum, Joseph A. M.; Karem, Ghazwan; Henderson, Marilyn; Lahnstein, Jelle; Beahan, Cherie T.; Bacic, Antony; Fincher, Geoffrey B.; Betts, Natalie S.; Burton, Rachel A.

    2015-01-01

    Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like—rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47–50% w/w) and non-cellulosic polysaccharides (16–22% w/w), and whole leaves were low in lignin (9–13% w/w). Of the dry mass of whole Agave leaves, 85–95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41–48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition. PMID:26305101

  1. Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study.

    PubMed

    Corbin, Kendall R; Byrt, Caitlin S; Bauer, Stefan; DeBolt, Seth; Chambers, Don; Holtum, Joseph A M; Karem, Ghazwan; Henderson, Marilyn; Lahnstein, Jelle; Beahan, Cherie T; Bacic, Antony; Fincher, Geoffrey B; Betts, Natalie S; Burton, Rachel A

    2015-01-01

    Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like--rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47-50% w/w) and non-cellulosic polysaccharides (16-22% w/w), and whole leaves were low in lignin (9-13% w/w). Of the dry mass of whole Agave leaves, 85-95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41-48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition.

  2. Rheology of interfacial protein-polysaccharide composites

    NASA Astrophysics Data System (ADS)

    Fischer, P.

    2013-05-01

    The morphology and mechanical properties of protein adsorption layers can significantly be altered by the presence of surfactants, lipids, particles, other proteins, and polysaccharides. In food emulsions, polysaccharides are primarily considered as bulk thickener but can under appropriate environmental conditions stabilize or destabilize the protein adsorption layer and, thus, the entire emulsion system. Despite their ubiquitous usage as stabilization agent, relatively few investigations focus on the interfacial rheology of composite protein/polysaccharide adsorption layers. The manuscript provides a brief review on both main stabilization mechanisms, thermodynamic phase separation and electrostatic interaction and discusses the rheological response in light of the environmental conditions such as ionic strength and pH.

  3. Serogroup quantitation of multivalent polysaccharide and polysaccharide-conjugate meningococcal vaccines from China.

    PubMed

    Cook, Matthew C; Gibeault, Sabrina; Filippenko, Vasilisa; Ye, Qiang; Wang, Junzhi; Kunkel, Jeremy P

    2013-07-01

    The active components of most meningococcal vaccines are four antigenic serogroup capsular polysaccharides (A, C, Y, W135). The vaccines, monovalent or multivalent mixtures of either free polysaccharides or polysaccharides conjugated to antigenic carrier proteins, may be in liquid or lyophilised formulations, with or without excipients. Acid hydrolysis and chromatographic methods for serogroup quantitation, which were previously optimised and qualified using polysaccharide-based standards and a narrow range of real vaccines, are here challenged with multiple lots of a broad assortment of additional multivalent polysaccharide-based meningococcal vaccine products. Centrifugal filtration successfully removed all interfering lactose excipient without loss of polysaccharides to allow for the determination of Y and W135 serogroups. Replicate operations by three different analysts indicated high method reproducibility. Results indicated some lot-to-lot and product-to-product variations. However, all vaccines were within general specifications for each serogroup polysaccharide, with the exception of all lots of one polysaccharide vaccine - which by these methods were found to be deficient in the serogroup A component only. These robust techniques are very useful for the evaluation of antigen content and consistency of manufacture. The deformulation, hydrolysis and chromatographic methods may be adaptable for the evaluation of other types of polysaccharide-based vaccines.

  4. Polysaccharides and bacterial plugging. [Leuconostoc bacteria

    SciTech Connect

    Fogler, H.S.

    1992-01-01

    The objectives of this research are to elucidate and model bacterial transport in porous media, to determine the importance of polysaccharides bridging as a retentive mechanism, and to identify key parameters that influence porous media plugging. This project has been subdivided into three tasks: Task 1 is the determination of the growth kinetics of the Leuconostoc bacteria and how they are affected by (1) the nutrient feed, and (2) surface effects; Task 2 will quantify the importance of polysaccharide production as a cell retention mechanism; and Task 3 is the elucidation of the rate of polysaccharide production and the combined effect that polysaccharide production and cell growth has upon plugging. Batch growth experiments have been conducted to determine the rate of cell growth, polymer production and nutrient consumption. The data from these experiments are currently being reduced to aid the development of an overall growth model.

  5. Leaf growth is conformal

    NASA Astrophysics Data System (ADS)

    Alim, Karen; Armon, Shahaf; Shraiman, Boris I.; Boudaoud, Arezki

    2016-10-01

    Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement field to 92%. This approach is applicable to any two-dimensional system with locally isotropic growth, enabling the deduction of the whole growth field just from observation of the tissue contour.

  6. Leaf growth is conformal.

    PubMed

    Alim, Karen; Armon, Shahaf; Shraiman, Boris I; Boudaoud, Arezki

    2016-01-01

    Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement field to 92%. This approach is applicable to any two-dimensional system with locally isotropic growth, enabling the deduction of the whole growth field just from observation of the tissue contour. PMID:27597439

  7. Polysaccharides and virulence of Burkholderia pseudomallei.

    PubMed

    Sarkar-Tyson, M; Thwaite, J E; Harding, S V; Smither, S J; Oyston, P C F; Atkins, T P; Titball, R W

    2007-08-01

    Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease of humans and animals. Gene clusters which encode capsular polysaccharide (type I O-PS) and LPS (type II O-PS), both of which play roles in virulence, have previously been identified. Here, the identification of two further putative clusters, type III O-PS and type IV O-PS, is reported. Mice challenged with type III O-PS or type IV O-PS mutants showed increased mean times to death (7.8 and 11.6 days) compared to those challenged with wild-type B. pseudomallei (3 days). To investigate the possible roles of polysaccharides in protection, mice were immunized with killed cells of wild-type B. pseudomallei or killed cells of B. pseudomallei with mutations in the O antigen, capsular polysaccharide, type III O-PS or type IV O-PS gene clusters. Immunization with all polysaccharide mutant strains resulted in delayed time to death compared to the naïve controls, following challenge with wild-type B. pseudomallei strain K96243. However, immunization with killed polysaccharide mutant strains conferred different degrees of protection, demonstrating the immunological importance of the polysaccharide clusters on the surface of B. pseudomallei.

  8. Monoclonal antibodies against plant cell wall polysaccharides

    SciTech Connect

    Hahn, M.G.; Bucheli, E.; Darvill, A.; Albersheim, P. )

    1989-04-01

    Monoclonal antibodies (McAbs) are useful tools to probe the structure of plant cell wall polysaccharides and to localize these polysaccharides in plant cells and tissues. Murine McAbs were generated against the pectic polysaccharide, rhamnogalacturonan I (RG-I), isolated from suspension-cultured sycamore cells. The McAbs that were obtained were grouped into three classes based upon their reactivities with a variety of plant polysaccharides and membrane glycoproteins. Eleven McAbs (Class I) recognize epitope(s) that appear to be immunodominant and are found in RG-I from sycamore and maize, citrus pectin, polygalacturonic acid, and membrane glycoproteins from suspension-cultured cells of sycamore, maize, tobacco, parsley, and soybean. A second group of five McAbs (Class II) recognize epitope(s) present in sycamore RG-I, but do not bind to any of the other polysaccharides or glycoproteins recognized by Class I. Lastly, one McAb (Class III) reacts with sycamore RG-I, sycamore and tamarind xyloglucan, and sycamore and rice glucuronoarabinoxylan, but does not bind to maize RG-I, polygalacturonic acid or the plant membrane glycoproteins recognized by Class I. McAbs in Classes II and III are likely to be useful in studies of the structure, biosynthesis and localization of plant cell wall polysaccharides.

  9. Wettability, polarity, and water absorption of holm oak leaves: effect of leaf side and age.

    PubMed

    Fernández, Victoria; Sancho-Knapik, Domingo; Guzmán, Paula; Peguero-Pina, José Javier; Gil, Luis; Karabourniotis, George; Khayet, Mohamed; Fasseas, Costas; Heredia-Guerrero, José Alejandro; Heredia, Antonio; Gil-Pelegrín, Eustaquio

    2014-09-01

    Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition, and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of holm oak (Quercus ilex) as a model. By measuring the leaf water potential 24 h after the deposition of water drops onto abaxial and adaxial surfaces, evidence for water penetration through the upper leaf side was gained in young and mature leaves. The structure and chemical composition of the abaxial (always present) and adaxial (occurring only in young leaves) trichomes were analyzed by various microscopic and analytical procedures. The adaxial surfaces were wettable and had a high degree of water drop adhesion in contrast to the highly unwettable and water-repellent abaxial holm oak leaf sides. The surface free energy and solubility parameter decreased with leaf age, with higher values determined for the adaxial sides. All holm oak leaf trichomes were covered with a cuticle. The abaxial trichomes were composed of 8% soluble waxes, 49% cutin, and 43% polysaccharides. For the adaxial side, it is concluded that trichomes and the scars after trichome shedding contribute to water uptake, while the abaxial leaf side is highly hydrophobic due to its high degree of pubescence and different trichome structure, composition, and density. Results are interpreted in terms of water-plant surface interactions, plant surface physical chemistry, and plant ecophysiology.

  10. Structural biopolymer preservation in Miocene leaf fossils from the Clarkia site, northern Idaho.

    PubMed Central

    Logan, G A; Boon, J J; Eglinton, G

    1993-01-01

    The 17- to 20-million-year-old locality at Clarkia, northern Idaho, is renowned for yielding amplifiable DNA from a magnolia leaf fossil. In-source pyrolysis-mass spectrometry and pyrolysis-gas chromatography/mass spectrometry now reveal that molecular preservation of biomacromolecules is highly selective; structural polysaccharides, cutin polyesters, and proteins were not preserved in detectable quantity in the leaf tissues, whereas both lignin and an aliphatic biopolymer were detected. This study points up the need for improved understanding of the precise modes and extent of preservation of biomacromolecules in fossil materials and sediments. PMID:11607375

  11. Comparison of Degradative Ability, Enzymatic Activity, and Palatability of Aquatic Hyphomycetes Grown on Leaf Litter

    PubMed Central

    Suberkropp, Keller; Arsuffi, Thomas L.; Anderson, John P.

    1983-01-01

    Stream fungi have the capacity to degrade leaf litter and, through their activities, to transform it into a more palatable food source for invertebrate detritivores. The objectives of the present study were to characterize various aspects of fungal modification of the leaf substrate and to examine the effects these changes have on leaf palatability to detritivores. Fungal species were grown on aspen leaves for two incubation times. Leaves were analyzed to determine the weight loss, the degree of softening of the leaf matrix, and the concentrations of ATP and nitrogen associated with leaves. The activities of a protease and 10 polysaccharide-degrading enzymes produced by each fungus were also determined. Most fungi caused similar changes in physicochemical characteristics of the leaves. All fungi exhibited the capability to depolymerize pectin, xylan, and cellulose. Differences among fungi were found in their capabilities to produce protease and certain glycosidases. Leaf palatability was assessed by offering leaves of all treatments to larvae of two caddisfly shredders (Trichoptera). Feeding preferences exhibited by the shredders were similar and indicated that they perceived distinct differences among fungi. Two fungal species were highly consumed, some moderately and others only slightly. No relationships were found between any of the fungal characteristics measured and detritivore feeding preferences. Apparently, interspecific differences among fungi other than parameters associated with biomass or degradation of structural polysaccharides influence fungal palatability to caddisfly detritivores. PMID:16346343

  12. Viscoelastic properties of levan polysaccharides

    NASA Astrophysics Data System (ADS)

    Noll, Kenneth; Rende, Deniz; Ozisik, Rahmi; Toksoy-Oner, Ebru

    2014-03-01

    Levan is a naturally occurring polysaccharide that is composed of β-D-fructofuranose units with β(2-6) linkages between fructose rings. It is synthesized by the action of a secreted levansucrase (EC 2.4.1.10) that converts sucrose into the levan externally (exopolysaccharide). Levan is a homopolysaccharide that is non-toxic, water soluble,, and has anti-tumor activity and low immunological response. Therefore, levan presents great potential to be used as a novel functional biopolymer in foods, feeds, cosmetics, pharmaceutical and chemical industries. Despite these favorable properties, levan has a moderately low mechanical properties and poor film forming capability. In the current study, the agglomeration behavior of levan in water and in saline solutions was investigated at 298 and 310 K by dynamic light scattering and transmission electron microscopy (TEM). The viscoelastic properties of neat and oxidized levan films were studied via nanoindentation experiments in the quasi-static and dynamic modes The material is partially based upon work supported by NSF under Grant Nos. 1200270 and 1003574, and TUBITAK 111M232.

  13. Deer predation on leaf miners via leaf abscission

    NASA Astrophysics Data System (ADS)

    Yamazaki, Kazuo; Sugiura, Shinji

    2008-03-01

    The evergreen oak Quercus gilva Blume sheds leaves containing mines of the leaf miner Stigmella sp. (Lepidoptera: Nepticulidae) earlier than leaves with no mines in early spring in Nara, central Japan. The eclosion rates of the leaf miner in abscised and retained leaves were compared in the laboratory to clarify the effects of leaf abscission on leaf miner survival in the absence of deer. The leaf miner eclosed successfully from both fallen leaves and leaves retained on trees. However, sika deer ( Cervus nippon centralis Kishida) feed on the fallen mined leaves. Field observations showed that deer consume many fallen leaves under Q. gilva trees, suggesting considerable mortality of leaf miners due to deer predation via leaf abscission. This is a previously unreported relationship between a leaf miner and a mammalian herbivore via leaf abscission.

  14. Freshwater Plants Synthesize Sulfated Polysaccharides: Heterogalactans from Water Hyacinth (Eicchornia crassipes)

    PubMed Central

    Dantas-Santos, Nednaldo; Gomes, Dayanne Lopes; Costa, Leandro Silva; Cordeiro, Sara Lima; Costa, Mariana Santos Santana Pereira; Trindade, Edvaldo Silva; Franco, Célia Regina Chavichiolo; Scortecci, Kátia Castanho; Leite, Edda Lisboa; Rocha, Hugo Alexandre Oliveira

    2012-01-01

    Sulfated polysaccharides (SP) are found mainly in seaweeds and animals. To date, they have only been found in six plants and all inhabit saline environments. Furthermore, there are no reports of SP in freshwater or terrestrial plants. As such, this study investigated the presence of SP in freshwaters Eichhornia crassipes, Egeria densa, Egeria naja, Cabomba caroliniana, Hydrocotyle bonariensis and Nymphaea ampla. Chemical analysis identified sulfate in N. ampla, H. bonariensis and, more specifically, E. crassipes. In addition, chemical analysis, FT-IR spectroscopy, histological analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA), as well as agarose gel electrophoresis detected SP in all parts of E. crassipes, primarily in the root (epidermis and vascular bundle). Galactose, glucose and arabinose are the main monosaccharides found in the sulfated polysaccharides from E. crassipes. In activated partial thromboplastin time (APTT) test, to evaluate the intrinsic coagulation pathway, SP from the root and rhizome prolonged the coagulation time to double the baseline value, with 0.1 mg/mL and 0.15 mg/mL, respectively. However, SP from the leaf and petiole showed no anticoagulant activity. Eichornia SP demonstrated promising anticoagulant potential and have been selected for further studies on bioguided fractionation; isolation and characterization of pure polysaccharides from this species. Additionally in vivo experiments are needed and are already underway. PMID:22312297

  15. Anticoagulant Activity of Polyphenolic-Polysaccharides Isolated from Melastoma malabathricum L.

    PubMed Central

    Abas, Faridah; Abdullah, Janna Ong; Mohd Tohit, Eusni Rahayu; Hamid, Muhajir

    2014-01-01

    Melastoma malabathricum Linn. is a perennial traditional medicine plants that grows abundantly throughout Asian countries. In this study, M. malabathricum Linn. leaf hot water crude extract with anticoagulant activity was purified through solid phase extraction cartridge and examined for the bioactive chemical constituents on blood coagulation reaction. The SPE purified fractions were, respectively, designated as F1, F2, F3, and F4, and each was subjected to the activated partial thromboplastin time (APTT) anticoagulant assay. Active anticoagulant fractions (F1, F2, and F3) were subjected to chemical characterisation evaluation. Besides, neutral sugar for carbohydrate part was also examined. F1, F2, and F3 were found to significantly prolong the anticoagulant activities in the following order, F1 > F2 > F3, in a dose dependent manner. In addition, carbohydrate, hexuronic acid, and polyphenolic moiety were measured for the active anticoagulant fractions (F1, F2, and F3). The characterisation of chemical constituents revealed that all these three fractions contained acidic polysaccharides (rhamnogalacturonan, homogalacturonan, and rhamnose hexose-pectic type polysaccharide) and polyphenolics. Hence, it was concluded that the presence of high hexuronic acids and polysaccharides, as well as polyphenolics in traditional medicinal plant, M. malabathricum, played a role in prolonging blood clotting in the intrinsic pathway. PMID:24987430

  16. Cell wall carbohydrates from fruit pulp of Argania spinosa: structural analysis of pectin and xyloglucan polysaccharides.

    PubMed

    Aboughe-Angone, Sophie; Nguema-Ona, Eric; Ghosh, Partha; Lerouge, Patrice; Ishii, Tadashi; Ray, Bimalendu; Driouich, Azeddine

    2008-01-14

    Isolated cell walls of Argania spinosa fruit pulp were fractionated into their polysaccharide constituents and the resulting fractions were analysed for monosaccharide composition and chemical structure. The data reveal the presence of homogalacturonan, rhamnogalacturonan-I (RG-I) and rhamnogalacturonan-II (RG-II) in the pectic fraction. RG-I is abundant and contains high amounts of Ara and Gal, indicative of an important branching in this polysaccharide. RG-II is less abundant than RG-I and exists as a dimer. Structural characterisation of xyloglucan using enzymatic hydrolysis, gas chromatography, MALDI-TOF-MS and methylation analysis shows that XXGG, XXXG, XXLG and XLLG are the major subunit oligosaccharides in the ratio of 0.6:1:1.2:1.6. This finding demonstrates that the major neutral hemicellulosic polysaccharide is a galacto-xyloglucan. In addition, Argania fruit xyloglucan has no XUFG, a novel xyloglucan motif recently discovered in Argania leaf cell walls. Finally, the isolation and analysis of arabinogalactan-proteins showed that Argania fruit pulp is rich in these proteoglycans. PMID:18005949

  17. Damped leaf flexure hinge

    NASA Astrophysics Data System (ADS)

    Chen, Zhong; Chen, Guisheng; Zhang, Xianmin

    2015-05-01

    Flexure-based mechanism like compliant actuation system embeds complex dynamics that will reduce the control bandwidth and limits their dynamic positioning precision. This paper presents a theoretical model of a leaf flexure hinge with damping layers using strain energy method and Kelvin damping model. The modified loss factor of the damped leaf flexure hinge is derived, and the equivalent viscous damping coefficient of the damped leaf hinge is obtained, which could be used to improve the pseudo-rigid-model. The free vibration signals of the hinge in three different damping configurations are measured. The experimental modal analysis also is performed on the three kinds of damped leaf flexure hinges in order to evaluate their 1st order bending natural frequency and vibration-suppressing effects. The evaluation of modified loss factor model also is performed. The experimental results indicate that the constrained layer damping can enhance the structure damping of the hinge even if only single damping layer each side, the modified loss factor model can get good predicts of a damped leaf flexure hinge in the frequency range below 1st order natural frequency, and it is necessary that the dimensional parameters of the damping layers and basic layer of the hinge should be optimized for simplification at the mechanism's design stage.

  18. Damped leaf flexure hinge.

    PubMed

    Chen, Zhong; Chen, Guisheng; Zhang, Xianmin

    2015-05-01

    Flexure-based mechanism like compliant actuation system embeds complex dynamics that will reduce the control bandwidth and limits their dynamic positioning precision. This paper presents a theoretical model of a leaf flexure hinge with damping layers using strain energy method and Kelvin damping model. The modified loss factor of the damped leaf flexure hinge is derived, and the equivalent viscous damping coefficient of the damped leaf hinge is obtained, which could be used to improve the pseudo-rigid-model. The free vibration signals of the hinge in three different damping configurations are measured. The experimental modal analysis also is performed on the three kinds of damped leaf flexure hinges in order to evaluate their 1st order bending natural frequency and vibration-suppressing effects. The evaluation of modified loss factor model also is performed. The experimental results indicate that the constrained layer damping can enhance the structure damping of the hinge even if only single damping layer each side, the modified loss factor model can get good predicts of a damped leaf flexure hinge in the frequency range below 1st order natural frequency, and it is necessary that the dimensional parameters of the damping layers and basic layer of the hinge should be optimized for simplification at the mechanism's design stage. PMID:26026549

  19. Immobilized phosphorylase for synthesis of polysaccharides from glucose

    NASA Technical Reports Server (NTRS)

    Marshall, D. L.

    1972-01-01

    Continuous processes for enzymatic production of carbohydrates from glucose are discussed. Key reactant in process is identified as phosphorylase which catalyzes reversible formation or degradation of polysaccharide. Chemical compounds and reactions to synthesize polysaccharides are analyzed.

  20. Immunomodulatory effects of a polysaccharide from Tamarindus indica.

    PubMed

    Sreelekha, T T; Vijayakumar, T; Ankanthil, R; Vijayan, K K; Nair, M K

    1993-04-01

    A polysaccharide isolated and purified from Tamarindus indica shows immunomodulatory activities such as phagocytic enhancement, leukocyte migration inhibition and inhibition of cell proliferation. These properties suggest that this polysaccharide from T. indica may have some biological applications.

  1. Neisseria meningitidis serogroup A capsular polysaccharide acetyltransferase, methods and compositions

    DOEpatents

    Stephens, David S.; Gudlavalleti, Seshu K.; Tzeng, Yih-Ling; Datta, Anup K.; Carlson, Russell W.

    2011-02-08

    Provided are methods for recombinant production of an O-acetyltransferase and methods for acetylating capsular polysaccharides, especially those of a Serogroup A Neisseria meningitidis using the recombinant O-acetyltransferase, and immunogenic compositions comprising the acetylated capsular polysaccharide.

  2. Ice nucleation activity of polysaccharides

    NASA Astrophysics Data System (ADS)

    Bichler, Magdalena; Felgitsch, Laura; Haeusler, Thomas; Seidl-Seiboth, Verena; Grothe, Hinrich

    2015-04-01

    Heterogeneous ice nucleation is an important process in the atmosphere. It shows direct impact on our climate by triggering ice cloud formation and therefore it has much influence on the radiation balance of our planet (Lohmann et al. 2002; Mishchenko et al. 1996). The process itself is not completely understood so far and many questions remain open. Different substances have been found to exhibit ice nucleation activity (INA). Due to their vast differences in chemistry and morphology it is difficult to predict what substance will make good ice nuclei and which will not. Hence simple model substances must be found and be tested regarding INA. Our work aims at gaining to a deeper understanding of heterogeneous ice nucleation. We intend to find some reference standards with defined chemistry, which may explain the mechanisms of heterogeneous ice nucleation. A particular focus lies on biological carbohydrates in regards to their INA. Biological carbohydrates are widely distributed in all kingdoms of life. Mostly they are specific for certain organisms and have well defined purposes, e.g. structural polysaccharides like chitin (in fungi and insects) and pectin (in plants), which has also water-binding properties. Since they are widely distributed throughout our biosphere and mostly safe to use for nutrition purposes, they are well studied and easily accessible, rendering them ideal candidates as proxies. In our experiments we examined various carbohydrates, like the already mentioned chitin and pectin, as well as their chemical modifications. Lohmann U.; A Glaciation Indirect Aerosol Effect Caused by Soot Aerosols; J. Geoph. Res.; Vol. 24 No.4; pp 11-1 - 11-4; 2002 Mishchenko M.I., Rossow W.B., Macke A., Lacis A. A.; Sensitivity of Cirrus Cloud Albedo, Bidirectional Reflectance and Optical Thickness Retrieval Accuracy to Ice Particle Shape, J. Geoph. Res.; Vol. 101, No D12; pp. 16,973 - 16,985; 1996

  3. Surface polysaccharides and quorum sensing are involved in the attachment and survival of Xanthomonas albilineans on sugarcane leaves.

    PubMed

    Mensi, Imene; Daugrois, Jean-Heinrich; Pieretti, Isabelle; Gargani, Daniel; Fleites, Laura A; Noell, Julie; Bonnot, Francois; Gabriel, Dean W; Rott, Philippe

    2016-02-01

    Xanthomonas albilineans, the causal agent of sugarcane leaf scald, is a bacterial plant pathogen that is mainly spread by infected cuttings and contaminated harvesting tools. However, some strains of this pathogen are known to be spread by aerial means and are able to colonize the phyllosphere of sugarcane before entering the host plant and causing disease. The objective of this study was to identify the molecular factors involved in the survival or growth of X. albilineans on sugarcane leaves. We developed a bioassay to test for the attachment of X. albilineans on sugarcane leaves using tissue-cultured plantlets grown in vitro. Six mutants of strain XaFL07-1 affected in surface polysaccharide production completely lost their capacity to survive on the sugarcane leaf surface. These mutants produced more biofilm in vitro and accumulated more cellular poly-β-hydroxybutyrate than the wild-type strain. A mutant affected in the production of small molecules (including potential biosurfactants) synthesized by non-ribosomal peptide synthetases (NRPSs) attached to the sugarcane leaves as well as the wild-type strain. Surprisingly, the attachment of bacteria on sugarcane leaves varied among mutants of the rpf gene cluster involved in bacterial quorum sensing. Therefore, quorum sensing may affect polysaccharide production, or both polysaccharides and quorum sensing may be involved in the survival or growth of X. albilineans on sugarcane leaves.

  4. Recalcitrant polysaccharide degradation by novel oxidative biocatalysts.

    PubMed

    Dimarogona, Maria; Topakas, Evangelos; Christakopoulos, Paul

    2013-10-01

    The classical hydrolytic mechanism for the degradation of plant polysaccharides by saprophytic microorganisms has been reconsidered after the recent landmark discovery of a new class of oxidases termed lytic polysaccharide monooxygenases (LPMOs). LPMOs are of increased biotechnological interest due to their implication in lignocellulosic biomass decomposition for the production of biofuels and high-value chemicals. They act on recalcitrant polysaccharides by a combination of hydrolytic and oxidative function, generating oxidized and non-oxidized chain ends. They are copper-dependent and require molecular oxygen and an external electron donor for their proper function. In this review, we present the recent findings concerning the mechanism of action of these oxidative enzymes and identify issues and questions to be addressed in the future. PMID:23995228

  5. Influence of polysaccharides on wine protein aggregation.

    PubMed

    Jaeckels, Nadine; Meier, Miriam; Dietrich, Helmut; Will, Frank; Decker, Heinz; Fronk, Petra

    2016-06-01

    Polysaccharides are the major high-molecular weight components of wines. In contrast, proteins occur only in small amounts in wine, but contribute to haze formation. The detailed mechanism of aggregation of these proteins, especially in combination with other wine components, remains unclear. This study demonstrates the different aggregation behavior between a buffer and a model wine system by dynamic light scattering. Arabinogalactan-protein, for example, shows an increased aggregation in the model wine system, while in the buffer system a reducing effect is observed. Thus, we could show the importance to examine the behavior of wine additives under conditions close to reality, instead of simpler buffer systems. Additional experiments on melting points of wine proteins reveal that only some isoforms of thaumatin-like proteins and chitinases are involved in haze formation. We can confirm interactions between polysaccharides and proteins, but none of these polysaccharides is able to prevent haze in wine.

  6. Learning from microbial strategies for polysaccharide degradation.

    PubMed

    Hemsworth, Glyn R; Déjean, Guillaume; Davies, Gideon J; Brumer, Harry

    2016-02-01

    Complex carbohydrates are ubiquitous in all kingdoms of life. As major components of the plant cell wall they constitute both a rich renewable carbon source for biotechnological transformation into fuels, chemicals and materials, and also form an important energy source as part of a healthy human diet. In both contexts, there has been significant, sustained interest in understanding how microbes transform these substrates. Classical perspectives of microbial polysaccharide degradation are currently being augmented by recent advances in the discovery of lytic polysaccharide monooxygenases (LPMOs) and polysaccharide utilization loci (PULs). Fundamental discoveries in carbohydrate enzymology are both advancing biological understanding, as well as informing applications in industrial biomass conversion and modulation of the human gut microbiota to mediate health benefits.

  7. Maple Leaf Outdoor Centre.

    ERIC Educational Resources Information Center

    Maguire, Molly; Gunton, Ric

    2000-01-01

    Maple Leaf Outdoor Centre (Ontario) has added year-round outdoor education facilities and programs to help support its summer camp for disadvantaged children. Schools, youth centers, religious groups, and athletic teams conduct their own programs, collaborate with staff, or use staff-developed programs emphasizing adventure education and personal…

  8. Bacterial leaf spot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial leaf spot has been reported in Australia (Queensland), Egypt, El Salvador, India, Japan, Nicaragua, Sudan, and the United States (Florida, Iowa, Kansas, Maryland, and Wisconsin). It occasionally causes locally severe defoliation and post-emergence damping-off and stunting. The disease is...

  9. Comparative leaf development in angiosperms.

    PubMed

    Tsukaya, Hirokazu

    2014-02-01

    Recent accumulation of our knowledge on basic leaf development mechanisms in model angiosperm species has allowed us to pursue evolutionary development (evo/devo) studies of various kinds of leaf development. As a result, unexpected findings and clues have been unearthed aiding our understanding of the mechanisms involved in the diversity of leaf morphology, although the covered remain limited. In this review, we highlight recent findings of diversified leaf development in angiosperms.

  10. Polysaccharide-based strategies for heart tissue engineering.

    PubMed

    Silva, Amanda K A; Juenet, Maya; Meddahi-Pellé, Anne; Letourneur, Didier

    2015-02-13

    Polysaccharides are abundant biomolecules in nature presenting important roles in a wide variety of living systems processes. Considering the structural and biological functions of polysaccharides, their properties have raised interest for tissue engineering. Herein, we described the latest advances in cardiac tissue engineering mediated by polysaccharides. We reviewed the data already obtained in vitro and in vivo in this field with several types of polysaccharides. Cardiac injection, intramyocardial in situ polymerization strategies, and scaffold-based approaches involving polysaccharides for heart tissue engineering are thus discussed.

  11. Anticorrosive Microbial Polysaccharides: Structure-Function Relationships

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-soluble microbial polysaccharides are often implicated in biofilm formation and are believed to mediate cell-cell aggregation and adhesion to surfaces. Generally, biofilm formation is considered harmful or undesirable, as it leads to increased drag, plugging of pores, dimished heat transfer, ...

  12. Antitumor activity of methylan polysaccharide derivatives.

    PubMed

    Ramachandran, Priyadharshini; Jeya, Marimuthu; Moon, Hee-Jung; Lee, Kyoung-Mi; Kim, In-Won; Kim, Jung-Hoe; Lee, Jung-Kul

    2010-07-01

    Methylan polysaccharide derivatives were prepared by dialkylaminoalkylation and reductive amination followed by quaternization. Their antitumor activity was investigated and a relationship between structure and activity is suggested. For quaternized DEAE-methylan at only 75 mug ml(-1), tumor cell proliferation was suppressed by 58-84% in three cell lines tested in the order Colo < Hela < HepG2. PMID:20349111

  13. Fucoidans — sulfated polysaccharides of brown algae

    NASA Astrophysics Data System (ADS)

    Usov, Anatolii I.; Bilan, M. I.

    2009-08-01

    The methods of isolation of fucoidans and determination of their chemical structures are reviewed. The fucoidans represent sulfated polysaccharides of brown algae, the composition of which varies from simple fucan sulfates to complex heteropolysaccharides. The currently known structures of such biopolymers are presented. A variety of the biological activities of fucoidans is briefly summarised.

  14. Plant-Polysaccharide-Degrading Enzymes from Basidiomycetes

    PubMed Central

    Rytioja, Johanna; Hildén, Kristiina; Yuzon, Jennifer; Hatakka, Annele; de Vries, Ronald P.

    2014-01-01

    SUMMARY Basidiomycete fungi subsist on various types of plant material in diverse environments, from living and dead trees and forest litter to crops and grasses and to decaying plant matter in soils. Due to the variation in their natural carbon sources, basidiomycetes have highly varied plant-polysaccharide-degrading capabilities. This topic is not as well studied for basidiomycetes as for ascomycete fungi, which are the main sources of knowledge on fungal plant polysaccharide degradation. Research on plant-biomass-decaying fungi has focused on isolating enzymes for current and future applications, such as for the production of fuels, the food industry, and waste treatment. More recently, genomic studies of basidiomycete fungi have provided a profound view of the plant-biomass-degrading potential of wood-rotting, litter-decomposing, plant-pathogenic, and ectomycorrhizal (ECM) basidiomycetes. This review summarizes the current knowledge on plant polysaccharide depolymerization by basidiomycete species from diverse habitats. In addition, these data are compared to those for the most broadly studied ascomycete genus, Aspergillus, to provide insight into specific features of basidiomycetes with respect to plant polysaccharide degradation. PMID:25428937

  15. Antitumor activity of methylan polysaccharide derivatives.

    PubMed

    Ramachandran, Priyadharshini; Jeya, Marimuthu; Moon, Hee-Jung; Lee, Kyoung-Mi; Kim, In-Won; Kim, Jung-Hoe; Lee, Jung-Kul

    2010-07-01

    Methylan polysaccharide derivatives were prepared by dialkylaminoalkylation and reductive amination followed by quaternization. Their antitumor activity was investigated and a relationship between structure and activity is suggested. For quaternized DEAE-methylan at only 75 mug ml(-1), tumor cell proliferation was suppressed by 58-84% in three cell lines tested in the order Colo < Hela < HepG2.

  16. Aldehyde-containing urea-absorbing polysaccharides

    NASA Technical Reports Server (NTRS)

    Mueller, W. A.; Hsu, G. C.; Marsh, H. E., Jr. (Inventor)

    1977-01-01

    A novel aldehyde containing polymer (ACP) is prepared by reaction of a polysaccharide with periodate to introduce aldehyde groups onto the C2 - C3 carbon atoms. By introduction of ether and ester groups onto the pendant primary hydroxyl solubility characteristics are modified. The ACP is utilized to absorb nitrogen bases such as urea in vitro or in vivo.

  17. Purification and characterization of Staphylococcus aureus type 8 capsular polysaccharide.

    PubMed Central

    Fournier, J M; Vann, W F; Karakawa, W W

    1984-01-01

    Clinical isolates of Staphylococcus aureus have been previously classified into eight types on the basis of their capsular polysaccharide. The high prevalence of the type 8 capsular polysaccharide among bacteremic isolates suggests the importance of this capsular antigen in staphylococcal disease. The capsular polysaccharide was purified from extracts of three clinical isolates of S. aureus type 8 of different geographic and temperal origin by ion-exchange chromatography and gel filtration. Gas chromatography, gas chromatography-mass spectrometry, and 13C-nuclear magnetic resonance showed that the type 8 capsular polysaccharide is composed of O-acetyl groups, N-acetylfucosamine, and an aminouronic acid similar to N-acetylgalactosaminouronic acid. The purified polysaccharide reacted only with type 8 antiserum in double diffusion experiments. Our analysis shows that the type 8 polysaccharide is both chemically and serologically distinct from teichoic acid and previously characterized polysaccharides of S. aureus. Images PMID:6429051

  18. Leaf absorbance and photosynthesis

    NASA Technical Reports Server (NTRS)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  19. Wettability, Polarity, and Water Absorption of Holm Oak Leaves: Effect of Leaf Side and Age1[OPEN

    PubMed Central

    Fernández, Victoria; Sancho-Knapik, Domingo; Guzmán, Paula; Peguero-Pina, José Javier; Gil, Luis; Karabourniotis, George; Khayet, Mohamed; Fasseas, Costas; Heredia-Guerrero, José Alejandro; Heredia, Antonio; Gil-Pelegrín, Eustaquio

    2014-01-01

    Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition, and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of holm oak (Quercus ilex) as a model. By measuring the leaf water potential 24 h after the deposition of water drops onto abaxial and adaxial surfaces, evidence for water penetration through the upper leaf side was gained in young and mature leaves. The structure and chemical composition of the abaxial (always present) and adaxial (occurring only in young leaves) trichomes were analyzed by various microscopic and analytical procedures. The adaxial surfaces were wettable and had a high degree of water drop adhesion in contrast to the highly unwettable and water-repellent abaxial holm oak leaf sides. The surface free energy and solubility parameter decreased with leaf age, with higher values determined for the adaxial sides. All holm oak leaf trichomes were covered with a cuticle. The abaxial trichomes were composed of 8% soluble waxes, 49% cutin, and 43% polysaccharides. For the adaxial side, it is concluded that trichomes and the scars after trichome shedding contribute to water uptake, while the abaxial leaf side is highly hydrophobic due to its high degree of pubescence and different trichome structure, composition, and density. Results are interpreted in terms of water-plant surface interactions, plant surface physical chemistry, and plant ecophysiology. PMID:24913938

  20. α-Amylase-assisted extraction of polysaccharides from Panax ginseng.

    PubMed

    Sun, Lin; Wu, Di; Ning, Xin; Yang, Guang; Lin, Ziheng; Tian, Meihong; Zhou, Yifa

    2015-04-01

    In this paper, α-amylase-assisted extraction was used to isolate the polysaccharide that remained in hot water-extracted ginseng. The yield of the polysaccharide was 9.0%, almost equal to that of the hot water-extracted polysaccharide. Using anion exchange and gel permeation chromatography, the polysaccharide was fractionated into a neutral polysaccharide fraction and six pectic fractions. The neutral fraction accounted for 76% of the polysaccharide and contained both amylopectin and amylose. The pectic polysaccharide fractions were identified to be arabinogalactan, type-I rhamnogalacturonan and homogalacturonan-type pectin by high-performance liquid chromatography, Fourier transform-infrared and nuclear magnetic resonance analysis. Structural and lymphocyte proliferation activity results showed that these polysaccharides were different from those extracted by hot water, indicating that ginseng contains complex polysaccharides with diverse structures, which results in its diverse pharmacological activities. The α-amylase-assisted extraction is a novel method for preparing ginseng polysaccharides and could be applied toward the further study and exploration of ginseng. These findings provide technical and theoretical support for ginseng pharmacology.

  1. Effects of selenizing angelica polysaccharide and selenizing garlic polysaccharide on immune function of murine peritoneal macrophage.

    PubMed

    Gao, Zhenzhen; Liu, Kuanhui; Tian, Weijun; Wang, Hongchao; Liu, Zhenguang; Li, Youying; Li, Entao; Liu, Cui; Li, Xiuping; Hou, Ranran; Yue, Chanjuan; Wang, Deyun; Hu, Yuanliang

    2015-07-01

    The effects of two selenizing polysaccharides (sCAP2 and sGPS6) on immune function of murine peritoneal macrophages taking two non-selenizing polysaccharides (CAP and GPS) and modifier Na2SeO3 as control. In vitro test, the changes of selenizing polysaccharides, non-selenizing polysaccharides and Na2SeO3 on murine macrophages function were evaluated by phagocytosis and nitric oxide (NO) secretion tests. In vivo test, the mice were injected respectively with 0.2, 0.4 and 0.6 mg of sCAP2, sGPS6, CAP and GPS, or Na2SeO3 80 μg or normal saline 0.4 mL. The peritoneal macrophages were collected and cultured to determine the contents of TNF-α, IL-6 and IL-10 in supernatants by enzyme-linked immunosorbent assay. The results showed that sCAP2 and sGPS6 could significantly promote the phagocytosis and secretion of NO and three cytokines of macrophages in comparison with CAP and GPS. sCAP2 possessed the strongest activity. This indicates that selenylation modification can further improve the immune-enhancing activity of polysaccharide, and sCAP2 could be as a new immunopotentiator.

  2. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    SciTech Connect

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  3. A serogroup A meningococcal polysaccharide vaccine

    PubMed Central

    Erwa, H. H.; Haseeb, M. A.; Idris, A. A.; Lapeyssonnie, L.; Sanborn, W. R.; Sippel, J. E.

    1973-01-01

    Vaccination against cerebrospinal meningitis (CSM) has regained interest with the use of capsular polysaccharides (or polyosides) of the meningococcus as specific immunizing agents. These compounds proved to be effective in the USA against meningitis caused by Neisseria meningitidis serotype C. This study considers whether the polysaccharides of the serotype A meningococcus, which is prevalent in the African CSM belt, could be protective in epidemic conditions. Taking advantage of the usual seasonal peak of CSM cases, controlled field trials were undertaken in the Sudan early in 1973. 21 640 persons were vaccinated, half of them with a meningococcal polyoside A vaccine and the other half with tetanus toxoid as a placebo. In the former group there were no cases of meningitis, whereas in the latter 10 cases were reported, of which 7 were confirmed by laboratory tests. These studies indicate that the meningococcal polyoside A vaccine is efficient in epidemic conditions and could be used to control outbreaks of meningococcal meningitis. PMID:4211056

  4. Microbial extracellular polysaccharides and plagioclase dissolution

    NASA Astrophysics Data System (ADS)

    Welch, S. A.; Barker, W. W.; Banfield, J. F.

    1999-05-01

    Bytownite feldspar was dissolved in batch reactors in solutions of starch (glucose polymer), gum xanthan (glucose, mannose, glucuronic acid), pectin (poly-galacturonic acid), and four alginates (mannuronic and guluronic acid) with a range of molecular weights (low, medium, high and uncharacterized) to evaluate the effect of extracellular microbial polymers on mineral dissolution rates. Solutions were analyzed for dissolved Si and Al as an indicator of feldspar dissolution. At neutral pH, feldspar dissolution was inhibited by five of the acid polysaccharides, gum xanthan, pectin, alginate low, alginate medium, alginate high, compared to an organic-free control. An uncharacterized alginate substantially enhanced both Si and Al release from the feldspar. Starch, a neutral polysaccharide, had no apparent effect. Under mildly acidic conditions, initial pH ≈ 4, all of the polymers enhanced feldspar dissolution compared to the inorganic controls. Si release from feldspar in starch solution exceeded the control by a factor of three. Pectin and gum xanthan increased feldspar dissolution by a factor of 10, and the alginates enhanced feldspar dissolution by a factor of 50 to 100. Si and Al concentrations increased with time, even though solutions were supersaturated with respect to several possible secondary phases. Under acidic conditions, initial pH ≈ 3, below the pK a of the carboxylic acid groups, dissolution rates increased, but the relative increase due to the polysaccharides is lower, approximately a factor of two to ten. Microbial extracellular polymers play a complex role in mineral weathering. Polymers appear to inhibit dissolution under some conditions, possibly by irreversibly binding to the mineral surfaces. The extracellular polysaccharides can also enhance dissolution by providing protons and complexing with ions in solution.

  5. Polysaccharide Nanosystems for Future Progress in Cardiovascular Pathologies

    PubMed Central

    Silva, Amanda Karine Andriola; Letourneur, Didier; Chauvierre, Cédric

    2014-01-01

    Natural polysaccharides have received a lot of attention in the biomedical field. Indeed, sources of polysaccharides, extracted or produced from plants, bacteria, fungi or algae, are diverse and renewable. Moreover, recent progresses in polysaccharide chemistry and nanotechnologies allow elaborating new dedicated nanosystems. Polysaccharide-based nanosystems may be designed for interacting in several biological processes. In particular, the atherothrombotic pathology is highly concerned by polysaccharide-mediated recognition. Atherothrombotic diseases, regardless of the anatomical localization, remain the main causes of morbidity and mortality in the industrialized world. This review intends to provide an overview on polysaccharide-based nanosystems as drug delivery systems and targeted contrast agents for molecular imaging with an emphasis on the treatment and imaging of cardiovascular pathologies. PMID:24723980

  6. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    NASA Astrophysics Data System (ADS)

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2009-07-01

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence (μXRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

  7. Marine Origin Polysaccharides in Drug Delivery Systems

    PubMed Central

    Cardoso, Matias J.; Costa, Rui R.; Mano, João F.

    2016-01-01

    Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents and extraction media, and their interaction with other biocompounds. Polysaccharides such as alginate, carrageenan and fucoidan can be extracted from algae, whereas chitosan and hyaluronan can be obtained from animal sources. Most marine polysaccharides have important biological properties such as biocompatibility, biodegradability, and anti-inflammatory activity, as well as adhesive and antimicrobial actions. Moreover, they can be modified in order to allow processing them into various shapes and sizes and may exhibit response dependence to external stimuli, such as pH and temperature. Due to these properties, these biomaterials have been studied as raw material for the construction of carrier devices for drugs, including particles, capsules and hydrogels. The devices are designed to achieve a controlled release of therapeutic agents in an attempt to fight against serious diseases, and to be used in advanced therapies, such as gene delivery or regenerative medicine. PMID:26861358

  8. Nanofiltration of polysaccharides from Agaricus subrufescens.

    PubMed

    Camelini, C M; Rezzadori, K; Benedetti, S; Proner, M C; Fogaça, L; Azambuja, A A; Giachini, A J; Rossi, M J; Petrus, J C C

    2013-12-01

    A simplified submerged airlift cultivation was established for the production of biomass from Agaricus subrufescens. In this work, soluble polysaccharides extracted from fungal mycelium, fruiting bodies, and the residual culture media were concentrated by nanofiltration. Total and high molar mass polysaccharides and soluble solids were determined in the concentrate for the three extracts. Additionally, the permeate flow, the influences of temperature and pressure, and the resistance to the permeate flow during filtration were also evaluated. Ayield of 5.5 g/L of biomass with 35%glucose conversion was obtained when 0.5 g/L of initial inoculum was employed. Average specific speed of growth was 0.4/day, with biomass productivity of about 0.76 g/(L day). Nanofiltration has yielded polysaccharide increases of 85, 82, and 92% in the extracts from fruiting bodies, mycelium, and liquid media, respectively. A reduction in the permeate flow was observed during filtration, and it was compensated by higher pressures and temperatures. The higher resistance to the permeate flux was caused by polarization due to concentration (polarized gel layer), reaching values of 88% for the culture media. Maximal resistance caused by the membrane reached values of 40% for the extract from the fruiting bodies. On the other hand, resistance caused by fouling was responsible for less than 3.5%. In conclusion, nanofiltration is efficient to concentrate these functional compounds extracted from A. subrufescens and can, therefore, be applied in different biotechnological areas.

  9. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    SciTech Connect

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2010-06-22

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

  10. Immunoregulatory activities of polysaccharides from mung bean.

    PubMed

    Yao, Yang; Zhu, Yingying; Ren, Guixing

    2016-03-30

    Ultrasonic treatment was performed on water-extractable polysaccharides from the seed of mung beans. Purified by anion-exchange and gel filtration chromatography, MWP-1' and MWP-2' were obtained. Average molecular weights (Mws) of MWP-1' and MWP-2' were 68.4 kDa, and 52.4 kDa, respectively. Monosaccharides components analysis indicated that MWP-1' was composed of Rha, Ara, Man and Gal in a molar percent of 0.4:2.6:5.3:0.7. MWP-2' was composed of Ara, Man, Gal and Glc in a molar percent of 0.5:1.4:2.1:0.4. In vitro study showed that both polysaccharides samples were able to stimulate the production of secretory molecules (NO, TNF-α and IL-6) of RAW264.7 murine macrophages in a dosage dependent manner. MWP-2' seemed to be the most potent and induced significantly higher the NO production. These findings suggest that the ultrasonic treatment polysaccharides isolated in our study have immune potentiation effects on macrophages.

  11. Immunochemical characterization of Brucella lipopolysaccharides and polysaccharides.

    PubMed Central

    Moreno, E; Speth, S L; Jones, L M; Berman, D T

    1981-01-01

    Purified lipopolysaccharide (LPS) extracted with phenol-water from smooth Brucella abortus was hydrolyzed with 1% acetic acid at 100 degrees C. The degraded polysaccharide (AH) released gave reactions of identity with the native polysaccharide hapten (NH) in phenol-water- or trichloroacetic acid-extracted endotoxin preparations of B. abortus and with the polysaccharide (poly B) extracted by trichloroacetic acid from rough B. melitensis strain B115. Poly B was present in the soluble cytoplasmic fraction but not in the membrane fraction, of disrupted B115 cells. It could not be extracted from three rough mutants of B. abortus or from B canis or B. ovis cells. Both AH and NH shared determinants present on smooth LPS and missing from poly B. Sugars found in purified LPS, NH, and AH included mannose, glucose, quinovosamine, glucosamine, and 2-keto-3-deoxyoctonate. Poly B contained only a trace amount of quinovosamine and no 2-keto-3-deoxyoctonate detectable by the thiobarbiturate assay. Sera from some rabbits immunized with pure smooth LPS and some, but not all, cows infected with field strains of B. abortus recognized the determinants missing from poly B. A subclass-specific enzyme-linked immunoassay showed that most of the antibody in sera from infected cows which binds to smooth LPS and to NH is of the immunoglobulin G1 subclass. Images PMID:6163716

  12. Evaluation of Phosphorylated Psyllium Seed Polysaccharide as a Release Retardant.

    PubMed

    Rao, Monica R P; Warrier, Deepa U; Rao, Shivani H

    2015-01-01

    The aim of the present study was to modify psyllium seed polysaccharide and evaluate the modified polysaccharide as release retardant in tablets employing ciprofloxacin hydrochloride as model drug. Studies on polysaccharide from psyllium husk has been reported but no work has been reported on characterization and modification of the polysaccharide present in the psyllium (Plantago ovata) seed and the use of the modified polysaccharide as a release retardant in tablets. In this study, the seed gum was modified using sodium trimetaphosphate as crosslinking agent. Sustained release matrix tablets of ciprofloxacin hydrochloride were prepared by wet granulation using various drug-polymer ratios. The polymers investigated were psyllium polysaccharide, phosphorylated psyllium polysaccharide and widely used release retardant hydroxypropyl methylcellulose K100M. The tablets were evaluated for hardness, friability, drug content, swelling profile and in vitro dissolution studies. The matrix tablets containing 1:3 proportion of drug-phosphorylated psyllium polysaccharide was found to have higher hardness as compared to tablets containing 1:1 and 1:2 proportions. The results of swelling behavior in water showed that the tablets containing 1:3 drug:phosphorylated psyllium polysaccharide ratio had swelling comparable to that of tablets containing 1:3 drug:hydroxypropyl methylcellulose ratio. The in vitro dissolution studies shows that the dissolution rate was retarded from 98.41 to 37.6% in 6 h with increase in concentration of phosphorylated psyllium polysaccharide from 100 to 300 mg. Formulations containing psyllium polysaccharide showed complete drug release in 8 h whereas those formulated with phosphorylated psyllium polysaccharide exhibited extended drug release over the 12 h period. Drug release kinetic studies revealed that drug release followed Korsmeyer-Peppas model. PMID:26798177

  13. Evaluation of Phosphorylated Psyllium Seed Polysaccharide as a Release Retardant

    PubMed Central

    Rao, Monica R. P.; Warrier, Deepa U.; Rao, Shivani H.

    2015-01-01

    The aim of the present study was to modify psyllium seed polysaccharide and evaluate the modified polysaccharide as release retardant in tablets employing ciprofloxacin hydrochloride as model drug. Studies on polysaccharide from psyllium husk has been reported but no work has been reported on characterization and modification of the polysaccharide present in the psyllium (Plantago ovata) seed and the use of the modified polysaccharide as a release retardant in tablets. In this study, the seed gum was modified using sodium trimetaphosphate as crosslinking agent. Sustained release matrix tablets of ciprofloxacin hydrochloride were prepared by wet granulation using various drug-polymer ratios. The polymers investigated were psyllium polysaccharide, phosphorylated psyllium polysaccharide and widely used release retardant hydroxypropyl methylcellulose K100M. The tablets were evaluated for hardness, friability, drug content, swelling profile and in vitro dissolution studies. The matrix tablets containing 1:3 proportion of drug-phosphorylated psyllium polysaccharide was found to have higher hardness as compared to tablets containing 1:1 and 1:2 proportions. The results of swelling behavior in water showed that the tablets containing 1:3 drug:phosphorylated psyllium polysaccharide ratio had swelling comparable to that of tablets containing 1:3 drug:hydroxypropyl methylcellulose ratio. The in vitro dissolution studies shows that the dissolution rate was retarded from 98.41 to 37.6% in 6 h with increase in concentration of phosphorylated psyllium polysaccharide from 100 to 300 mg. Formulations containing psyllium polysaccharide showed complete drug release in 8 h whereas those formulated with phosphorylated psyllium polysaccharide exhibited extended drug release over the 12 h period. Drug release kinetic studies revealed that drug release followed Korsmeyer-Peppas model. PMID:26798177

  14. 7 CFR 29.2528 - Leaf.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.2528 Section 29.2528 Agriculture Regulations...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2528 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  15. 7 CFR 29.3525 - Leaf.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  16. 7 CFR 29.1028 - Leaf.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.1028 Section 29.1028 Agriculture Regulations... Type 92) § 29.1028 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  17. 7 CFR 29.3033 - Leaf.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  18. Antibacterial and antiviral study of dialdehyde polysaccharides

    NASA Astrophysics Data System (ADS)

    Song, Le

    Concerns for microbial contamination and infection to the general population, especially the spread of drug-resistant microorganisms, have greatly increased. Polymeric biocides have been found to be a feasible strategy to inactivate drug-resistant bacteria. However, current polymeric biocide systems involve multi-step chemical reactions and they are not cost-effective. Desirable antimicrobial systems need to be designed to be environmentally friendly, broad-spectrum effective against microorganisms, flexible for various delivery methods and economically affordable. We demonstrated that dialdehyde polysaccharides (including dialdehyde starch and dialdehdye cellulose) were broad-spectrum polymeric biocides against gram-positive/negative bacteria, bacteriophages and human virus. These polymers can be easily converted from starch and cellulose through one-step periodate oxidation. Destructions of microorganism by dialdehyde polysaccharides have been achieved in aqueous suspension or by solid surface contact. The dialdehdye functions of dialdehdye polysaccharides were found to be the dominant action against microorganism. The reactivity of the dialdehyde functionality was found to be pH-dependent as well as related to the dispersion of dialdehyde polysaccharides. Degradation of dialdehyde starch during cooking was confirmed. Degradation of dialdehyde starch was more liable in alkaline condition. Carboxylic acid and conjugated aldehyde functionalities were the two main degradation products, confirmed from the spectroscopic studies. The pH effect on the polysaccharide structure and the corresponding antimicrobial activity was very complicated. No decisive conclusions could be obtained from this study. Liner inactivation kinetics was found for dialdehyde starch aqueous suspension against bacteria. This linear inactivation kinetics was derived from the pseudo-first chemical reaction between the dialdehyde starch and the bacteria. The established inactivation kinetics was

  19. Fungal Polysaccharides: Biological Activity Beyond the Usual Structural Properties

    PubMed Central

    Rodrigues, Marcio L.; Nimrichter, Leonardo; Cordero, Radames J. B.; Casadevall, Arturo

    2011-01-01

    Studies on structure and function of polysaccharides in biological systems classically involve sequence and compositional analyses, anomeric configuration, type of glycosidic linkage, and presence of substituents. Recent studies, however, indicates that other structural parameters, so far little explored, can directly influence the biological activity of microbial polysaccharides. Among these parameters, we highlight the molecular dimensions of Cryptococcus neoformans polysaccharides, which appear to be inversely correlated with their immunobiological activity. These recent observations raise new concepts about the structure and function of polysaccharides, which stimulates the design of new experimental approaches and suggests previously unknown applications. PMID:21886639

  20. Polysaccharide based Copolymers as Supramolecular Systems in Biomedical Applications.

    PubMed

    Célia Monteiro de Paula, Regina; Andrade Feitosa, Judith Pessoa; Beserra Paula, Haroldo César

    2015-01-01

    Polysaccharides are natural polymers, obtained from a large variety of sources ranging from fungi to more complex organisms such as birds and whales. Their use for pharmaceutical and biomedical applications has been the subject of numerous researches by the world´s academia. Polysaccharide chemical/physical modifications leading to graft copolymers are discussed in this review, focusing on those nanosystems that are potential candidates for drug delivery applications. Therefore, this review focuses on the biomedical application of polysaccharide based copolymers, particularly as nanocarriers. Copolymer of polysaccharides such as alginate, cellulose, chitosan, dextran, guar, hyaluronic acid, pullulan and starch as drug delivery nanocarriers will be discussed. PMID:26424388

  1. Ultrasound extraction of polysaccharides from mulberry leaves and their effect on enhancing antioxidant activity.

    PubMed

    Zhang, Dong-Yang; Wan, Yi; Xu, Jian-Yi; Wu, Guo-Hua; Li, Long; Yao, Xiao-Hui

    2016-02-10

    A Box-Behnken design (BBD) was applied to optimize the ultrasound-assisted extraction of polysaccharides from mulberry leaves. Under the optimum conditions of an extraction temperature of 57 °C, an extraction time of 80 min and a liquid/solid ratio of 53 mL/g, the mulberry leaf polysaccharide (MLP) yield was 6.92 ± 0.29%. Then, three fractions of MLPs were obtained by deproteinization, dialysis and decolorization. The carbohydrate content, FT-IR spectrum and monosaccharide composition of the MLPs were also investigated. The antioxidant activities of the three fractions were compared, and the results indicated that the antioxidant activities decreased with the increasing MLP purity. Therefore, highly concentrated MLPs were shown to have very little antioxidant activity. After quercetin (10 μg/mL) was added, the antioxidant activities were improved significantly. This result showed that MLPs and quercetin have a synergistic effect on the antioxidant activity. Although the MLPs have very little antioxidant activity alone, they greatly enhance the antioxidant activity of flavonoids. Thus, MLPs can be used as an antioxidant activity enhancer in the food industry.

  2. Ultrasound extraction of polysaccharides from mulberry leaves and their effect on enhancing antioxidant activity.

    PubMed

    Zhang, Dong-Yang; Wan, Yi; Xu, Jian-Yi; Wu, Guo-Hua; Li, Long; Yao, Xiao-Hui

    2016-02-10

    A Box-Behnken design (BBD) was applied to optimize the ultrasound-assisted extraction of polysaccharides from mulberry leaves. Under the optimum conditions of an extraction temperature of 57 °C, an extraction time of 80 min and a liquid/solid ratio of 53 mL/g, the mulberry leaf polysaccharide (MLP) yield was 6.92 ± 0.29%. Then, three fractions of MLPs were obtained by deproteinization, dialysis and decolorization. The carbohydrate content, FT-IR spectrum and monosaccharide composition of the MLPs were also investigated. The antioxidant activities of the three fractions were compared, and the results indicated that the antioxidant activities decreased with the increasing MLP purity. Therefore, highly concentrated MLPs were shown to have very little antioxidant activity. After quercetin (10 μg/mL) was added, the antioxidant activities were improved significantly. This result showed that MLPs and quercetin have a synergistic effect on the antioxidant activity. Although the MLPs have very little antioxidant activity alone, they greatly enhance the antioxidant activity of flavonoids. Thus, MLPs can be used as an antioxidant activity enhancer in the food industry. PMID:26686153

  3. Extraction, chemical analysis of Angelica sinensis polysaccharides and antioxidant activity of the polysaccharides in ischemia-reperfusion rats.

    PubMed

    Zhang, Song; He, Ben; Ge, Junbo; Li, Huibin; Luo, Xiuying; Zhang, Hui; Li, Yuhui; Zhai, Changlin; Liu, Pingang; Liu, Xin; Fei, Xuetao

    2010-11-01

    Angelica sinensis polysaccharides were analyzed using high performance liquid chromatography (HPLC) and Fourier Transform Infrared (FT-IR). The major sugar of the polysaccharide was saccharose (18.55%); and the sugar constituted about 83% of the monomer content. Glucose and fructose were found as minor components of the polysaccharides. The FT-IR spectra of A. sinensis polysaccharides are used for determination of their structural features. The FT-IR spectrum of A. sinensis polysaccharides showed bands at 1641 cm(-1), 1415 cm(-1), 1050 cm(-1) and 926 cm(-1) characteristic for the carboxylic group. Absorptions at 2920-2930 cm(-1) are attributed to asymmetrical stretching vibration of CH(2)-group. Medium stretch observed in the range 1650-1400 cm(-1) is assigned to C-C stretching of polysaccharides. Cardioprotective effects of A. sinensis polysaccharides were evaluated by using myocardial ischemia/reperfusion (IR) rats. A. sinensis polysaccharides treatment significantly reduced myocardial infarction size, enhanced CT-1 and antioxidant enzymes activity, downregulated caspase-12 mRNA expression in rats. The study strongly suggests the cardioprotective activity of A. sinensis polysaccharides in limiting ischemia-reperfusion induced myocardial injury. PMID:20691723

  4. Immunomodulatory dietary polysaccharides: a systematic review of the literature

    PubMed Central

    2010-01-01

    Background A large body of literature suggests that certain polysaccharides affect immune system function. Much of this literature, however, consists of in vitro studies or studies in which polysaccharides were injected. Their immunologic effects following oral administration is less clear. The purpose of this systematic review was to consolidate and evaluate the available data regarding the specific immunologic effects of dietary polysaccharides. Methods Studies were identified by conducting PubMed and Google Scholar electronic searches and through reviews of polysaccharide article bibliographies. Only articles published in English were included in this review. Two researchers reviewed data on study design, control, sample size, results, and nature of outcome measures. Subsequent searches were conducted to gather information about polysaccharide safety, structure and composition, and disposition. Results We found 62 publications reporting statistically significant effects of orally ingested glucans, pectins, heteroglycans, glucomannans, fucoidans, galactomannans, arabinogalactans and mixed polysaccharide products in rodents. Fifteen controlled human studies reported that oral glucans, arabinogalactans, heteroglycans, and fucoidans exerted significant effects. Although some studies investigated anti-inflammatory effects, most studies investigated the ability of oral polysaccharides to stimulate the immune system. These studies, as well as safety and toxicity studies, suggest that these polysaccharide products appear to be largely well-tolerated. Conclusions Taken as a whole, the oral polysaccharide literature is highly heterogenous and is not sufficient to support broad product structure/function generalizations. Numerous dietary polysaccharides, particularly glucans, appear to elicit diverse immunomodulatory effects in numerous animal tissues, including the blood, GI tract and spleen. Glucan extracts from the Trametes versicolor mushroom improved survival and

  5. Methods of saccharification of polysaccharides in plants

    DOEpatents

    Howard, John; Fake, Gina

    2014-04-29

    Saccharification of polysaccharides of plants is provided, where release of fermentable sugars from cellulose is obtained by adding plant tissue composition. Production of glucose is obtained without the need to add additional .beta.-glucosidase. Adding plant tissue composition to a process using a cellulose degrading composition to degrade cellulose results in an increase in the production of fermentable sugars compared to a process in which plant tissue composition is not added. Using plant tissue composition in a process using a cellulose degrading enzyme composition to degrade cellulose results in decrease in the amount of cellulose degrading enzyme composition or exogenously applied cellulase required to produce fermentable sugars.

  6. In vitro antioxidant activity of polysaccharide from Gardenia jasminoides ellis

    USGS Publications Warehouse

    Fan, Y.; Ge, Z.; Luo, A.

    2011-01-01

    A water-soluble polysaccharide, GP, was isolated from Gardenia jasminoides Ellis through hot water extraction followed by ethanol precipitation. The in vitro free radicals scavenging tests exhibited that GP has significant scavenging abilities especially for ABTS, DPPH, and hydroxyl radicals, which suggests that the polysaccharide GP is a novel antioxidant. ?? 2011 Academic Journals.

  7. Structural modification of polysaccharides: A biochemical-genetic approach

    NASA Technical Reports Server (NTRS)

    Kern, Roger G.; Petersen, Gene R.

    1991-01-01

    Polysaccharides have a wide range of industrial and biomedical applications. An industry trend is underway towards the increased use of bacteria to produce polysaccharides. Long term goals of this work are the adaptation and enhancement of saccharide properties for electronic and optic applications. In this report we illustrate the application of enzyme-bearing bacteriophage on strains of the enteric bacterium Klebsiella pneumoniae, which produces a polysaccharide with the relatively rare rheological property of drag-reduction. This has resulted in the production of new polysaccharides with enhanced rheological properties. Our laboratory is developing techniques for processing and structurally modifying bacterial polysaccharides and oligosaccharides which comprise their basic polymeric repeat units. Our research has focused on bacteriophage which produce specific polysaccharide degrading enzymes. This has lead to the development of enzymes generated by bacteriophage as tools for polysaccharide modification and purification. These enzymes were used to efficiently convert the native material to uniform-sized high molecular weight polymers, or alternatively into high-purity oligosaccharides. Enzyme-bearing bacteriophage also serve as genetic selection tools for bacteria that produce new families of polysaccharides with modified structures.

  8. Bacterial Extracellular Polysaccharides in Biofilm Formation and Function.

    PubMed

    Limoli, Dominique H; Jones, Christopher J; Wozniak, Daniel J

    2015-06-01

    Microbes produce a biofilm matrix consisting of proteins, extracellular DNA, and polysaccharides that is integral in the formation of bacterial communities. Historical studies of polysaccharides revealed that their overproduction often alters the colony morphology and can be diagnostic in identifying certain species. The polysaccharide component of the matrix can provide many diverse benefits to the cells in the biofilm, including adhesion, protection, and structure. Aggregative polysaccharides act as molecular glue, allowing the bacterial cells to adhere to each other as well as surfaces. Adhesion facilitates the colonization of both biotic and abiotic surfaces by allowing the bacteria to resist physical stresses imposed by fluid movement that could separate the cells from a nutrient source. Polysaccharides can also provide protection from a wide range of stresses, such as desiccation, immune effectors, and predators such as phagocytic cells and amoebae. Finally, polysaccharides can provide structure to biofilms, allowing stratification of the bacterial community and establishing gradients of nutrients and waste products. This can be advantageous for the bacteria by establishing a heterogeneous population that is prepared to endure stresses created by the rapidly changing environments that many bacteria encounter. The diverse range of polysaccharide structures, properties, and roles highlight the importance of this matrix constituent to the successful adaptation of bacteria to nearly every niche. Here, we present an overview of the current knowledge regarding the diversity and benefits that polysaccharide production provides to bacterial communities within biofilms. PMID:26185074

  9. Effect of Nitrogen on Polysaccharide Production in a Porphyridium sp.

    PubMed

    Arad, S M; Friedman, O D; Rotem, A

    1988-10-01

    Porphyridium cultures grown on either nitrate or ammonium as the nitrogen source showed similar patterns of growth and cell wall polysaccharide production. The effect of nitrogen on growth and cell wall polysaccharide production was studied by applying three regimens of supply: batch mode, in which nitrate was supplied at the beginning of the experiment and became depleted at day 6; continual mode, in which nitrate was added daily; and deficient mode, in which the cells were cultured in a nitrate-free medium. Growth was similar in the batch- and continual-mode cultures, whereas it was totally inhibited in the deficient-mode culture. Polysaccharide content (per volume) was highest in the batch-mode culture and lowest in the deficient-mode culture. However, polysaccharide production per cell was similar in the continual- and deficient-mode cultures, the highest value being found in the batch-mode culture. In addition to its effect on polysaccharide content, nitrogen affected the polysaccharide distribution between soluble and bound polysaccharides. In the deficientmode culture, most of the cell wall polysaccharide was dissolved in the medium.

  10. Bacterial Extracellular Polysaccharides in Biofilm Formation and Function

    PubMed Central

    Limoli, Dominique H.; Jones, Christopher J.; Wozniak, Daniel J.

    2015-01-01

    Microbes produce a biofilm matrix consisting of proteins, extracellular DNA, and polysaccharides that is integral in the formation of bacterial communities. Historical studies of polysaccharides revealed that their overproduction often alters the colony morphology and can be diagnostic in identifying certain species. The polysaccharide component of the matrix can provide many diverse benefits to the cells in the biofilm, including adhesion, protection, and structure. Aggregative polysaccharides act as molecular glue, allowing the bacterial cells to adhere to each other as well as surfaces. Adhesion facilitates the colonization of both biotic and abiotic surfaces by allowing the bacteria to resist physical stresses imposed by fluid movement that could separate the cells from a nutrient source. Polysaccharides can also provide protection from a wide range of stresses, such as desiccation, immune effectors, and predators such as phagocytic cells and amoebae. Finally, polysaccharides can provide structure to biofilms, allowing stratification of the bacterial community and establishing gradients of nutrients and waste products. This can be advantageous for the bacteria by establishing a heterogeneous population that is prepared to endure stresses created by the rapidly changing environments that many bacteria encounter. The diverse range of polysaccharide structures, properties, and roles highlight the importance of this matrix constituent to the successful adaptation of bacteria to nearly every niche. Here, we present an overview of the current knowledge regarding the diversity and benefits that polysaccharide production provides to bacterial communities within biofilms. PMID:26185074

  11. Isolation and characterization of structural components of Aloe vera L. leaf pulp.

    PubMed

    Ni, Y; Turner, D; Yates, K M; Tizard, I

    2004-12-20

    The clear pulp, also known as inner gel, of Aloe vera L. leaf is widely used in various medical, cosmetic and nutraceutical applications. Many beneficial effects of this plant have been attributed to the polysaccharides present in the pulp. However, discrepancies exist regarding the composition of pulp polysaccharide species and an understanding of pulp structure in relation to its chemical composition has been lacking. Thus, we examined pulp structure, isolated structural components and determined their carbohydrate compositions along with analyzing a partially purified pulp-based product (Acemannan hydrogel) used to make Carrisyn hydrogel wound dressing. Light and electron microscopy showed that the pulp consisted of large clear mesophyll cells with a diameter as large as 1000 microm. These cells were composed of cell walls and cell membranes along with a very limited number of degenerated cellular organelles. No intact cellular organelles were found in mesophyll cells. Following disruption of pulp by homogenization, three components were isolated by sequential centrifugation. They were thin clear sheets, microparticles and a viscous liquid gel, which corresponded to cell wall, degenerated cellular organelles and liquid content of mesophyll cells based on morphological and chemical analysis. These three components accounted for 16.2% (+/-3.8), 0.70% (+/-0) and 83.1% of the pulp on a dry weight basis. The carbohydrate composition of each component was distinct; liquid gel contained mannan, microparticles contained galactose-rich polysaccharide(s) and cell walls contained an unusually high level of galacturonic acid (34%, w/w; Gal A). The same three components were also found in Acemannan Hydrogel with mannan as the predominant component. Thus, different pulp structural components are associated with different polysaccharides and thus may potentially be different functionally. These findings may help lay a basis for further studies and development of better

  12. Methods for degrading or converting plant cell wall polysaccharides

    DOEpatents

    Berka, Randy; Cherry, Joel

    2008-08-19

    The present invention relates to methods for converting plant cell wall polysaccharides into one or more products, comprising: treating the plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into the one or more products. The present invention also relates to methods for producing an organic substance, comprising: (a) saccharifying plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into saccharified material; (b) fermenting the saccharified material of step (a) with one or more fermenting microoganisms; and (c) recovering the organic substance from the fermentation.

  13. The Antiviral Activities and Mechanisms of Marine Polysaccharides: An Overview

    PubMed Central

    Wang, Wei; Wang, Shi-Xin; Guan, Hua-Shi

    2012-01-01

    Recently, the studies on the antiviral activities of marine natural products, especially marine polysaccharides, are attracting more and more attention all over the world. Marine-derived polysaccharides and their lower molecular weight oligosaccharide derivatives have been shown to possess a variety of antiviral activities. This paper will review the recent progress in research on the antiviral activities and the mechanisms of these polysaccharides obtained from marine organisms. In particular, it will provide an update on the antiviral actions of the sulfated polysaccharides derived from marine algae including carrageenans, alginates, and fucans, relating to their structure features and the structure–activity relationships. In addition, the recent findings on the different mechanisms of antiviral actions of marine polysaccharides and their potential for therapeutic application will also be summarized in detail. PMID:23235364

  14. Characterization of polysaccharides from Ganoderma spp. using saccharide mapping.

    PubMed

    Wu, Ding-Tao; Xie, Jing; Hu, De-Jun; Zhao, Jing; Li, Shao-Ping

    2013-09-12

    Polysaccharides from Ganoderma spp. and their adulterants were firstly investigated and compared using saccharide mapping, enzymatic (endo-1,3-β-D-glucanase and pectinase) digestion followed by polysaccharide analysis using carbohydrate gel electrophoresis analysis. The results showed that both 1,3-β-D-glucosidic and 1,4-α-D-galactosiduronic linkages were existed in Lingzhi (Ganoderma lucidum and Ganoderma sinense), and the similarity of polysaccharides from G. lucidum and G. sinense was high, which may contribute to rational use of Lingzhi. Different species of Ganoderma and their adulterants can be differentiated based on the saccharide mapping, which is helpful to well understand the structural characters of polysaccharides from different species of Ganoderma and to improve the quality control of polysaccharides in Lingzhi.

  15. Leaf hydraulics II: vascularized tissues.

    PubMed

    Rockwell, Fulton E; Holbrook, N Michele; Stroock, Abraham D

    2014-01-01

    Current models of leaf hydration employ an Ohm's law analogy of the leaf as an ideal capacitor, neglecting the resistance to flow between cells, or treat the leaf as a plane sheet with a source of water at fixed potential filling the mid-plane, neglecting the discrete placement of veins as well as their resistance. We develop a model of leaf hydration that considers the average conductance of the vascular network to a representative areole (region bounded by the vascular network), and represent the volume of tissue within the areole as a poroelastic composite of cells and air spaces. Solutions to the 3D flow problem are found by numerical simulation, and these results are then compared to 1D models with exact solutions for a range of leaf geometries, based on a survey of temperate woody plants. We then show that the hydration times given by these solutions are well approximated by a sum of the ideal capacitor and plane sheet times, representing the time for transport through the vasculature and tissue respectively. We then develop scaling factors relating this approximate solution to the 3D model, and examine the dependence of these scaling factors on leaf geometry. Finally, we apply a similar strategy to reduce the dimensions of the steady state problem, in the context of peristomatal transpiration, and consider the relation of transpirational gradients to equilibrium leaf water potential measurements.

  16. [Antigenic polysaccharides of bacteria. 22. Structure of the O-specific polysaccharide chain of Proteus hauseri lipopolysaccharide].

    PubMed

    Vinogradov, E V; Shashkov, A S; Knirel', Iu A; Kochetkov, N K; Kholodkova, E V

    1987-05-01

    The following structure of the repeating unit of the Proteus hauseri O-specific polysaccharide was established on the basis of monosaccharide composition and 13C NMR data of the polysaccharide and products of its Smith degradation and partial cleavage with hydrogen fluoride: (Formula: see text).

  17. Leaf Relative Water Content Estimated from Leaf Reflectance and Transmittance

    NASA Technical Reports Server (NTRS)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2016-01-01

    Remotely sensing the water status of plants and the water content of canopies remain long term goals of remote sensing research. In the research we report here, we used optical polarization techniques to monitor the light reflected from the leaf interior, R, as well as the leaf transmittance, T, as the relative water content (RWC) of corn (Zea mays) leaves decreased. Our results show that R and T both change nonlinearly. The result show that the nonlinearities cancel in the ratio R/T, which appears linearly related to RWC for RWC less than 90%. The results suggest that potentially leaf water status and perhaps even canopy water status could be monitored starting from leaf and canopy optical measurements.

  18. Regulation of Compound Leaf Development

    PubMed Central

    Wang, Yuan; Chen, Rujin

    2013-01-01

    Leaf morphology is one of the most variable, yet inheritable, traits in the plant kingdom. How plants develop a variety of forms and shapes is a major biological question. Here, we discuss some recent progress in understanding the development of compound or dissected leaves in model species, such as tomato (Solanum lycopersicum), Cardamine hirsuta and Medicago truncatula, with an emphasis on recent discoveries in legumes. We also discuss progress in gene regulations and hormonal actions in compound leaf development. These studies facilitate our understanding of the underlying regulatory mechanisms and put forward a prospective in compound leaf studies. PMID:27135488

  19. Structural characterization of polysaccharides from bamboo

    NASA Astrophysics Data System (ADS)

    Kamil, Ruzaimah Nik Mohamad; Yusuf, Nur'aini Raman; Yunus, Normawati M.; Yusup, Suzana

    2014-10-01

    The alkaline and water soluble polysaccharides were isolate by sequential extractions with distilled water, 60% ethanol containing 1%, 5% and 8% NaOH. The samples were prepared at 60 °C for 3 h from local bamboo. The functional group of the sample were examined using FTIR analysis. The most precipitate obtained is from using 60% ethanol containing 8% NaOH with yield of 2.6%. The former 3 residues isolated by sequential extractions with distilled water, 60% ethanol containing 1% and 5% NaOH are barely visible after filtering with cellulose filter paper. The FTIR result showed that the water-soluble polysaccharides consisted mainly of OH group, CH group, CO indicates the carbohydrate and sugar chain. The sample weight loss was slightly decreased with increasing of temperature.

  20. Organized polysaccharide fibers as stable drug carriers.

    PubMed

    Janaswamy, Srinivas; Gill, Kristin L; Campanella, Osvaldo H; Pinal, Rodolfo

    2013-04-15

    Many challenges arise during the development of new drug carrier systems, and paramount among them are safety, solubility and controlled release requirements. Although synthetic polymers are effective, the possibility of side effects imposes restrictions on their acceptable use and dose limits. Thus, a new drug carrier system that is safe to handle and free from side effects is very much in need and food grade polysaccharides stand tall as worthy alternatives. Herein, we demonstrate for the first time the feasibility of sodium iota-carrageenan fibers and their distinctive water pockets to embed and release a wide variety of drug molecules. Structural analysis has revealed the existence of crystalline network in the fibers even after encapsulating the drug molecules, and iota-carrageenan maintains its characteristic and reproducible double helical structure suggesting that the composites thus produced are reminiscent of cocrystals. The melting properties of iota-carrageenan:drug complexes are distinctly different from those of either drug or iota-carrageenan fiber. The encapsulated drugs are released in a sustained manner from the fiber matrix. Overall, our research provides an elegant opportunity for developing effective drug carriers with stable network toward enhancing and/or controlling bioavailability and extending shelf-life of drug molecules using GRAS excipients, food polysaccharides, that are inexpensive and non-toxic.

  1. Organized polysaccharide fibers as stable drug carriers

    PubMed Central

    Janaswamy, Srinivas; Gill, Kristin L.; Campanella, Osvaldo H.; Pinal, Rodolfo

    2013-01-01

    Many challenges arise during the development of new drug carrier systems, and paramount among them are safety, solubility and controlled release requirements. Although synthetic polymers are effective, the possibility of side effects imposes restrictions on their acceptable use and dose limits. Thus, a new drug carrier system that is safe to handle and free from side effects is very much in need and food grade polysaccharides stand tall as worthy alternatives. Herein, we demonstrate for the first time the feasibility of sodium iota-carrageenan fibers and their distinctive water pockets to embed and release a wide variety of drug molecules. Structural analysis has revealed the existence of crystalline network in the fibers even after encapsulating the drug molecules, and iota-carrageenan maintains its characteristic and reproducible double helical structure suggesting that the composites thus produced are reminiscent of cocrystals. The melting properties of iota-carrageenan:drug complexes are distinctly different from those of either drug or iota-carrageenan fiber. The encapsulated drugs are released in a sustained manner from the fiber matrix. Overall, our research provides an elegant opportunity for developing effective drug carriers with stable network toward enhancing and/or controlling bioavailability and extending shelf-life of drug molecules using GRAS excipients, food polysaccharides, that are inexpensive and non–toxic. PMID:23544530

  2. Nanoengineering of vaccines using natural polysaccharides.

    PubMed

    Cordeiro, Ana Sara; Alonso, María José; de la Fuente, María

    2015-11-01

    Currently, there are over 70 licensed vaccines, which prevent the pathogenesis of around 30 viruses and bacteria. Nevertheless, there are still important challenges in this area, which include the development of more active, non-invasive, and thermo-resistant vaccines. Important biotechnological advances have led to safer subunit antigens, such as proteins, peptides, and nucleic acids. However, their limited immunogenicity has demanded potent adjuvants that can strengthen the immune response. Particulate nanocarriers hold a high potential as adjuvants in vaccination. Due to their pathogen-like size and structure, they can enhance immune responses by mimicking the natural infection process. Additionally, they can be tailored for non-invasive mucosal administration (needle-free vaccination), and control the delivery of the associated antigens to a specific location and for prolonged times, opening room for single-dose vaccination. Moreover, they allow co-association of immunostimulatory molecules to improve the overall adjuvant capacity. The natural and ubiquitous character of polysaccharides, together with their intrinsic immunomodulating properties, their biocompatibility, and biodegradability, justify their interest in the engineering of nanovaccines. In this review, we aim to provide a state-of-the-art overview regarding the application of nanotechnology in vaccine delivery, with a focus on the most recent advances in the development and application of polysaccharide-based antigen nanocarriers.

  3. Hyperbranched acidic polysaccharide from green tea.

    PubMed

    Yang, Liqun; Fu, Shanshan; Zhu, Xiane; Zhang, Li-Ming; Yang, Yanrui; Yang, Xiaomin; Liu, Hui

    2010-12-13

    An acidic tea polysaccharide (ALTPS), isolated from green tea ( Camellia sinensis ), was characterized as a hyperbranched glycoprotein containing the acidic heteropolysaccharide chains and the protein residues from the results of UV-vis, FTIR, one- and two-dimensional NMR, GC, GC-MS, and amino acid analyses. Solution properties of ALTPS were investigated by static and dynamic light scattering analyses and viscometry. The results indicated that the viscosity behavior of ALTPS exhibited a typical polyelectrolyte effect in distilled water, which may be avoided by adding salts. The low intrinsic viscosity of ALTPS in the solutions (8-15 mL/g) is attributed to its hyperbranched structure. By application of the polymer solution theory, it was revealed that ALTPS was present in a sphere-like conformation in the solutions as a result of the hyperbranched structure. The TEM image further confirmed that ALTPS existed in a spherical conformation in aqueous NaCl solution. Glucose was absorbed by ALTPS, which may be one of blood glucose lowering mechanisms of tea polysaccharides.

  4. Hormonal Regulation of Leaf Abscission

    PubMed Central

    Jacobs, William P.

    1968-01-01

    A review is given of the progress made during the last 6 years in elucidating the nature, locus of action, and transport properties of the endogenous hormones that control leaf abscission. PMID:16657014

  5. Experiments in Whole Leaf Photosynthesis

    ERIC Educational Resources Information Center

    Stewart, J. C.; And Others

    1974-01-01

    Described is a simple experimental system, which uses radioactive carbon dioxide to study whole leaf photosynthesis under a variety of conditions. Other experiments and simple apparatus for the experiments are also described. (Author/RH)

  6. 7 CFR 29.3036 - Leaf surface.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Leaf surface. The smoothness or roughness of the web or lamina of a tobacco leaf. Leaf surface is... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf surface. 29.3036 Section 29.3036 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  7. 7 CFR 29.3036 - Leaf surface.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Leaf surface. The smoothness or roughness of the web or lamina of a tobacco leaf. Leaf surface is... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf surface. 29.3036 Section 29.3036 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  8. 7 CFR 29.3036 - Leaf surface.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Leaf surface. The smoothness or roughness of the web or lamina of a tobacco leaf. Leaf surface is... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf surface. 29.3036 Section 29.3036 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  9. 7 CFR 29.3036 - Leaf surface.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Leaf surface. The smoothness or roughness of the web or lamina of a tobacco leaf. Leaf surface is... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf surface. 29.3036 Section 29.3036 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  10. 7 CFR 29.3036 - Leaf surface.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Leaf surface. The smoothness or roughness of the web or lamina of a tobacco leaf. Leaf surface is... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf surface. 29.3036 Section 29.3036 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  11. Why do leaf-tying caterpillars abandon their leaf ties?

    PubMed

    Sliwinski, Michelle; Sigmon, Elisha

    2013-01-01

    Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats), but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm(2) leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently abandon their leaf

  12. What determines a leaf's shape?

    PubMed

    Dkhar, Jeremy; Pareek, Ashwani

    2014-01-01

    The independent origin and evolution of leaves as small, simple microphylls or larger, more complex megaphylls in plants has shaped and influenced the natural composition of the environment. Significant contributions have come from megaphyllous leaves, characterized usually as flat, thin lamina entrenched with photosynthetic organelles and stomata, which serve as the basis of primary productivity. During the course of evolution, the megaphylls have attained complexity not only in size or venation patterns but also in shape. This has fascinated scientists worldwide, and research has progressed tremendously in understanding the concept of leaf shape determination. Here, we review these studies and discuss the various factors that contributed towards shaping the leaf; initiated as a small bulge on the periphery of the shoot apical meristem (SAM) followed by asymmetric outgrowth, expansion and maturation until final shape is achieved. We found that the underlying factors governing these processes are inherently genetic: PIN1 and KNOX1 are indicators of leaf initiation, HD-ZIPIII, KANADI, and YABBY specify leaf outgrowth while ANGUSTIFOLIA3 and GROWTH-REGULATING FACTOR5 control leaf expansion and maturation; besides, recent research has identified new players such as APUM23, known to specify leaf polarity. In addition to genetic control, environmental factors also play an important role during the final adjustment of leaf shape. This immense amount of information available will serve as the basis for studying and understanding innovative leaf morphologies viz. the pitchers of the carnivorous plant Nepenthes which have evolved to provide additional support to the plant survival in its nutrient-deficient habitat. In hindsight, formation of the pitcher tube in Nepenthes might involve the recruitment of similar genetic mechanisms that occur during sympetaly in Petunia. PMID:25584185

  13. What determines a leaf's shape?

    PubMed

    Dkhar, Jeremy; Pareek, Ashwani

    2014-01-01

    The independent origin and evolution of leaves as small, simple microphylls or larger, more complex megaphylls in plants has shaped and influenced the natural composition of the environment. Significant contributions have come from megaphyllous leaves, characterized usually as flat, thin lamina entrenched with photosynthetic organelles and stomata, which serve as the basis of primary productivity. During the course of evolution, the megaphylls have attained complexity not only in size or venation patterns but also in shape. This has fascinated scientists worldwide, and research has progressed tremendously in understanding the concept of leaf shape determination. Here, we review these studies and discuss the various factors that contributed towards shaping the leaf; initiated as a small bulge on the periphery of the shoot apical meristem (SAM) followed by asymmetric outgrowth, expansion and maturation until final shape is achieved. We found that the underlying factors governing these processes are inherently genetic: PIN1 and KNOX1 are indicators of leaf initiation, HD-ZIPIII, KANADI, and YABBY specify leaf outgrowth while ANGUSTIFOLIA3 and GROWTH-REGULATING FACTOR5 control leaf expansion and maturation; besides, recent research has identified new players such as APUM23, known to specify leaf polarity. In addition to genetic control, environmental factors also play an important role during the final adjustment of leaf shape. This immense amount of information available will serve as the basis for studying and understanding innovative leaf morphologies viz. the pitchers of the carnivorous plant Nepenthes which have evolved to provide additional support to the plant survival in its nutrient-deficient habitat. In hindsight, formation of the pitcher tube in Nepenthes might involve the recruitment of similar genetic mechanisms that occur during sympetaly in Petunia.

  14. The immunostimulating role of lichen polysaccharides: a review.

    PubMed

    Shrestha, Gajendra; St Clair, Larry L; O'Neill, Kim L

    2015-03-01

    The immune system has capacity to suppress the development or progression of various malignancies including cancer. Research on the immunomodulating properties of polysaccharides obtained from plants, microorganisms, marine organisms, and fungi is growing rapidly. Among the various potential sources, lichens, symbiotic systems involving a fungus and an alga and/or a cyanobacterium, show promise as a potential source of immunomodulating compounds. It is well known that lichens produce an abundance of structurally diverse polysaccharides. However, only a limited number of studies have explored the immunostimulating properties of lichen polysaccharides. Published studies have shown that some lichen polysaccharides enhance production of nitrous oxide (NO) by macrophages and also alter the production levels of various proinflammatory and antiinflammatory cytokines (IL-10, IL-12, IL-1β, TNF-α, and IFN-α/β) by macrophages and dendritic cells. Although there are only a limited number of studies examining the role of lichen polysaccharides, all results suggest that lichen polysaccharides can induce immunomodulatory responses in macrophages and dendritic cells. Thus, a detailed evaluation of immunomodulatory capacity of lichen polysaccharides could provide a unique opportunity for the discovery of novel therapeutic agents. PMID:25339289

  15. Antibiofilm activity of Actinobacillus pleuropneumoniae serotype 5 capsular polysaccharide.

    PubMed

    Karwacki, Michael T; Kadouri, Daniel E; Bendaoud, Meriem; Izano, Era A; Sampathkumar, Vandana; Inzana, Thomas J; Kaplan, Jeffrey B

    2013-01-01

    Cell-free extracts isolated from colony biofilms of Actinobacillus pleuropneumoniae serotype 5 were found to inhibit biofilm formation by Staphylococcus aureus, S. epidermidis and Aggregatibacter actinomycetemcomitans, but not by A. pleuropneumoniae serotype 5 itself, in a 96-well microtiter plate assay. Physical and chemical analyses indicated that the antibiofilm activity in the extract was due to high-molecular-weight polysaccharide. Extracts isolated from a mutant strain deficient in the production of serotype 5 capsular polysaccharide did not exhibit antibiofilm activity. A plasmid harboring the serotype 5 capsule genes restored the antibiofilm activity in the mutant extract. Purified serotype 5 capsular polysaccharide also exhibited antibiofilm activity against S. aureus. A. pleuropneumoniae wild-type extracts did not inhibit S. aureus growth, but did inhibit S. aureus intercellular adhesion and binding of S. aureus cells to stainless steel surfaces. Furthermore, polystyrene surfaces coated with A. pleuropneumoniae wild-type extracts, but not with capsule-mutant extracts, resisted S. aureus biofilm formation. Our findings suggest that the A. pleuropneumoniae serotype 5 capsule inhibits cell-to-cell and cell-to-surface interactions of other bacteria. A. pleuropneumoniae serotype 5 capsular polysaccharide is one of a growing number of bacterial polysaccharides that exhibit broad-spectrum, nonbiocidal antibiofilm activity. Future studies on these antibiofilm polysaccharides may uncover novel functions for bacterial polysaccharides in nature, and may lead to the development of new classes of antibiofilm agents for industrial and clinical applications. PMID:23691104

  16. Antibiofilm Activity of Actinobacillus pleuropneumoniae Serotype 5 Capsular Polysaccharide

    PubMed Central

    Karwacki, Michael T.; Kadouri, Daniel E.; Bendaoud, Meriem; Izano, Era A.; Sampathkumar, Vandana; Inzana, Thomas J.; Kaplan, Jeffrey B.

    2013-01-01

    Cell-free extracts isolated from colony biofilms of Actinobacillus pleuropneumoniae serotype 5 were found to inhibit biofilm formation by Staphylococcus aureus, S. epidermidis and Aggregatibacter actinomycetemcomitans, but not by A. pleuropneumoniae serotype 5 itself, in a 96-well microtiter plate assay. Physical and chemical analyses indicated that the antibiofilm activity in the extract was due to high-molecular-weight polysaccharide. Extracts isolated from a mutant strain deficient in the production of serotype 5 capsular polysaccharide did not exhibit antibiofilm activity. A plasmid harboring the serotype 5 capsule genes restored the antibiofilm activity in the mutant extract. Purified serotype 5 capsular polysaccharide also exhibited antibiofilm activity against S. aureus. A. pleuropneumoniae wild-type extracts did not inhibit S. aureus growth, but did inhibit S. aureus intercellular adhesion and binding of S. aureus cells to stainless steel surfaces. Furthermore, polystyrene surfaces coated with A. pleuropneumoniae wild-type extracts, but not with capsule-mutant extracts, resisted S. aureus biofilm formation. Our findings suggest that the A. pleuropneumoniae serotype 5 capsule inhibits cell-to-cell and cell-to-surface interactions of other bacteria. A. pleuropneumoniae serotype 5 capsular polysaccharide is one of a growing number of bacterial polysaccharides that exhibit broad-spectrum, nonbiocidal antibiofilm activity. Future studies on these antibiofilm polysaccharides may uncover novel functions for bacterial polysaccharides in nature, and may lead to the development of new classes of antibiofilm agents for industrial and clinical applications. PMID:23691104

  17. Cell-Wall Polysaccharides of Developing Flax Plants.

    PubMed Central

    Gorshkova, T. A.; Wyatt, S. E.; Salnikov, V. V.; Gibeaut, D. M.; Ibragimov, M. R.; Lozovaya, V. V.; Carpita, N. C.

    1996-01-01

    Flax (Linum usitatissimum L.) fibers originate from procambial cells of the protophloem and develop in cortical bundles that encircle the vascular cylinder. We determined the polysaccharide composition of the cell walls from various organs of the developing flax plant, from fiber-rich strips peeled from the stem, and from the xylem. Ammonium oxalate-soluble polysaccharides from all tissues contained 5-linked arabinans with low degrees of branching, rhamnogalacturonans, and polygalacturonic acid. The fiber-rich peels contained, in addition, substantial amounts of a buffer-soluble, 4-linked galactan branched at the 0-2 and 0-3 positions with nonreducing terminal-galactosyl units. The cross-linking glycans from all tissues were (fucogalacto)xyloglucan, typical of type-I cell walls, xylans containing (1->)-[beta]-D-xylosyl units branched exclusively at the xylosyl O-2 with t-(4-O-methyl)-glucosyluronic acid units, and (galacto)glucomannans. Tissues containing predominantly primary cell wall contained a larger proportion of xyloglucan. The xylem cells were composed of about 60% 4-xylans, 32% cellulose, and small amounts of pectin and the other cross-linking polysaccharides. The noncellulosic polysaccharides of flax exhibit an uncommonly low degree of branching compared to similar polysaccharides from other flowering plants. Although the relative abundance of the various noncellulosic polysaccharides varies widely among the different cell types, the linkage structure and degree of branching of several of the noncellulosic polysaccharides are invariant. PMID:12226214

  18. The immunostimulating role of lichen polysaccharides: a review.

    PubMed

    Shrestha, Gajendra; St Clair, Larry L; O'Neill, Kim L

    2015-03-01

    The immune system has capacity to suppress the development or progression of various malignancies including cancer. Research on the immunomodulating properties of polysaccharides obtained from plants, microorganisms, marine organisms, and fungi is growing rapidly. Among the various potential sources, lichens, symbiotic systems involving a fungus and an alga and/or a cyanobacterium, show promise as a potential source of immunomodulating compounds. It is well known that lichens produce an abundance of structurally diverse polysaccharides. However, only a limited number of studies have explored the immunostimulating properties of lichen polysaccharides. Published studies have shown that some lichen polysaccharides enhance production of nitrous oxide (NO) by macrophages and also alter the production levels of various proinflammatory and antiinflammatory cytokines (IL-10, IL-12, IL-1β, TNF-α, and IFN-α/β) by macrophages and dendritic cells. Although there are only a limited number of studies examining the role of lichen polysaccharides, all results suggest that lichen polysaccharides can induce immunomodulatory responses in macrophages and dendritic cells. Thus, a detailed evaluation of immunomodulatory capacity of lichen polysaccharides could provide a unique opportunity for the discovery of novel therapeutic agents.

  19. Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf.

    PubMed

    Simonin, Kevin A; Burns, Emily; Choat, Brendan; Barbour, Margaret M; Dawson, Todd E; Franks, Peter J

    2015-03-01

    Leaf hydraulic conductance (k leaf) is a central element in the regulation of leaf water balance but the properties of k leaf remain uncertain. Here, the evidence for the following two models for k leaf in well-hydrated plants is evaluated: (i) k leaf is constant or (ii) k leaf increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨstem-leaf), stomatal conductance (g s), k leaf, and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO₂ concentration were evaluated. Results show that for well-watered plants k leaf is positively dependent on E. Here, this property is termed the dynamic conductance, k leaf(E), which incorporates the inherent k leaf at zero E, which is distinguished as the static conductance, k leaf(0). Growth under different CO₂ concentrations maintained the same relationship between k leaf and E, resulting in similar k leaf(0), while operating along different regions of the curve owing to the influence of CO₂ on g s. The positive relationship between k leaf and E minimized variation in ΔΨstem-leaf. This enables leaves to minimize variation in Ψleaf and maximize g s and CO₂ assimilation rate over the diurnal course of evaporative demand.

  20. Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf

    PubMed Central

    Simonin, Kevin A.; Burns, Emily; Choat, Brendan; Barbour, Margaret M.; Dawson, Todd E.; Franks, Peter J.

    2015-01-01

    Leaf hydraulic conductance (k leaf) is a central element in the regulation of leaf water balance but the properties of k leaf remain uncertain. Here, the evidence for the following two models for k leaf in well-hydrated plants is evaluated: (i) k leaf is constant or (ii) k leaf increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨstem–leaf), stomatal conductance (g s), k leaf, and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO2 concentration were evaluated. Results show that for well-watered plants k leaf is positively dependent on E. Here, this property is termed the dynamic conductance, k leaf(E), which incorporates the inherent k leaf at zero E, which is distinguished as the static conductance, k leaf(0). Growth under different CO2 concentrations maintained the same relationship between k leaf and E, resulting in similar k leaf(0), while operating along different regions of the curve owing to the influence of CO2 on g s. The positive relationship between k leaf and E minimized variation in ΔΨstem–leaf. This enables leaves to minimize variation in Ψleaf and maximize g s and CO2 assimilation rate over the diurnal course of evaporative demand. PMID:25547915

  1. Optimization for ultrasonic-microwave synergistic extraction of polysaccharides from Cornus officinalis and characterization of polysaccharides.

    PubMed

    Yin, Xiulian; You, Qinghong; Jiang, Zhonghai; Zhou, Xinghai

    2016-02-01

    Ultrasonic-microwave synergistic extraction (UMSE) of polysaccharides from Cornus officinalis was optimized by response surface methodology (RSM). The effect of four different factors on the yield of C. officinalis polysaccharides (COP) was studied. RSM results showed that the optimal conditions were extraction time of 31.49823 min, microwave power of 99.39769 W, and water-to-raw material ratio of 28.16273. The COP yield was 11.38±0.31% using the modified optimal conditions, which was consistent with the value predicted by the model. The crude COP was purified by DEAE-Cellulose 52 chromatography and Sephadex G-100 chromatography. Five fractions, namely, crude COP, COP-1, COP-2, COP-3, and COP-4, were obtained. Monosaccharide composition analysis revealed that the COP was composed of glucose, arabinose, fucose, xylose, mannose, and rhamnose. Preliminary structural characterizations of COP were conducted by scanning electron microscopy and Fourier transform infrared spectroscopy.

  2. Enzymatic method for improving the injectability of polysaccharides. [US Patent Application

    DOEpatents

    Griffith, W.L.; Compere, A.L.; Holleman, J.W.

    A method for enhancing the ability of polysaccharides in aqueous solution to flow through a porous medium comprises contacting the polysaccharides with an endoenzyme capable of hydrolyzing at least one of the linkages of the sugar units of the polysaccharides and maintaining the polysaccharides in contact with the enzyme under hydrolysis conditions for a time sufficient to decrease the tendency of the polysaccharides to plug the porous medium yet insufficient to decrease the viscosity of the aqueous polysaccharides by more than 25%. The partially hydrolyzed polysaccharides are useful as thickening agents for flooding water used to recover oil from oil-containing subterranean formations.

  3. Leaf exsertion, leaf elongation, and leaf senescence in Eriophorum vaginatum and Carex Bigelowii

    SciTech Connect

    Shaver, G.R.; Yandow, T.; Laundre, J.

    1990-01-01

    Most of the common sedges of arctic vegetation show a pattern of leaf production in which the exsertion and elongation of new leaves is more or less simultaneous with the senescence of old leaves. The present study was designed to increase our understanding of the variability sequential leaf production by arctic sedges, and to determine some of the controls on that variability. We did this in two ways: first, we compared the sequential patterns of leaf growth and senescence in E. vaginatum with those of Carex Bigelowii Torr. at two tussock tundra sites near Toolik Lake on the North Slope of Alaska. Second, we compared the responses of leaf growth in these species in control and fertilized plots and in two microenvironments thought to differ sharply in nutrient availability and total productivity. 29 refs., 28 figs., 2 tabs.

  4. Chemical Structures and Bioactivities of Sulfated Polysaccharides from Marine Algae

    PubMed Central

    Jiao, Guangling; Yu, Guangli; Zhang, Junzeng; Ewart, H. Stephen

    2011-01-01

    Sulfated polysaccharides and their lower molecular weight oligosaccharide derivatives from marine macroalgae have been shown to possess a variety of biological activities. The present paper will review the recent progress in research on the structural chemistry and the bioactivities of these marine algal biomaterials. In particular, it will provide an update on the structural chemistry of the major sulfated polysaccharides synthesized by seaweeds including the galactans (e.g., agarans and carrageenans), ulvans, and fucans. It will then review the recent findings on the anticoagulant/antithrombotic, antiviral, immuno-inflammatory, antilipidemic and antioxidant activities of sulfated polysaccharides and their potential for therapeutic application. PMID:21566795

  5. Spectroscopic manifestation of stretching vibrations of glycosidic linkage in polysaccharides

    NASA Astrophysics Data System (ADS)

    Nikonenko, N. A.; Buslov, D. K.; Sushko, N. I.; Zhbankov, R. G.

    2005-10-01

    Manifestation of stretching vibrations of glycosidic linkage in the infrared spectra of polysaccharides (native, microcrystalline, mercerized celluloses, amylose, starches) has been studied using the regularized method of deconvolution. It has been shown that the glycosidic linkage formation in the polysaccharides is characterized by the appearance of new absorption bands in the 1175-1140 cm -1 range as compared to their corresponding monomers. In the 1000-920 cm -1 region differences between the infrared spectra of polysaccharides due to the changes in the glycosidic linkage configuration have been found.

  6. Use of paramagnetic chelated metal derivatives of polysaccharides and spin-labeled polysaccharides as contrast agents in magnetic resonance imaging

    SciTech Connect

    Bligh, S.W.; Harding, C.T.; Sadler, P.J.; Bulman, R.A.; Bydder, G.M.; Pennock, J.M.; Kelly, J.D.; Latham, I.A.; Marriott, J.A. )

    1991-02-01

    Soluble and insoluble polysaccharides were derivatized with diethylenetriaminepentaacetic acid (DTPA) and/or spin-labeled with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). Polysaccharides derivatized with DTPA were prepared via cyanogen bromide activation, coupling to a diamine linker, and to DTPA anhydride. Spin-labeled polysaccharides were also prepared via cyanogen bromide activation. The extent of derivatization for dextran (18 kDa) was about 120 glucose units per DTPA, and for cellulose and starch about 15-30 units per DTPA. For spin-labeled polysaccharides, the average loading ranged from 1 nitroxide per 16 glucose units for starch to 181 for dextran (82 kDa). These derivatized paramagnetic polysaccharides were shown to be more effective relaxants than the small paramagnetic molecules alone. Both soluble and insoluble polysaccharide-linker-DTPA-Gd(3) complexes were effectively cleared from the body (rats) after oral administration. After intravenous administration, the biodistribution of dextran-linker-DTPA-Gd(3) complexes differed significantly from that of GdDTPA. Reduction of the nitroxide by ascorbic acid was retarded in the polysaccharide derivatives, particularly in starch derivatized with both nitroxide and linker-DTPA-Cu(2). These agents showed contrast enhancement in the gastrointestinal tract of rabbits.

  7. Evidence for bioadhesive effects of polysaccharides and polysaccharide-containing herbs in an ex vivo bioadhesion assay on buccal membranes.

    PubMed

    Schmidgall, J; Schnetz, E; Hensel, A

    2000-02-01

    Aqueous extracts of polysaccharide-containing plants are widely used in therapy for irritated mucus membranes in the pharynx region. In order to prove the existence of mucilaginous effects of polysaccharide hydrocolloids on epithelia an ex vivo system based on porcine buccal membranes was established. The tissue culture was stable and there was no indication of cytolytic processes during the 5 hour incubation period. This was confirmed through histological studies and the respective LDH values as toxicity marker. The test system was shown to discriminate the adhesive effects of different raw polysaccharides, obtained from a variety of medicinal plants. While polysaccharides from Altheae officinalis, Plantago lanceolata, Malva moschata, or Tilia cordata showed only moderate bioadhesion to epithelial tissue, strong adhesive processes were observed with polysaccharides from Fucus vesiculosus and Calendula officinalis. The adhesive effects were concentration-dependent. Histological studies of membranes, incubated with a fluorescence-labelled rhamnogalacturonan, indicated the presence of distinct polysaccharide layers on the apical membrane surface. With these results, adsorption effects of certain polysaccharides on mucus membranes were shown for the first time. Such effects suggest that this may account, at least in part, for the therapeutic effects of mucilage-containing plants in the treatment of irritated buccal membranes. PMID:10705734

  8. Lytic Polysaccharide Monooxygenases in Biomass Conversion.

    PubMed

    Hemsworth, Glyn R; Johnston, Esther M; Davies, Gideon J; Walton, Paul H

    2015-12-01

    The derivation of second-generation biofuels from non-edible biomass is viewed as crucial for establishing a sustainable bio-based economy for the future. The inertness of lignocellulosic biomass makes its breakdown for conversion into fuels and other compounds a challenge. Enzyme cocktails can be utilized in the bio-refinery for lignocellulose deconstruction but until recently their costs were regarded as high. Lytic polysaccharide monooxygenases (LPMOs) offer tremendous promise for further process improvements owing to their ability to boost the activity of biomass-degrading enzyme consortia. Combining data from multiple disciplines, progress has been made in understanding the biochemistry of LPMOs. We review the academic literature in this area and highlight some of the key questions that remain.

  9. Nutraceutical functionalities of polysaccharides from marine invertebrates.

    PubMed

    Choi, Byeong-Dae; Choi, Yeung Joon

    2012-01-01

    Many researchers are seeking functional materials from marine resources. These marine resources can be used as traditional food additives, and specifically, these are based on polysaccharides. To date, there is a big opportunity to develop new high-value added products with indispensable functional characteristics, which can be used in nutraceuticals either as additives or supplements. Also, a crossover in the pharmaceutical market may be established. Some glycosaminoglycans (GAGs) mimetic-type molecules are already being utilized in the field of nutrition as well as in the cosmetics industry. This chemical is used as a dietary supplement to maintain the structure and function of cartilages, for the relief of pain caused by osteoarthritic joints, and can also be used as an anti-inflammatory agent. Recently, in relation to the prevalence of mad cow disease and avian influenza, the production of GAGs from marine invertebrates offers new market opportunities as compared with that obtained from bovine or avian livestock. PMID:22361178

  10. Campylobacter Polysaccharide Capsules: Virulence and Vaccines

    PubMed Central

    Guerry, Patricia; Poly, Frédéric; Riddle, Mark; Maue, Alexander C.; Chen, Yu-Han; Monteiro, Mario A.

    2012-01-01

    Campylobacter jejuni remains a major cause of bacterial diarrhea worldwide and is associated with numerous sequelae, including Guillain Barré Syndrome, inflammatory bowel disease, reactive arthritis, and irritable bowel syndrome. C. jejuni is unusual for an intestinal pathogen in its ability to coat its surface with a polysaccharide capsule (CPS). These capsular polysaccharides vary in sugar composition and linkage, especially those involving heptoses of unusual configuration and O-methyl phosphoramidate linkages. This structural diversity is consistent with CPS being the major serodeterminant of the Penner scheme, of which there are 47 C. jejuni serotypes. Both CPS expression and expression of modifications are subject to phase variation by slip strand mismatch repair. Although capsules are virulence factors for other pathogens, the role of CPS in C. jejuni disease has not been well defined beyond descriptive studies demonstrating a role in serum resistance and for diarrhea in a ferret model of disease. However, perhaps the most compelling evidence for a role in pathogenesis are data that CPS conjugate vaccines protect against diarrheal disease in non-human primates. A CPS conjugate vaccine approach against this pathogen is intriguing, but several questions need to be addressed, including the valency of CPS types required for an effective vaccine. There have been numerous studies of prevalence of CPS serotypes in the developed world, but few studies from developing countries where the disease incidence is higher. The complexity and cost of Penner serotyping has limited its usefulness, and a recently developed multiplex PCR method for determination of capsule type offers the potential of a more rapid and affordable method. Comparative studies have shown a strong correlation of the two methods and studies are beginning to ascertain CPS-type distribution worldwide, as well as examination of correlation of severity of illness with specific CPS types. PMID:22919599

  11. Antiobesity properties of mushroom polysaccharides – A Review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mushrooms are widely consumed for their nutritional and health benefits. To stimulate broader interest in the reported health-promoting properties of bioactive mushroom polysaccharides, this presentation will survey the chemistry (isolation and structural characterization) and reported antiobesity ...

  12. Enzymatic synthesis of oligo- and polysaccharide fatty acid esters.

    PubMed

    van den Broek, Lambertus A M; Boeriu, Carmen G

    2013-03-01

    Amphiphilic oligo- and polysaccharides (e.g. polysaccharide alkyl or alkyl-aryl esters) form a new class of polymers with exceptional properties. They function as polymeric surfactants, whilst maintaining most of the properties of the starting polymeric material such as emulsifying, gelling, and film forming properties combined with partial water solubility or permeability. At present carbohydrate fatty acid esters are generally obtained by chemical methods using toxic solvents and organic and inorganic catalysts that leave residual traces in the final products. Enzymatic reactions offer an attractive alternative route for the synthesis of polysaccharide esters. In this review the state of the art of enzymatic synthesis of oligo- and polysaccharides fatty esters has been described.

  13. Synbiotic matrices derived from plant oligosaccharides and polysaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A porous synbiotic matrix was prepared by lyophilization of alginate and pectin or fructan oligosaccharides and polysaccharides cross-linked with calcium. These synbiotic matrices were excellent physical structures to support the growth of Lactobacillus acidophilus (1426) and Lactobacillus reuteri (...

  14. Extraction and antioxidant activity of polysaccharides from Rana chensinensis skin.

    PubMed

    Wang, Zhanyong; Zhao, Yuanyuan; Su, Tingting

    2015-01-22

    The extraction process of polysaccharides from Rana chensinensis skin was optimized by using a Box-Behnken design. The optimum extraction conditions were as follows: extraction time, 4.96h; extraction temperature, 100°C; ratio of water to raw material, 60; and extraction frequency, 1. Under these conditions, the experimental polysaccharide yield was 2.03±0.14%, which agreed with the predicted yield. The purified polysaccharide RCSP II was successfully obtained by diethylaminoethanol-Sepharose and Sepharose CL-6B column chromatography. In vitro experiments showed that RCSP II exhibited a strong scavenging activity against superoxide anion and 1,1-diphenyl-2-picrylhydrazyl radicals but a weak scavenging activity against hydroxyl radicals. RCSP II also showed a strong reducing capacity. Thus, this polysaccharide can be used as a natural antioxidant in functional foods or medicines.

  15. Detection of Inulin, a Prebiotic Polysaccharide, in Maple Syrup.

    PubMed

    Sun, Jiadong; Ma, Hang; Seeram, Navindra P; Rowley, David C

    2016-09-28

    Maple syrup is a widely consumed plant-derived natural sweetener produced by concentrating xylem sap collected from certain maple (Acer) species. During thermal evaporation of water, natural phytochemical components are concentrated in maple syrup. The polymeric components from maple syrup were isolated by ethanol precipitation, dialysis, and anion exchange chromatography and structurally characterized by glycosyl composition analysis, glycosyl linkage analysis, and nuclear magnetic resonance spectroscopy. Among the maple syrup polysaccharides, one neutral polysaccharide was characterized as inulin with a broad molecular weight distribution, representing the first isolation of this prebiotic carbohydrate from a xylem sap. In addition, two acidic polysaccharides with structural similarity were identified as arabinogalactans derived from rhamnogalacturonan type I pectic polysaccharides.

  16. Microwave-assisted extraction of polysaccharides from mulberry leaves.

    PubMed

    Thirugnanasambandham, K; Sivakumar, V; Maran, J Prakash

    2015-01-01

    In this study, microwave-assisted extraction (MAE) of polysaccharides from mulberry leaves was investigated using response surface methodology (RSM). The effects of three extraction factors on the yield of polysaccharides was examined. The results showed that optimum extraction conditions were determined as follows: weight of the sample of 20 g, microwave power of 170 W, extraction time of 10 min. Under these optimal extraction conditions, polysaccharide yield was found to be 9.41%. Three factors-three level Box-Behnken response surface design (BBD) coupled with RSM was used to model the extraction process. ANOVA was used to examine the statistical significance of the developed model. Extracted polysaccharide was analyzed using Fourier transform infrared (FT-IR) spectroscopy.

  17. Detection of Inulin, a Prebiotic Polysaccharide, in Maple Syrup.

    PubMed

    Sun, Jiadong; Ma, Hang; Seeram, Navindra P; Rowley, David C

    2016-09-28

    Maple syrup is a widely consumed plant-derived natural sweetener produced by concentrating xylem sap collected from certain maple (Acer) species. During thermal evaporation of water, natural phytochemical components are concentrated in maple syrup. The polymeric components from maple syrup were isolated by ethanol precipitation, dialysis, and anion exchange chromatography and structurally characterized by glycosyl composition analysis, glycosyl linkage analysis, and nuclear magnetic resonance spectroscopy. Among the maple syrup polysaccharides, one neutral polysaccharide was characterized as inulin with a broad molecular weight distribution, representing the first isolation of this prebiotic carbohydrate from a xylem sap. In addition, two acidic polysaccharides with structural similarity were identified as arabinogalactans derived from rhamnogalacturonan type I pectic polysaccharides. PMID:27612524

  18. How to pattern a leaf.

    PubMed

    Bolduc, N; O'Connor, D; Moon, J; Lewis, M; Hake, S

    2012-01-01

    Leaf development presents a tremendous resource for tackling the question of patterning in biology. Leaves can be simple or highly dissected. They may have elaborated parts such as the tendrils of a pea leaf or the rolled blade of a carnivorous pitcher plant. Despite the variation in size, shape, and function, all leaves initiate in the same manner: from the flanks of a meristem. The maize leaf is useful for analysis of patterning due to the wealth of mutants and the distinct tissues along the proximal distal axis. The blade is distal, the sheath is proximal, and the ligule forms at the blade/sheath boundary. Establishment of this boundary involves the transcription factors LIGULELESS1 and LIGULELESS2 and the kinase LIGULELESS NARROW. The meristem-specific protein KNOTTED1 (KN1) binds and modulates the lg2 gene. Given the localization of KN1 at the proximal end of the leaf from the time of inception, we hypothesize that KN1 has a role in establishing the very proximal end of the leaf, whereas an auxin maximum guides the growing distal tip. PMID:23174765

  19. Safety Assessment of Microbial Polysaccharide Gums as Used in Cosmetics.

    PubMed

    Fiume, Monice M; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2016-07-01

    The Cosmetic Ingredient Review Expert Panel assessed the safety of 34 microbial polysaccharide gums for use in cosmetics, finding that these ingredients are safe in cosmetic formulations in the present practices of use and concentration. The microbial polysaccharide gums named in this report have a variety of reported functions in cosmetics, including emulsion stabilizer, film former, binder, viscosity-increasing agent, and skin-conditioning agent. The Panel reviewed available animal and clinical data in making its determination of safety. PMID:27383198

  20. Composition of the Capsular and Extracellular Polysaccharides of Rhizobium japonicum

    PubMed Central

    Mort, Andrew J.; Bauer, Wolfgang D.

    1980-01-01

    The chemical compositions of the capsular and extracellular polysaccharides of two strains of Rhizobium japonicum (311b 138 and 110) have been determined and correlated as a function of culture age with the ability of the bacteria from which they were obtained to bind soybean seed lectin. Each of the polysaccharides contains approximately constant amounts of mannosyl, glucosyl, and galacturonosyl residues in a molar ratio of 1:2:1. In addition they contain variable amounts of galactosyl and 4-O-methyl galactosyl residues. The total of galactose plus 4-O-methyl galactose, however, is constant and equivalent to the amount of mannose, indicating that the 4-O-methyl galactose residues arise by methylation of galactose residues in the polysaccharides. In both strains the proportion of galactose to methyl galactose is considerably greater in the polysaccharide from bacteria which do bind lectin than in the polysaccharide from bacteria which do not bind lectin. In addition to the changes in polysaccharide composition, there is a reduction of about 50% in the percentage of cells which are encapsulated as the cultures mature from early to late log phase. Since only capsulated cells bind lectin, the combination of the change in capsular composition and loss of encapsulation is probably sufficient to account for the loss of lectin binding capacity during growth of cultures of Rhizobium japonicum 311b 138 and 110. Images PMID:16661379

  1. Mapping the polysaccharide degradation potential of Aspergillus niger

    PubMed Central

    2012-01-01

    Background The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For each type of hemicellulose, a complex mixture of enzymes is required for complete conversion to fermentable monosaccharides. In plant-biomass degrading fungi, these enzymes are regulated and released by complex regulatory structures. In this study, we present a methodology for evaluating the potential of a given fungus for polysaccharide degradation. Results Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from Aspergillus niger, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan. Conclusions The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in A. niger. PMID:22799883

  2. [Analysis of thickening polysaccharides by the improved diethyldithioacetal derivatization method].

    PubMed

    Akiyama, Takumi; Yamazaki, Takeshi; Tanamoto, Kenichi

    2011-01-01

    The identification test for thickening polysaccharides containing neutral saccharides and uronic acids was investigated by GC analysis of constituent monosaccharides. The reported method, in which monosaccharides were converted to diethyldithioacetal derivatives with ethanethiol followed by trimethylsilylation, was improved in terms of operability and reproducibility of GC/MS analysis. The suitability of the improved diethyldithioacetal derivatization method was determined for seven thickening polysaccharides, i.e., carob bean gum, guar gum, karaya gum, gum arabic, gum ghatti, tragacanth gum and peach gum. The samples were acid-hydrolyzed to form monosaccharides. The hydrolysates were derivatized and analyzed with GC/FID. Each sugar derivative was detected as a single peak and was well separated from others on the chromatograms. The amounts of constituent monosaccharides in thickening polysaccharides were successfully estimated. Seven polysaccharides were distinguished from each other on the basis of constituent monosaccharides. Further examination of the time period of hydrolysis of polysaccharides using peach gum showed that the optimal times were not the same for all monosaccharides. A longer time was needed to hydrolyze glucuronic acid than neutral saccharides. The findings suggest that hydrolysis time may sometimes affect the analytical results on composition of constituent monosaccharides in polysaccharides.

  3. Antitussive activity of polysaccharides isolated from the Malian medicinal plants.

    PubMed

    Sutovská, M; Franová, S; Priseznaková, L; Nosálová, G; Togola, A; Diallo, D; Paulsen, B S; Capek, P

    2009-04-01

    From the leaves of popular Malian medicinal plants Trichilia emetica (TE) and Opilia celtidifolia (OC), and fruits of Crossopteryx febrifuga (CF) water and water-ethanol soluble polysaccharide materials were isolated. The results of chemical analysis of the crude polysaccharides showed the dominance of the arabinogalactan ( approximately 54%) and the rhamnogalacturonan ( approximately 30%) in T. emetica leaves, the arabinogalactan ( approximately 60%), the rhamnogalacturonan ( approximately 14%) and the glucuronoxylan ( approximately 14%) in O. celtidifolia leaves, and pectic type of polysaccharides ( approximately 75%) with a lower content of the arabinogalactan ( approximately 17%) in C. febrifuga fruits. The plant polysaccharides showed various biological effects on the citric acid-induced cough reflex and reactivity of airways smooth muscle in vivo conditions. T. emetica and O. celtidifolia polysaccharides possessed significant cough-suppressive effect on chemically induced cough. Furthermore, values of specific airways resistance pointed on bronchodilatory property of polysaccharides isolated from O. celtidifolia. However, the crude extract from C. febrifuga in the same dose as T. emetica and O. celtidifolia did not influence the experimentally induced cough as well as reactivity of airways smooth muscle despite of the fact that the water-ethanol extract is recommended for cough therapy in Mali in the form of syrup.

  4. Antitussive activity of polysaccharides isolated from the Malian medicinal plants.

    PubMed

    Sutovská, M; Franová, S; Priseznaková, L; Nosálová, G; Togola, A; Diallo, D; Paulsen, B S; Capek, P

    2009-04-01

    From the leaves of popular Malian medicinal plants Trichilia emetica (TE) and Opilia celtidifolia (OC), and fruits of Crossopteryx febrifuga (CF) water and water-ethanol soluble polysaccharide materials were isolated. The results of chemical analysis of the crude polysaccharides showed the dominance of the arabinogalactan ( approximately 54%) and the rhamnogalacturonan ( approximately 30%) in T. emetica leaves, the arabinogalactan ( approximately 60%), the rhamnogalacturonan ( approximately 14%) and the glucuronoxylan ( approximately 14%) in O. celtidifolia leaves, and pectic type of polysaccharides ( approximately 75%) with a lower content of the arabinogalactan ( approximately 17%) in C. febrifuga fruits. The plant polysaccharides showed various biological effects on the citric acid-induced cough reflex and reactivity of airways smooth muscle in vivo conditions. T. emetica and O. celtidifolia polysaccharides possessed significant cough-suppressive effect on chemically induced cough. Furthermore, values of specific airways resistance pointed on bronchodilatory property of polysaccharides isolated from O. celtidifolia. However, the crude extract from C. febrifuga in the same dose as T. emetica and O. celtidifolia did not influence the experimentally induced cough as well as reactivity of airways smooth muscle despite of the fact that the water-ethanol extract is recommended for cough therapy in Mali in the form of syrup. PMID:19150368

  5. Regioselective sulfation of Artemisia sphaerocephala polysaccharide: Characterization of chemical structure.

    PubMed

    Wang, Junlong; Yang, Wen; Wang, Jiancheng; Wang, Xia; Wu, Fang; Yao, Jian; Zhang, Ji; Lei, Ziqiang

    2015-11-20

    The biological activities of sulfated polysaccharides are related to the substitution positions of functional groups. In this study, regioselective sulfation of Artemisia sphaerocephala polysaccharides (SRSASP) was prepared by using triphenylchloromethane (TrCl) as protecting precursor. FT-IR spectra and X-ray photoelectron spectroscopy (XPS) showed that SO(3-) group (S(6+), high binding energy of 168.7eV) was widely present in sulfated polysaccharides. (13)C NMR spectroscopy showed that C-2 and C-3 substitution was occurred but not fully sulfation. Meanwhile, C-6 substituted signals near 65ppm were not observed. The degree of substitution varied from 0.44 to 0.63 in SRSASP which could be attributed to the low reactivity at secondary hydroxyl. Monosaccharide composition result showed a decrease in the ratio of mannose/glucose, indicating the change of chemical composition in sulfated polysaccharides. In size-exclusion chromatograph analysis, a decrease in molecular weight and broadening of molecular weight distribution of sulfated polysaccharides was also observed. It could be attributed to the hydrolysis of polysaccharide in the sulfated reaction.

  6. Marine derived polysaccharides for biomedical applications: chemical modification approaches.

    PubMed

    d'Ayala, Giovanna Gomez; Malinconico, Mario; Laurienzo, Paola

    2008-01-01

    Polysaccharide-based biomaterials are an emerging class in several biomedical fields such as tissue regeneration, particularly for cartilage, drug delivery devices and gelentrapment systems for the immobilization of cells. Important properties of the polysaccharides include controllable biological activity, biodegradability, and their ability to form hydrogels. Most of the polysaccharides used derive from natural sources; particularly, alginate and chitin, two polysaccharides which have an extensive history of use in medicine, pharmacy and basic sciences, and can be easily extracted from marine plants (algae kelp) and crab shells, respectively. The recent rediscovery of poly-saccharidebased materials is also attributable to new synthetic routes for their chemical modification, with the aim of promoting new biological activities and/or to modify the final properties of the biomaterials for specific purposes. These synthetic strategies also involve the combination of polysaccharides with other polymers. A review of the more recent research in the field of chemical modification of alginate, chitin and its derivative chitosan is presented. Moreover, we report as case studies the results of our recent work concerning various different approaches and applications of polysaccharide-based biomaterials, such as the realization of novel composites based on calcium sulphate blended with alginate and with a chemically modified chitosan, the synthesis of novel alginate-poly(ethylene glycol) copolymers and the development of a family of materials based on alginate and acrylic polymers of potential interest as drug delivery systems. PMID:18830142

  7. Degradation of hemicellulosic and cellulosic polysaccharides in pickled green olives.

    PubMed

    Sánchez-Romero, C; Guillén, R; Heredia, A; Jiménez, A; Fernández-Bolaños, J

    1998-01-01

    Changes that take place in the hemicellulosic and cellulosic polysaccharide fractions of the cell wall of olives (Olea europaea pomiformis, Manzanilla variety) during "Spanish style" processing have been studied. A comparative study of the extraction of hemicellulosic polysaccharides with and without prior delignification showed that these compounds could be extracted without previous delignification of the cell wall material. The depectinated material was sequentially extracted with 1 M and 4 M potassium hydroxide. In the unprocessed fruit, the neutral polysaccharides of the 1 M potassium hydroxide-soluble fraction contained mainly xyloglucans with significant amounts of arabinans. In the 4 M potassium hydroxide-soluble fraction, xyloglucans were the most important polysaccharide. The apparent molecular weight of these polysaccharides was 40 to 250 kDa. In addition, hemicelluloses (xylans and xyloglucans), which it was not possible to isolate in the previous stages of fractionation, were also found to be closely linked to the cellulose fraction. The most important changes during processing were the decrease in the molecular weight of xyloglucans in the 4 M potassium hydroxide-soluble fraction and the substantial decrease in the cellulose fraction, which in quantitative terms was one of the largest decreases that took place in the components of the total cell wall polysaccharides. PMID:9708258

  8. Marine derived polysaccharides for biomedical applications: chemical modification approaches.

    PubMed

    d'Ayala, Giovanna Gomez; Malinconico, Mario; Laurienzo, Paola

    2008-09-03

    Polysaccharide-based biomaterials are an emerging class in several biomedical fields such as tissue regeneration, particularly for cartilage, drug delivery devices and gelentrapment systems for the immobilization of cells. Important properties of the polysaccharides include controllable biological activity, biodegradability, and their ability to form hydrogels. Most of the polysaccharides used derive from natural sources; particularly, alginate and chitin, two polysaccharides which have an extensive history of use in medicine, pharmacy and basic sciences, and can be easily extracted from marine plants (algae kelp) and crab shells, respectively. The recent rediscovery of poly-saccharidebased materials is also attributable to new synthetic routes for their chemical modification, with the aim of promoting new biological activities and/or to modify the final properties of the biomaterials for specific purposes. These synthetic strategies also involve the combination of polysaccharides with other polymers. A review of the more recent research in the field of chemical modification of alginate, chitin and its derivative chitosan is presented. Moreover, we report as case studies the results of our recent work concerning various different approaches and applications of polysaccharide-based biomaterials, such as the realization of novel composites based on calcium sulphate blended with alginate and with a chemically modified chitosan, the synthesis of novel alginate-poly(ethylene glycol) copolymers and the development of a family of materials based on alginate and acrylic polymers of potential interest as drug delivery systems.

  9. Oral versus postingestive origin of polysaccharide appetite in the rat.

    PubMed

    Sclafani, A; Nissenbaum, J W

    1987-01-01

    Previous studies have revealed that rats consume substantial amounts of polysaccharide solutions, even if the solutions are made bitter with the addition of sucrose octa acetate (SOA). The present experiment used the gastric sham-feeding preparation to determine if it is the orosensory or postingestive properties of polysaccharides that motivate rats to consume polysaccharide (Polycose) solutions. In Experiment 1, food deprived rats sham fed less of a 0.05% SOA + 32% Polycose solution than they did of a 32% glucose solution, but their SOA-Polycose intake was still considerable (44 ml/hr). The same rats refused to sham feed SOA-gum and SOA-sugar solutions that were similar to the SOA-Polycose solution in bitter taste, viscosity and free sugar content. In Experiment 2, rats sham fed as much of a 32% Polycose solution as they did of a 32% sucrose solution. Despite the gastric fistula, some of the ingested Polycose was absorbed as evidenced by an increase in the rats' blood glucose levels. The addition of acarbose, a drug that inhibits polysaccharide digestion, to the Polycose solution blocked the increase in blood glucose, but did not reduce the rats' sham feeding of the solution. These findings indicate that it is the orosensory (presumably taste) properties of polysaccharide solutions, not their postingestive effects, that initially attract rats to the solutions. The results question the assumption that polysaccharides are "tasteless" to animals.

  10. Correlation Between Chain Architecture and Hydration Water Structure in Polysaccharides

    NASA Astrophysics Data System (ADS)

    Grossutti, Michael; Dutcher, John

    The physical properties of confined water can differ dramatically from those of bulk water. Hydration water associated with polysaccharides provides a particularly important example of confined water, with differences in polysaccharide structure providing different spatially confined environments for water adsorption. We have used attenuated total reflection infrared (ATR-IR) spectroscopy to investigate the structure of hydration water in films of three different polysaccharides under controlled relative humidity (RH) conditions. We compare the results obtained for films of highly branched, monodisperse phytoglycogen nanoparticles to those obtained for two unbranched polysaccharides, hyaluronic acid (HA) and chitosan. We find similarities between water structuring in the two linear polysaccharides, and significant differences for phytoglycogen. In particular, the phytoglycogen nanoparticles exhibited high network water connectivity, and a large increase in the fraction of multimer water clusters with increasing RH, whereas the water structure for HA and chitosan was found to be insensitive to changes in RH. These measurements provide unique insight into the relationship between the chain architecture and hydration of polysaccharides.

  11. Correlation Between Chain Architecture and Hydration Water Structure in Polysaccharides.

    PubMed

    Grossutti, Michael; Dutcher, John R

    2016-03-14

    The physical properties of confined water can differ dramatically from those of bulk water. Hydration water associated with polysaccharides provides a particularly interesting example of confined water, because differences in polysaccharide structure provide different spatially confined environments for water sorption. We have used attenuated total reflection infrared (ATR-IR) spectroscopy to investigate the structure of hydration water in films of three different polysaccharides under controlled relative humidity (RH) conditions. We compare the results obtained for films of highly branched, dendrimer-like phytoglycogen nanoparticles to those obtained for two unbranched polysaccharides, hyaluronic acid (HA), and chitosan. We find similarities between the water structuring in the two linear polysaccharides and significant differences for phytoglycogen. In particular, the results suggest that the high degree of branching in phytoglycogen leads to a much more well-ordered water structure (low density, high connectivity network water), indicating the strong influence of chain architecture on the structuring of water. These measurements provide unique insight into the relationship between the structure and hydration of polysaccharides, which is important for understanding and exploiting these sustainable nanomaterials in a wide range of applications.

  12. Polysaccharide based nanogels in the drug delivery system: Application as the carrier of pharmaceutical agents.

    PubMed

    Debele, Tilahun Ayane; Mekuria, Shewaye Lakew; Tsai, Hsieh-Chih

    2016-11-01

    Polysaccharide-based nanoparticles have fascinated attention as a vesicle of different pharmaceutical agents due to their unique multi-functional groups in addition to their physicochemical properties, including biocompatibility and biodegradability. The existence of multi-functional groups on the polysaccharide backbone permits facile chemical or biochemical modification to synthesize polysaccharide based nanoparticles with miscellaneous structures. Polysaccharide-based nanogels have high water content, large surface area for multivalent bioconjugation, tunable size, and interior network for the incorporation of different pharmaceutical agents. These unique properties offer great potential for the utilization of polysaccharide-based nanogels in the drug delivery systems. Hence, this review describes chemistry of certain common polysaccharides, several methodologies used to synthesize polysaccharide nanoparticles and primarily focused on the polysaccharide (or polysaccharide derivative) based nanogels as the carrier of pharmaceutical agents. PMID:27524098

  13. Structural studies of the O-specific polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense type strain Sp7.

    PubMed

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2013-10-18

    Lipopolysaccharide was obtained by phenol-water extraction from dried bacterial cells of Azospirillum brasilense type strain Sp7. Mild acid hydrolysis of the lipopolysaccharide followed by GPC on Sephadex G-50 resulted in a polysaccharide mixture, which was studied by composition and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy. The following polysaccharide structures were established, where italics indicate a non-stoichiometric (∼40%) 2-O-methylation of l-rhamnose.

  14. Biophysical control of leaf temperature

    NASA Astrophysics Data System (ADS)

    Dong, N.; Prentice, I. C.; Wright, I. J.

    2014-12-01

    In principle sunlit leaves can maintain their temperatures within a narrower range than ambient temperatures. This is an important and long-known (but now overlooked) prediction of energy balance theory. Net radiation at leaf surface in steady state (which is reached rapidly) must be equal to the combination of sensible and latent heat exchanges with surrounding air, the former being proportional to leaf-to-air temperature difference (ΔT), the latter to the transpiration rate. We present field measurements of ΔT which confirm the existence of a 'crossover temperature' in the 25-30˚C range for species in a tropical savanna and a tropical rainforest environment. This finding is consistent with a simple representation of transpiration as a function of net radiation and temperature (Priestley-Taylor relationship) assuming an entrainment factor (ω) somewhat greater than the canonical value of 0.26. The fact that leaves in tropical forests are typically cooler than surrounding air, often already by solar noon, is consistent with a recently published comparison of MODIS day-time land-surface temperatures with air temperatures. Theory further predicts a strong dependence of leaf size (which is inversely related to leaf boundary-layer conductance, and therefore to absolute magnitude of ΔT) on moisture availability. Theoretically, leaf size should be determined by either night-time constraints (risk of frost damage to active leaves) or day-time constraints (risk of heat stress damage),with the former likely to predominate - thereby restricting the occurrence of large leaves - at high latitudes. In low latitudes, daytime maximum leaf size is predicted to increase with temperature, provided that water is plentiful. If water is restricted, however, transpiration cannot proceed at the Priestley-Taylor rate, and it quickly becomes advantageous for plants to have small leaves, which do not heat up much above the temperature of their surroundings. The difference between leaf

  15. Carrageenans, Sulphated Polysaccharides of Red Seaweeds, Differentially Affect Arabidopsis thaliana Resistance to Trichoplusia ni (Cabbage Looper)

    PubMed Central

    Sangha, Jatinder S.; Khan, Wajahatullah; Ji, Xiuhong; Zhang, Junzeng; Mills, Aaron A. S.; Critchley, Alan T.; Prithiviraj, Balakrishnan

    2011-01-01

    Carrageenans are a collective family of linear, sulphated galactans found in a number of commercially important species of marine red alga. These polysaccharides are known to elicit defense responses in plant and animals and possess anti-viral properties. We investigated the effect of foliar application of ι-, κ- and λ-carrageenans (representing various levels of sulphation) on Arabidopsis thaliana in resistance to the generalist insect Trichoplusia ni (cabbage looper) which is known to cause serious economic losses in crop plants. Plants treated with ι- and κ-carrageenan showed reduced leaf damage, whereas those treated with λ- carrageenan were similar to that of the control. In a no-choice test, larval weight was reduced by more than 20% in ι- and κ- carrageenan treatments, but unaffected by λ-carrageenan. In multiple choice tests, carrageenan treated plants attracted fewer T. ni larvae by the fourth day following infestation as compared to the control. The application of carrageenans did not affect oviposition behaviour of T. ni. Growth of T. ni feeding on an artificial diet amended with carrageenans was not different from that fed with untreated control diet. ι-carrageenan induced the expression of defense genes; PR1, PDF1.2, and TI1, but κ- and λ-carrageenans did not. Besides PR1, PDF1.2, and TI1, the indole glucosinolate biosynthesis genes CYP79B2, CYP83B1 and glucosinolate hydrolysing QTL, ESM1 were up-regulated by ι-carrageenan treatment at 48 h post infestation. Gas chromatography-mass spectrometry analysis of carrageenan treated leaves showed increased concentrations of both isothiocyanates and nitriles. Taken together, these results show that carrageenans have differential effects on Arabidopsis resistance to T. ni and that the degree of sulphation of the polysaccharide chain may well mediate this effect. PMID:22046375

  16. The polysaccharide from Tamarindus indica (TS-polysaccharide) protects cultured corneal-derived cells (SIRC cells) from ultraviolet rays.

    PubMed

    Raimondi, L; Lodovici, M; Guglielmi, F; Banchelli, G; Ciuffi, M; Boldrini, E; Pirisino, R

    2003-03-01

    The aim of this work was to investigate the possible protective effect of a new viscosising agent, TS-polysaccharide, on corneal-derived cells (SIRC) exposed to ultraviolet-B rays. To verify this, SIRC cells were first exposed, in the absence or in the presence of TS-polysaccharide (1% w/v), for 9 s at the UV-B source and then post-incubated for 45 min at 37 degrees C. After this period the hydrogen peroxide (H(2)O(2)) accumulated in the medium and the concentration of 8-hydroxy-2'-deoxy-guanosine (8-OHdG) in cell DNA was measured. In addition, the amount of (3)H-methyl-thymidine incorporated in cellular DNA was evaluated after 18 h from irradiation. Our results show that cells exposed to UV-B rays accumulate H(2)O(2), and have higher levels of 8OHdG and a lower amount of (3)H-methyl-thymidine incorporated in DNA than control cells. In the presence of TS-polysaccharide, the H(2)O(2) and 8-OHdG accumulation, and the (3)H-methyl-thymidine incorporation were significantly reduced with respect to the values measured in cells exposed in the absence of the polysaccharide. We propose a protective role of the polysaccharide in reducing UV-B derived DNA damage to eye cells. This finding could be of some clinical importance when the polysaccharide is used as a delivery system for ophthalmic preparations.

  17. Behavior of Leaf Meristems and Their Modification

    PubMed Central

    Ichihashi, Yasunori; Tsukaya, Hirokazu

    2015-01-01

    A major source of diversity in flowering plant form is the extensive variability of leaf shape and size. Leaf formation is initiated by recruitment of a handful of cells flanking the shoot apical meristem (SAM) to develop into a complex three-dimensional structure. Leaf organogenesis depends on activities of several distinct meristems that are established and spatiotemporally differentiated after the initiation of leaf primordia. Here, we review recent findings in the gene regulatory networks that orchestrate leaf meristem activities in a model plant Arabidopsis thaliana. We then discuss recent key studies investigating the natural variation in leaf morphology to understand how the gene regulatory networks modulate leaf meristems to yield a substantial diversity of leaf forms during the course of evolution. PMID:26648955

  18. Spectral reflectance relationships to leaf water stress

    NASA Technical Reports Server (NTRS)

    Ripple, William J.

    1986-01-01

    Spectral reflectance data were collected from detached snapbean leaves in the laboratory with a multiband radiometer. Four experiments were designed to study the spectral response resulting from changes in leaf cover, relative water content of leaves, and leaf water potential. Spectral regions included in the analysis were red (630-690 nm), NIR (760-900 nm), and mid-IR (2.08-2.35 microns). The red and mid-IR bands showed sensitivity to changes in both leaf cover and relative water content of leaves. The NIR was only highly sensitive to changes in leaf cover. Results provided evidence that mid-IR reflectance was governed primarily by leaf moisture content, although soil reflectance was an important factor when leaf cover was less than 100 percent. High correlations between leaf water potentials and reflectance were attributed to covariances with relative water content of leaves and leaf cover.

  19. An Innovative Way to Monitor Leaf Age

    NASA Astrophysics Data System (ADS)

    Garnello, A.; Paredes, K.; Trinh, U.; Saleska, S. R.; Wu, J.

    2013-12-01

    Anthony John Garnello, Karina Paredes, Uyen Khanh Ho Trinh, Jin Wu, Scott Saleska Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA Abstract: Leaf age is an important characteristic for controlling plant functional performance and is associated with the changes of leaf physical, chemical, and physiological properties. Understanding how plant physiology changes over time will allow more accurate predictions of growth patterns, and a more comprehensive understanding of vegetative life histories. There still lacks an efficient technique in monitoring leaf age, tagging leaves is still the only way to accurately monitor leaf age. The goal of this study is to develop a multi-metric, accurate technique for better monitoring of leaf age. In order to acquire true leaf age records, 10 individual plant species were selected at the University of Arizona campus, and newly flushing leaves were tagged and monitored during the Monsoon season (from early June, 2013, to mid October, 2013). Every 2 weeks, 10 to 15 leaves in relative age order were harvested from each 1-meter branch to measure multiple key leaf metrics, including leaf thickness (via micrometer), fresh and dry weight, fresh and dry area (via ImageJ software), and leaf hyperspectral reflectance (via a handheld ASD Field Pro). Other leaf traits were also derived from our measurements, such as specific leaf area (SLA), leaf density (fresh weight/leaf volume), water percentage, and shrinkage ratio (1-dry area/fresh area). The hyperspectral version of vegetation index (a ratio derived from two spectral channels) was generated for each branch sample, by randomly selecting two channels from within the spectral domain of 350 nm to 2500 nm. The preliminary result documents three types of hyperspectral vegetation index (VI) which are highly related with leaf relative age order (R2>0.9). These include the sensitive spectral domains correlated with (a) leaf pigments (~550nm) and leaf physical

  20. Hypoglycemic Effects of Crude Polysaccharide from Purslane

    PubMed Central

    Gong, Fayong; Li, Fenglin; Zhang, Lili; Li, Jing; Zhang, Zhong; Wang, Guangyao

    2009-01-01

    The effects of crude polysaccharide from Purslane (CPP) on body weight (bw), blood glucose, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), triglyceride (TG) and serum insulin levels were studied in diabetes mellitus mice. CPP treatment (200, 400 mg/kg bw) for 28 days resulted in a significant decrease in the concentrations of fasting blood glucose (FBG), TC and TG. Furthermore, CPP significantly increased the concentration of HDL-c, body weight and serum insulin level in the mice. In addition, according to acute toxicity studies and single cell gel electrophoresis analysis, CPP did not produce any physical or behavioral signs of toxicity. More significantly, our data demonstrated CPP exhibited the best effects at the dose of 400 mg/kg bw. The above results suggest that CPP can control blood glucose and modulate the metabolism of glucose and blood lipids in diabetes mellitus mice, so we conclude that CPP should be evaluated as a candidate for future studies on diabetes mellitus. PMID:19399226

  1. Immunomodulatory Polysaccharide from Chlorophytum borivilianum Roots

    PubMed Central

    Thakur, Mayank; Connellan, Paul; Deseo, Myrna A.; Morris, Carol; Dixit, Vinod K.

    2011-01-01

    Chlorophytum borivilianum Santapau & Fernandes (Liliaceae) is an ayurvedic Rasayana herb with immunostimulating properties. The polysaccharide fraction (CBP) derived from hot water extraction of C. borivilianum (CB), comprising of ∼31% inulin-type fructans and ∼25% acetylated mannans (of hot water-soluble extract), was evaluated for its effect on natural killer (NK) cell activity (in vitro). Human peripheral blood mononuclear cells (PBMCs), isolated from whole blood on a Ficoll-Hypaque density gradient, were tested in the presence or absence of varying concentrations of each C. borivilianum fraction for modulation of NK cell cytotoxic activity toward K562 cells. Preliminary cytotoxicity evaluation against P388 cells was performed to establish non-cytotoxic concentrations of the different fractions. Testing showed the observed significant stimulation of NK cell activity to be due to the CBP of C. borivilianum. Furthermore, in vivo evaluation carried out on Wistar strain albino rats for humoral response to sheep red blood cells (SRBCs) and immunoglobulin-level determination using enzyme-linked immunosorbent assay (ELISA), exhibited an effectiveness of C. borivilianum aqueous extract in improving immune function. Present results provide useful information for understanding the role of CBP in modulating immune function. PMID:21792363

  2. Molecular investigations of flaxseed mucilage polysaccharides.

    PubMed

    Roulard, Romain; Petit, Emmanuel; Mesnard, François; Rhazi, Larbi

    2016-05-01

    The molecular properties of flaxseed mucilage were determined using a multi-angle laser light scattering (MALLS) detector coupled on-line to size exclusion chromatography (SEC) and asymmetric flow field-flow fractionation (AF4). Water and salt solution were tested as mobile phases. The SEC-MALLS method gave partial information and enabled molecular characterization of disaggregated mucilage molecules. Regardless of the eluent used, the observed Mw ranged from about 1.6 × 10(6) to more than 10 × 10(6) g/mol for mucilage polysaccharides. The AF4-MALLS system enabled a complete analysis of mucilage carbohydrate aggregates in water, in which two populations were satisfactorily separated. The molecular weight distribution (MWD) of molecules ranged from 1.5 × 10(6) to more than 4 × 10(8) g/mol. Experiments showed that the conformational structure of mucilage molecules was strongly influenced by ionic strength. Mucilage carbohydrates exhibited a spherical and compact structure in NaCl solution while they displayed a random-coil conformation in water. PMID:26851358

  3. Extracellular polysaccharide production by thraustochytrid protists.

    PubMed

    Jain, Ruchi; Raghukumar, Seshagiri; Tharanathan, R; Bhosle, N B

    2005-01-01

    Four strains of marine stramenopilan protists, the thraustochytrids, were studied for their ability to produce extracellular polysaccharides (EPSs). Observations by light and scanning electron microscopy revealed the production of a matrix of EPS around groups of cells in stationary cultures. EPS in shake culture filtrates ranged from 0.3 to 1.1 g/L. EPS production, which was studied in greater detail in 2 isolates, SC-1 and CW1, increased with age of cultures, reaching a peak in the stationary phase. Anion exchange chromatography yielded a single fraction of the EPS of both species. The EPS contained 39% to 53% sugars, besides proteins, lipids, uronic acids, and sulfates. Molecular weight of the EPS produced by SC-1 was approximately 94 kDa, and that of CW1, 320 kDa. Glucose formed the major component in the EPS of both isolates-galactose, mannose, and arabinose being the other components. Cultures of both isolates survived air-drying up to a period of 96 hours, suggesting a role for EPS in preventing desiccation of cells.

  4. Molecular investigations of flaxseed mucilage polysaccharides.

    PubMed

    Roulard, Romain; Petit, Emmanuel; Mesnard, François; Rhazi, Larbi

    2016-05-01

    The molecular properties of flaxseed mucilage were determined using a multi-angle laser light scattering (MALLS) detector coupled on-line to size exclusion chromatography (SEC) and asymmetric flow field-flow fractionation (AF4). Water and salt solution were tested as mobile phases. The SEC-MALLS method gave partial information and enabled molecular characterization of disaggregated mucilage molecules. Regardless of the eluent used, the observed Mw ranged from about 1.6 × 10(6) to more than 10 × 10(6) g/mol for mucilage polysaccharides. The AF4-MALLS system enabled a complete analysis of mucilage carbohydrate aggregates in water, in which two populations were satisfactorily separated. The molecular weight distribution (MWD) of molecules ranged from 1.5 × 10(6) to more than 4 × 10(8) g/mol. Experiments showed that the conformational structure of mucilage molecules was strongly influenced by ionic strength. Mucilage carbohydrates exhibited a spherical and compact structure in NaCl solution while they displayed a random-coil conformation in water.

  5. Analysis of Circadian Leaf Movements.

    PubMed

    Müller, Niels A; Jiménez-Gómez, José M

    2016-01-01

    The circadian clock is a molecular timekeeper that controls a wide variety of biological processes. In plants, clock outputs range from the molecular level, with rhythmic gene expression and metabolite content, to physiological processes such as stomatal conductance or leaf movements. Any of these outputs can be used as markers to monitor the state of the circadian clock. In the model plant Arabidopsis thaliana, much of the current knowledge about the clock has been gained from time course experiments profiling expression of endogenous genes or reporter constructs regulated by the circadian clock. Since these methods require labor-intensive sample preparation or transformation, monitoring leaf movements is an interesting alternative, especially in non-model species and for natural variation studies. Technological improvements both in digital photography and image analysis allow cheap and easy monitoring of circadian leaf movements. In this chapter we present a protocol that uses an autonomous point and shoot camera and free software to monitor circadian leaf movements in tomato. PMID:26867616

  6. The Anti-Oxidant and Antitumor Properties of Plant Polysaccharides.

    PubMed

    Jiao, Rui; Liu, Yingxia; Gao, Hao; Xiao, Jia; So, Kwok Fai

    2016-01-01

    Oxidative stress has been increasingly recognized as a major contributing factor in a variety of human diseases, from inflammation to cancer. Although certain parts of signaling pathways are still under investigation, detailed molecular mechanisms for the induction of diseases have been elucidated, especially the link between excessive oxygen reactive species (ROS) damage and tumorigenesis. Emerging evidence suggests anti-oxidant therapy can play a key role in treating those diseases. Among potential drug resources, plant polysaccharides are natural anti-oxidant constituents important for human health because of their long history in ethnopharmacology, wide availability and few side effects upon consumption. Plant polysaccharides have been shown to possess anti-oxidant, anti-inflammation, cell viability promotion, immune-regulation and antitumor functions in a number of disease models, both in laboratory studies and in the clinic. In this paper, we reviewed the research progress of signaling pathways involved in the initiation and progression of oxidative stress- and cancer-related diseases in humans. The natural sources, structural properties and biological actions of several common plant polysaccharides, including Lycium barbarum, Ginseng, Zizyphus Jujuba, Astragalus lentiginosus, and Ginkgo biloba are discussed in detail, with emphasis on their signaling pathways. All of the mentioned common plant polysaccharides have great potential to treat oxidative stress and cancinogenic disorders in cell models, animal disease models and clinical cases. ROS-centered pathways (e.g. mitochondrial autophagy, MAPK and JNK) and transcription factor-related pathways (e.g. NF-[Formula: see text]B and HIF) are frequently utilized by these polysaccharides with or without the further involvement of inflammatory and death receptor pathways. Some of the polysaccharides may also influence tumorigenic pathways, such as Wnt and p53 to play their anti-tumor roles. In addition, current

  7. LEAF: A Microcomputer Program for Constructing the Tukey Stem and Leaf Graph.

    ERIC Educational Resources Information Center

    Pascale, Pietro J.; Smith, Joseph

    1986-01-01

    This paper presents a BASIC microcomputer program that constructs the Tukey (1977) stem and leaf graph. Options within the LEAF program include a modified stem and leaf where the stem is split and a parallel stem and leaf graph where two separate sets of data are displayed from a common stem. (Author)

  8. 7 CFR 29.2529 - Leaf scrap.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2529 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole...

  9. 7 CFR 29.3034 - Leaf scrap.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco...

  10. 7 CFR 29.3526 - Leaf scrap.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from...

  11. 7 CFR 29.6022 - Leaf scrap.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap...

  12. 7 CFR 29.3035 - Leaf structure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Leaf structure. The cell development of a leaf as indicated by its porosity or solidity. (See Elements... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf structure. 29.3035 Section 29.3035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  13. 7 CFR 29.3527 - Leaf structure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Type 95) § 29.3527 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.3527 Section 29.3527 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  14. 7 CFR 29.3035 - Leaf structure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Leaf structure. The cell development of a leaf as indicated by its porosity or solidity. (See Elements... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf structure. 29.3035 Section 29.3035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  15. 7 CFR 29.1030 - Leaf structure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Type 92) § 29.1030 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf structure. 29.1030 Section 29.1030 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  16. 7 CFR 29.6023 - Leaf structure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by its... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  17. 7 CFR 29.3527 - Leaf structure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Type 95) § 29.3527 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf structure. 29.3527 Section 29.3527 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  18. 7 CFR 29.1030 - Leaf structure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Type 92) § 29.1030 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.1030 Section 29.1030 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  19. 7 CFR 29.3527 - Leaf structure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Type 95) § 29.3527 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf structure. 29.3527 Section 29.3527 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  20. 7 CFR 29.6023 - Leaf structure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by its... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  1. 7 CFR 29.6023 - Leaf structure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by its... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  2. 7 CFR 29.1030 - Leaf structure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Type 92) § 29.1030 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf structure. 29.1030 Section 29.1030 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  3. 7 CFR 29.6023 - Leaf structure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by its... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  4. 7 CFR 29.1030 - Leaf structure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Type 92) § 29.1030 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf structure. 29.1030 Section 29.1030 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  5. 7 CFR 29.3035 - Leaf structure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Leaf structure. The cell development of a leaf as indicated by its porosity or solidity. (See Elements... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf structure. 29.3035 Section 29.3035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  6. 7 CFR 29.3527 - Leaf structure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Type 95) § 29.3527 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf structure. 29.3527 Section 29.3527 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  7. 7 CFR 29.3035 - Leaf structure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Leaf structure. The cell development of a leaf as indicated by its porosity or solidity. (See Elements... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf structure. 29.3035 Section 29.3035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  8. 7 CFR 29.3035 - Leaf structure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Leaf structure. The cell development of a leaf as indicated by its porosity or solidity. (See Elements... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.3035 Section 29.3035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  9. 7 CFR 29.3527 - Leaf structure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Type 95) § 29.3527 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf structure. 29.3527 Section 29.3527 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  10. 7 CFR 29.6023 - Leaf structure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by its... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  11. 7 CFR 29.1030 - Leaf structure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Type 92) § 29.1030 Leaf structure. The cell development of a leaf as indicated by its porosity. (See... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf structure. 29.1030 Section 29.1030 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  12. Adjuvanticity of compound astragalus polysaccharide and sulfated epimedium polysaccharide per os.

    PubMed

    Chen, Xingying; Chen, Xiaolan; Qiu, Shulei; Hu, Yuanliang; Wang, Deyun; Liu, Xu; Zhao, Xiaojuan; Liu, Cui; Chen, Xinghui

    2013-11-01

    On the basis of previous researches, compound astragalus polysaccharide (APS) and sulfated epimedium polysaccharide (sEPS) oral liquid (AEO) was prepared. Three hundred and twenty 14-day-old chickens were randomly assigned into eight groups and vaccinated with ND vaccine except for blank control (BC) group, repeated vaccination at 28 days old. At the same time of each vaccination, the chickens in three experimental groups were taken orally with AEO, respectively, at three doses, in two component control groups with APS and sEPS, once a day for three successive days; in injection control group were injected with AEI once, and in vaccination control (VC) and BC groups were not administrated. On days 7, 14, 21, 28 and 35 after the first vaccination, peripheral lymphocyte proliferation, the serum antibody titer, IFN-γ and IL-2 concentrations and on day 35 immune organ index were measured. The results showed that AEO at high and medium doses could significantly promote lymphocyte proliferation and development of immune organ, enhance antibody titer and IFN-γ and IL-2 concentration, which was stronger than actions of AEI and two components. The results confirmed that AEO possessed reliable immunoenhancement and could be exploited into an oral immunopotentiator.

  13. Comparison of half and full-leaf shape feature extraction for leaf classification

    NASA Astrophysics Data System (ADS)

    Sainin, Mohd Shamrie; Ahmad, Faudziah; Alfred, Rayner

    2016-08-01

    Shape is the main information for leaf feature that most of the current literatures in leaf identification utilize the whole leaf for feature extraction and to be used in the leaf identification process. In this paper, study of half-leaf features extraction for leaf identification is carried out and the results are compared with the results obtained from the leaf identification based on a full-leaf features extraction. Identification and classification is based on shape features that are represented as cosines and sinus angles. Six single classifiers obtained from WEKA and seven ensemble methods are used to compare their performance accuracies over this data. The classifiers were trained using 65 leaves in order to classify 5 different species of preliminary collection of Malaysian medicinal plants. The result shows that half-leaf features extraction can be used for leaf identification without decreasing the predictive accuracy.

  14. 7 CFR 29.1162 - Leaf (B Group).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Specifications, and Tolerances B1L—Choice Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil... percent. B2L—Fine Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil, deep color.... B3L—Good Quality Lemon Leaf Ripe, firm leaf structure, medium body, oily, strong color...

  15. 7 CFR 29.1162 - Leaf (B Group).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Specifications, and Tolerances B1L—Choice Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil... percent. B2L—Fine Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil, deep color.... B3L—Good Quality Lemon Leaf Ripe, firm leaf structure, medium body, oily, strong color...

  16. 7 CFR 29.1162 - Leaf (B Group).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Specifications, and Tolerances B1L—Choice Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil... percent. B2L—Fine Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil, deep color.... B3L—Good Quality Lemon Leaf Ripe, firm leaf structure, medium body, oily, strong color...

  17. 7 CFR 29.1162 - Leaf (B Group).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Specifications, and Tolerances B1L—Choice Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil... percent. B2L—Fine Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil, deep color.... B3L—Good Quality Lemon Leaf Ripe, firm leaf structure, medium body, oily, strong color...

  18. 7 CFR 29.1162 - Leaf (B Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Specifications, and Tolerances B1L—Choice Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil... percent. B2L—Fine Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil, deep color.... B3L—Good Quality Lemon Leaf Ripe, firm leaf structure, medium body, oily, strong color...

  19. Isolation of high quality and polysaccharide-free DNA from leaves of Dimorphandra mollis (Leguminosae), a tree from the Brazilian Cerrado.

    PubMed

    Souza, H A V; Muller, L A C; Brandão, R L; Lovato, M B

    2012-03-22

    Dimorphandra mollis (Leguminosae), known as faveiro and fava d'anta, is a tree that is widely distributed throughout the Brazilian Cerrado (a savanna-like biome). This species is economically valuable and has been extensively exploited because its fruits contain the flavonoid rutin, which is used to produce medications for human circulatory diseases. Knowledge about its genetic diversity is needed to guide decisions about the conservation and rational use of this species in order to maintain its diversity. DNA extraction is an essential step for obtaining good results in a molecular analysis. However, DNA isolation from plants is usually compromised by excessive contamination by secondary metabolites. DNA extraction of D. mollis, mainly from mature leaves, results in a highly viscous mass that is difficult to handle and use in techniques that require pure DNA. We tested four protocols for plant DNA extraction that can be used to minimize problems such as contamination by polysaccharides, which is more pronounced in material from mature leaves. The protocol that produced the best DNA quality initially utilizes a sorbitol buffer to remove mucilaginous polysaccharides. The macerated leaf material is washed with this buffer until there is no visible mucilage in the sample. This protocol is adequate for DNA extraction both from young and mature leaves, and could be useful not only for D. mollis but also for other species that have high levels of polysaccharide contamination during the extraction process.

  20. Extraction, purification and elicitor activities of polysaccharides from Chrysanthemum indicum.

    PubMed

    Du, Ningning; Tian, Wei; Zheng, Dongfang; Zhang, Xinyi; Qin, Pinyan

    2016-01-01

    Polysaccharides isolated from Chrysanthemum indicum were studied for their pathogen-derived resistance against Sclerotium rolfsii sacc in Atractylodis maceocephalae koidz. The total sugar content and monosaccharide analysis were determined by phenol-sulfuric acid method and gas chromatography, and infrared spectroscopy performed for simple structure information. The activities of CAT and POD as protective enzymes in A. maceocephalae leaves were evaluated. The purified polysaccharides exhibited strong CAT and POD activities in inoculated with S. rolfsii in A. macrocephala leaves, attained the maximum value 568.3 Ug(-1)min(-1) and 604.4 Ug(-1)min(-1)respectively. Whereas, when compared with the control plants, 20mg/ml purified polysaccharides exhibited the strongest CAT and POD activities. Notably, the treatments of A. macepcephalae seedlings with C. indicum polysaccharides (CIP) decreased disease index development caused by S. rolfsii. The disease index after 10 days was significantly reduced when the seedlings treated with 20mg/ml CIP, 4.41 compared to the control plants 32.00. Given together, these results indicated that purified polysaccharides derived from C. indicum may be useful as a natural inducer. PMID:26562553

  1. Masquerading microbial pathogens: Capsular polysaccharides mimic host-tissue molecules

    PubMed Central

    Cress, Brady F.; Englaender, Jacob A.; He, Wenqin; Kasper, Dennis; Linhardt, Robert J.; Koffas, Mattheos A. G.

    2014-01-01

    Summary Bacterial pathogens bearing capsular polysaccharides identical to mammalian glycans benefit from an additional level of protection from host immune response. The increasing prevalence of antibiotic resistant bacteria portends an impending post-antibiotic age, characterized by diminishing efficacy of common antibiotics and routine application of multifaceted, complementary therapeutic approaches to treat bacterial infections, particularly multidrug-resistant organisms. The first line of defense for most bacterial pathogens consists of a physical and immunological barrier known as the capsule, commonly composed of a viscous layer of carbohydrates that are covalently bound to the cell wall in Gram-positive bacteria or often to lipids of the outer membrane in many Gram-negative bacteria. Bacterial capsular polysaccharides are a diverse class of high molecular weight polysaccharides contributing to virulence of many human pathogens in the gut, respiratory tree, urinary tract, and other host tissues, by hiding cell-surface components that might otherwise elicit host immune response. This review highlights capsular polysaccharides that are structurally identical or similar to polysaccharides found in mammalian tissues, including polysialic acid and glycosaminoglycan capsules hyaluronan, heparosan, and chondroitin. Such non-immunogenic coatings render pathogens insensitive to certain immune responses, effectively increasing residence time in host tissues and enabling pathologically relevant population densities to be reached. Biosynthetic pathways and capsular involvement in immune system evasion are described providing a basis for potential therapies aimed at supplementing or replacing antibiotic treatment. PMID:24372337

  2. Aspergillus Enzymes Involved in Degradation of Plant Cell Wall Polysaccharides

    PubMed Central

    de Vries, Ronald P.; Visser, Jaap

    2001-01-01

    Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes. Enzymatic degradation of these polymers has received attention for many years and is becoming a more and more attractive alternative to chemical and mechanical processes. Over the past 15 years, much progress has been made in elucidating the structural characteristics of these polysaccharides and in characterizing the enzymes involved in their degradation and the genes of biotechnologically relevant microorganisms encoding these enzymes. The members of the fungal genus Aspergillus are commonly used for the production of polysaccharide-degrading enzymes. This genus produces a wide spectrum of cell wall-degrading enzymes, allowing not only complete degradation of the polysaccharides but also tailored modifications by using specific enzymes purified from these fungi. This review summarizes our current knowledge of the cell wall polysaccharide-degrading enzymes from aspergilli and the genes by which they are encoded. PMID:11729262

  3. Crosslinked ionic polysaccharides for stimuli-sensitive drug delivery.

    PubMed

    Alvarez-Lorenzo, Carmen; Blanco-Fernandez, Barbara; Puga, Ana M; Concheiro, Angel

    2013-08-01

    Polysaccharides are gaining increasing attention as components of stimuli-responsive drug delivery systems, particularly since they can be obtained in a well characterized and reproducible way from the natural sources. Ionic polysaccharides can be readily crosslinked to render hydrogel networks sensitive to a variety of internal and external variables, and thus suitable for switching drug release on-off through diverse mechanisms. Hybrids, composites and grafted polymers can reinforce the responsiveness and widen the range of stimuli to which polysaccharide-based systems can respond. This review analyzes the state of the art of crosslinked ionic polysaccharides as components of delivery systems that can regulate drug release as a function of changes in pH, ion nature and concentration, electric and magnetic field intensity, light wavelength, temperature, redox potential, and certain molecules (enzymes, illness markers, and so on). Examples of specific applications are provided. The information compiled demonstrates that crosslinked networks of ionic polysaccharides are suitable building blocks for developing advanced externally activated and feed-back modulated drug delivery systems.

  4. Chemical studies on the polysaccharides of Salicornia brachiata.

    PubMed

    Sanandiya, Naresh D; Siddhanta, A K

    2014-11-01

    A group of 12 polysaccharide extracts were prepared from the tips, stem and roots of an Indian halophyte Salicornia brachiata Roxb. obtained by sequential extractions with cold water (CW), hot water (HW), aqueous ammonium oxalate (OX) and aqueous sodium hydroxide (ALK) solutions. Monosaccharide composition analysis revealed that all the polysaccharide extract samples consisted primarily of rhamnose, arabinose, mannose, galactose, glucose, whereas ribose and xylose were present only in some of the extracts. All the extracts exhibited low apparent viscosity (1.47-2.02 cP) and sulphate and contained no prominent toxic metal ions. Fucose was detected only in OX extract of the roots. These polysaccharides were found to be heterogeneous and highly branched (glycoside linkage analysis, size-exclusion chromatography, (13)C-NMR, FT-IR, circular dichroism and optical rotation data). Physico-chemical analyses of these polysaccharides including uronic acid, sulphate and protein contents were also carried out. This constitutes the first report on the profiling of Salicornia polysaccharides.

  5. Rapid bacterial degradation of polysaccharides in anoxic marine systems

    SciTech Connect

    Arnosti, C.; Repeta, D.J.; Blough, N.V. )

    1994-06-01

    Extracellular hydrolysis of organic macromolecules is often assumed to be the slow step in remineralization of organic matter. The authors tested this assumption by comparing the degradation of four polysaccharides (pullulan, laminarin, and two polysaccharides isolated from the marine cyanobacterium Synechococcus WH7335) to determine whether size, linkage position, or anomeric linkage affected rates or mechanisms of carbohydrate degradation by mixed cultures of anaerobic bacteria enriched from marine sediments. Gel permeation chromatography and nuclear magnetic resonance spectroscopy (NMR) were used to follow the extracellular conversion of high molecular weight polysaccharides to lower molecular weight polysaccharides and oligosaccharides which were subsequently remineralized. In all cases, substrate degradation was rapid. NMR spectra showed that preferential hydrolysis occurred at specific chemical linkages, and extracellular enzymatic hydrolysis of polysaccharides occurred far more rapidly than bacterial uptake and remineralization of the lower molecular weight oligosaccharides produced through enzymatic hydrolysis. Substrate size was not a significant determinant of remineralization rate: High molecular weight does not always correlate with slow degradation rate. The hypothesis that extracellular enzymatic hydrolysis is a slow step in the degradation of macromolecular organic matter in marine systems needs to be critically re-examined.

  6. Hot-compressed water extraction of polysaccharides from soy hulls.

    PubMed

    Liu, Hua-Min; Wang, Fei-Yun; Liu, Yu-Lan

    2016-07-01

    The polysaccharides of soy hulls were extracted by hot-compressed water at temperatures of 110 from 180°C and various treatment times (10-150min) in a batch system. It was determined that a moderate temperature and short time are suitable for the preparation of polysaccharides. The structure of xylan and the inter- and intra-chain hydrogen bonding of cellulose fibrils in the soy hulls were not significantly broken down. The polysaccharides obtained were primarily composed of α-L-arabinofuranosyl units, 4-O-methyl-glucuronic acid units and α-D-galactose units attached with substituted units. A sugar analysis indicated that arabinose was the major component, constituting 35.6-46.9% of the polysaccharide products extracted at 130°C, 140°C, and 150°C. This investigation contributes to the knowledge of the polysaccharides of soy by-products, which can reduce the environmental impact of waste from the food industries. PMID:26920272

  7. Leaf physiognomy and climate: A multivariate analysis

    NASA Astrophysics Data System (ADS)

    Davis, J. M.; Taylor, S. E.

    1980-11-01

    Research has demonstrated that leaf physiognomy is representative of the local or microclimate conditions under which plants grow. The physiognomy of leaf samples from Oregon, Michigan, Missouri, Tennessee, and the Panama Canal Zone has been related to the microclimate using Walter diagrams and Thornthwaite water-budget data. A technique to aid paleoclimatologists in identifying the nature of the microclimate from leaf physiognomy utilizes statistical procedures to classify leaf samples into one of six microclimate regimes based on leaf physiognomy information available from fossilized samples.

  8. Hormonal regulation of leaf senescence in Lilium.

    PubMed

    Arrom, Laia; Munné-Bosch, Sergi

    2012-10-15

    In addition to floral senescence and longevity, the control of leaf senescence is a major factor determining the quality of several cut flowers, including Lilium, in the commercial market. To better understand the physiological process underlying leaf senescence in this species, we evaluated: (i) endogenous variation in the levels of phytohormones during leaf senescence, (ii) the effects of leaf darkening in senescence and associated changes in phytohormones, and (iii) the effects of spray applications of abscisic acid (ABA) and pyrabactin on leaf senescence. Results showed that while gibberellin 4 (GA(4)) and salicylic acid (SA) contents decreased, that of ABA increased during the progression of leaf senescence. However, dark-induced senescence increased ABA levels, but did not affect GA(4) and SA levels, which appeared to correlate more with changes in air temperature and/or photoperiod than with the induction of leaf senescence. Furthermore, spray applications of pyrabactin delayed the progression of leaf senescence in cut flowers. Thus, we conclude that (i) ABA plays a major role in the regulation of leaf senescence in Lilium, (ii) darkness promotes leaf senescence and increases ABA levels, and (iii) exogenous applications of pyrabactin inhibit leaf senescence in Lilium, therefore suggesting that it acts as an antagonist of ABA in senescing leaves of cut lily flowers. PMID:22854182

  9. Hormonal regulation of leaf senescence in Lilium.

    PubMed

    Arrom, Laia; Munné-Bosch, Sergi

    2012-10-15

    In addition to floral senescence and longevity, the control of leaf senescence is a major factor determining the quality of several cut flowers, including Lilium, in the commercial market. To better understand the physiological process underlying leaf senescence in this species, we evaluated: (i) endogenous variation in the levels of phytohormones during leaf senescence, (ii) the effects of leaf darkening in senescence and associated changes in phytohormones, and (iii) the effects of spray applications of abscisic acid (ABA) and pyrabactin on leaf senescence. Results showed that while gibberellin 4 (GA(4)) and salicylic acid (SA) contents decreased, that of ABA increased during the progression of leaf senescence. However, dark-induced senescence increased ABA levels, but did not affect GA(4) and SA levels, which appeared to correlate more with changes in air temperature and/or photoperiod than with the induction of leaf senescence. Furthermore, spray applications of pyrabactin delayed the progression of leaf senescence in cut flowers. Thus, we conclude that (i) ABA plays a major role in the regulation of leaf senescence in Lilium, (ii) darkness promotes leaf senescence and increases ABA levels, and (iii) exogenous applications of pyrabactin inhibit leaf senescence in Lilium, therefore suggesting that it acts as an antagonist of ABA in senescing leaves of cut lily flowers.

  10. Polysaccharide-Based Membranes in Food Packaging Applications.

    PubMed

    Ferreira, Ana R V; Alves, Vítor D; Coelhoso, Isabel M

    2016-01-01

    Plastic packaging is essential nowadays. However, the huge environmental problem caused by landfill disposal of non-biodegradable polymers in the end of life has to be minimized and preferentially eliminated. The solution may rely on the use of biopolymers, in particular polysaccharides. These macromolecules with film-forming properties are able to produce attracting biodegradable materials, possibly applicable in food packaging. Despite all advantages of using polysaccharides obtained from different sources, some drawbacks, mostly related to their low resistance to water, mechanical performance and price, have hindered their wider use and commercialization. Nevertheless, with increasing attention and research on this field, it has been possible to trace some strategies to overcome the problems and recognize solutions. This review summarizes some of the most used polysaccharides in food packaging applications. PMID:27089372

  11. Marine Polysaccharides from Algae with Potential Biomedical Applications

    PubMed Central

    de Jesus Raposo, Maria Filomena; de Morais, Alcina Maria Bernardo; de Morais, Rui Manuel Santos Costa

    2015-01-01

    There is a current tendency towards bioactive natural products with applications in various industries, such as pharmaceutical, biomedical, cosmetics and food. This has put some emphasis in research on marine organisms, including macroalgae and microalgae, among others. Polysaccharides with marine origin constitute one type of these biochemical compounds that have already proved to have several important properties, such as anticoagulant and/or antithrombotic, immunomodulatory ability, antitumor and cancer preventive, antilipidaemic and hypoglycaemic, antibiotics and anti-inflammatory and antioxidant, making them promising bioactive products and biomaterials with a wide range of applications. Their properties are mainly due to their structure and physicochemical characteristics, which depend on the organism they are produced by. In the biomedical field, the polysaccharides from algae can be used in controlled drug delivery, wound management, and regenerative medicine. This review will focus on the biomedical applications of marine polysaccharides from algae. PMID:25988519

  12. [Discussion on polysaccharide determination methods in new Chinese drug research].

    PubMed

    Li, Ji-Ping

    2014-09-01

    According to existing problems in polysaccharide determination methods in new Chinese drug applications, the method suitability, chemical reference selection, components interference and method research were introduced. The author suggests that suitable determination method should be selected according to the structure and property of the polysaccharide, and validated. Some influent factors should be examined to assure the accuracy of the method, such as the stability and using amount of the visualizing reagent, visualizing time, maximum detection wavelength etc. Monosaccharide and other water soluble components should be removed from polysaccharide sample, and suitable reference substance and detection wavelength should be selected. It should pay attention to mutual interference of neutral and acidic saccharide, and use inhibitor to eliminate the interference. Because the slopes of the standard curves are different for different monosaccharide, it is proposed that the types and ratios of the monosaccharide in heteroglycan should be understood, and mixed reference substance solution in the ratio is prepared for determination. PMID:25522636

  13. Antioxidant activity of herbal polysaccharides and cough reflex.

    PubMed

    Nosalova, G; Jurecek, L; Hromadkova, Z; Kostalova, Z; Sadlonova, V

    2013-01-01

    The extraction of Fallopia sachalinensis leaves resulted in two fractions (FS-1 and FS-2). Chemical and spectral analyses of samples revealed the prevalence of pectic polysaccharides with high galacturonic acid, arabinose, galactose, and rhamnose content. Arabinogalactan with a higher content of phenolic prevailed in the FS-1, whereas rhamnogalacturonan predominated in the FS-2 fraction. Both polysaccharides showed significant antioxidant activity according to DPPH and FRAP assays. Evaluation of antitussive activity in healthy adult conscious guinea pigs after oral application of 50 and 75 mg/kg of the FS-2 polysaccharide extracts showed a significant suppression of cough reflex, without an influence on specific airway resistance. The suppression of cough was comparable with that of codeine.

  14. Release of polysaccharide by sonication of cells ( Porphyridium sp.)

    NASA Astrophysics Data System (ADS)

    Faerman, V.; Mukmenev, I.; Shreiber, I.

    2009-03-01

    The paper deals with experimental data concerning the interaction of acoustical waves with microbial cell (Porphyridium sp.). The aim of the present paper was to increase the amount of biopolymer released from the microorganisms biomass with the aid ultrasound irradiation without scission or a decrease in the molecular weight. The results indicated that the amount of polysaccharide (for example) released from the cell pellet could be enhanced by ultrasound, depending on the frequency and energy of the ultrasound. The sugar composition remain the same, but the apparent viscosity of polysaccharide aqueous solutions decreased, indicated that some changes in the molecular shape and size occurred. When ultrasound irradiation was applied in the presence of either CO2 or CO2 + H2, the apparent viscosity of polysaccharide aqueous solutions increased (versus usual ultrasound treatment).

  15. Polysaccharide-Based Membranes in Food Packaging Applications.

    PubMed

    Ferreira, Ana R V; Alves, Vítor D; Coelhoso, Isabel M

    2016-01-01

    Plastic packaging is essential nowadays. However, the huge environmental problem caused by landfill disposal of non-biodegradable polymers in the end of life has to be minimized and preferentially eliminated. The solution may rely on the use of biopolymers, in particular polysaccharides. These macromolecules with film-forming properties are able to produce attracting biodegradable materials, possibly applicable in food packaging. Despite all advantages of using polysaccharides obtained from different sources, some drawbacks, mostly related to their low resistance to water, mechanical performance and price, have hindered their wider use and commercialization. Nevertheless, with increasing attention and research on this field, it has been possible to trace some strategies to overcome the problems and recognize solutions. This review summarizes some of the most used polysaccharides in food packaging applications.

  16. Designing Whey Protein-Polysaccharide Particles for Colloidal Stability.

    PubMed

    Wagoner, Ty; Vardhanabhuti, Bongkosh; Foegeding, E Allen

    2016-01-01

    Interactions between whey proteins and polysaccharides, in particular the formation of food-grade soluble complexes, are of interest because of potential functional and health benefits. A specific application that has not received much attention is the use of complexes for enhanced colloidal stability of protein sols, such as protein-containing beverages. In beverages, the primary goal is the formation of complexes that remain dispersed after thermal processing and extended storage. This review highlights recent progress in the area of forming whey protein-polysaccharide soluble complexes that would be appropriate for beverage applications. Research in this area indicates that soluble complexes can be formed and stabilized that are reasonably small in size and possess a large surface charge that would predict colloidal stability. Selection of specific proteins and polysaccharides can be tailored to desired conditions. The principal challenges involve overcoming restrictions on protein concentration and ensuring that protein remains bioavailable.

  17. Polysaccharide-Based Membranes in Food Packaging Applications

    PubMed Central

    Ferreira, Ana R. V.; Alves, Vítor D.; Coelhoso, Isabel M.

    2016-01-01

    Plastic packaging is essential nowadays. However, the huge environmental problem caused by landfill disposal of non-biodegradable polymers in the end of life has to be minimized and preferentially eliminated. The solution may rely on the use of biopolymers, in particular polysaccharides. These macromolecules with film-forming properties are able to produce attracting biodegradable materials, possibly applicable in food packaging. Despite all advantages of using polysaccharides obtained from different sources, some drawbacks, mostly related to their low resistance to water, mechanical performance and price, have hindered their wider use and commercialization. Nevertheless, with increasing attention and research on this field, it has been possible to trace some strategies to overcome the problems and recognize solutions. This review summarizes some of the most used polysaccharides in food packaging applications. PMID:27089372

  18. Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

    PubMed Central

    de Jesus Raposo, Maria Filomena; de Morais, Rui Manuel Santos Costa; de Morais, Alcina Maria Miranda Bernardo

    2013-01-01

    Marine microalgae have been used for a long time as food for humans, such as Arthrospira (formerly, Spirulina), and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The present review puts up-to-date the research on the biological activities and applications of polysaccharides, active biocompounds synthesized by marine unicellular algae, which are, most of the times, released into the surrounding medium (exo- or extracellular polysaccharides, EPS). It goes through the most studied activities of sulphated polysaccharides (sPS) or their derivatives, but also highlights lesser known applications as hypolipidaemic or hypoglycaemic, or as biolubricant agents and drag-reducers. Therefore, the great potentials of sPS from marine microalgae to be used as nutraceuticals, therapeutic agents, cosmetics, or in other areas, such as engineering, are approached in this review. PMID:23344113

  19. Preparation and characterization of mucilage polysaccharide for biomedical applications.

    PubMed

    Archana, G; Sabina, K; Babuskin, S; Radhakrishnan, K; Fayidh, Mohammed A; Babu, P Azhagu Saravana; Sivarajan, M; Sukumar, M

    2013-10-15

    In the present investigation, the polysaccharide/mucilage from waste of Abelmoscus esculentus by modification in hot extraction using two different solvents (Acetone, Methanol) were extracted, characterized and further compared with seaweed polysaccharide for their potential applications. The percentage yield, emulsifying capacity and swelling index of this mucilage were determined. The macro algae and okra waste, gave high % yield (22.2% and 8.6% respectively) and good emulsifying capacity (EC%=52.38% and 54.76% respectively) with acetone, compared to methanol (11.3% and 0.28%; EC%=50%) (PH=7) while swelling index was greater with methanol than acetone extracts respectively. The infrared (I.R.) spectrum of the samples was recorded to investigate the chemical structure of mucilage. Thermal analysis of the mucilage was done with TGA (Thermal Gravimetric Analyzer) and DSC (Differential Scanning Calorimeter) which showed both okra and algal polysaccharide were thermostable hydrogels. PMID:23987320

  20. [Study on oral absorption enhancers of astragalus polysaccharides].

    PubMed

    Chen, Xiao-Yun; Tan, Xiao-Bin; Sun, E; Liu, Dan; Jia, Xiao-Bin; Zhang, Zhen-Hai

    2014-04-01

    Astragalus polysaccharides was lounded to 4-(2-aminoethylphenol), followed by labeling the APS-Tyr with fluorescein-5-isothiocyanate (FITC) at the secondary amino group. The absorption enhancement effects of low molecular weight chitosan and protamine on astragalus polysaccharides were evaluated via Caco-2 cell culture model. The results show that the fluorecent labeling compound has good stability and high sensitivity. On the other hand low molecular weight chitosan and protamine also can promoted absorption of the astragalus polysaccharides without any cytotoxity, and the absorption increase was more significant with increasing the amount of low molecular weight chitosan and protamine. At the same time, the low molecular weight chitosan has slightly better effect. The transepithelial electric resistance (TEER) of Caco-2 cells show that absorption enhancers could improve its membrane transport permeability by opening tight junctions between cells and increasing the cell membrane fluidity.

  1. Reviews on Mechanisms of In Vitro Antioxidant Activity of Polysaccharides

    PubMed Central

    Wang, Junqiao; Hu, Shuzhen; Nie, Shaoping; Yu, Qiang; Xie, Mingyong

    2016-01-01

    It is widely acknowledged that the excessive reactive oxygen species (ROS) or reactive nitrogen species (RNS) induced oxidative stress will cause significant damage to cell structure and biomolecular function, directly or indirectly leading to a number of diseases. The overproduction of ROS/RNS will be balanced by nonenzymatic antioxidants and antioxidant enzymes. Polysaccharide or glycoconjugates derived from natural products are of considerable interest from the viewpoint of potent in vivo and in vitro antioxidant activities recently. Particularly, with regard to the in vitro antioxidant systems, polysaccharides are considered as effective free radical scavenger, reducing agent, and ferrous chelator in most of the reports. However, the underlying mechanisms of these antioxidant actions have not been illustrated systematically and sometimes controversial results appeared among various literatures. To address this issue, we summarized the latest discoveries and advancements in the study of antioxidative polysaccharides and gave a detailed description of the possible mechanisms. PMID:26682009

  2. Fine Structure of Extracellular Polysaccharide of Erwinia amylovora†

    PubMed Central

    Politis, D. J.; Goodman, R. N.

    1980-01-01

    Virulent E9 and avirulent E8 strains of Erwinia amylovora were shown by means of light, transmission, and scanning microscopy to be, respectively, encapsulated and unencapsulated. Difficulty was encountered in stabilizing the fibrillar-appearing capsular extracellular polysaccharide. We suggest that the ephemeral nature of extracellular polysaccharide is due to the collapse of its extended structure upon dehydration. This occurs when bacteria are prepared for either transmission or scanning electron microscopy. The electron micrographs support our previous biochemical and immunological studies contending that the capsule is composed of tightly bound and loosely held components. The preparation of bacteria in freeze-dried colonies has permitted us to observe and explain the fluidity of the encapsulated strain. We suggest that this fluidity is a reflection of the loosely held extracellular polysaccharide or slime. Images PMID:16345638

  3. The relationship of leaf photosynthetic traits – Vcmax and Jmax – to leaf nitrogen, leaf phosphorus, and specific leaf area: a meta-analysis and modeling study

    PubMed Central

    Walker, Anthony P; Beckerman, Andrew P; Gu, Lianhong; Kattge, Jens; Cernusak, Lucas A; Domingues, Tomas F; Scales, Joanna C; Wohlfahrt, Georg; Wullschleger, Stan D; Woodward, F Ian

    2014-01-01

    Great uncertainty exists in the global exchange of carbon between the atmosphere and the terrestrial biosphere. An important source of this uncertainty lies in the dependency of photosynthesis on the maximum rate of carboxylation (Vcmax) and the maximum rate of electron transport (Jmax). Understanding and making accurate prediction of C fluxes thus requires accurate characterization of these rates and their relationship with plant nutrient status over large geographic scales. Plant nutrient status is indicated by the traits: leaf nitrogen (N), leaf phosphorus (P), and specific leaf area (SLA). Correlations between Vcmax and Jmax and leaf nitrogen (N) are typically derived from local to global scales, while correlations with leaf phosphorus (P) and specific leaf area (SLA) have typically been derived at a local scale. Thus, there is no global-scale relationship between Vcmax and Jmax and P or SLA limiting the ability of global-scale carbon flux models do not account for P or SLA. We gathered published data from 24 studies to reveal global relationships of Vcmax and Jmax with leaf N, P, and SLA. Vcmax was strongly related to leaf N, and increasing leaf P substantially increased the sensitivity of Vcmax to leaf N. Jmax was strongly related to Vcmax, and neither leaf N, P, or SLA had a substantial impact on the relationship. Although more data are needed to expand the applicability of the relationship, we show leaf P is a globally important determinant of photosynthetic rates. In a model of photosynthesis, we showed that at high leaf N (3 gm−2), increasing leaf P from 0.05 to 0.22 gm−2 nearly doubled assimilation rates. Finally, we show that plants may employ a conservative strategy of Jmax to Vcmax coordination that restricts photoinhibition when carboxylation is limiting at the expense of maximizing photosynthetic rates when light is limiting. PMID:25473475

  4. The relationship of leaf photosynthetic traits - V cmax and J max - to leaf nitrogen, leaf phosphorus, and specific leaf area: a meta-analysis and modeling study.

    PubMed

    Walker, Anthony P; Beckerman, Andrew P; Gu, Lianhong; Kattge, Jens; Cernusak, Lucas A; Domingues, Tomas F; Scales, Joanna C; Wohlfahrt, Georg; Wullschleger, Stan D; Woodward, F Ian

    2014-08-01

    Great uncertainty exists in the global exchange of carbon between the atmosphere and the terrestrial biosphere. An important source of this uncertainty lies in the dependency of photosynthesis on the maximum rate of carboxylation (V cmax) and the maximum rate of electron transport (J max). Understanding and making accurate prediction of C fluxes thus requires accurate characterization of these rates and their relationship with plant nutrient status over large geographic scales. Plant nutrient status is indicated by the traits: leaf nitrogen (N), leaf phosphorus (P), and specific leaf area (SLA). Correlations between V cmax and J max and leaf nitrogen (N) are typically derived from local to global scales, while correlations with leaf phosphorus (P) and specific leaf area (SLA) have typically been derived at a local scale. Thus, there is no global-scale relationship between V cmax and J max and P or SLA limiting the ability of global-scale carbon flux models do not account for P or SLA. We gathered published data from 24 studies to reveal global relationships of V cmax and J max with leaf N, P, and SLA. V cmax was strongly related to leaf N, and increasing leaf P substantially increased the sensitivity of V cmax to leaf N. J max was strongly related to V cmax, and neither leaf N, P, or SLA had a substantial impact on the relationship. Although more data are needed to expand the applicability of the relationship, we show leaf P is a globally important determinant of photosynthetic rates. In a model of photosynthesis, we showed that at high leaf N (3 gm(-2)), increasing leaf P from 0.05 to 0.22 gm(-2) nearly doubled assimilation rates. Finally, we show that plants may employ a conservative strategy of J max to V cmax coordination that restricts photoinhibition when carboxylation is limiting at the expense of maximizing photosynthetic rates when light is limiting.

  5. Degradation of pectic polysaccharides in pickled green olives.

    PubMed

    Sánchez-Romero, C; Guillén, R; Heredia, A; Jiménez, A; Fernández-Bolaños, J

    1998-01-01

    The changes that occur in the pectic fractions in the cell wall of olives of the Manzanilla variety (Olea europaea pomiformis) during processing (initial treatment at high pH and subsequent lactic fermentation) have been researched. After studying various conditions for fractionating the pectic polysaccharides, the most adequate were chosen, involving sequential extraction with water, imidazole-hydrochloric acid buffer, sodium carbonate, 1 M potassium hydroxide, and 4 M potassium hydroxide. In the unprocessed fruit, the fractions studied consist mainly of high-molecular-weight acidic polysaccharides (70 to 250 kDa): homogalacturonans, rhamnogalacturonans, and branched arabinans. These were found in different proportions depending on the extraction agent used. At the same time, significant amounts of relatively low-molecular-weight (10 to 10.5 kDa) neutral branched arabinans were found in the water-soluble fraction. As a result of the processing, changes occurred in the proportions of the different groups of polysaccharides in accordance with changes in their solubility characteristics. These changes were reflected in the processed fruit by (i) and increase in the neutral branched arabinans in the water-soluble fraction due to the increased presence of such polysaccharides originally found in the carbonate and 4 M KOH-soluble fractions; (ii) an increase in homogalacturonans and rhamnogalacturonans, without significant changes in molecular weights, in the imidazole-soluble fraction as a result of the increased presence of corresponding polysaccharides originally found in the carbonate-soluble and water-soluble fractions; (iii) a substantial increase in uronic acids in the 1 M potassium hydroxide-soluble fraction, preferentially as low-molecular-weight polysaccharides; and (iv) a solubilization of arabinans in the 4 M potassium hydroxide-soluble fraction. PMID:9708257

  6. Structural features of the exocellular polysaccharides of Mycobacterium tuberculosis.

    PubMed Central

    Lemassu, A; Daffé, M

    1994-01-01

    The cell envelope which surrounds pathogenic mycobacteria is postulated to be a defence barrier against phagocytic cells and its outermost constituents have a tendency to accumulate in the culture medium. The present work demonstrates that the exocellular material of Mycobacterium tuberculosis contains large amounts of polysaccharides with only traces, if any at all, of lipids. Three types of polysaccharides were purified by anion-exchange and gel-filtration chromatography; all were found to be neutral compounds devoid of acyl substituents. They consisted of D-glucan, D-arabino-D-mannan and D-mannan, which were eluted from gel-filtration columns in positions corresponding to molecular masses of 123, 13 and 4 kDa respectively. Their predominant structural features were determined by the characterization of the per-O-methyl derivatives of enzymic, acetolysis and Smith-degradation products and by 1H- and 13C-n.m.r. spectroscopy of the purified polysaccharides, using mono- and two-dimensional homonuclear chemical-shift correlated spectroscopy and two-dimensional heteronuclear (1H/13C) spectroscopy. The glucan which represented up to 90% of the polysaccharides was composed of repeating units of five or six-->4-alpha-D-Glcp-1--> residues and a -->4-alpha-D-Glcp substituted at position 6 with an alpha-D-Glcp, indicating a glycogen-like highly branched structure not related to the so-called polysaccharide-II previously identified in tuberculin. The arabinomannan consisted of a mannan segment composed of a -->6-alpha-D-Man-1--> core substituted at some positions 2 with an alpha-D-Manp. The arabinan termini of the arabinomannan were found to be extensively capped with mannosyl residues. The possibility that these polysaccharides contribute to the persistence of the tubercle bacillus in the macrophage by molecular mimicry is discussed. PMID:8297342

  7. Leaf Senescence by Magnesium Deficiency

    PubMed Central

    Tanoi, Keitaro; Kobayashi, Natsuko I.

    2015-01-01

    Magnesium ions (Mg2+) are the second most abundant cations in living plant cells, and they are involved in various functions, including photosynthesis, enzyme catalysis, and nucleic acid synthesis. Low availability of Mg2+ in an agricultural field leads to a decrease in yield, which follows the appearance of Mg-deficient symptoms such as chlorosis, necrotic spots on the leaves, and droop. During the last decade, a variety of physiological and molecular responses to Mg2+ deficiency that potentially link to leaf senescence have been recognized, allowing us to reconsider the mechanisms of Mg2+ deficiency. This review focuses on the current knowledge about the physiological responses to Mg2+ deficiency including a decline in transpiration, accumulation of sugars and starch in source leaves, change in redox states, increased oxidative stress, metabolite alterations, and a decline in photosynthetic activity. In addition, we refer to the molecular responses that are thought to be related to leaf senescence. With these current data, we give an overview of leaf senescence induced by Mg deficiency. PMID:27135350

  8. Yeasts colonizing the leaf surfaces.

    PubMed

    Sláviková, Elena; Vadkertiová, Renata; Vránová, Dana

    2007-08-01

    The yeasts were isolated from the leaf surfaces of ten species of trees. The study site was a forest park (Zelezná Studnicka) of the Small Carpathians mountain range. One hundred and thirty seven yeast strains belonging to 13 genera were isolated from 320 samples of leaves and needles. Seventeen yeast species were isolated, but only seven occurred regularly: Aureobasidium pullulans, Cryptococcus laurentii, Pichia anomala, Metschnikowia pulcherrima, Saccharomyces sp., Lachancea thermotolerans, and Rhodotorula glutinis. The remaining species were isolated from the leaves and needles of three or less tree species. A. pullulans, Cr. laurentii, and P. anomala were the most frequently found species and they occurred on leaves and needles of all ten tree species. Saccharomyces sp. occurred in leaf samples collected from eight kinds of trees. M. pulcherrima and L. thermotolerans were found in samples collected from six species of trees. Both these species occurred almost always on the leaves of deciduous trees. Rh. glutinis was the most frequently isolated carotenoids producing species. We have found out that the ascomycetous and basidiomycetous species were present in the leaf samples in approximately equal frequency, contrary to the soil samples taken from this forest park, where the ascomycetous species were found rarely.

  9. Chitosan: A Promising Marine Polysaccharide for Biomedical Research

    PubMed Central

    Periayah, Mercy Halleluyah; Halim, Ahmad Sukari; Saad, Arman Zaharil Mat

    2016-01-01

    Biomaterials created 50 years ago are still receiving considerable attention for their potential to support development in the biomedical field. Diverse naturally obtained polysaccharides supply a broad range of resources applicable in the biomedical field. Lately, chitosan, a marine polysaccharide derived from chitins—which are extracted from the shells of arthropods such as crab, shrimp, and lobster—is becoming the most wanted biopolymer for use toward therapeutic interventions. This is a general short review of chitosan, highlighting the history, properties, chemical structure, processing method, and factors influencing the usage of chitosan derivatives in the biomedical field. PMID:27041872

  10. The framework of polysaccharide monooxygenase structure and chemistry.

    PubMed

    Span, Elise A; Marletta, Michael A

    2015-12-01

    Polysaccharide monooxygenases, or PMOs (also known as lytic PMOs or LPMOs), are a group of enzymes discovered in recent years to catalyze the oxidative degradation of carbohydrate polymers. The PMO catalytic domain has a β-sandwich fold that bears a strong resemblance to both immunoglobulin (Ig) and fibronectin type III (FnIII) domains. PMOs are secreted by fungi and bacteria, and there is recent evidence for their roles in pathogenesis, in addition to biomass processing. This review addresses the biological origins and functions of emerging PMO families, as well as describes the aspects of PMO structure that support the chemistry of copper-catalyzed, oxidative polysaccharide degradation.

  11. [Immunostimulating action of polysaccharides (heteroglycans) from higher plants].

    PubMed

    Wagner, H; Proksch, A; Riess-Maurer, I; Vollmar, A; Odenthal, S; Stuppner, H; Jurcic, K; Le Turdu, M; Fang, J N

    1985-01-01

    From the water or alcaline-water extracts of Echinacea purpurea (L.) Moench. and -angustifolia DC., Eupatorium cannabium L. and -perfoliatum L., Chamomilla recutita L. Rauscher, Calendula officinalis L., Baptisia tinctoria (L.) R. B., Achyrocline satureioides DC., Arnica montana L., Sabal serrulata Roem. et Schult., and Eleutherococcus (Acanthopanax) senticosus Maxim. polysaccharide fractions with molecular weights in the range of 25 000 to 500 000 and higher have been isolated, which, according to the granulocytes- and carbon clearance tests, showed significant immunostimulating activities. The isolated compounds belong to the group of watersoluble, acidic branched-chain heteroglycans. Their immunostimulating activity is compared and discussed with respect to other polysaccharides of biological activity.

  12. Impact of immobilized polysaccharide chiral stationary phases on enantiomeric separations.

    PubMed

    Ali, Imran; Aboul-Enein, Hassan Y

    2006-04-01

    Immobilized polysaccharide-based chiral stationary phases (CSPs) are gaining importance in the resolution of racemic compounds due to their stable nature on working with normal solvents and those prohibited for use with coated phases (tetrahydrofuran, chloroform, dichloromethane, acetone, 1,4-dioxane, ethyl acetate, and certain other ethers). This review discusses the use of immobilized polysaccharide CSPs in the chiral resolution of various racemates by liquid chromatography. The discussion includes immobilization methodologies, enantioselectivities, efficiencies, and a comparison of chiral recognition capabilities of coated vs. immobilized CSPs. Some applications of immobilized CSPs to the chiral resolution of racemic compounds are also presented. PMID:16830488

  13. Chitosan: A Promising Marine Polysaccharide for Biomedical Research.

    PubMed

    Periayah, Mercy Halleluyah; Halim, Ahmad Sukari; Saad, Arman Zaharil Mat

    2016-01-01

    Biomaterials created 50 years ago are still receiving considerable attention for their potential to support development in the biomedical field. Diverse naturally obtained polysaccharides supply a broad range of resources applicable in the biomedical field. Lately, chitosan, a marine polysaccharide derived from chitins-which are extracted from the shells of arthropods such as crab, shrimp, and lobster-is becoming the most wanted biopolymer for use toward therapeutic interventions. This is a general short review of chitosan, highlighting the history, properties, chemical structure, processing method, and factors influencing the usage of chitosan derivatives in the biomedical field.

  14. Evidence for microbial polysaccharide preparations containing polyester substituents.

    PubMed

    Giammatteo, P J; Stipanovic, A J; Nero, V P; Robison, P D

    1990-10-01

    CPMAS 13C-n.m.r. spectroscopy was employed to characterize the composition and solid phase morphology of gellan, welan, rhamsan and NW11. Spectra indicated that commercial preparations of these polysaccharides, which share a similar molecular backbone, contain a non-carbohydrate component exhibiting four inequivalent carbon atoms. Isolation of this component, followed by 13C-n.m.r. in CHCl3 and MS analysis, revealed its structure to be poly(beta-hydroxybutyrate). Evidence is presented which suggests that this polyester may be a covalent adduct to the above polysaccharides, although this cannot be unambiguously determined at this time. Further experimentation is in progress.

  15. Chitosan: A Promising Marine Polysaccharide for Biomedical Research.

    PubMed

    Periayah, Mercy Halleluyah; Halim, Ahmad Sukari; Saad, Arman Zaharil Mat

    2016-01-01

    Biomaterials created 50 years ago are still receiving considerable attention for their potential to support development in the biomedical field. Diverse naturally obtained polysaccharides supply a broad range of resources applicable in the biomedical field. Lately, chitosan, a marine polysaccharide derived from chitins-which are extracted from the shells of arthropods such as crab, shrimp, and lobster-is becoming the most wanted biopolymer for use toward therapeutic interventions. This is a general short review of chitosan, highlighting the history, properties, chemical structure, processing method, and factors influencing the usage of chitosan derivatives in the biomedical field. PMID:27041872

  16. The Influence of Leaf Angle and Leaf Surface Characteristics on the Process of Rainfall Interception

    NASA Astrophysics Data System (ADS)

    Holder, C.; Ginebra, R.; Webb, R.

    2015-12-01

    Individual choice in plant selection for household landscaping influences differences in runoff from urban watersheds because the variation in plant canopy architecture results in rainfall interception differences. Understanding the variables that influence rainfall interception and understanding the mechanism of rainfall interception are important concepts for sustainable watershed management. The broad objective of this study was to explore the influence of leaf hydrophobicity, water droplet retention, and leaf angle on the mechanism and process of rainfall interception and raindrop impaction on leaf surfaces of common tree species from the semi-arid regions of the western United States. Leaf hydrophobicity is determined by the cohesive forces of the water molecules among themselves and the adhesive forces that result from the molecular interactions between the water droplet and the leaf surface. Water droplet retention is a measure of how easily a water droplet drains off a leaf surface. The specific hypotheses examined were 1) larger raindrops falling on leaf surfaces will deflect the leaf to an angle greater than the water droplet retention angle; 2) an increased leaf angle, whether from natural position or deflection due to droplet impact and retention, reduces interception from raindrop impaction on hydrophobic and hydrophilic leaf surfaces; and 3) increased droplet size and frequency decrease rainfall interception more significantly in the hydrophilic case. These hypotheses were addressed in a laboratory experiment by 1) measuring leaf hydrophobicity and water droplet retention using a goniometer with a tilting base; 2) measuring leaf traits such as leaf area, leaf surface roughness, trichome density, and specific storage capacity; 3) examining raindrop splash on leaf surfaces with varying leaf hydrophobicity, water droplet retention, and leaf angle with a raindrop generator and high-speed video camera; and 4) modeling the impact of raindrop splash on leaf

  17. LeafJ: an ImageJ plugin for semi-automated leaf shape measurement.

    PubMed

    Maloof, Julin N; Nozue, Kazunari; Mumbach, Maxwell R; Palmer, Christine M

    2013-01-21

    High throughput phenotyping (phenomics) is a powerful tool for linking genes to their functions (see review and recent examples). Leaves are the primary photosynthetic organ, and their size and shape vary developmentally and environmentally within a plant. For these reasons studies on leaf morphology require measurement of multiple parameters from numerous leaves, which is best done by semi-automated phenomics tools. Canopy shade is an important environmental cue that affects plant architecture and life history; the suite of responses is collectively called the shade avoidance syndrome (SAS). Among SAS responses, shade induced leaf petiole elongation and changes in blade area are particularly useful as indices. To date, leaf shape programs (e.g. SHAPE, LAMINA, LeafAnalyzer, LEAFPROCESSOR) can measure leaf outlines and categorize leaf shapes, but can not output petiole length. Lack of large-scale measurement systems of leaf petioles has inhibited phenomics approaches to SAS research. In this paper, we describe a newly developed ImageJ plugin, called LeafJ, which can rapidly measure petiole length and leaf blade parameters of the model plant Arabidopsis thaliana. For the occasional leaf that required manual correction of the petiole/leaf blade boundary we used a touch-screen tablet. Further, leaf cell shape and leaf cell numbers are important determinants of leaf size. Separate from LeafJ we also present a protocol for using a touch-screen tablet for measuring cell shape, area, and size. Our leaf trait measurement system is not limited to shade-avoidance research and will accelerate leaf phenotyping of many mutants and screening plants by leaf phenotyping.

  18. Leaf drop affects herbivory in oaks.

    PubMed

    Pearse, Ian S; Karban, Richard

    2013-11-01

    Leaf phenology is important to herbivores, but the timing and extent of leaf drop has not played an important role in our understanding of herbivore interactions with deciduous plants. Using phylogenetic general least squares regression, we compared the phenology of leaves of 55 oak species in a common garden with the abundance of leaf miners on those trees. Mine abundance was highest on trees with an intermediate leaf retention index, i.e. trees that lost most, but not all, of their leaves for 2-3 months. The leaves of more evergreen species were more heavily sclerotized, and sclerotized leaves accumulated fewer mines in the summer. Leaves of more deciduous species also accumulated fewer mines in the summer, and this was consistent with the idea that trees reduce overwintering herbivores by shedding leaves. Trees with a later leaf set and slower leaf maturation accumulated fewer herbivores. We propose that both leaf drop and early leaf phenology strongly affect herbivore abundance and select for differences in plant defense. Leaf drop may allow trees to dispose of their herbivores so that the herbivores must recolonize in spring, but trees with the longest leaf retention also have the greatest direct defenses against herbivores.

  19. Leaf drop affects herbivory in oaks.

    PubMed

    Pearse, Ian S; Karban, Richard

    2013-11-01

    Leaf phenology is important to herbivores, but the timing and extent of leaf drop has not played an important role in our understanding of herbivore interactions with deciduous plants. Using phylogenetic general least squares regression, we compared the phenology of leaves of 55 oak species in a common garden with the abundance of leaf miners on those trees. Mine abundance was highest on trees with an intermediate leaf retention index, i.e. trees that lost most, but not all, of their leaves for 2-3 months. The leaves of more evergreen species were more heavily sclerotized, and sclerotized leaves accumulated fewer mines in the summer. Leaves of more deciduous species also accumulated fewer mines in the summer, and this was consistent with the idea that trees reduce overwintering herbivores by shedding leaves. Trees with a later leaf set and slower leaf maturation accumulated fewer herbivores. We propose that both leaf drop and early leaf phenology strongly affect herbivore abundance and select for differences in plant defense. Leaf drop may allow trees to dispose of their herbivores so that the herbivores must recolonize in spring, but trees with the longest leaf retention also have the greatest direct defenses against herbivores. PMID:23774946

  20. Leaf P increase outpaces leaf N in an Inner Mongolia grassland over 27 years.

    PubMed

    Mi, Zhaorong; Huang, Yuanyuan; Gan, Huijie; Zhou, Wenjia; Flynn, Dan F B; He, Jin-Sheng

    2015-01-01

    The dynamics of leaf nitrogen (N) and phosphorus (P) have been intensively explored in short-term experiments, but rarely at longer timescales. Here, we investigated leaf N : P stoichiometry over a 27-year interval in an Inner Mongolia grassland by comparing leaf N : P concentration of 2006 with that of 1979. Across 80 species, both leaf N and P increased, but the increase in leaf N lagged behind that of leaf P, leading to a significant decrease in the N : P ratio. These changes in leaf N : P stoichiometry varied among functional groups. For leaf N, grasses increased, woody species tended to increase, whereas forbs showed no change. Unlike leaf N, leaf P of grasses and forbs increased, whereas woody species showed no change. Such changes may reflect N deposition and P release induced by soil acidification over the past decades. The interannual effect of precipitation may somewhat have reduced the soil available N, leading to the more modest increase of leaf N than of leaf P. Thus, leaf N : P stoichiometry significantly responded to long-term environmental changes in this temperate steppe, but different functional groups responded differently. Our results indicate that conclusions of plant stoichiometry under short-term N fertilization should be treated with caution when extrapolating to longer timescales.

  1. Pivotal roles of the outer membrane polysaccharide export and polysaccharide copolymerase protein families in export of extracellular polysaccharides in gram-negative bacteria.

    PubMed

    Cuthbertson, Leslie; Mainprize, Iain L; Naismith, James H; Whitfield, Chris

    2009-03-01

    Many bacteria export extracellular polysaccharides (EPS) and capsular polysaccharides (CPS). These polymers exhibit remarkably diverse structures and play important roles in the biology of free-living, commensal, and pathogenic bacteria. EPS and CPS production represents a major challenge because these high-molecular-weight hydrophilic polymers must be assembled and exported in a process spanning the envelope, without compromising the essential barrier properties of the envelope. Emerging evidence points to the existence of molecular scaffolds that perform these critical polymer-trafficking functions. Two major pathways with different polymer biosynthesis strategies are involved in the assembly of most EPS/CPS: the Wzy-dependent and ATP-binding cassette (ABC) transporter-dependent pathways. They converge in an outer membrane export step mediated by a member of the outer membrane auxiliary (OMA) protein family. OMA proteins form outer membrane efflux channels for the polymers, and here we propose the revised name outer membrane polysaccharide export (OPX) proteins. Proteins in the polysaccharide copolymerase (PCP) family have been implicated in several aspects of polymer biogenesis, but there is unequivocal evidence for some systems that PCP and OPX proteins interact to form a trans-envelope scaffold for polymer export. Understanding of the precise functions of the OPX and PCP proteins has been advanced by recent findings from biochemistry and structural biology approaches and by parallel studies of other macromolecular trafficking events. Phylogenetic analyses reported here also contribute important new insight into the distribution, structural relationships, and function of the OPX and PCP proteins. This review is intended as an update on progress in this important area of microbial cell biology.

  2. Structure identification of a polysaccharide purified from Lycium barbarium fruit.

    PubMed

    Yuan, Yunfei; Wang, Yan-Bo; Jiang, Yueming; Prasad, K Nagendra; Yang, Jiali; Qu, Hongxia; Wang, Ying; Jia, Yongxia; Mo, Hui; Yang, Bao

    2016-01-01

    The water-soluble bioactive polysaccharides can contribute to the health benefits of Lycium barbarium fruit. However, the structure characteristics of these polysaccharides remain unclear yet. An important polysaccharide (LBPA) was isolated and purified from L. barbarium in this work. It was identified by chemical and spectroscopic methods as arabinogalactan with β-d-(1→6)-galactan as backbone, which was different to any reported polysaccharides from this species before. This arabinogalactan was comprised of Araf, Galp, GlcpA and Rhap with a molar ratio of 9.2:6.6:1.0:0.9. The side chains, including α-l-Araf-(1→, α-l-Araf-(1→5)-α-l-Araf-(1→, β-l-Araf-(1→5)-α-l-Araf-(1→ and α-l-Rhap-(1→4)-β-d-GlcpA-(1→6)-β-d-Galp-(1→, were linked to β-d-(1→6)-galactan at O-3. The putative structure was drawn as below. The molecular weight was determined to be 470,000g/mol by gel permeation chromatography.

  3. Construction of Electrochemical Chiral Interfaces with Integrated Polysaccharides via Amidation.

    PubMed

    Bao, Liping; Chen, Xiaohui; Yang, Baozhu; Tao, Yongxin; Kong, Yong

    2016-08-24

    Polysaccharides of sodium carboxymethyl cellulose (CMC) and chitosan (CS) were integrated together via amidation reactions between the carboxyl groups on sodium CMC and the amino groups on CS. Compared with individual sodium CMC and CS, the integrated polysaccharides with a mass ratio of 1:1, CMC-CS (1:1), exhibited a three-dimensional (3D) porous network structure, resulting in a significantly enhanced hydrophility due to the exposed polar functional groups in the CMC-CS (1:1). Chiral interfaces were constructed with the integrated polysaccharides and used for electrochemical enantiorecognition of tryptophan (Trp) isomers. The CMC-CS (1:1) chiral interfaces exhibited excellent selectivity toward the Trp isomers owing to the highly hydrophilic feature of CMC-CS (1:1) and the different steric hindrance during the formation of H bonds between Trp isomers and CMC-CS (1:1). Also, the optimization in the preparation of integrated polysaccharides such as mass ratio and combination mode (amidation or electrostatic interactions) was investigated. The CMC-CS (1:1) presented the ability of determining the percentage of d-Trp in racemic mixtures, and thus, the proposed electrochemical chiral interfaces could be regarded as a potential biosensing platform for enantiorecognition of chiral compounds. PMID:27487166

  4. Determining the polysaccharide composition of plant cell walls.

    PubMed

    Pettolino, Filomena A; Walsh, Cherie; Fincher, Geoffrey B; Bacic, Antony

    2012-09-01

    The plant cell wall is a chemically complex structure composed mostly of polysaccharides. Detailed analyses of these cell wall polysaccharides are essential for our understanding of plant development and for our use of plant biomass (largely wall material) in the food, agriculture, fabric, timber, biofuel and biocomposite industries. We present analytical techniques not only to define the fine chemical structures of individual cell wall polysaccharides but also to estimate the overall polysaccharide composition of cell wall preparations. The procedure covers the preparation of cell walls, together with gas chromatography-mass spectrometry (GC-MS)-based methods, for both the analysis of monosaccharides as their volatile alditol acetate derivatives and for methylation analysis to determine linkage positions between monosaccharide residues as their volatile partially methylated alditol acetate derivatives. Analysis time will vary depending on both the method used and the tissue type, and ranges from 2 d for a simple neutral sugar composition to 2 weeks for a carboxyl reduction/methylation linkage analysis. PMID:22864200

  5. Polysaccharides as Alternative Moisture Retention Agents for Shrimp.

    PubMed

    Torti, Michael J; Sims, Charles A; Adams, Charles M; Sarnoski, Paul J

    2016-03-01

    Phosphates are used as moisture retention agents (MRAs) by the shrimp industry. Although they are effective, phosphates are expensive, need to be listed on a food label, and overuse can often lead to a higher product cost for consumers. Polysaccharides were researched as alternative MRAs. Polysaccharides are usually inexpensive, are considered natural, and can have nutritional benefits. Research was conducted to determine whether polysaccharides yielded similar functional impacts as phosphates. Treatments included a 0.5% fibercolloid solution isolated from citrus peel, an 8% pectin solution, a 0.5% xanthan gum (XG) solution, a 1% carboxymethyl cellulose solution, and conventionally used 4% sodium tripolyphosphate (STP). Experimental treatments were compared to a distilled water control to gauge effectiveness. Freezing, boiling, and oven drying studies were performed to determine how moisture retention in shrimp differed using these different treatments. Water activity was measured to determine any potential differences in shelf life. Solution uptake was also determined to understand how well the treatments enhanced water binding. For moisture loss by freezing, 4% STP and the 0.5% fibercolloid solution functioned the best. The 4% STP treated shrimp lost the least amount of moisture during boiling. The 0.5% fibercolloid and 0.5% XG treatment outperformed phosphates in respect to moisture uptake ability. None of the treatments had a major effect on water activity. All treatments were rated similar in consumer sensory acceptability tests except for pectin, which was rated lower by the sensory panel. Overall, polysaccharides were found to be viable alternatives to phosphates.

  6. Structure of pectic polysaccharides from sunflower salts-soluble fraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The manuscript discusses the structural features of pectin polysaccharides extracted from seedless sunflower head residues. The analysis using 1H, 13C and two-dimensional gHSQC NMR showed various numbers of methyl and hydroxyl groups attached to the anomeric carbons in the pectin backbone at differe...

  7. Polysaccharide degradation systems of the saprophytic bacterium Cellvibrio japonicus

    DOE PAGESBeta

    Gardner, Jeffrey G.

    2016-06-04

    Study of recalcitrant polysaccharide degradation by bacterial systems is critical for understanding biological processes such as global carbon cycling, nutritional contributions of the human gut microbiome, and the production of renewable fuels and chemicals. One bacterium that has a robust ability to degrade polysaccharides is the Gram-negative saprophyte Cellvibrio japonicus. A bacterium with a circuitous history, C. japonicus underwent several taxonomy changes from an initially described Pseudomonas sp. Most of the enzymes described in the pre-genomics era have also been renamed. Furthermore, this review aims to consolidate the biochemical, structural, and genetic data published on C. japonicus and its remarkablemore » ability to degrade cellulose, xylan, and pectin substrates. Initially, C. japonicus carbohydrate-active enzymes were studied biochemically and structurally for their novel polysaccharide binding and degradation characteristics, while more recent systems biology approaches have begun to unravel the complex regulation required for lignocellulose degradation in an environmental context. Also included is a discussion for the future of C. japonicus as a model system, with emphasis on current areas unexplored in terms of polysaccharide degradation and emerging directions for C. japonicus in both environmental and biotechnological applications.« less

  8. Determining the polysaccharide composition of plant cell walls.

    PubMed

    Pettolino, Filomena A; Walsh, Cherie; Fincher, Geoffrey B; Bacic, Antony

    2012-09-01

    The plant cell wall is a chemically complex structure composed mostly of polysaccharides. Detailed analyses of these cell wall polysaccharides are essential for our understanding of plant development and for our use of plant biomass (largely wall material) in the food, agriculture, fabric, timber, biofuel and biocomposite industries. We present analytical techniques not only to define the fine chemical structures of individual cell wall polysaccharides but also to estimate the overall polysaccharide composition of cell wall preparations. The procedure covers the preparation of cell walls, together with gas chromatography-mass spectrometry (GC-MS)-based methods, for both the analysis of monosaccharides as their volatile alditol acetate derivatives and for methylation analysis to determine linkage positions between monosaccharide residues as their volatile partially methylated alditol acetate derivatives. Analysis time will vary depending on both the method used and the tissue type, and ranges from 2 d for a simple neutral sugar composition to 2 weeks for a carboxyl reduction/methylation linkage analysis.

  9. Extraction, Characterization and Immunological Activity of Polysaccharides from Rhizoma gastrodiae

    PubMed Central

    Chen, Juncheng; Tian, Shan; Shu, Xiaoying; Du, Hongtao; Li, Na; Wang, Junru

    2016-01-01

    A response surface and Box-Behnken design approach was applied to augment polysaccharide extraction from the residue of Rhizoma gastrodiae. Statistical analysis revealed that the linear and quadratic terms for three variables during extraction exhibited obvious effects on extraction yield. The optimum conditions were determined to be a liquid-to-solid ratio of 54 mL/g, an extraction temperature of 74 °C, an extraction time of 66 min, and three extractions. These conditions resulted in a maximum Rhizoma gastrodiae polysaccharide (RGP) extraction yield of 6.11% ± 0.13%. Two homogeneous polysaccharides (RGP-1a and RGP-1b) were obtained using DEAE cellulose-52 and Sephadex G-100 columns. The preliminary characterization of RGP-1a and RGP-1b was performed using HPLC-RID, HPGPC, and FTIR. Tests of the immunological activity in vitro showed that the two polysaccharides could significantly stimulate macrophages to release NO and enhance phagocytosis in a dose-dependent manner. In particular, RGP-1b (200 μg/mL) and LPS (2 μg/mL) had almost the same influence on the NO production and phagocytic activity of RAW 264.7 macrophages (p > 0.05). All the data obtained indicate that RGP-1a and RGP-1b have the potential to be developed as a health food. PMID:27347944

  10. Polysaccharide Colloids as Smart Vehicles in Cancer Therapy.

    PubMed

    Caro, Carlos; Pozo, David

    2015-01-01

    Cancer disease is one of the leading causes of morbidity and mortality worldwide, with approximately 14 million new cases and around 8 million cancer-related deaths yearly. Estimates expect to increase these figures over the next few years. Therefore, it is very important to develop more effective and targeted therapies. Polysaccharides are widely used for biomedical and pharmaceutical applications due to their interesting properties, and can be utilised in the production of nanovehicles for drug delivery, since they frequently extend the half-life and improve the stability of chemotherapeutic agents in bloodstream allowing them to reach the tumour tissue. Moreover, polysaccharide-based nanovehicles are generally expected to increase the therapeutic benefit by reducing the undesired side effects and promoting a more efficient cellular uptake. Here, we highlight the application of various polysaccharides as nanovehicles in cancer therapy, focusing mainly on in vivo applications and describing the main advantages of each designed system in a critical way. The use of different polysaccharides interacting with metal nanoparticles to develop new nanovehicles for cancer therapy will also be discussed.

  11. Viscofying properties of corn fiber gum with various polysaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of corn fiber gum (CFG) on the aqueous solutions of a series of widely-used commercial polysaccharides has been studied by rheological techniques using stress synergism index to evaluate its viscosifying action. Though CFG solution exhibited Newtonian fluid behaviour with a very low vis...

  12. Functional Exploration of the Polysaccharide Lyase Family PL6

    PubMed Central

    Mathieu, Sophie; Henrissat, Bernard; Labre, Flavien; Skjåk-Bræk, Gudmund; Helbert, William

    2016-01-01

    Alginate, the main cell-wall polysaccharide of brown algae, is composed of two residues: mannuronic acid (M-residues) and, its C5-epimer, guluronic acid (G-residues). Alginate lyases define a class of enzymes that cleave the glycosidic bond of alginate by β-elimination. They are classified according to their ability to recognize the distribution of M- and G-residues and are named M-, G- or MG-lyases. In the CAZy database, alginate lyases have been grouped by sequence similarity into seven distinct polysaccharide lyase families. The polysaccharide lyase family PL6 is subdivided into three subfamilies. Subfamily PL6_1 includes three biochemically characterized enzymes (two alginate lyases and one dermatan sulfatase lyase). No characterized enzymes have been described in the two other subfamilies (PL6_2 and PL6_3). To improve the prediction of polysaccharide-lyase activity in the PL6 family, we re-examined the classification of the PL6 family and biochemically characterized a set of enzymes reflecting the diversity of the protein sequences. Our results show that subfamily PL6_1 includes two dermatan sulfates lyases and several alginate lyases that have various substrate specificities and modes of action. In contrast, subfamilies PL6_2 and PL6_3 were found to contain only endo-poly-MG-lyases. PMID:27438604

  13. Chemistry and biology of arabinofuranosyl- and galactofuranosyl-containing polysaccharides.

    PubMed

    Houseknecht, J B; Lowary, T L

    2001-12-01

    Polysaccharides containing galactofuranosyl and arabinofuranosyl residues are key components of many microorganisms. Recent investigations have provided a greater understanding of the biosynthetic pathways by which these glycans are assembled. Concomitant with these biochemical studies, an increasing number of chemical syntheses of oligofuranosides have been reported and new methods for their assembly have been developed.

  14. Bacterial polysaccharide which binds Rhizobium trifolii to clover root hairs.

    PubMed Central

    Dazzo, F B; Brill, W J

    1979-01-01

    Immunofluorescence, quantitative immunoprecipitation, and inhibition of bacterial agglutination and passive hemagglutination indicate that cross-reactive antigenic determinants are present on the surface of Rhizobium trifolii and clover roots. These determinants are immunochemically unique to this Rhizobium-legume cross-inoculation group. The multivalent lectin trifoliin and antibody to the clover root antigenic determinants bind competitively to two acidic heteropolysaccharides isolated from capsular material of R. Trifolii 0403. The major polysaccharide is an antigen which lacks heptose, 2-keto-3-deoxyoctulosonic acid, and endotoxic lipid A. The minor polysaccharide in the capsular material of R. Trifolii 0403 contains the same antigen in addition to heptose, 2-keto-3-deoxyoctonate, and lipid A. The acidic polysaccharides of two strains of R. trifolii share the clover r-ot cross-reactive antigenic determinant despite other differences in their carbohydrate composition. Studies with monovalent antigen-binding fragments of anti-clover root antibody and Azotobacter vinelandii hybrid transformants carrying the unique antigenic determinant suggest that these polysaccharides bind R. trifolii to the clover root hair tips which contain trifoliin. Images PMID:86535

  15. Genotoxicity Study of Polysaccharide Fraction from Astragalus membranaceus's Aerial Parts

    PubMed Central

    Park, Yeong-Chul; Kim, Min Hee; Kim, Jung Woo; Kim, Jong-Bong; Lee, Jae Geun; Yu, Chang Yeon; Kim, Seung-Hyun; Chung, Ill Min; Kim, Jae Kwang; Choi, Ri Na

    2014-01-01

    Radix Astragali, the root of Astragalus (A.) membranaceus, has been applied in a variety of diseases for a long time in Asian countries such as Korea and China. In addition, the aerial parts such as leaves and stems of A. membranaceus have received a great deal of attention. Recently, the polysaccharide fraction showing a potent immunomoduating activity was isolated from the aerial parts of A. membranaceus. Thus, the aerial parts of A. membranaceus would be worthy enough for a food material and a dietary supplement. However, they should be safe even though valuable. In our previous study, it was estimated that NOAEL for female rats are 5000 mg/kg/day of the crude polysaccharide fraction from A. membranaceus-aboveground parts. As a series of safety evaluation, genotoxicity test for the crude polysaccharide fraction was carried out in this study. In conclusion, the three genotoxicity assays provided strong overall support that the crude polysaccharide fraction lacks mutagenic and/or clastogenic potential under the GLP-based test conditions. This indicates the aerial parts of A. membranaceus would be safe enough for a food material and a dietary supplement. PMID:25071923

  16. Catalytic synthesis of sulfated polysaccharides I: Characterization of chemical structure.

    PubMed

    Wang, Junlong; Yang, Wen; Yang, Ting; Zhang, Xiaonuo; Zuo, Yuan; Tian, Jia; Yao, Jian; Zhang, Ji; Lei, Ziqiang

    2015-03-01

    In the present study, sulfated derivatives of Artemisia sphaerocephala polysaccharide (SASP) with high degree of substitution (DS) were synthesized by using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst in homogeneous conditions. It was found that DMAP/DCC showed marked improvement in DS of sulfated samples. Compared to sulfated derivatives without catalyst, the DS of SASP increased from 0.91 to 1.28 with an increment in dosage of DMAP from 0 to 10 mg. The influence of DMAP/DCC on the DS of sulfated derivatives was depended on the content of DMAP. The effect of DMAP might be due to its strong coordination to the hydroxy group. The results of FT-IR and X-ray photoelectron spectroscopy (XPS) indicated that SO3- group (S6+, binding energy of 172.3 eV) was widely present in sulfated polysaccharide molecules. 13C NMR results indicated that C-6 substitution was predominant for sulfated polysaccharide when compared with other positions. In the sulfation reaction, a sharp decrease in MW was observed. DMAP/DCC was an effective catalyst system in sulfated modification of polysaccharide. PMID:25499892

  17. Comparison of antioxidant and antiproliferation activities of polysaccharides from eight species of medicinal mushrooms.

    PubMed

    Chen, Peiying; Yong, Yangyang; Gu, Yifan; Wang, Zeliang; Zhang, Shizhu; Lu, Ling

    2015-01-01

    Polysaccharides from mushrooms including Pleurotus eryngii, P. ostreatus, P. nebrodensis, Lentinus edodes, Hypsizygus marmoreus, Flammulina velutipes, Ganoderma lucidum, and Hericium erinaceus were isolated by water extraction and alcohol precipitation. Our results suggest that all tested polysaccharides have the significant antioxidant capacities of scavenging free radicals (1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals). Among them, the H. erinaceus polysaccharide exhibits the highest 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, whereas the L. edodes polysaccharide shows the strongest scavenging ability for hydroxyl radicals. Furthermore, using the MCF-7 breast cancer cell line and HeLa cells, all 8 selected polysaccharides are able to inhibit the proliferation of tumor cells, but the strength of inhibition varied depending on the mushroom species and the concentration used. Notably, G. lucidum polysaccharide shows the highest inhibition activity on MCF-7 cells. By comparison, H. erinaceus polysaccharide has the strongest inhibitory effect on HeLa cells. Moreover, high-performance liquid chromatography with a carbohydrate analysis column showed significant differences in polysaccharide components among these mushrooms. Thus our data suggest that the different species of mushrooms have the variable functions because of their own specific polysaccharide components. The 8 mushroom polysaccharides have the potential to be used as valuable functional food additives or sources of therapeutic agents for antioxidant and cancer treatments, especially polysaccharides from H. erinaceus, L. edodes, and G. lucidum.

  18. Comparison of antioxidant and antiproliferation activities of polysaccharides from eight species of medicinal mushrooms.

    PubMed

    Chen, Peiying; Yong, Yangyang; Gu, Yifan; Wang, Zeliang; Zhang, Shizhu; Lu, Ling

    2015-01-01

    Polysaccharides from mushrooms including Pleurotus eryngii, P. ostreatus, P. nebrodensis, Lentinus edodes, Hypsizygus marmoreus, Flammulina velutipes, Ganoderma lucidum, and Hericium erinaceus were isolated by water extraction and alcohol precipitation. Our results suggest that all tested polysaccharides have the significant antioxidant capacities of scavenging free radicals (1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals). Among them, the H. erinaceus polysaccharide exhibits the highest 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, whereas the L. edodes polysaccharide shows the strongest scavenging ability for hydroxyl radicals. Furthermore, using the MCF-7 breast cancer cell line and HeLa cells, all 8 selected polysaccharides are able to inhibit the proliferation of tumor cells, but the strength of inhibition varied depending on the mushroom species and the concentration used. Notably, G. lucidum polysaccharide shows the highest inhibition activity on MCF-7 cells. By comparison, H. erinaceus polysaccharide has the strongest inhibitory effect on HeLa cells. Moreover, high-performance liquid chromatography with a carbohydrate analysis column showed significant differences in polysaccharide components among these mushrooms. Thus our data suggest that the different species of mushrooms have the variable functions because of their own specific polysaccharide components. The 8 mushroom polysaccharides have the potential to be used as valuable functional food additives or sources of therapeutic agents for antioxidant and cancer treatments, especially polysaccharides from H. erinaceus, L. edodes, and G. lucidum. PMID:25954912

  19. In vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis.

    PubMed

    Chen, Mei-Zhen; Xie, Hao-Gui; Yang, La-Wei; Liao, Zao-Hui; Yu, Jie

    2010-10-01

    In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides (PGL), Gracilaria lemaneiformis polysaccharide fraction-1 (GL-1), Gracilaria lemaneiformis polysaccharide fraction-2 (GL-2) and Gracilaria lemaneiformis polysaccharide fraction-3 (GL-3) were studied by the Methyl thiazolyl tetrazolium (MTT) method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect (CPE) on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit (PFU), MTT and CPE methods. The results showed: i) Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii) Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides (PGL and GL-2) both of which exhibited higher antiviral activity; iii) A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions.

  20. Physicochemical characteristics and biological activities of polysaccharide fractions from Phellinus baumii cultured with different methods.

    PubMed

    Li, Tingting; Yang, Yan; Liu, Yanfang; Zhou, Shuai; Yan, Meng Qiu; Wu, Di; Zhang, Jingsong; Tang, Chuanhong

    2015-11-01

    Nine polysaccharide fractions were obtained from the fruiting bodies, submerged mycelia, and solid state fermented products of Phellinus baumii using different concentrations of ethanol precipitation. The chemical characteristics and in vitro immunological activities of the nine polysaccharide fractions were compared and studied. Results indicated that the fractions precipitated with 50% ethanol had higher yields of polysaccharides and submerged mycelia contributed to high extraction yields of polysaccharides and possessed higher polysaccharide contents. HPSEC-MALLS-RI analysis showed that the molecular weight (Mw) of polysaccharide fractions from these three materials decreased with the increasing of precipitated ethanol concentration. The Mw of fruiting body polysaccharide fractions ranged from 1.98×10(4)Da to 1.89×10(6)Da. Large-molecular-weight polysaccharides (from 2.11×10(6)Da to 2.01×10(7)Da) were found in submerged mycelia. Some lower-molecular-weight polysaccharide components were found in solid fermented products. Different culture methods contributed to significant differences in monosaccharide components and molar ratios. The 50% ethanol precipitated fractions exhibited more complexity on monosaccharide compositions comparing with fractions precipitated with 30% and 70% ethanol. Polysaccharide fractions derived from submerged mycelia exhibited higher macrophages stimulation activities. Submerged culture was found to be a suitable method to prepare active polysaccharides because of its short culture span and reasonable cost. PMID:26344493

  1. Effect of Porphyridium sp. polysaccharide on malignant cell transformation by Moloney murine sarcoma virus.

    PubMed

    Huleihel, M; Arad, S

    2001-01-01

    The polysaccharide produced by the red microalga Porphyridium sp. was highly inhibitory for cell transformation of mouse fibroblast cells by an MSV-124 virus stock. This inhibition was most effective if the polysaccharide was added 2 h before or at the time of infection. The finding that the inhibition of cell transformation by MuSV-124 was reversible after removal of the polysaccharide suggested that Porphyridium sp. polysaccharide inhibited a late step after provirus integration into the host genome. Addition of the polysaccharide post-infection significantly reduced the number of transformed cells, but its effect was less marked than that obtained when the polysaccharide was added before or at the time of infection. These findings support the possibility that the polysaccharide may affect early steps in virus replication cycle, such as virus absorption into the host cells, in addition to its effect on a late step after provirus integration.

  2. Polysaccharide from seeds of Plantago asiatica L. affects lipid metabolism and colon microbiota of mouse.

    PubMed

    Hu, Jie-Lun; Nie, Shao-Ping; Wu, Qi-Meng; Li, Chang; Fu, Zhi-Hong; Gong, Joshua; Cui, Steve W; Xie, Ming-Yong

    2014-01-01

    Polysaccharide from the seeds of Plantago asiatica L. was given via oral administration to mice (0.4 g/kg body weight, 30 days) to observe its effects on mouse nutrient metabolism and colon microbiota. It was found the polysaccharide intake could lower the apparent absorption of lipid. Total triglyceride, cholesterol, and atherogenic index in blood serum with total lipid and cholesterol levels in liver of polysaccharide group mice were all significantly lower than those of the control group (p < 0.05). Furthermore, the effect of the polysaccharide intake on mouse colon bacterial communities was investigated. Mice from the polysaccharide group showed a higher colon bacterial diversity than the control group. Bacteroides sp., Eubacterium sp., butyrate-producing bacteria Butyrivibrio sp., and probiotics Bifidobacterium bifidum , Lactobacillus fermentum , and Lactobacillus reuteri in mouse colon were all increased after polysaccharide intake. These indicated that the intake of polysaccharide from P. asiatica L. could be beneficial for lipid metabolism and colon microbiota. PMID:24341731

  3. Extraction, purification and antioxidant activities of the polysaccharides from maca (Lepidium meyenii).

    PubMed

    Zha, Shenghua; Zhao, Qingsheng; Chen, Jinjin; Wang, Liwei; Zhang, Guifeng; Zhang, Hong; Zhao, Bing

    2014-10-13

    Water-soluble polysaccharides were separated from maca (Lepidium meyenii) aqueous extract (MAE). The crude polysaccharides were deproteinized by Sevag method. During the preparation process of maca polysaccharides, amylase and glucoamylase effectively removed starch in maca polysaccharides. Four Lepidium meyenii polysaccharides (LMPs) were obtained by changing the concentration of ethanol in the process of polysaccharide precipitation. All of the LMPs were composed of rhamnose, arabinose, glucose and galactose. Antioxidant activity tests revealed that LMP-60 showed good capability of scavenging hydroxyl free radical and superoxide radical at 2.0mg/mL, the scavenging rate was 52.9% and 85.8%, respectively. Therefore, the results showed that maca polysaccharides had a high antioxidant activity and could be explored as the source of bioactive compounds. PMID:25037390

  4. Classification and quantification of leaf curvature

    PubMed Central

    Liu, Zhongyuan; Jia, Liguo; Mao, Yanfei; He, Yuke

    2010-01-01

    Various mutants of Arabidopsis thaliana deficient in polarity, cell division, and auxin response are characterized by certain types of leaf curvature. However, comparison of curvature for clarification of gene function can be difficult without a quantitative measurement of curvature. Here, a novel method for classification and quantification of leaf curvature is reported. Twenty-two mutant alleles from Arabidopsis mutants and transgenic lines deficient in leaf flatness were selected. The mutants were classified according to the direction, axis, position, and extent of leaf curvature. Based on a global measure of whole leaves and a local measure of four regions in the leaves, the curvature index (CI) was proposed to quantify the leaf curvature. The CI values accounted for the direction, axis, position, and extent of leaf curvature in all of the Arabidopsis mutants grown in growth chambers. Comparison of CI values between mutants reveals the spatial and temporal variations of leaf curvature, indicating the strength of the mutant alleles and the activities of the corresponding genes. Using the curvature indices, the extent of curvature in a complicated genetic background becomes quantitative and comparable, thus providing a useful tool for defining the genetic components of leaf development and to breed new varieties with leaf curvature desirable for the efficient capture of sunlight for photosynthesis and high yields. PMID:20400533

  5. Compound leaf development in model plant species.

    PubMed

    Bar, Maya; Ori, Naomi

    2015-02-01

    Plant leaves develop in accordance with a common basic program, which is flexibly adjusted to the species, developmental stage and environment. Two key stages of leaf development are morphogenesis and differentiation. In the case of compound leaves, the morphogenesis stage is prolonged as compared to simple leaves, allowing for the initiation of leaflets. Here, we review recent advances in the understanding of how plant hormones and transcriptional regulators modulate compound leaf development, yielding a substantial diversity of leaf forms, focusing on four model compound leaf organisms: cardamine (Cardamine hirsuta), tomato (Solanum lycopersicum), medicago (Medicago truncatula) and pea (Pisum sativum).

  6. Compositional analysis of leaf cuticular membranes isolated from tea plants (Camellia sinensis L.).

    PubMed

    Tsubaki, Shuntaro; Sakumoto, Shunichi; Uemura, Norihiro; Azuma, Jun-ichi

    2013-05-01

    Chemical constituents of cuticular membranes (CMs) isolated from three tea cultivars (Camellia sinensis (L.) O. Kuntze cvs. Yabukita, Samidori and Gokou) were compared. All CMs from the adaxial side of the leaves showed higher accumulation of wax, cutin and polysaccharide, while those from the abaxial side were abundant in cutan, showing the adaptation of the adaxial side to abiotic stresses, such as wind and rain, in contrast to the abaxial side, which provides defence against pathogens. Yabukita, a major tea cultivar in Japan, developed thick CMs while Samidori and Gokou, shade-cultivated tea cultivars, had lighter CMs, reflecting their thin and soft leaves. CMs rapidly accumulated 9,10-epoxy-18-hydroxyoctadecanoic acid at a very early stage of leaf development. Additionally, shade treatment did not influence cutin biosynthesis in CMs, reflecting high adaptation of tea leaves under low light levels.

  7. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  8. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  9. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  10. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  11. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  12. 7 CFR 28.464 - Leaf Grade 4.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade 4. 28.464 Section 28.464 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Upland Cotton § 28.464 Leaf Grade 4. Leaf Grade 4 is leaf which is within the range represented...

  13. 7 CFR 28.461 - Leaf Grade 1.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade 1. 28.461 Section 28.461 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Upland Cotton § 28.461 Leaf Grade 1. Leaf Grade 1 is leaf which is within the range represented...

  14. 7 CFR 28.466 - Leaf Grade 6.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade 6. 28.466 Section 28.466 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Upland Cotton § 28.466 Leaf Grade 6. Leaf Grade 6 is leaf which is within the range represented...

  15. 7 CFR 28.465 - Leaf Grade 5.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade 5. 28.465 Section 28.465 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Upland Cotton § 28.465 Leaf Grade 5. Leaf Grade 5 is leaf which is within the range represented...

  16. 7 CFR 28.462 - Leaf Grade 2.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade 2. 28.462 Section 28.462 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Upland Cotton § 28.462 Leaf Grade 2. Leaf Grade 2 is leaf which is within the range represented...

  17. 7 CFR 28.463 - Leaf Grade 3.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade 3. 28.463 Section 28.463 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Upland Cotton § 28.463 Leaf Grade 3. Leaf Grade 3 is leaf which is within the range represented...

  18. 7 CFR 28.467 - Leaf Grade 7.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade 7. 28.467 Section 28.467 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Upland Cotton § 28.467 Leaf Grade 7. Leaf Grade 7 is leaf which is within the range represented...

  19. Enzymatic polymerization to novel polysaccharides having a glucose-N-acetylglucosamine repeating unit, a cellulose-chitin hybrid polysaccharide.

    PubMed

    Kobayashi, Shiro; Makino, Akira; Matsumoto, Hironori; Kunii, Shigeru; Ohmae, Masashi; Kiyosada, Toshitsugu; Makiguchi, Ken; Matsumoto, Akira; Horie, Michinobu; Shoda, Shin-Ichiro

    2006-05-01

    A cellulose-chitin hybrid polysaccharide having alternatingly beta(1-->4)-linked D-glucose (Glc) and N-acetyl-d-glucosamine (GlcNAc) was synthesized via two modes of enzymatic polymerization. First, a sugar oxazoline monomer of Glcbeta(1-->4)GlcNAc (1) was designed as a transition-state analogue substrate (TSAS) monomer for chitinase catalysis. Monomer 1 was recognized by chitinase from Bacillus sp., giving rise to a cellulose-chitin hybrid polysaccharide (2) via ring-opening polyaddition with perfect regioselectivity and stereochemistry. Molecular weight (M(n)) of 2 reached 4030, which corresponds to 22 saccharide units. Second, a sugar fluoride monomer of GlcNAcbeta(1-->4)Glc (3) was synthesized for the catalysis of cellulase from Trichoderma viride. The enzyme catalyzed polycondensation of 3, providing a cellulose-chitin hybrid polysaccharide (4) in regio- and stereoselective manner. M(n) of 4 reached 2840, which corresponds to 16 saccharide units. X-ray diffraction measurements revealed that these hybrid polysaccharides did not form any characteristic crystalline structures. Furthermore, these unnatural hybrids of 2 and 4 were successfully digested by lysozyme from human neutrophils.

  20. Wind-induced leaf transpiration

    NASA Astrophysics Data System (ADS)

    Huang, Cheng-Wei; Chu, Chia-Ren; Hsieh, Cheng-I.; Palmroth, Sari; Katul, Gabriel G.

    2015-12-01

    While the significance of leaf transpiration (fe) on carbon and water cycling is rarely disputed, conflicting evidence has been reported on how increasing mean wind speed (U) impacts fe from leaves. Here, conditions promoting enhancement or suppression of fe with increasing U for a wide range of environmental conditions are explored numerically using leaf-level gas exchange theories that combine a stomatal conductance model based on optimal water use strategies (maximizing the 'net' carbon gain at a given fe), energy balance considerations, and biochemical demand for CO2. The analysis showed monotonic increases in fe with increasing U at low light levels. However, a decline in modeled fe with increasing U were predicted at high light levels but only in certain instances. The dominant mechanism explaining this decline in modeled fe with increasing U is a shift from evaporative cooling to surface heating at high light levels. New and published sap flow measurements for potted Pachira macrocarpa and Messerschmidia argentea plants conducted in a wind tunnel across a wide range of U (2 - 8 m s-1) and two different soil moisture conditions were also employed to assess how fe varies with increasing U. The radiative forcing imposed in the wind tunnel was only restricted to the lower end of expected field conditions. At this low light regime, the findings from the wind tunnel experiments were consistent with the predicted trends.

  1. “Breath figures” on leaf surfaces—formation and effects of microscopic leaf wetness

    PubMed Central

    Burkhardt, Juergen; Hunsche, Mauricio

    2013-01-01

    “Microscopic leaf wetness” means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 μm, microscopic leaf wetness is about two orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the type and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g., ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past. PMID:24167510

  2. "Breath figures" on leaf surfaces-formation and effects of microscopic leaf wetness.

    PubMed

    Burkhardt, Juergen; Hunsche, Mauricio

    2013-01-01

    "Microscopic leaf wetness" means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 μm, microscopic leaf wetness is about two orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the type and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g., ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

  3. Antioxidant Activity of Water-soluble Polysaccharides from Brasenia schreberi

    PubMed Central

    Xiao, Huiwen; Cai, Xueru; Fan, Yijun; Luo, Aoxue

    2016-01-01

    Objective: In order to investigate the antioxidant activities of polysaccharides (BPL-1 and BPL-2), one of the most important functional constituents in Brasenia schreberi was isolated from the external mucilage of B. schreberi (BPL-1) and the plant in vivo (BPL-2). This paper examines the relationship between the content of sulfuric radicals and uronic acid in BPL and the antioxidant activity of BPL. Materials and Methods: The free radicals, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) and 1,1-diphnyl-2-picrylhydrazyl (DPPH-), were used to determine the antioxidant activity of BPL. The Fourier-transform infrared spectroscopy of BPL-1 and BPL-2 revealed typical characteristics of polysaccharides. Results: The two sample types had different contents. This was proved by their different adsorption peak intensities. The IC50 values of BPL-1 (31.189 mg/ml) and BPL-2 (1.863 mg/ml) showed significant DPPH radical scavenging activity. Based on the quantification of ABTS radical scavenging, the IC50 value of BPL-1 (5.460 mg/ml) was higher than that of BPL-2 (0.239 mg/ml). Therefore, in terms of the reducing power, the IC50 value of BPL-1 was too high to determine, and the IC50 value of BPL-2 was found to be 50.557 mg/ml. Hence, the antioxidant activity and total reducing power were high, and they were greater in BPL-2 than in BPL-1. In addition, BPL-2 was found to have more sulfuric radicals and uronic acid than BPL-1. Conclusion: The contents of sulfuric radicals and uronic acid are significantly correlated to the antioxidant activity and reducing power of BPL; the more sulfuric radicals and uronic acid, the more antioxidant activity and reducing power BPL has. SUMMARY The water-soluble crude polysaccharides obtained from the external mucilage and the Brasenia schreberi plant in vivo were confirmed to have high contents of sulfuric radicals and uronic acidBoth BPL-1 and BPL-2 exhibited antioxidative activity and reducing power, and their antioxidative

  4. Antioxidant Activity of Water-soluble Polysaccharides from Brasenia schreberi

    PubMed Central

    Xiao, Huiwen; Cai, Xueru; Fan, Yijun; Luo, Aoxue

    2016-01-01

    Objective: In order to investigate the antioxidant activities of polysaccharides (BPL-1 and BPL-2), one of the most important functional constituents in Brasenia schreberi was isolated from the external mucilage of B. schreberi (BPL-1) and the plant in vivo (BPL-2). This paper examines the relationship between the content of sulfuric radicals and uronic acid in BPL and the antioxidant activity of BPL. Materials and Methods: The free radicals, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) and 1,1-diphnyl-2-picrylhydrazyl (DPPH-), were used to determine the antioxidant activity of BPL. The Fourier-transform infrared spectroscopy of BPL-1 and BPL-2 revealed typical characteristics of polysaccharides. Results: The two sample types had different contents. This was proved by their different adsorption peak intensities. The IC50 values of BPL-1 (31.189 mg/ml) and BPL-2 (1.863 mg/ml) showed significant DPPH radical scavenging activity. Based on the quantification of ABTS radical scavenging, the IC50 value of BPL-1 (5.460 mg/ml) was higher than that of BPL-2 (0.239 mg/ml). Therefore, in terms of the reducing power, the IC50 value of BPL-1 was too high to determine, and the IC50 value of BPL-2 was found to be 50.557 mg/ml. Hence, the antioxidant activity and total reducing power were high, and they were greater in BPL-2 than in BPL-1. In addition, BPL-2 was found to have more sulfuric radicals and uronic acid than BPL-1. Conclusion: The contents of sulfuric radicals and uronic acid are significantly correlated to the antioxidant activity and reducing power of BPL; the more sulfuric radicals and uronic acid, the more antioxidant activity and reducing power BPL has. SUMMARY The water-soluble crude polysaccharides obtained from the external mucilage and the Brasenia schreberi plant in vivo were confirmed to have high contents of sulfuric radicals and uronic acidBoth BPL-1 and BPL-2 exhibited antioxidative activity and reducing power, and their antioxidative

  5. Leaf Histology--Two Modern Methods.

    ERIC Educational Resources Information Center

    Freeman, H. E.

    1984-01-01

    Two methods for examining leaf structure are presented; both methods involve use of "superglue." The first method uses the glue to form a thin, permanent, direct replica of a leaf surface on a microscope slide. The second method uses the glue to examine the three-dimensional structure of spongy mesophyll. (JN)

  6. 7 CFR 30.2 - Leaf tobacco.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf tobacco. 30.2 Section 30.2 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.2...

  7. 7 CFR 30.2 - Leaf tobacco.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf tobacco. 30.2 Section 30.2 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.2...

  8. 7 CFR 30.2 - Leaf tobacco.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf tobacco. 30.2 Section 30.2 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.2...

  9. 7 CFR 30.2 - Leaf tobacco.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf tobacco. 30.2 Section 30.2 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.2...

  10. 7 CFR 30.2 - Leaf tobacco.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf tobacco. 30.2 Section 30.2 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.2...

  11. 7 CFR 29.1029 - Leaf scrap.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.1029 Section 29.1029 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1029 Leaf scrap. A byproduct of stemmed and unstemmed tobacco....

  12. 7 CFR 29.2277 - Leaf scrap.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2277 Section 29.2277 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and...

  13. Evolutionary and Environmental Forces Sculpting Leaf Development.

    PubMed

    Chitwood, Daniel H; Sinha, Neelima R

    2016-04-01

    Leaf shape is spectacularly diverse. As a major component of plant architecture and an interface for light capture, gas exchange, and thermoregulation, the potential contributions of leaves to plant fitness are innumerable. Particularly because of their intimate association and interaction with the surrounding environment, both the plasticity of leaf shape during the lifetime of a plant and the evolution of leaf shape over geologic time are revealing with respect to leaf function. Leaf shapes arise within a developmental context that constrains both their evolution and environmental plasticity. Quantitative models capturing genetic diversity, developmental context, and environmental plasticity will be required to fully understand the evolution and development of leaf shape and its response to environmental pressures. In this review, we discuss recent literature demonstrating that distinct molecular pathways are modulated by specific environmental inputs, the output of which regulates leaf dissection. We propose a synthesis explaining both historical patterns in the paleorecord and conserved plastic responses in extant plants. Understanding the potential adaptive value of leaf shape, and how to molecularly manipulate it, will prove to be invaluable in designing crops optimized for future climates. PMID:27046820

  14. 7 CFR 29.2530 - Leaf structure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2530 Leaf structure. The cell development of... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.2530 Section 29.2530 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  15. 7 CFR 29.2530 - Leaf structure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2530 Leaf structure. The cell development of... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf structure. 29.2530 Section 29.2530 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  16. 7 CFR 29.2278 - Leaf structure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... structure. The cell development of a leaf as indicated by its porosity. (See chart, § 29.2351.) ... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf structure. 29.2278 Section 29.2278 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  17. 7 CFR 29.2278 - Leaf structure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... structure. The cell development of a leaf as indicated by its porosity. (See chart, § 29.2351.) ... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf structure. 29.2278 Section 29.2278 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  18. 7 CFR 29.2530 - Leaf structure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2530 Leaf structure. The cell development of... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf structure. 29.2530 Section 29.2530 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  19. 7 CFR 29.2530 - Leaf structure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2530 Leaf structure. The cell development of... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf structure. 29.2530 Section 29.2530 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  20. 7 CFR 29.2278 - Leaf structure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... structure. The cell development of a leaf as indicated by its porosity. (See chart, § 29.2351.) ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.2278 Section 29.2278 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  1. 7 CFR 29.2530 - Leaf structure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2530 Leaf structure. The cell development of... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf structure. 29.2530 Section 29.2530 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  2. 7 CFR 29.2278 - Leaf structure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... structure. The cell development of a leaf as indicated by its porosity. (See chart, § 29.2351.) ... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf structure. 29.2278 Section 29.2278 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  3. 7 CFR 29.2278 - Leaf structure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... structure. The cell development of a leaf as indicated by its porosity. (See chart, § 29.2351.) ... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf structure. 29.2278 Section 29.2278 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  4. [Quantitive variation of polysaccharides and alcohol-soluble extracts in F1 generation of Dendrobium officinale].

    PubMed

    Zhang, Xiao-Ling; Liu, Jing-Jing; Wu, Ling-Shang; Si, Jin-Ping; Guo, Ying-Ying; Yu, Jie; Wang, Lin-Hua

    2013-11-01

    Using phenol-sulfuric acid method and hot-dip method of alcohol-soluble extracts, the contents of polysaccharides and alcohol-soluble extracts in 11 F1 generations of Dendrobium officinale were determined. The results showed that the polysaccharides contents in samples collected in May and February were 32.89%-43.07% and 25.77%-35.25%, respectively, while the extracts contents were 2.81%-4.85% and 7.90%-17.40%, respectively. They were significantly different among families. The content of polysaccharides in offspring could be significantly improved by hybridization between parents with low and high polysaccharides contents, and the hybrid vigor was obvious. Cross breeding was an effective way for breeding new varieties with higher polysaccharides contents. Harvest time would significantly affect the contents of polysaccharides and alcohol-soluble extracts. The contents of polysaccharides in families collected in May were higher than those of polysaccharides in families collected in February, but the extracts content had the opposite variation. The extents of quantitative variation of polysaccharides and alcohol-soluble extracts were different among families, and each family had its own rules. It would be significant in giving full play to their role as the excellent varieties and increasing effectiveness by studying on the quantitative accumulation regularity of polysaccharides and alcohol-soluble extracts in superior families (varieties) of D. officinale to determine the best harvesting time. PMID:24494555

  5. Coprecipitation of Th(4+) and the purified extracellular polysaccharide produced by bacterium Bradyrhizobium (Chamaecytisus) BGA-1.

    PubMed

    Díaz-Marrero, Ana R; Santamaría, Mónica; Hernández, Jairo; Corzo, Javier

    2004-08-01

    The soil bacterium Bradyrhizobium (Chamaecytisus) strain BGA-1 produces an extracellular polymeric substance (EPS) that, in the presence of Fe(3+), Al(3+) or Th(4+) solutions, forms a gel-like precipitate composed of polysaccharide, protein, lipopolysaccharide and the metal. Precipitation of the main component of the EPS, the extracellular polysaccharide, and thorium was studied. The precipitate was stable, but redissolved at pH values below 3.0 or in the presence of 10 mM EDTA. In the precipitate, the ratio thorium/basic repeating unit of the polysaccharide ranged from 0.4 to 0.8 mol/mol. Soluble polysaccharide-thorium complexes were not found, and larger polysaccharide molecules were precipitated in preference to smaller ones. Kinetic studies showed a non-linear dependence of the precipitate on the concentrations of both thorium and polysaccharide. The behaviors of the purified polysaccharide and of whole EPS with the thorium-containing precipitate were compared. The results suggested that EPS components other than polysaccharide are able to modify the precipitating ability of the polysaccharide. Thus, whole EPS is a better substrate than the purified polysaccharide for the removal of thorium from its solutions.

  6. Immunogenicity of meningococcal B polysaccharide conjugated to tetanus toxoid or CRM197 via adipic acid dihydrazide.

    PubMed

    Bartoloni, A; Norelli, F; Ceccarini, C; Rappuoli, R; Costantino, P

    1995-04-01

    Vaccine development against Group B Neisseria meningitidis is complicated by the nature of the capsular polysaccharide, which is alpha 2-8-linked poly-sialic acid, identical in structure to the poly-sialic acid found in many mammalian tissues during development. To test the feasibility of a vaccine based on this polysaccharide, we synthesized several conjugates of meningococcal B polysaccharide linked to a carrier protein (tetanus toxoid or diphtheria CRM197), via an adipic acid dihydrazide (ADH) spacer. All conjugates induced a strong immune response. However, most of the antibodies were not directed against the Meningococcus B polysaccharide and could not be inhibited by the purified polysaccharide alone. Further investigations showed that the antibodies recognized an epitope composed by the junction between the spacer and the polysaccharide and protein, that is not present in the native polysaccharide and is generated during the coupling reaction. This epitope becomes immunodominant with respect to the poorly immunogenic polysaccharide. While the majority of the immune response is directed against the above epitope, the conjugates induced also an immune response against the Meningococcus B polysaccharide. The anti-Meningococcus B antibodies elicited are of the IgM and IgG class and are inhibitable by the polysaccharide. Moreover, they are bactericidal, thus suggesting that they would induce protection against disease. PMID:7543714

  7. The Potential of Brittle Star Extracted Polysaccharide in Promoting Apoptosis via Intrinsic Signaling Pathway

    PubMed Central

    Baharara, Javad; Amini, Elaheh

    2015-01-01

    Background: Anti-cancer potential of marine natural products such as polysaccharides represented therapeutic potential in oncological researches. In this study, total polysaccharide from brittle star [Ophiocoma erinaceus (O. erinaceus)] was extracted and chemopreventive efficacy of Persian Gulf brittle star polysaccharide was investigated in HeLa human cervical cancer cells. Methods: To extract polysaccharide, dried brittle stars were ground and extracted mechanically. Then, detection of polysaccharide was performed by phenol sulfuric acid, Ultra Violet (UV)-sulfuric acid method and FTIR. The anti proliferative activity of isolated polysaccharide was examined by MTT assay and evaluation of cell death was done through morphological cell changes; Propodium Iodide staining, fluorescence microscopy and caspase-3, -9 enzymatic measurements. To assess its underlying mechanism, expression of Bax, Bcl-2 was evaluated. Results: The polysaccharide detection methods demonstrated isolation of crude polysaccharide from Persian Gulf brittle star. The results revealed that O. erinaceus polysaccharide suppressed the proliferation of HeLa cells in a dose and time dependent manner. Morphological observation of DAPI and Acridine Orange/Propodium Iodide staining was documented by typical characteristics of apoptotic cell death. Flow cytometry analyses exhibited the accumulation of treated cells in sub-G1 region. Additionally, polysaccharide extracted induced intrinsic apoptosis via up-regulation of caspase-3, caspase-9 and Bax along with down-regulation of Bcl-2 in HeLa cells. Conclusion: Taken together, the apoptosis inducing effect of brittle star polysaccharide via intrinsic pathway confirmed the anti tumor potential of marine polysaccharide. Therefore, these findings proposed new insight into anti cancer properties of brittle star polysaccharide as a promising agent in cervical cancer treatment. PMID:26605009

  8. Possible Roles of Strigolactones during Leaf Senescence

    PubMed Central

    Yamada, Yusuke; Umehara, Mikihisa

    2015-01-01

    Leaf senescence is a complicated developmental process that involves degenerative changes and nutrient recycling. The progress of leaf senescence is controlled by various environmental cues and plant hormones, including ethylene, jasmonic acid, salicylic acid, abscisic acid, cytokinins, and strigolactones. The production of strigolactones is induced in response to nitrogen and phosphorous deficiency. Strigolactones also accelerate leaf senescence and regulate shoot branching and root architecture. Leaf senescence is actively promoted in a nutrient-poor soil environment, and nutrients are transported from old leaves to young tissues and seeds. Strigolactones might act as important signals in response to nutrient levels in the rhizosphere. In this review, we discuss the possible roles of strigolactones during leaf senescence. PMID:27135345

  9. Relating Stomatal Conductance to Leaf Functional Traits

    PubMed Central

    Kröber, Wenzel; Plath, Isa; Heklau, Heike; Bruelheide, Helge

    2015-01-01

    Leaf functional traits are important because they reflect physiological functions, such as transpiration and carbon assimilation. In particular, morphological leaf traits have the potential to summarize plants strategies in terms of water use efficiency, growth pattern and nutrient use. The leaf economics spectrum (LES) is a recognized framework in functional plant ecology and reflects a gradient of increasing specific leaf area (SLA), leaf nitrogen, phosphorus and cation content, and decreasing leaf dry matter content (LDMC) and carbon nitrogen ratio (CN). The LES describes different strategies ranging from that of short-lived leaves with high photosynthetic capacity per leaf mass to long-lived leaves with low mass-based carbon assimilation rates. However, traits that are not included in the LES might provide additional information on the species' physiology, such as those related to stomatal control. Protocols are presented for a wide range of leaf functional traits, including traits of the LES, but also traits that are independent of the LES. In particular, a new method is introduced that relates the plants’ regulatory behavior in stomatal conductance to vapor pressure deficit. The resulting parameters of stomatal regulation can then be compared to the LES and other plant functional traits. The results show that functional leaf traits of the LES were also valid predictors for the parameters of stomatal regulation. For example, leaf carbon concentration was positively related to the vapor pressure deficit (vpd) at the point of inflection and the maximum of the conductance-vpd curve. However, traits that are not included in the LES added information in explaining parameters of stomatal control: the vpd at the point of inflection of the conductance-vpd curve was lower for species with higher stomatal density and higher stomatal index. Overall, stomata and vein traits were more powerful predictors for explaining stomatal regulation than traits used in the LES

  10. Relating Stomatal Conductance to Leaf Functional Traits.

    PubMed

    Kröber, Wenzel; Plath, Isa; Heklau, Heike; Bruelheide, Helge

    2015-10-12

    Leaf functional traits are important because they reflect physiological functions, such as transpiration and carbon assimilation. In particular, morphological leaf traits have the potential to summarize plants strategies in terms of water use efficiency, growth pattern and nutrient use. The leaf economics spectrum (LES) is a recognized framework in functional plant ecology and reflects a gradient of increasing specific leaf area (SLA), leaf nitrogen, phosphorus and cation content, and decreasing leaf dry matter content (LDMC) and carbon nitrogen ratio (CN). The LES describes different strategies ranging from that of short-lived leaves with high photosynthetic capacity per leaf mass to long-lived leaves with low mass-based carbon assimilation rates. However, traits that are not included in the LES might provide additional information on the species' physiology, such as those related to stomatal control. Protocols are presented for a wide range of leaf functional traits, including traits of the LES, but also traits that are independent of the LES. In particular, a new method is introduced that relates the plants' regulatory behavior in stomatal conductance to vapor pressure deficit. The resulting parameters of stomatal regulation can then be compared to the LES and other plant functional traits. The results show that functional leaf traits of the LES were also valid predictors for the parameters of stomatal regulation. For example, leaf carbon concentration was positively related to the vapor pressure deficit (vpd) at the point of inflection and the maximum of the conductance-vpd curve. However, traits that are not included in the LES added information in explaining parameters of stomatal control: the vpd at the point of inflection of the conductance-vpd curve was lower for species with higher stomatal density and higher stomatal index. Overall, stomata and vein traits were more powerful predictors for explaining stomatal regulation than traits used in the LES.

  11. Changes in Leaf Trichomes and Epicuticular Flavonoids during Leaf Development in Three Birch Taxa

    PubMed Central

    VALKAMA, ELENA; SALMINEN, JUHA-PEKKA; KORICHEVA, JULIA; PIHLAJA, KALEVI

    2004-01-01

    • Background and Aims Changes in number of trichomes and in composition and concentrations of their exudates throughout leaf development may have important consequences for plant adaptation to abiotic and biotic factors. In the present study, seasonal changes in leaf trichomes and epicuticular flavonoid aglycones in three Finnish birch taxa (Betula pendula, B. pubescens ssp. pubescens, and B. pubescens ssp. czerepanovii) were followed. • Methods Trichome number and ultrastructure were studied by means of light, scanning and transmission electron microscopy, while flavonoid aglycones in ethanolic leaf surface extracts were analysed by high-pressure liquid chromatography. • Key Results Density of both glandular and non-glandular trichomes decreased drastically with leaf expansion while the total number of trichomes per leaf remained constant, indicating that the final number of trichomes is established early in leaf development. Cells of glandular trichomes differentiate before those of the epidermis and produce secreted material only during the relatively short period (around 1–2 weeks) of leaf unfolding and expansion. In fully expanded leaves, glandular trichomes appeared to be at the post-secretory phase and function mainly as storage organs; they contained lipid droplets and osmiophilic material (probably phenolics). Concentrations (mg g−1 d. wt) of surface flavonoids decreased with leaf age in all taxa. However, the changes in total amount (µg per leaf) of flavonoids during leaf development were taxon-specific: no changes in B. pubescens ssp. czerepanovii, increase in B. pendula and in B. pubescens ssp. pubescens followed by the decline in the latter taxon. Concentrations of most of the individual leaf surface flavonoids correlated positively with the density of glandular trichomes within species, suggesting the participation of glandular trichomes in production of surface flavonoids. • Conclusions Rapid decline in the density of leaf trichomes and

  12. Two WUSCHEL-related homeobox genes, narrow leaf2 and narrow leaf3, control leaf width in rice.

    PubMed

    Ishiwata, Aiko; Ozawa, Misa; Nagasaki, Hiroshi; Kato, Makio; Noda, Yusaku; Yamaguchi, Takahiro; Nosaka, Misuzu; Shimizu-Sato, Sae; Nagasaki, Akie; Maekawa, Masahiko; Hirano, Hiro-Yuki; Sato, Yutaka

    2013-05-01

    Leaf shape is one of the key determinants of plant architecture. Leaf shape also affects the amount of sunlight captured and influences photosynthetic efficiency; thus, it is an important agronomic trait in crop plants. Understanding the molecular mechanisms governing leaf shape is a central issue of plant developmental biology and agrobiotechnology. Here, we characterized the narrow-leaf phenotype of FL90, a linkage tester line of rice (Oryza sativa). Light and scanning electron microscopic analyses of FL90 leaves revealed defects in the development of marginal regions and a reduction in the number of longitudinal veins. The narrow-leaf phenotype of FL90 shows a two-factor recessive inheritance and is caused by the loss of function of two WUSCHEL-related homeobox genes, NAL2 and NAL3 (NAL2/3), which are duplicate genes orthologous to maize NS1 and NS2 and to Arabidopsis PRS. The overexpression of NAL2/3 in transgenic rice plants results in wider leaves containing increased numbers of veins, suggesting that NAL2/3 expression regulates leaf width. Thus, NAL2/3 can be used to modulate leaf shape and improve agronomic yield in crop plants. PMID:23420902

  13. A model for leaf initiation

    PubMed Central

    Abraham-Shrauner, Barbara; Pickard, Barbara G

    2011-01-01

    A biophysical model is proposed for how leaf primordia are positioned on the shoot apical
    meristem in both spiral and whorl phyllotaxes. Primordia are initiated by signals that propagate
    in the epidermis in both azimuthal directions away from the cotyledons or the most recently
    specified primordia. The signals are linear waves as inferred from the spatial periodicity of the
    divergence angle and a temporal periodicity. The periods of the waves, which represent actively
    transported auxin, are much smaller than the plastochron interval. Where oppositely directed
    waves meet at one or more angular positions on the periphery of the generative circle, auxin
    concentration builds and as in most models this stimulates local movement of auxin to
    underlying cells, where it promotes polarized cell division and expansion. For higher order
    spirals the wave model requires asymmetric function of auxin transport; that is, opposite wave
    speeds differ. An algorithm for determination of the angular positions of leaves in common leaf
    phyllotaxic configurations is proposed. The number of turns in a pattern repeat, number of leaves
    per level and per pattern repeat, and divergence angle are related to speed of auxin transport and
    radius of the generative circle. The rule for composition of Fibonacci or Lucas numbers
    associated with some phyllotaxes is discussed. A subcellular model suggests how the shoot
    meristem might specify either symmetric or asymmetric transport of auxin away from the
    forming primordia that produce it. Biological tests that could make or break the mathematical
    and molecular hypotheses are proposed. PMID:22212121

  14. A cytochemical and immunocytochemical analysis of the wall labyrinth apparatus in leaf transfer cells in Elodea canadensis

    PubMed Central

    Ligrone, Roberto; Vaughn, Kevin C.; Rascio, Nicoletta

    2011-01-01

    Background and Aims Transfer cells are plant cells specialized in apoplast/symplast transport and characterized by a distinctive wall labyrinth apparatus. The molecular architecture and biochemistry of the labyrinth apparatus are poorly known. The leaf lamina in the aquatic angiosperm Elodea canadensis consists of only two cell layers, with the abaxial cells developing as transfer cells. The present study investigated biochemical properties of wall ingrowths and associated plasmalemma in these cells. Methods Leaves of Elodea were examined by light and electron microscopy and ATPase activity was localized cytochemically. Immunogold electron microscopy was employed to localize carbohydrate epitopes associated with major cell wall polysaccharides and glycoproteins. Key Results The plasmalemma associated with the wall labyrinth is strongly enriched in light-dependent ATPase activity. The wall ingrowths and an underlying wall layer share an LM11 epitope probably associated with glucuronoarabinoxylan and a CCRC-M7 epitope typically associated with rhamnogalacturonan I. No labelling was observed with LM10, an antibody that recognizes low-substituted and unsubstituted xylan, a polysaccharide consistently associated with secondary cell walls. The JIM5 and JIM7 epitopes, associated with homogalacturonan with different degrees of methylation, appear to be absent in the wall labyrinth but present in the rest of cell walls. Conclusions The wall labyrinth apparatus of leaf transfer cells in Elodea is a specialized structure with distinctive biochemical properties. The high level of light-dependent ATPase activity in the plasmalemma lining the wall labyrinth is consistent with a formerly suggested role of leaf transfer cells in enhancing inorganic carbon inflow. The wall labyrinth is a part of the primary cell wall. The discovery that the wall ingrowths in Elodea have an antibody-binding pattern divergent, in part, from that of the rest of cell wall suggests that their

  15. [FTIR Spectroscopic Characterization of Material Composition in Functional Leaf of Cotton under Stress of Potassium and Boron].

    PubMed

    Wu, Xiu-wen; Hao, Yan-shu; Lei, Jing; Jiang, Cun-cang

    2016-03-01

    Potassium (K) and boron (B) are essential nutrient elements for plants, and the elements play an important role for plant growth, development and physiological metabolism. Cotton has a higher demand for K and B; K deficiency or B deficiency often occurs in cotton though. To reveal the component changes in functional leaf of cotton under K and B stress and investigate effects on material composition from K and B. A pot experiment was conducted at Huazhong Agricultural University. (1) the characteristic peaks at 1 546.86, 1 438.85, 1 153.39 and 1 024.17 cm(-1) disappeared due to B deficiency, and relative absorbance of other characteristic peaks was decreased compared with normal, which suggested that the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in cotent when lack of K. (2) the relative absorbance of all characteristic peaks was increased in the B-deficient cotton leaves compared with normal, suggesting B deficiency leads to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates because of the hindered transportation. (3) lack of both potassium and boron, induced significant changes to both the locations and relative absorbance of characteristic peaks, and the content of protein, and soluble sugar and other carbohydrates increased, while the content of nucleic acids and polysaccharides dropped. K deficiency led to the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in content; B deficiency gave rise to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates; the content of protein and soluble sugar and other carbohydrates increased, while the content of nucleic acids and polysaccharides dropped when K and B were all in short supply.

  16. [FTIR Spectroscopic Characterization of Material Composition in Functional Leaf of Cotton under Stress of Potassium and Boron].

    PubMed

    Wu, Xiu-wen; Hao, Yan-shu; Lei, Jing; Jiang, Cun-cang

    2016-03-01

    Potassium (K) and boron (B) are essential nutrient elements for plants, and the elements play an important role for plant growth, development and physiological metabolism. Cotton has a higher demand for K and B; K deficiency or B deficiency often occurs in cotton though. To reveal the component changes in functional leaf of cotton under K and B stress and investigate effects on material composition from K and B. A pot experiment was conducted at Huazhong Agricultural University. (1) the characteristic peaks at 1 546.86, 1 438.85, 1 153.39 and 1 024.17 cm(-1) disappeared due to B deficiency, and relative absorbance of other characteristic peaks was decreased compared with normal, which suggested that the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in cotent when lack of K. (2) the relative absorbance of all characteristic peaks was increased in the B-deficient cotton leaves compared with normal, suggesting B deficiency leads to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates because of the hindered transportation. (3) lack of both potassium and boron, induced significant changes to both the locations and relative absorbance of characteristic peaks, and the content of protein, and soluble sugar and other carbohydrates increased, while the content of nucleic acids and polysaccharides dropped. K deficiency led to the structures of protein, fiber, soluble sugar and ribosome in cotton functional leaf changed and decreased in content; B deficiency gave rise to the accumulation in leaves of protein, and fiber, soluble sugar and other carbohydrates; the content of protein and soluble sugar and other carbohydrates increased, while the content of nucleic acids and polysaccharides dropped when K and B were all in short supply. PMID:27400504

  17. Melissotarsus ants are likely able to digest plant polysaccharides.

    PubMed

    Mony, Ruth; Dejean, Alain; Bilong, Charles Félix Bilong; Kenne, Martin; Rouland-Lefèvre, Corinne

    2013-10-01

    Melissotarsus ants have an extremely specialized set of behaviours. Both workers and gynes tunnel galleries in their host tree bark. Workers walk with their mesothoracic legs pointing upwards and tend Diaspididae hemiptera for their flesh. The ants use their forelegs to plug the galleries with silk that they secrete themselves. We hypothesised that the ants' energetic needs for nearly constant gallery digging could be satisfied through the absorption of host tree tissues; so, using basic techniques, we examined the digestive capacities of workers from two species. We show that workers are able to degrade oligosaccharides and heterosides as well as, to a lesser degree, polysaccharides. This is one of the rare reports on ants able to digest plant polysaccharides other than starch.

  18. Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi

    NASA Astrophysics Data System (ADS)

    van Bogaert, Inge N. A.; de Maeseneire, Sofie L.; Vandamme, Erick J.

    Several yeasts and yeast-like fungi are known to produce extracellular polysaccharides. Most of these contain D-mannose, either alone or in combination with other sugars or phosphate. A large chemical and structural variability is found between yeast species and even among different strains. The types of polymers that are synthesized can be chemically characterized as mannans, glucans, phosphoman-nans, galactomannans, glucomannans and glucuronoxylomannans. Despite these differences, almost all of the yeast exopolysaccharides display some sort of biological activity. Some of them have already applications in chemistry, pharmacy, cosmetics or as probiotic. Furthermore, some yeast exopolysaccharides, such as pullulan, exhibit specific physico-chemical and rheological properties, making them useful in a wide range of technical applications. A survey is given here of the production, the characteristics and the application potential of currently well studied yeast extracellular polysaccharides.

  19. Modification of cell wall polysaccharides during retting of cassava roots.

    PubMed

    Ngolong Ngea, Guillaume Legrand; Guillon, Fabienne; Essia Ngang, Jean Justin; Bonnin, Estelle; Bouchet, Brigitte; Saulnier, Luc

    2016-12-15

    Retting is an important step in traditional cassava processing that involves tissue softening of the roots to transform the cassava into flour and various food products. The tissue softening that occurs during retting was attributed to the degradation of cell wall pectins through the action of pectin-methylesterase and pectate-lyase that possibly originated from a microbial source or the cassava plant itself. Changes in cell wall composition were investigated during retting using chemical analysis, specific glycanase degradation and immuno-labelling of cell wall polysaccharides. Pectic 1,4-β-d-galactan was the main cell wall polysaccharide affected during the retting of cassava roots. This result suggested that better control of pectic galactan degradation and a better understanding of the degradation mechanism by endogenous endo-galactanase and/or exogenous microbial enzymes might contribute to improve the texture properties of cassava products. PMID:27451197

  20. Enzyme processivity changes with the extent of recalcitrant polysaccharide degradation.

    PubMed

    Hamre, Anne Grethe; Lorentzen, Silje Benedicte; Väljamäe, Priit; Sørlie, Morten

    2014-12-20

    Glycoside hydrolases depolymerize polysaccharides. They can subtract single carbohydrate chains from polymer crystals and cleave glycosidic bonds without dissociating from the substrate after each catalytic event. This processivity is thought to conserve energy during polysaccharide degradation. Herein, we compare the processivity of components of the chitinolytic machinery of Serratia marcescens. The two processive chitinases ChiA and ChiB, the ChiB-W97A mutant, and the endochitinase ChiC were analyzed for the extent of degradation of three different chitin substrates. Moreover, enzyme processivity was assessed on the basis of the [(GlcNAc)2]/[GlcNAc] product ratio. The results show that the apparent processivity (Papp) greatly diminishes with the extent of degradation and confirm the hypothesis that Papp is limited by the length of obstacle free path on the substrate.

  1. Carbohydrase Systems of Saccharophagus degradans Degrading Marine Complex Polysaccharides

    PubMed Central

    Hutcheson, Steven W.; Zhang, Haitao; Suvorov, Maxim

    2011-01-01

    Saccharophagus degradans 2–40 is a γ-subgroup proteobacterium capable of using many of the complex polysaccharides found in the marine environment for growth. To utilize these complex polysaccharides, this bacterium produces a plethora of carbohydrases dedicated to the processing of a carbohydrate class. Aiding in the identification of the contributing genes and enzymes is the known genome sequence for this bacterium. This review catalogs the genes and enzymes of the S. degradans genome that are likely to function in the systems for the utilization of agar, alginate, α- and β-glucans, chitin, mannans, pectins, and xylans and discusses the cell biology and genetics of each system as it functions to transfer carbon back to the bacterium. PMID:21731555

  2. Modification of cell wall polysaccharides during retting of cassava roots.

    PubMed

    Ngolong Ngea, Guillaume Legrand; Guillon, Fabienne; Essia Ngang, Jean Justin; Bonnin, Estelle; Bouchet, Brigitte; Saulnier, Luc

    2016-12-15

    Retting is an important step in traditional cassava processing that involves tissue softening of the roots to transform the cassava into flour and various food products. The tissue softening that occurs during retting was attributed to the degradation of cell wall pectins through the action of pectin-methylesterase and pectate-lyase that possibly originated from a microbial source or the cassava plant itself. Changes in cell wall composition were investigated during retting using chemical analysis, specific glycanase degradation and immuno-labelling of cell wall polysaccharides. Pectic 1,4-β-d-galactan was the main cell wall polysaccharide affected during the retting of cassava roots. This result suggested that better control of pectic galactan degradation and a better understanding of the degradation mechanism by endogenous endo-galactanase and/or exogenous microbial enzymes might contribute to improve the texture properties of cassava products.

  3. Polysaccharides from Chinese tea: recent advance on bioactivity and function.

    PubMed

    Cao, Hui

    2013-11-01

    Tea (Camellia sinensis) has a long history of medicinal use in Asian countries such as China, Japan, India and Thailand as ancient as 500,000 years ago. Tea is globally one of the most popular and lowest cost beverages, next only to water. Tea leaves are popularly consumed with unfermented (green tea), semi-fermented (oolong tea), and fermented (black and puerh) forms. The chemical composition of tea mainly includes polyphenols (TPP), proteins, polysaccharides (TPS), chlorophyll, and alkaloids. Great advances have been made in chemical and bioactive studies of catechins and polyphenols from tea in recent decades. However, polysaccharides from tea materials have received much less consideration than TPP. Recently, TPS from tea leaves and flowers have attracted great interest. The number of relevant publications has increased rapidly in recent years. Herein, the bioactivities and function aspects of TPS from Chinese tea were reviewed. PMID:23994784

  4. Experience with Salmonella typhi Vi capsular polysaccharide vaccine.

    PubMed

    Hessel, L; Debois, H; Fletcher, M; Dumas, R

    1999-09-01

    Typhoid fever remains an important health threat in many parts of the world, with an estimated 16 million cases and 600,000 deaths occurring each year. The emergence of Salmonella typhi strains multiply resistant to antibiotics has complicated the treatment of this disease. Field experience of 8 years shows that a vaccine composed of purified Vi capsular polysaccharide of Salmonella typhi, given as a single intramuscular or deep subcutaneous injection, has consistent immunogenicity and efficacy. Side effects, based on reports since 1989, are infrequent and mild. Furthermore, the Vi vaccine may be administered simultaneously with other common "travel" vaccines, at two different sites of injection, without affecting immunogenicity and tolerability. This review presents an update of the development and clinical experience with the Salmonella typhi Vi polysaccharide vaccine (Typhim Vi; Pasteur Mérieux Connaught, France).

  5. The pretreatment effects on the antioxidant activity of jujube polysaccharides.

    PubMed

    Qu, Chenling; Yu, Songcheng; Jin, Huali; Wang, Jinshui; Luo, Li

    2013-10-01

    Pretreatment is vital to keep the bioactivities of polysaccharides. In this paper, the effects of hot water, ultrasonic and microwave extraction, as well as the effects of protein and pigment removal steps, on the antioxidant activity of water soluble polysaccharides in jujube (WSPJ) were studied. Hydroxyl free radical (OH) scavenging activity was adopted to determine the antioxidant activity of WSPJ. The results showed that OH scavenging activity of WSPJ extracted by ultrasonic wave was higher than that extracted by hot water and by microwave. Furthermore, power parameter in both ultrasonic and microwave extraction affected the OH scavenging activity dramatically. On the other hand, Sevag reagent was better than trichloroacetic acid (TCA), TCA with 1-butanol (TCA-B) and hydrochloric acid for protein removal, and H2O2 was better than active carbon for pigment removal to keep the antioxidant activity of WSPJ.

  6. Fermentation of polysaccharides by Klebsiella and other facultative bacilli

    SciTech Connect

    Ochuba, G.U.; Von Riesen, V.L.

    1980-05-01

    Fermentations of 10 polysaccharides by species of the family Enterobacteriaceae were examined. Algin, guar, karaya, xanthan, and xylan were not fermented by any of the strains tested. Most of the activity was found in the tribe Klebsielleae. Klebseilla oxytoca fermented amylopectin (97% of the strains studied), carrageenan (100%), inulin (68%), polypectate (100%), and tragacanth (100%). Klebsiella pneumoniae fermented amylopectin (91%), carrageenan (100%), and tragacanth (86%). Carraggeenan was also fermented by Enterobacter aerogenes (100%), Enterobacter agglomerans (63%), Enterobacter cloacae (95%), and pectobacterium (38%). pectobacterium shared polypectate fermentation (100%) with K. oxytoca. With one exception, Serratia strains were negative on all polysaccharides. These results, along with other evidence, indicate that (i) the genus Klebsiella is biochemically the most versatile genus of the tribe, (ii) because of its distinct characteristics, K. oxytoca warrants species designation separate from K. pneumoniae, and (iii) some food additives generally considered indigestible can be metabolized by a few species of facultative bacilli, whereas others appear to be resistant.

  7. Fermentation of polysaccharides by Klebsielleae and other facultative bacilli.

    PubMed

    Ochuba, G U; von Riesen, V L

    1980-05-01

    Fermentations of 10 polysaccharides by species of the family Enterobacteriaceae were examined. Algin, guar, karaya, xanthan, and xylan were not fermented by any of the strains tested. Most of the activity was found in the tribe Klebsielleae. Klebsiella oxytoca fermented amylopectin (97% of the strains studied), carrageenan (100%), inulin (68%), polypectate (100%), and tragacanth (100%). Klebsiella pneumoniae fermented amylopectin (91%), carrageenan (100%), and tragacanth (86%). Carrageenan was also fermented by Enterobacter aerogenes (100%), Enterobacter agglomerans (63%), Enterobacter cloacae (95%), and Pectobacterium (38%). Pectobacterium shared polypectate fermentation (100%) with K. oxytoca. With one exception, Serratia strains were negative on all polysaccharides. These results, along with other evidence, indicate that (i) the genus Klebsiella is biochemically the most versatile genus of the tribe, (ii) because of its distinct characteristics, K. oxytoca warrants species designation separate from K. pneumoniae, and (iii) some food additives generally considered indigestible can be metabolized by a few species of facultative bacilli, whereas others appear to be resistant.

  8. Evaluation of anticoagulant activity of two algal polysaccharides.

    PubMed

    Faggio, C; Pagano, M; Dottore, A; Genovese, G; Morabito, M

    2016-09-01

    Marine algae are important sources of phycocolloids like agar, carrageenans and alginates used in industrial applications. Algal polysaccharides have emerged as an important class of bioactive products showing interesting properties. The aim of our study was to evaluate the potential uses as anticoagulant drugs of algal sulphate polysaccharides extracted from Ulva fasciata (Chlorophyta) and Agardhiella subulata (Rhodophyta) collected in Ganzirri Lake (Cape Peloro Lagoon, north-eastern Sicily, Italy). Toxicity of algal extracts through trypan blue test and anticoagulant action measured by activated partial thromboplastin time (APTT), prothrombin time (PT) test has been evaluated. Algal extracts showed to prolong the PT and APTT during the coagulation cascade and to avoid the blood coagulation of samples. Furthermore, the algal extracts lack toxic effects towards cellular metabolism and their productions are relatively at low cost. This permits to consider the algae as the biological source of the future.

  9. Complete structure of the polysaccharide from Streptococcus sanguis J22

    SciTech Connect

    Abeygunawardana, C.; Bush, C.A. ); Cisar, J.O. )

    1990-01-09

    The cell wall polysaccharides of certain oral streptococci such as Streptococcus sanguis strains 34 and J22, although immunologically distinct, act as receptors for the fimbrial lectins of Actinomyces viscosus T14V. The authors report the complete covalent structure of the polysaccharide from S. sanguis J22 which is composed of a heptasaccharide subunit linked by phosphodiester bonds. The repeating subunit, which contains {alpha}-GalNAc, {alpha}-rhamnose, {beta}-rhamnose, {beta}-glucose, and {beta}-galactose all in the pyranoside form and {beta}-galactofuranose, is compared with the previously published structure of the polysaccharide from strain 34. The structure has been determined almost exclusively by high-resolution nuclear magnetic resonance methods. The {sup 1}H and {sup 13}C NMR spectra of the polysaccharides from both strains 34 and J22 have been completely assigned. The stereochemistry of pyranosides was assigned from J{sub H-H} values determined from phase-sensitive COSY spectra, and acetamido sugars were assigned by correlation of the resonances of the amide {sup 1}H with the sugar ring protons. The {sup 13}C spectra were assigned by {sup 1}H-detected multiple-quantum correlation (HMQC) spectra, and the assignments were confirmed by {sup 1}H-detected multiple-bond correlation (HMBC) spectra. The positions of the glycosidic linkages were assigned by detection of three-bond {sup 1}H-{sup 13}C correlation across the glycosidic linkage in the HMBC spectra. The positions of the phosphodiester linkages were determined by splittings observed in the {sup 13}C resonances due to {sup 31}P coupling and also by {sup 1}H-detected {sup 31}P correlation spectroscopy.

  10. Lubrication, adsorption, and rheology of aqueous polysaccharide solutions.

    PubMed

    Stokes, Jason R; Macakova, Lubica; Chojnicka-Paszun, Agnieszka; de Kruif, Cornelis G; de Jongh, Harmen H J

    2011-04-01

    Aqueous lubrication is currently at the forefront of tribological research due to the desire to learn and potentially mimic how nature lubricates biotribological contacts. We focus here on understanding the lubrication properties of naturally occurring polysaccharides in aqueous solution using a combination of tribology, adsorption, and rheology. The polysaccharides include pectin, xanthan gum, gellan, and locus bean gum that are all widely used in food and nonfood applications. They form rheologically complex fluids in aqueous solution that are both shear thinning and elastic, and their normal stress differences at high shear rates are found to be characteristic of semiflexible/rigid molecules. Lubrication is studied using a ball-on-disk tribometer with hydrophobic elastomer surfaces, mimicking biotribological contacts, and the friction coefficient is measured as a function of speed across the boundary, mixed, and hydrodynamic lubrication regimes. The hydrodynamic regime, where the friction coefficient increases with increasing lubricant entrainment speed, is found to depend on the viscosity of the polysaccharide solutions at shear rates of around 10(4) s(-1). The boundary regime, which occurs at the lowest entrainment speeds, depends on the adsorption of polymer to the substrate. In this regime, the friction coefficient for a rough substrate (400 nm rms roughness) is dependent on the dry mass of polymer adsorbed to the surface (obtained from surface plasmon resonance), while for a smooth substrate (10 nm rms roughness) the friction coefficient is strongly dependent on the hydrated wet mass of adsorbed polymer (obtained from quartz crystal microbalance, QCM-D). The mixed regime is dependent on both the adsorbed film properties and lubricant's viscosity at high shear rates. In addition, the entrainment speed where the friction coefficient is a minimum, which corresponds to the transition between the hydrodynamic and mixed regime, correlates linearly with the ratio

  11. Polysaccharides as Alternative Moisture Retention Agents for Shrimp.

    PubMed

    Torti, Michael J; Sims, Charles A; Adams, Charles M; Sarnoski, Paul J

    2016-03-01

    Phosphates are used as moisture retention agents (MRAs) by the shrimp industry. Although they are effective, phosphates are expensive, need to be listed on a food label, and overuse can often lead to a higher product cost for consumers. Polysaccharides were researched as alternative MRAs. Polysaccharides are usually inexpensive, are considered natural, and can have nutritional benefits. Research was conducted to determine whether polysaccharides yielded similar functional impacts as phosphates. Treatments included a 0.5% fibercolloid solution isolated from citrus peel, an 8% pectin solution, a 0.5% xanthan gum (XG) solution, a 1% carboxymethyl cellulose solution, and conventionally used 4% sodium tripolyphosphate (STP). Experimental treatments were compared to a distilled water control to gauge effectiveness. Freezing, boiling, and oven drying studies were performed to determine how moisture retention in shrimp differed using these different treatments. Water activity was measured to determine any potential differences in shelf life. Solution uptake was also determined to understand how well the treatments enhanced water binding. For moisture loss by freezing, 4% STP and the 0.5% fibercolloid solution functioned the best. The 4% STP treated shrimp lost the least amount of moisture during boiling. The 0.5% fibercolloid and 0.5% XG treatment outperformed phosphates in respect to moisture uptake ability. None of the treatments had a major effect on water activity. All treatments were rated similar in consumer sensory acceptability tests except for pectin, which was rated lower by the sensory panel. Overall, polysaccharides were found to be viable alternatives to phosphates. PMID:26849189

  12. Interrelation between the crystallinity of polysaccharides and water absorption

    NASA Astrophysics Data System (ADS)

    Prusov, A. N.; Prusova, S. M.; Radugin, M. V.; Zakharov, A. G.

    2014-05-01

    The maximum sorption of water and its vapors is calculated using experimental data from calorimetric and effusion studies of flax, wood, and cotton cellulose. X-day diffraction is used to determine the crystallinity of cellulose samples. The equations relating crystallinity ( X) with maximum sorption and the enthalpy of interaction between cellulose and water are presented. Experimental results and the literature data on water sorption by chitin, chitosan and other polysaccharides show that our equations for calculating crystallinity are correct.

  13. Synthesis of Calocybe indica var. APK2 polysaccharide repeating unit.

    PubMed

    Zhang, Lei; Zhu, Xiangming

    2014-06-01

    The first total synthesis of p-methoxyphenyl α-l-fucopyranosyl-(1→6)-α-d-galactopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside (2) was achieved starting from five monosaccharide building blocks. This structure represents the repeating unit of the polysaccharide isolated from edible mushroom Calocybe indica var. APK2, and was synthesized in high overall yield via a convergent '3+2' glycosylation strategy.

  14. EXTRACELLULAR POLYSACCHARIDES OF ALGAE: EFFECTS ON LIFE-SUPPORT SYSTEMS.

    PubMed

    MOORE, B G; TISCHER, R G

    1964-08-01

    The amount of extracellular polysaccharide produced by eight species of green and blue-green algae ranges from 174 milligrams per liter to 557 milligrams per liter. Most of the polymers are composed of four monosaccharides: a hexose, a pentose, a methyl pentose, and uronic acid. The production of excessive amounts of these photosynthetic end products will undoubtedly influence the effective recycling time of growth media in life-support systems.

  15. High molecular weight polysaccharide that binds and inhibits virus

    DOEpatents

    Konowalchuk, Thomas W

    2014-01-14

    This invention provides a high molecular weight polysaccharide capable of binding to and inhibiting virus and related pharmaceutical formulations and methods on inhibiting viral infectivity and/or pathogenicity, as well as immunogenic compositions. The invention further methods of inhibiting the growth of cancer cells and of ameliorating a symptom of aging. Additionally, the invention provides methods of detecting and/or quantifying and/or isolating viruses.

  16. The opsX locus of Xanthomonas campestris affects host range and biosynthesis of lipopolysaccharide and extracellular polysaccharide.

    PubMed Central

    Kingsley, M T; Gabriel, D W; Marlow, G C; Roberts, P D

    1993-01-01

    Xanthomonas campestris pv. citrumelo strain 3048 is the causal agent of citrus bacterial leaf spot disease and has a wide host range that includes rutaceous and leguminous plants. A spontaneous prototrophic mutant of strain 3048 (strain M28) that had lost virulence on citrus but retained virulence on bean plants was recovered. Growth studies in planta showed that M28 cells died rapidly in citrus leaves but grew normally in bean leaves. In addition to the loss of citrus-specific virulence, M28 displayed the following mutant phenotypes in culture: decreased growth rate, reduction of the amount of exopolysaccharide (to ca. 25% of the amount in 3048), loss of capsules, and significant alterations of the two 3048 lipopolysaccharide (LPS) bands visualized by silver stain on polyacrylamide gels, consistent with a defect(s) in LPS assembly. A 38-kb DNA fragment from a 3048 total DNA library that complemented the mutant phenotypes of M28 was identified. The 38-kb fragment did not hybridize to two similarly sized fragments carrying different hrp (hypersensitive response and pathogenicity) genes cloned from 3048. Subcloning, DNA sequence analyses, and gene disruption experiments were used to identify a single gene, opsX (for outer-membrane polysaccharide), responsible for the mutant phenotypes of M28. At least one other gene downstream from opsX also affected the same phenotypes and may be part of a gene cluster. We report here the DNA sequence and transcriptional start site of opsX. A search of protein sequence data bases with the predicted 31.3-kDa OpsX sequence found strong similarity to Lsi-1 of Neisseria gonorrhoeae and RfaQ of Escherichia coli (both are involved in LPS core assembly). The host-specific virulence function of opsX appears to involve biosynthesis of the extracellular polysaccharide and a complete LPS. Both may be needed in normal amounts for protection from citrus, but not bean, defense compounds. Images PMID:8376331

  17. Extraction of polysaccharides from Phellinus nigricans mycelia and their antioxidant activities in vitro.

    PubMed

    Wang, Zhanyong; Wang, Chenyu; Quan, Yue

    2014-01-01

    In this study, response surface methodology was employed to optimize the extraction of polysaccharides from Phellinus nigricans mycelia. A central composite design was adopted to determine optimum parameters (extraction time, extraction temperature, extraction frequency, and ratio of water to raw material) that could yield a maximum polysaccharide. Results revealed the following optimum extraction conditions: extraction time, 2.8h; ratio of water to raw material, 28; extraction frequency, 5; and extraction temperature, 95 °C. Under optimized conditions, the experimental yield of P. nigricans mycelia polysaccharides was 15.33 ± 0.21%, which is consistent with the predicted yield. The antioxidant activity assay in vitro showed that the polysaccharides exhibited a high scavenging activity against superoxide anion, hydroxyl, and 1,1-diphenyl-2-picrylhydrazyl radicals. These polysaccharides also exhibited a strong reducing power. Thus, these polysaccharides can be used as natural antioxidants in functional foods or medicine.

  18. Antitumor polysaccharides from mushrooms: a review on the structural characteristics, antitumor mechanisms and immunomodulating activities.

    PubMed

    Meng, Xin; Liang, Hebin; Luo, Lixin

    2016-04-01

    Mushrooms are popular folk medicines that have attracted considerable attention because of their efficient antitumor activities. This review covers existing research achievements on the mechanisms of isolated mushroom polysaccharides, particularly (1→3)-β-D-glucans. Our review also describes the function in modulating the immune system and potential tumor-inhibitory effects of polysaccharides. The antitumor mechanisms of mushroom polysaccharides are mediated by stimulated T cells or other immune cells. These polysaccharides are able to trigger various cellular responses, such as the expression of cytokines and nitric oxide. Most polysaccharides could bind other conjugate molecules, such as polypeptides and proteins, whose conjugation always possess strong antitumor activities. The purpose of this review is to summarize available information, and to reflect the present situation of polysaccharide research filed with a view for future direction. PMID:26974354

  19. Characterization of polysaccharides extracted from spent coffee grounds by alkali pretreatment.

    PubMed

    Ballesteros, Lina F; Cerqueira, Miguel A; Teixeira, José A; Mussatto, Solange I

    2015-01-01

    Spent coffee grounds (SCG), obtained during the processing of coffee powder with hot water to make soluble coffee, are the main coffee industry residues and retain approximately seventy percent of the polysaccharides present in the roasted coffee beans. The purpose of this study was to extract polysaccharides from SCG by using an alkali pretreatment with sodium hydroxide at 25°C, and determine the chemical composition, as well as the antioxidant and antimicrobial properties of the extracted polysaccharides. Galactose (60.27%mol) was the dominant sugar in the recovered polysaccharides, followed by arabinose (19.93%mol), glucose (15.37%mol) and mannose (4.43%mol). SCG polysaccharides were thermostable, and presented a typical carbohydrate pattern. Additionally, they showed good antioxidant activity through different methods and presented high antimicrobial percent inhibition against Phoma violacea and Cladosporium cladosporioides (41.27% and 54.60%, respectively). These findings allow identifying possible applications for these polysaccharides in the food industry.

  20. Polysaccharides from Umbilicaria esculenta cultivated in Huangshan Mountain and immunomodulatory activity.

    PubMed

    Du, Yi-Qun; Liu, Yong; Wang, Jun-Hui

    2015-01-01

    Umbilicaria esculenta cultivated in Huangshan Mountain (HSSE) is precious edible and medicinal lichen. In this study, four polysaccharide fractions designated as UEP1, UEP2, UEP3, and UEP4 were isolated from HSSE with water extraction at different temperature. The physico-chemical properties and immunomodulatory activities of polysaccharide fractions were investigated. The results indicated that UEP1, UEP2, UEP3 and UEP4 were acid polysaccharide with 0.50%, 0.62%, 0.63%, and 0.83% of uronic acid contents, respectively. Four polysaccharide fractions were mainly composed of glucose, galactose and mannose with different molar ratio. In the in vitro immunomodulatory assay, all the polysaccharide fractions (20-500 μg/mL) could increase the NO production and phagocytic activity of RAW 264.7 cells in a dose-dependent manner. This work demonstrated that the polysaccharides from HSSE could be used as potential biological response modifier. PMID:25316425

  1. Marine Polysaccharides: A Source of Bioactive Molecules for Cell Therapy and Tissue Engineering

    PubMed Central

    Senni, Karim; Pereira, Jessica; Gueniche, Farida; Delbarre-Ladrat, Christine; Sinquin, Corinne; Ratiskol, Jacqueline; Godeau, Gaston; Fischer, Anne-Marie; Helley, Dominique; Colliec-Jouault, Sylvia

    2011-01-01

    The therapeutic potential of natural bioactive compounds such as polysaccharides, especially glycosaminoglycans, is now well documented, and this activity combined with natural biodiversity will allow the development of a new generation of therapeutics. Advances in our understanding of the biosynthesis, structure and function of complex glycans from mammalian origin have shown the crucial role of this class of molecules to modulate disease processes and the importance of a deeper knowledge of structure-activity relationships. Marine environment offers a tremendous biodiversity and original polysaccharides have been discovered presenting a great chemical diversity that is largely species specific. The study of the biological properties of the polysaccharides from marine eukaryotes and marine prokaryotes revealed that the polysaccharides from the marine environment could provide a valid alternative to traditional polysaccharides such as glycosaminoglycans. Marine polysaccharides present a real potential for natural product drug discovery and for the delivery of new marine derived products for therapeutic applications. PMID:22131964

  2. Thermal stress resistance and aging effects of Panax notoginseng polysaccharides on Caenorhabditis elegans.

    PubMed

    Feng, Shiling; Cheng, Haoran; Xu, Zhou; Shen, Shian; Yuan, Ming; Liu, Jing; Ding, Chunbang

    2015-11-01

    Panax notoginseng attract public attention due to their potential biomedical properties and corresponding health benefits. The present study investigated the anti-aging and thermal stress resistance effects of polysaccharides from P. notoginseng on Caenorhabditis elegans. Results showed polysaccharides had little scavenging ability of reactive oxygen species (ROS) in vitro, but significantly extended lifespan of C. elegans, especially the main root polysaccharide (MRP) which prolongs the mean lifespan of wild type worms by 21%. Further study demonstrated that the heat stress resistance effect of polysaccharides on C. elegans might be attributed to the elevation of antioxidant enzyme activities (both superoxide dismutase (SOD) and catalase (CAT)) and the reduction lipid peroxidation of malondialdehyde (MDA) level. Taken together, the results provided a scientific basis for the further exploitation of the mechanism of longer lifespan controlled by P. notoginseng polysaccharides on C. elegans. The P. notoginseng polysaccharides might be considered as a potential source to delay aging.

  3. DECOMPOSITION AND BINDING ACTION OF A POLYSACCHARIDE FROM CHROMOBACTERIUM VIOLACIUM IN SOIL.

    PubMed

    MARTIN, J P; RICHARDS, S J

    1963-06-01

    Martin, J. P. (University of California, Riverside) and S. J. Richards. Decomposition and binding action of a polysaccharide from Chromobacterium violaceum in soil. J. Bacteriol. 85:1288-1294. 1963.-The decomposition rate and binding effect in soil of a polysaccharide from Chromobacterium violaceum was compared with that of a variety of bacterial and plant polysaccharides and more complex organic residues. Most of the polysaccharides tested decomposed more readily than mature plant residues and fungus mycelium. The ease of decomposition varied, however, and polysaccharide from C. violaceum over a period of 1 month was more resistant than corn stalks, Rhodes grass, bean straw, and orange leaves. During the first week, it was as resistant to decay as pine needles. The C. violaceum polysaccharide was more effective in binding or aggregating the soil than all others tested. It also reduced the bulk density of Greenfield sandy loam and increased hydraulic conductivity in neutral soil. PMID:14047219

  4. Carboxymethylated degraded polysaccharides from Enteromorpha prolifera: Preparation and in vitro antioxidant activity.

    PubMed

    Shi, Mei-Jia; Wei, Xiaoyi; Xu, Jie; Chen, Bing-Jie; Zhao, De-Yin; Cui, Shuai; Zhou, Tao

    2017-01-15

    In order to improve the bioactivities of the polysaccharide from Enteromorpha prolifera (PE), crude PE (Mw 1400kDa) was degraded to low molecular weight polysaccharide (44kDa) in the presence of hydrogen peroxide/ascorbic acid, followed by carboxymethylation. The reaction conditions for carboxymethylation of degraded polysaccharide (DPE) were optimized by Response Surface Methodology. The carboxymethyled degraded polysaccharide (CDPE) obtained under optimized conditions, with a degree of carboxymethylation of 0.849, was characterized by FT-IR and (13)C NMR. The molecular weight of CDPE was measured to be 53.7kDa. CDPE was evaluated for its antioxidant activity by determining the ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals, and by determining the ferric reducing power. The antioxidant activity of CDPE was found to be greatly improved in comparison with degraded polysaccharide (DPE) and crude polysaccharide from Enteromorpha prolifera (PE). PMID:27542452

  5. [Antitumor Activity of Polysaccharides from Ganoderma lucidum Mycelium: in vivo Comparative Study].

    PubMed

    Krasnopolskaya, L M; Yarina, M S; Avtonomova, A V; Usov, A I; Isakova, E B; Bukchman, V M

    2015-01-01

    Fractions of water soluble and alkali soluble polysaccharides, as well as fucogalactan, a water soluble polysaccharide, and xylomannan, an alkali soluble polysaccharide, were isolated from the Ganoderma lucidum submerged mycelium. When administered orally, the polysaccharides showed antitumor activity in vivo on murine models of solid tumors. Xylomannan and fucogalactan showed the highest antitumor activity. Sensitivity to xylomannan was more pronounced in adenocarcinoma Ca755 as compared to the T-cell lymphocytic leukemia P388. The antitumor activity of the water soluble polysaccharides total fractions from the mycelium and fruiting bodies of the G. lucidum strain was almost identical. The maximum antitumor effect of the mycelium water soluble polysaccharides total fraction was observed with the use of the daily dose of 2 mg/kg.

  6. Novel imaging technologies for characterization of microbial extracellular polysaccharides

    PubMed Central

    Lilledahl, Magnus B.; Stokke, Bjørn T.

    2015-01-01

    Understanding of biology is underpinned by the ability to observe structures at various length scales. This is so in a historical context and is also valid today. Evolution of novel insight often emerges from technological advancement. Recent developments in imaging technologies that is relevant for characterization of extraceullar microbiological polysaccharides are summarized. Emphasis is on scanning probe and optical based techniques since these tools offers imaging capabilities under aqueous conditions more closely resembling the physiological state than other ultramicroscopy imaging techniques. Following the demonstration of the scanning probe microscopy principle, novel operation modes to increase data capture speed toward video rate, exploitation of several cantilever frequencies, and advancement of utilization of specimen mechanical properties as contrast, also including their mode of operation in liquid, have been developed on this platform. Combined with steps in advancing light microscopy with resolution beyond the far field diffraction limit, non-linear methods, and combinations of the various imaging modalities, the potential ultramicroscopy toolbox available for characterization of exopolysaccharides (EPS) are richer than ever. Examples of application of such ultramicroscopy strategies range from imaging of isolated microbial polysaccharides, structures being observed when they are involved in polyelectrolyte complexes, aspects of their enzymatic degradation, and cell surface localization of secreted polysaccharides. These, and other examples, illustrate that the advancement in imaging technologies relevant for EPS characterization supports characterization of structural aspects. PMID:26074906

  7. Sulfation patterns determine cellular internalization of heparin-like polysaccharides

    PubMed Central

    Raman, Karthik; Mencio, Caitlin; Desai, Umesh R.; Kuberan, Balagurunathan

    2013-01-01

    Heparin is a highly sulfated polysaccharide which serves biologically relevant roles as an anticoagulant and anti-cancer agent. While it is well known that modification of heparin’s sulfation pattern can drastically influence its ability to bind growth factors and other extracellular molecules, very little is known about the cellular uptake of heparin and the role sulfation patterns serve in affecting its internalization. In this study, we chemically synthesized several fluorescently-labeled heparins consisting of a variety of sulfation patterns. These polysaccharides were thoroughly characterized using anion exchange chromatography and size exclusion chromatography. Subsequently, we utilized flow cytometry and confocal imaging to show that sulfation patterns differentially affect the amount of heparin uptake in multiple cell types. This study provides the first comprehensive analysis of the effect of sulfation pattern on the cellular internalization of heparin or heparan sulfate like polysaccharides. The results of this study expand current knowledge regarding heparin internalization and provide insights into developing more effective heparin-based drug conjugates for applications in intracellular drug delivery. PMID:23398560

  8. Thermal analysis of some natural polysaccharide materials by isoconversional method.

    PubMed

    Iqbal, Mohammad S; Massey, Shazma; Akbar, Jamshed; Ashraf, Chaudhary M; Masih, Rashid

    2013-09-01

    Isoconversional thermal analysis of some important polysaccharides from functional foods is reported. Various thermal parameters including apparent activation energy (Ea), pre-exponential factor (A) were worked out, and the fitness of data to different models describing the degradation kinetics of polysaccharides was studied. The polysaccharides from Mimosa pudica (MP), Plantago ovata (PO), Argyreia speciosa (AS), Acacia nilotica (AN), P. ovata husk (HK) and Acacia modesta (AM) exhibited multistep degradation while those from Astragalus gummifer (AG), Salvia aegyptiaca (SA) and Ocimum basicilicum (OB) degraded mainly in single step. Generally, the degradation was exothermal. The average Ea values as determined by Flynn-Wall-Ozawa method were found to be in the range 132-187 kJ mol(-1). The mean comprehensive index of thermal stability (ITS) fell in the range 0.33-0.43. All the materials under investigation except those from SA and AS appear to be as stable as some of the important commercial materials used as pharmaceutical ingredients. Model-fitting analysis revealed that the major degradation step follows first-order kinetics.

  9. Recombinant expression of Streptococcus pneumoniae capsular polysaccharides in Escherichia coli

    PubMed Central

    Kay, Emily J.; Yates, Laura E.; Terra, Vanessa S.; Cuccui, Jon; Wren, Brendan W.

    2016-01-01

    Currently, Streptococcus pneumoniae is responsible for over 14 million cases of pneumonia worldwide annually, and over 1 million deaths, the majority of them children. The major determinant for pathogenesis is a polysaccharide capsule that is variable and is used to distinguish strains based on their serotype. The capsule forms the basis of the pneumococcal polysaccharide vaccine (PPV23) that contains purified capsular polysaccharide from 23 serotypes, and the pneumococcal conjugate vaccine (PCV13), containing 13 common serotypes conjugated to CRM197 (mutant diphtheria toxin). Purified capsule from S. pneumoniae is required for pneumococcal conjugate vaccine production, and costs can be prohibitively high, limiting accessibility of the vaccine in low-income countries. In this study, we demonstrate the recombinant expression of the capsule-encoding locus from four different serotypes of S. pneumoniae within Escherichia coli. Furthermore, we attempt to identify the minimum set of genes necessary to reliably and efficiently express these capsules heterologously. These E. coli strains could be used to produce a supply of S. pneumoniae serotype-specific capsules without the need to culture pathogenic bacteria. Additionally, these strains could be applied to synthetic glycobiological applications: recombinant vaccine production using E. coli outer membrane vesicles or coupling to proteins using protein glycan coupling technology. PMID:27110302

  10. O-Acetylation of Plant Cell Wall Polysaccharides

    PubMed Central

    Gille, Sascha; Pauly, Markus

    2011-01-01

    Plant cell walls are composed of structurally diverse polymers, many of which are O-acetylated. How plants O-acetylate wall polymers and what its function is remained elusive until recently, when two protein families were identified in the model plant Arabidopsis that are involved in the O-acetylation of wall polysaccharides – the reduced wall acetylation (RWA) and the trichome birefringence-like (TBL) proteins. This review discusses the role of these two protein families in polysaccharide O-acetylation and outlines the differences and similarities of polymer acetylation mechanisms in plants, fungi, bacteria, and mammals. Members of the TBL protein family had been shown to impact pathogen resistance, freezing tolerance, and cellulose biosynthesis. The connection of TBLs to polysaccharide O-acetylation thus gives crucial leads into the biological function of wall polymer O-acetylation. From a biotechnological point understanding the O-acetylation mechanism is important as acetyl-substituents inhibit the enzymatic degradation of wall polymers and released acetate can be a potent inhibitor in microbial fermentations, thus impacting the economic viability of, e.g., lignocellulosic based biofuel production. PMID:22639638

  11. Superlubricity of a natural polysaccharide from the alga Porphyridium sp.

    NASA Astrophysics Data System (ADS)

    Gourdon, Delphine; Lin, Qi; Israelachvili, Jacob

    2005-03-01

    Using a surface forces apparatus we have studied the adhesive and lubrication forces of mica surfaces separated by a molecularly-thin, sub-nanometer, film of a high molecular weight (2.6 MDa) naturally occurring anionic polysaccharide adsorbed from aqueous solution. The adhesion and friction forces of the biopolymer were monitored as a function of time, shearing distance and driving velocity under a large range of compressive loads. Although the thickness of the confined biopolymer was <1 nm, the friction was ultra-low (coefficient of friction = 0.015) at pressures up to 100 atm and over 4 decades of velocity with no wear. Complementary atomic force microscopy imaging in solution shows that the biopolymer adsorbs well to the mica surface but remains mobile and easily dragged upon shearing. The good adsorption of this polysaccharide to negatively charged surfaces, its low friction, its robustness (high-load carrying capacity and wear protection), as well as the weak (logarithmic) dependency of the friction on the sliding velocity make it, or this class of polyelectrolytes, excellent candidates for use in water-based lubricant fluids and as potential additives to synovial fluid in joints and other biolubricating fluids. The physical reasons for the tribological properties of this polysaccharide will be discussed.

  12. Polysaccharides with immunomodulating properties from the bark of Parkia biglobosa.

    PubMed

    Zou, Yuan-Feng; Zhang, Bing-Zhao; Inngjerdingen, Kari Tvete; Barsett, Hilde; Diallo, Drissa; Michaelsen, Terje Einar; El-Zoubair, Elnour; Paulsen, Berit Smestad

    2014-01-30

    The bark of Parkia biglobosa is used in traditional medicine to cure a wide range of illnesses. Polysaccharides were extracted from the bark with 50% ethanol-water, 50°C and 100°C water, and seven active fractions obtained by anion exchange chromatography and gel filtration. The complement fixation and macrophage stimulating activities of the different fractions were determined. The acidic fractions PBEII-I and PBEII-IV were the most active in the complement fixation assay, but the other fractions were also potent compared to the positive control BPII from Biophytum petersianum. Fractions PBEII-I and PBEII-IV were also the most potent fractions in stimulating macrophages to release nitric oxide. Structural studies showed that PBEII-I and PBEII-IV were pectic type polysaccharides, containing arabinogalactan type II structures. The observed differences in biological activities among the seven purified polysaccharide sub-fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes.

  13. Biosynthesis and Degradation of Mono-, Oligo-, and Polysaccharides: Introduction

    NASA Astrophysics Data System (ADS)

    Wilson, Iain B. H.

    Glycomolecules, whether they be mono-, oligo-, or polysaccharides or simple glycosides, are—as any biological molecules—the products of biosynthetic processes; on the other hand, at the end of their lifespan, they are also subject to degradation. The beginning point, biochemically, is the fixation of carbon by photosynthesis; subsequent metabolism in plants and other organisms results in the generation of the various monosaccharides. These must be activated—typically as nucleotide sugars or lipid-phosphosugars—before transfer by glycosyltransferases can take place in order to produce the wide variety of oligo- and polysaccharides seen in Nature; complicated remodelling processes may take place—depending on the pathway—which result in partial trimming of a precursor by glycosidases prior to the addition of further monosaccharide units. Upon completion of the 'life' of a glycoconjugate, glycosidases will degrade the macromolecule finally into monosaccharide units which can be metabolized or salvaged for incorporation into new glycan chains. In modern glycoscience, a wide variety of methods—genetic, biochemical, analytical—are being employed in order to understand these various pathways and to place them within their biological and medical context. In this chapter, these processes and relevant concepts and methods are introduced, prior to elaboration in the subsequent more specialized chapters on biosynthesis and degradation of mono-, oligo-, and polysaccharides.

  14. Characterization of diferuloylated pectic polysaccharides from quinoa (Chenopodium quinoa WILLD.).

    PubMed

    Wefers, Daniel; Gmeiner, Bianca M; Tyl, Catrin E; Bunzel, Mirko

    2015-08-01

    In plants belonging to the order of Caryophyllales, pectic neutral side chains can be substituted with ferulic acid. The ability of ferulic acid to form intra- and/or intermolecular polysaccharide cross-links by dimerization was shown by the isolation and characterization of diferulic acid oligosaccharides from monocotyledonous plants. In this study, two diferulic acid oligosaccharides were isolated from the enzymatic hydrolyzate of seeds of the dicotyledonous pseudocereal quinoa by gel permeation chromatography and preparative HPLC and unambiguously identified by LC-MS(2) and 1D/2D NMR spectroscopy. The isolated oligosaccharides are comprised of 5-5- and 8-O-4-diferulic acid linked to the O2-position of the nonreducing residue of two (1→5)-linked arabinobioses. To get insight into the structure and the degree of phenolic acid substitution of the diferuloylated polysaccharides, polymeric sugar composition, glycosidic linkages, and polysaccharide-bound monomeric phenolic acids and diferulic acids were analyzed. This study demonstrates that diferulic acids are involved into intramolecular and/or intermolecular cross-linking of arabinan chains and may have a major impact on cell wall architecture of quinoa and other dicotyledonous plants of the order of Caryophyllales.

  15. Thermal analysis of some natural polysaccharide materials by isoconversional method.

    PubMed

    Iqbal, Mohammad S; Massey, Shazma; Akbar, Jamshed; Ashraf, Chaudhary M; Masih, Rashid

    2013-09-01

    Isoconversional thermal analysis of some important polysaccharides from functional foods is reported. Various thermal parameters including apparent activation energy (Ea), pre-exponential factor (A) were worked out, and the fitness of data to different models describing the degradation kinetics of polysaccharides was studied. The polysaccharides from Mimosa pudica (MP), Plantago ovata (PO), Argyreia speciosa (AS), Acacia nilotica (AN), P. ovata husk (HK) and Acacia modesta (AM) exhibited multistep degradation while those from Astragalus gummifer (AG), Salvia aegyptiaca (SA) and Ocimum basicilicum (OB) degraded mainly in single step. Generally, the degradation was exothermal. The average Ea values as determined by Flynn-Wall-Ozawa method were found to be in the range 132-187 kJ mol(-1). The mean comprehensive index of thermal stability (ITS) fell in the range 0.33-0.43. All the materials under investigation except those from SA and AS appear to be as stable as some of the important commercial materials used as pharmaceutical ingredients. Model-fitting analysis revealed that the major degradation step follows first-order kinetics. PMID:23578630

  16. Polysaccharide extraction from Sphallerocarpus gracilis roots by response surface methodology.

    PubMed

    Ma, Tingting; Sun, Xiangyu; Tian, Chengrui; Luo, Jiyang; Zheng, Cuiping; Zhan, Jicheng

    2016-07-01

    The extraction process of Sphallerocarpus gracilis root polysaccharides (SGRP) was optimized using response surface methodology with two methods [hot-water extraction (HWE) and ultrasonic-assisted extraction (UAE)]. The antioxidant activities of SGRP were determined, and the structural features of the untreated materials (HWE residue and UAE residue) and the extracted polysaccharides were compared by scanning electron microscopy. Results showed that the optimal UAE conditions were extraction temperature of 81°C, extraction time of 1.7h, liquid-solid ratio of 17ml/g, ultrasonic power of 300W and three extraction cycles. The optimal HWE conditions were 93°C extraction temperature, 3.6h extraction time, 21ml/g liquid-solid ratio and three extraction cycles. UAE offered a higher extraction yield with a shorter time, lower temperature and a lower solvent consumption compared with HWE, and the extracted polysaccharides possessed a higher antioxidant capacity. Therefore, UAE could be used as an alternative to conventional HWE for SGRP extraction. PMID:27032488

  17. Characterization of diferuloylated pectic polysaccharides from quinoa (Chenopodium quinoa WILLD.).

    PubMed

    Wefers, Daniel; Gmeiner, Bianca M; Tyl, Catrin E; Bunzel, Mirko

    2015-08-01

    In plants belonging to the order of Caryophyllales, pectic neutral side chains can be substituted with ferulic acid. The ability of ferulic acid to form intra- and/or intermolecular polysaccharide cross-links by dimerization was shown by the isolation and characterization of diferulic acid oligosaccharides from monocotyledonous plants. In this study, two diferulic acid oligosaccharides were isolated from the enzymatic hydrolyzate of seeds of the dicotyledonous pseudocereal quinoa by gel permeation chromatography and preparative HPLC and unambiguously identified by LC-MS(2) and 1D/2D NMR spectroscopy. The isolated oligosaccharides are comprised of 5-5- and 8-O-4-diferulic acid linked to the O2-position of the nonreducing residue of two (1→5)-linked arabinobioses. To get insight into the structure and the degree of phenolic acid substitution of the diferuloylated polysaccharides, polymeric sugar composition, glycosidic linkages, and polysaccharide-bound monomeric phenolic acids and diferulic acids were analyzed. This study demonstrates that diferulic acids are involved into intramolecular and/or intermolecular cross-linking of arabinan chains and may have a major impact on cell wall architecture of quinoa and other dicotyledonous plants of the order of Caryophyllales. PMID:25983037

  18. Novel imaging technologies for characterization of microbial extracellular polysaccharides.

    PubMed

    Lilledahl, Magnus B; Stokke, Bjørn T

    2015-01-01

    Understanding of biology is underpinned by the ability to observe structures at various length scales. This is so in a historical context and is also valid today. Evolution of novel insight often emerges from technological advancement. Recent developments in imaging technologies that is relevant for characterization of extraceullar microbiological polysaccharides are summarized. Emphasis is on scanning probe and optical based techniques since these tools offers imaging capabilities under aqueous conditions more closely resembling the physiological state than other ultramicroscopy imaging techniques. Following the demonstration of the scanning probe microscopy principle, novel operation modes to increase data capture speed toward video rate, exploitation of several cantilever frequencies, and advancement of utilization of specimen mechanical properties as contrast, also including their mode of operation in liquid, have been developed on this platform. Combined with steps in advancing light microscopy with resolution beyond the far field diffraction limit, non-linear methods, and combinations of the various imaging modalities, the potential ultramicroscopy toolbox available for characterization of exopolysaccharides (EPS) are richer than ever. Examples of application of such ultramicroscopy strategies range from imaging of isolated microbial polysaccharides, structures being observed when they are involved in polyelectrolyte complexes, aspects of their enzymatic degradation, and cell surface localization of secreted polysaccharides. These, and other examples, illustrate that the advancement in imaging technologies relevant for EPS characterization supports characterization of structural aspects.

  19. Purification, Characterization and Biological Activity of Polysaccharides from Dendrobium officinale.

    PubMed

    Huang, Kaiwei; Li, Yunrong; Tao, Shengchang; Wei, Gang; Huang, Yuechun; Chen, Dongfeng; Wu, Chengfeng

    2016-01-01

    Polysaccharide (DOPA) from the stem of D. officinale, as well as two fractions (DOPA-1 and DOPA-2) of it, were isolated and purified by DEAE cellulose-52 and Sephacryl S-300 chromatography, and their structural characteristics and bioactivities were investigated. The average molecular weights of DOPA-1 and DOPA-2 were 394 kDa and 362 kDa, respectively. They were mainly composed of d-mannose, d-glucose, and had a backbone consisting of 1,4-linked β-d-Manp and 1,4-linked β-d-Glcp with O-acetyl groups. Bioactivity studies indicated that both DOPA and its purified fractions (DOPA-1 and DOPA-2) could activate splenocytes and macrophages. The D. officinale polysaccharides had stimulatory effects on splenocytes, T-lymphocytes and B-lymphocytes, promoting the cell viability and NO production of RAW 264.7 macrophages. Furthermore, DOPA, DOPA-1 and DOPA-2 were found to protect RAW 264.7 macrophages against hydrogen peroxide (H₂O₂)-induced oxidative injury by promoting cell viability, suppressing apoptosis and ameliorating oxidative lesions. These results suggested that D. officinale polysaccharides possessed antioxidant activity and mild immunostimulatory activity. PMID:27248989

  20. Acidification increases microbial polysaccharide degradation in the ocean

    NASA Astrophysics Data System (ADS)

    Piontek, J.; Lunau, M.; Händel, N.; Borchard, C.; Wurst, M.; Engel, A.

    2009-12-01

    With the accumulation of anthropogenic carbon dioxide (CO2), a proceeding decline in seawater pH has been induced that is referred to as ocean acidification. The ocean's capacity for CO2 storage is strongly affected by biological processes, whose feedback potential is difficult to evaluate. The main source of CO2 in the ocean is the decomposition and subsequent respiration of organic molecules by heterotrophic bacteria. However, very little is known about potential effects of ocean acidification on bacterial degradation activity. This study reveals that the degradation of polysaccharides, a major component of marine organic matter, by bacterial extracellular enzymes was significantly accelerated during experimental simulation of ocean acidification. Results were obtained from pH perturbation experiments, where rates of extracellular α- and β-glucosidase were measured and the loss of neutral and acidic sugars from phytoplankton-derived polysaccharides was determined. Our study suggests that a faster bacterial turnover of polysaccharides at lowered ocean pH has the potential to affect the cycling of organic carbon in the future ocean by weakening the biological carbon pump and increasing the respiratory production of CO2.

  1. Acidification increases microbial polysaccharide degradation in the ocean

    NASA Astrophysics Data System (ADS)

    Piontek, J.; Lunau, M.; Händel, N.; Borchard, C.; Wurst, M.; Engel, A.

    2010-05-01

    With the accumulation of anthropogenic carbon dioxide (CO2), a proceeding decline in seawater pH has been induced that is referred to as ocean acidification. The ocean's capacity for CO2 storage is strongly affected by biological processes, whose feedback potential is difficult to evaluate. The main source of CO2 in the ocean is the decomposition and subsequent respiration of organic molecules by heterotrophic bacteria. However, very little is known about potential effects of ocean acidification on bacterial degradation activity. This study reveals that the degradation of polysaccharides, a major component of marine organic matter, by bacterial extracellular enzymes was significantly accelerated during experimental simulation of ocean acidification. Results were obtained from pH perturbation experiments, where rates of extracellular α- and β-glucosidase were measured and the loss of neutral and acidic sugars from phytoplankton-derived polysaccharides was determined. Our study suggests that a faster bacterial turnover of polysaccharides at lowered ocean pH has the potential to reduce carbon export and to enhance the respiratory CO2 production in the future ocean.

  2. Sulfated Seaweed Polysaccharides as Multifunctional Materials in Drug Delivery Applications

    PubMed Central

    Cunha, Ludmylla; Grenha, Ana

    2016-01-01

    In the last decades, the discovery of metabolites from marine resources showing biological activity has increased significantly. Among marine resources, seaweed is a valuable source of structurally diverse bioactive compounds. The cell walls of marine algae are rich in sulfated polysaccharides, including carrageenan in red algae, ulvan in green algae and fucoidan in brown algae. Sulfated polysaccharides have been increasingly studied over the years in the pharmaceutical field, given their potential usefulness in applications such as the design of drug delivery systems. The purpose of this review is to discuss potential applications of these polymers in drug delivery systems, with a focus on carrageenan, ulvan and fucoidan. General information regarding structure, extraction process and physicochemical properties is presented, along with a brief reference to reported biological activities. For each material, specific applications under the scope of drug delivery are described, addressing in privileged manner particulate carriers, as well as hydrogels and beads. A final section approaches the application of sulfated polysaccharides in targeted drug delivery, focusing with particular interest the capacity for macrophage targeting. PMID:26927134

  3. Ultrasonic-assisted production of antioxidative polysaccharides from Crassostrea hongkongensis.

    PubMed

    Cai, Bingna; Pan, Jianyu; Wan, Peng; Chen, Deke; Long, Shujun; Sun, Huili

    2014-10-01

    The beneficial effects of oyster extract against various disorders and diseases induced by oxidative stress have aroused great interest. In this article, ultrasonic-assisted enzymolysis was employed to produce polysaccharides of Crassostrea hongkongensis (CHP) and their antioxidant activity was investigated. A single-factor experiment and then a four-factor, three-level Box-Behnken design were first used to optimize ultrasonic extraction for polysaccharides. On the basis of ridge analysis, the optimum conditions are obtained as ultrasonic treatment time of 24 min, power of 876 W, temperature of 49°C, and material-solvent ratio of 1:6 (w/v). It is found that ultrasound pretreatment before protease hydrolysis was a great help to improve CHP yield and purity, especially more favorable with flavorzyme, neutrase, alcalase, and pepsin. Furthermore, the polysaccharide fraction, which was obtained by ultrasonic pretreatment and then alcalase hydrolysis at the conditions of 3000 U/g, 55°C, pH 8.0, for 4 hr, exhibited an obvious scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (98.48 ± 0.55% and 99.20 ± 0.12%, respectively) and a lenoleic acid peroxidation inhibition effect (85.48 ± 0.65%) at a concentration of 5.0 mg/mL. These results reveal the potential application of CHP in functional food and nutraceuticals.

  4. Immunomodulatory activity and partial characterisation of polysaccharides from Momordica charantia.

    PubMed

    Deng, Yuan-Yuan; Yi, Yang; Zhang, Li-Fang; Zhang, Rui-Fen; Zhang, Yan; Wei, Zhen-Cheng; Tang, Xiao-Jun; Zhang, Ming-Wei

    2014-01-01

    Momordica charantia Linn. is used as an edible and medicinal vegetable in sub-tropical areas. Until now, studies on its composition and related activities have been confined to compounds of low molecular mass, and no data have been reported concerning the plant's polysaccharides. In this work, a crude polysaccharide of M. charantia (MCP) fruit was isolated by hot water extraction and then purified using DEAE-52 cellulose anion-exchange chromatography to produce two main fractions MCP1 and MCP2. The immunomodulatory effects and physicochemical characteristics of these fractions were investigated in vitro and in vivo. The results showed that intragastric administration of 150 or 300 mg·kg-·d⁻¹ of MCP significantly increased the carbolic particle clearance index, serum haemolysin production, spleen index, thymus index and NK cell cytotoxicity to normal control levels in cyclophosphamide (Cy)-induced immunosuppressed mice. Both MCP1 and MCP2 effectively stimulated normal and concanavalin A-induced splenic lymphocyte proliferation in vitro at various doses. The average molecular weights of MCP1 and MCP2, which were measured using high-performance gel permeation chromatography, were 8.55×10⁴ Da and 4.41×10⁵ Da, respectively. Both fractions exhibited characteristic polysaccharide bands in their Fourier transform infrared spectrum. MCP1 is mainly composed of glucose and galactose, and MCP2 is mainly composed of glucose, mannose and galactose. The results indicate that MCP and its fractions have good potential as immunotherapeutic adjuvants. PMID:25178064

  5. Leaf wetness distribution within a potato crop

    NASA Astrophysics Data System (ADS)

    Heusinkveld, B. G.

    2010-07-01

    The Netherlands has a mild maritime climate and therefore the major interest in leaf wetness is associated with foliar plant diseases. During moist micrometeorological conditions (i.e. dew, fog, rain), foliar fungal diseases may develop quickly and thereby destroy a crop quickly. Potato crop monocultures covering several hectares are especially vulnerable to such diseases. Therefore understanding and predicting leaf wetness in potato crops is crucial in crop disease control strategies. A field experiment was carried out in a large homogeneous potato crop in the Netherlands during the growing season of 2008. Two innovative sensor networks were installed as a 3 by 3 grid at 3 heights covering an area of about 2 hectares within two larger potato crops. One crop was located on a sandy soil and one crop on a sandy peat soil. In most cases leaf wetting starts in the top layer and then progresses downward. Leaf drying takes place in the same order after sunrise. A canopy dew simulation model was applied to simulate spatial leaf wetness distribution. The dew model is based on an energy balance model. The model can be run using information on the above-canopy wind speed, air temperature, humidity, net radiation and within canopy air temperature, humidity and soil moisture content and temperature conditions. Rainfall was accounted for by applying an interception model. The results of the dew model agreed well with the leaf wetness sensors if all local conditions were considered. The measurements show that the spatial correlation of leaf wetness decreases downward.

  6. Antimicrobial effect of Pistacia atlantica leaf extract

    PubMed Central

    Ali Roozegar, Mohamad; Azizi Jalilian, Farid; Reza Havasian, Mohamad; Panahi, Jafar; Pakzad, Iraj

    2016-01-01

    The antimicrobial effect of the mastic tree (Pistacia atlantica) under in vitro conditions has been reported. Therefore, it is of interest to evaluate the effect of the plant leaf extract (aqueous) on bacterial load in mouth and saliva. The leaf of the Pistacia atlantica plant was collected and cleaned, dried at 40⁰c and then powdered. The extraction was carried out using the maceration method in vacuum with the rotary evaporator device. Bacterial inhibition (Streptococcus species) by the leaf extract was studied using the disc diffusion and embedding sink diffusion methods. The values of MIC and MBC were determined. The collected data was further analyzed using t-test and repeated measure statistical tests. The disc diffusion technique showed a significant inhibitory effect for Pistacia atlantica leaf extract on S. mutans (ATCC 35668) and S. mitis (ATCC 49456) with inhibition zones of 19 and 25 millimeters, respectively. This is for the highest leaf extract concentration used in this study (p<0.01). The values of MIC and MBC for S.mutans was 60, 90 μg/ml and for S. mitis was 75, 110 μg/ml (p<0.01 significance). The leaf extract has no significant effect on S. salivarius (ATCC 13419). Thus, the antimicrobial properties of the aqueous leaf extract from Pistacia atlantica is demonstrated in this study. PMID:27212840

  7. Deciduous leaf drop reduces insect herbivory.

    PubMed

    Karban, Richard

    2007-08-01

    Deciduous leaf fall is thought to be an adaptation that allows plants living in seasonal environments to reduce water loss and damage during unfavorable periods while increasing photosynthetic rates during favorable periods. Observations of natural variation in leaf shedding suggest that deciduous leaf fall may also allow plants to reduce herbivory. I tested this hypothesis by experimentally manipulating leaf retention for Quercus lobata and observing natural rates of herbivory. Quercus lobata is primarily deciduous although individuals show considerable natural variation in leaf retention. Oak saplings with no leaves through winter experienced reduced attack by cynipid gall makers the following spring. This pattern was consistent with the positive correlation between natural leaf persistence and gall numbers. These cynipids do not overwinter on the leaves that trees retain through winter, although they appear to use persistent leaves as oviposition cues. If these results are general for woody plants in continental temperate habitats, they suggest that an important and unrecognized consequence of deciduous leaf shedding may be a reduction in herbivore damage, and that this effect should be included in models of deciduous and evergreen behavior. PMID:17375327

  8. Antimicrobial effect of Pistacia atlantica leaf extract.

    PubMed

    Ali Roozegar, Mohamad; Azizi Jalilian, Farid; Reza Havasian, Mohamad; Panahi, Jafar; Pakzad, Iraj

    2016-01-01

    The antimicrobial effect of the mastic tree (Pistacia atlantica) under in vitro conditions has been reported. Therefore, it is of interest to evaluate the effect of the plant leaf extract (aqueous) on bacterial load in mouth and saliva. The leaf of the Pistacia atlantica plant was collected and cleaned, dried at 40⁰c and then powdered. The extraction was carried out using the maceration method in vacuum with the rotary evaporator device. Bacterial inhibition (Streptococcus species) by the leaf extract was studied using the disc diffusion and embedding sink diffusion methods. The values of MIC and MBC were determined. The collected data was further analyzed using t-test and repeated measure statistical tests. The disc diffusion technique showed a significant inhibitory effect for Pistacia atlantica leaf extract on S. mutans (ATCC 35668) and S. mitis (ATCC 49456) with inhibition zones of 19 and 25 millimeters, respectively. This is for the highest leaf extract concentration used in this study (p<0.01). The values of MIC and MBC for S.mutans was 60, 90 μg/ml and for S. mitis was 75, 110 μg/ml (p<0.01 significance). The leaf extract has no significant effect on S. salivarius (ATCC 13419). Thus, the antimicrobial properties of the aqueous leaf extract from Pistacia atlantica is demonstrated in this study. PMID:27212840

  9. Simple method for refining arabinan polysaccharides by alcohol extraction of the prune, Prunus domestica L.

    PubMed

    Hara, Yukari; Mizukawa, Hitomi; Yamamoto, Hirotaka; Ikami, Takao; Kato, Koji; Yabe, Tomio

    2013-01-01

    L-Arabinose is a useful sugar in the food industry. We demonstrate here simple methods for refining arabinan polysaccharides by alcohol extraction from prune, Prunus domestica L., as a source of L-arabinose. Alcohol-soluble polysaccharides were purified from a solution of prune extracted by 80% ethanol. After fractionating the polysaccharides by ion-exchange chromatography, arabinans were identified as mainly constituted by (1→5)-linked arabinofuranosyl units.

  10. Treatment Characteristics of Polysaccharides and Endotoxin Using Oxygen Plasma Produced by RF Discharge

    NASA Astrophysics Data System (ADS)

    Kitazaki, Satoshi; Hayashi, Nobuya; Goto, Masaaki

    2010-10-01

    Treatment of polysaccharides and endotoxin were attempted using oxygen plasma produced by RF discharge. Oxygen radicals observed by optical light emission spectra are factors of decomposition of polysaccharides and endotoxin. Fourier transform infrared spectra indicate that most of chemical bonds in the polysaccharides are dissociated after irradiation of the oxygen plasma. Also, the decomposition rate of endotoxin was approximately 90% after irradiation of the oxygen plasma for 180 min.

  11. Treatment Characteristics of Polysaccharides and Endotoxin Using Oxygen Plasma Produced by RF Discharge

    SciTech Connect

    Kitazaki, Satoshi; Hayashi, Nobuya; Goto, Masaaki

    2010-10-13

    Treatment of polysaccharides and endotoxin were attempted using oxygen plasma produced by RF discharge. Oxygen radicals observed by optical light emission spectra are factors of decomposition of polysaccharides and endotoxin. Fourier transform infrared spectra indicate that most of chemical bonds in the polysaccharides are dissociated after irradiation of the oxygen plasma. Also, the decomposition rate of endotoxin was approximately 90% after irradiation of the oxygen plasma for 180 min.

  12. [Determination of constituents of polysaccharide and contents of saccharide from Mongolian medicine Agari-8].

    PubMed

    Zhao, Yu-Ying; Song, Juan-Juan; Zhao, Yu-Qin; Xu, Xiu-Ting; Hai, Ping

    2007-04-01

    The water soluble polysaccharide was extracted from Agari-8, and the contents of the water soluble polysaccharide were determined by phenyl hydrate-sulfuric acid method. The average recovery was 101.80%. The RSD was 0. 92Y. The components of the water soluble polysaccharide were identified by gas chromatography with: arabinose, xylose, mannose and glucose in the molar ratio of 0.40 : 0.10 : 5.67 : 22.78. Their IR and UV spectra were studied. PMID:17608211

  13. Global Climatic Controls On Leaf Size

    NASA Astrophysics Data System (ADS)

    Wright, I. J.; Prentice, I. C.; Dong, N.; Maire, V.

    2015-12-01

    Since the 1890s it's been known that the wet tropics harbour plants with exceptionally large leaves. Yet the observed latitudinal gradient of leaf size has never been fully explained: it is still unclear which aspects of climate are most important for understanding geographic trends in leaf size, a trait that varies many thousand-fold among species. The key is the leaf-to-air temperature difference, which depends on the balance of energy inputs (irradiance) and outputs (transpirational cooling, losses to the night sky). Smaller leaves track air temperatures more closely than larger leaves. Widely cited optimality-based theories predict an advantage for smaller leaves in dry environments, where transpiration is restricted, but are silent on the latitudinal gradient. We aimed to characterize and explain the worldwide pattern of leaf size. Across 7900 species from 651 sites, here we show that: large-leaved species predominate in wet, hot, sunny environments; smaller-leaved species typify hot, sunny environments only when arid; small leaves are required to avoid freezing in high latitudes and at high elevation, and to avoid overheating in dry environments. This simple pattern was unclear in earlier, more limited analyses. We present a simple but robust, fresh approach to energy-balance modelling for both day-time and night-time leaf-to-air temperature differences, and thus risk of overheating and of frost damage. Our analysis shows night-chilling is important as well as day-heating, and simplifies leaf temperature modelling. It provides both a framework for modelling leaf size constraints, and a solution to one of the oldest conundrums in ecology. Although the path forward is not yet fully clear, because of its role in controlling leaf temperatures we suggest that climate-related leaf size constraints could usefully feature in the next generation of land ecosystem models.

  14. An Apparent Anomaly in Peanut Leaf Conductance

    PubMed Central

    Pallas, James E.

    1980-01-01

    Conductance to gaseous transfer is normally considered to be greater from the abaxial than from the adaxial side of a leaf. Measurements of the conductance to water vapor of peanut leaves (Arachis hypogaea L.) under well watered and stress conditions in a controlled environment, however, indicated a 2-fold higher conductance from the adaxial side of the leaf than from the abaxial. Studies of conductance as light level was varied showed an increase in conductance from either surface with increasing light level, but conductance was always greater from the adaxial surface at any given light level. In contrast, measurements of soybean (Glycine max [L.] Merr.) and snapbean (Phaseolus vulgaris L.) leaf conductance showed an approximate 2-fold greater conductance from the abaxial surface than from the adaxial. Approximately the same number of stomata were present on both peanut leaf surfaces and stomatal size was similar. Electron microscopic examination of peanut leaves did not reveal any major structural differences between stomata on the two surfaces that would account for the differences in conductance. Light microscope studies of leaf sections revealed an extensive network of bundle sheaths with achloraplastic bundle sheath extensions; the lower epidermis was lined with a single layer of large achloraplastic parenchyma cells. Measurements of net photosynthesis made on upper and lower leaf surfaces collectively and individually indicated that two-thirds of the peanut leaf's total net photosynthesis can be attributed to diffusion of CO2 through the adaxial leaf surface. Possibly the high photosynthetic efficiency of peanut cultivars as compared with certain other C3 species is associated with the greater conductance of CO2 through their upper leaf surfaces. Images PMID:16661294

  15. Transcriptome Analysis of Shade-Induced Inhibition on Leaf Size in Relay Intercropped Soybean

    PubMed Central

    Gong, Wanzhuo; Qi, Pengfei; Du, Junbo; Sun, Xin; Wu, Xiaoling; Song, Chun; Liu, Weiguo; Wu, Yushan; Yu, Xiaobo; Yong, Taiwen; Wang, Xiaochun; Yang, Feng; Yan, Yanhong; Yang, Wenyu

    2014-01-01

    Multi-species intercropping is a sustainable agricultural practice worldwide used to utilize resources more efficiently. In intercropping systems, short crops often grow under vegetative shade of tall crops. Soybean, one important legume, is often planted in intercropping. However, little is known about the mechanisms of shade inhibition effect on leaf size in soybean leaves at the transcriptome level. We analyzed the transcriptome of shaded soybean leaves via RNA-Seq technology. We found that transcription 1085 genes in mature leaves and 1847 genes in young leaves were significantly affected by shade. Gene ontology analyses showed that expression of genes enriched in polysaccharide metabolism was down-regulated, but genes enriched in auxin stimulus were up-regulated in mature leaves; and genes enriched in cell cycling, DNA-replication were down-regulated in young leaves. These results suggest that the inhibition of higher auxin content and shortage of sugar supply on cell division and cell expansion contribute to smaller and thinner leaf morphology, which highlights potential research targets such as auxin and sugar regulation on leaves for crop adaptation to shade in intercropping. PMID:24886785

  16. Transcriptome analysis of shade-induced inhibition on leaf size in relay intercropped soybean.

    PubMed

    Gong, Wanzhuo; Qi, Pengfei; Du, Junbo; Sun, Xin; Wu, Xiaoling; Song, Chun; Liu, Weiguo; Wu, Yushan; Yu, Xiaobo; Yong, Taiwen; Wang, Xiaochun; Yang, Feng; Yan, Yanhong; Yang, Wenyu

    2014-01-01

    Multi-species intercropping is a sustainable agricultural practice worldwide used to utilize resources more efficiently. In intercropping systems, short crops often grow under vegetative shade of tall crops. Soybean, one important legume, is often planted in intercropping. However, little is known about the mechanisms of shade inhibition effect on leaf size in soybean leaves at the transcriptome level. We analyzed the transcriptome of shaded soybean leaves via RNA-Seq technology. We found that transcription 1085 genes in mature leaves and 1847 genes in young leaves were significantly affected by shade. Gene ontology analyses showed that expression of genes enriched in polysaccharide metabolism was down-regulated, but genes enriched in auxin stimulus were up-regulated in mature leaves; and genes enriched in cell cycling, DNA-replication were down-regulated in young leaves. These results suggest that the inhibition of higher auxin content and shortage of sugar supply on cell division and cell expansion contribute to smaller and thinner leaf morphology, which highlights potential research targets such as auxin and sugar regulation on leaves for crop adaptation to shade in intercropping.

  17. Rising from the Sea: Correlations between Sulfated Polysaccharides and Salinity in Plants

    PubMed Central

    Aquino, Rafael S.; Grativol, Clicia; Mourão, Paulo A. S.

    2011-01-01

    High salinity soils inhibit crop production worldwide and represent a serious agricultural problem. To meet our ever-increasing demand for food, it is essential to understand and engineer salt-resistant crops. In this study, we evaluated the occurrence and function of sulfated polysaccharides in plants. Although ubiquitously present in marine algae, the presence of sulfated polysaccharides among the species tested was restricted to halophytes, suggesting a possible correlation with salt stress or resistance. To test this hypothesis, sulfated polysaccharides from plants artificially and naturally exposed to different salinities were analyzed. Our results revealed that the sulfated polysaccharide concentration, as well as the degree to which these compounds were sulfated in halophytic species, were positively correlated with salinity. We found that sulfated polysaccharides produced by Ruppia maritima Loisel disappeared when the plant was cultivated in the absence of salt. However, subjecting the glycophyte Oryza sativa Linnaeus to salt stress did not induce the biosynthesis of sulfated polysaccharides but increased the concentration of the carboxylated polysaccharides; this finding suggests that negatively charged cell wall polysaccharides might play a role in coping with salt stress. These data suggest that the presence of sulfated polysaccharides in plants is an adaptation to high salt environments, which may have been conserved during plant evolution from marine green algae. Our results address a practical biological concept; additionally, we suggest future strategies that may be beneficial when engineering salt-resistant crops. PMID:21552557

  18. Salt Effect on the Antioxidant Activity of Red Microalgal Sulfated Polysaccharides in Soy-Bean Formula.

    PubMed

    Burg, Ariela; Oshrat, Levy-Ontman

    2015-10-01

    Sulfated polysaccharides produced by microalgae, which are known to exhibit various biological activities, may potentially serve as natural antioxidant sources. To date, only a few studies have examined the antioxidant bioactivity of red microalgal polysaccharides. In this research, the effect of different salts on the antioxidant activities of two red microalgal sulfated polysaccharides derived from Porphyridium sp. and Porphyridium aerugineum were studied in a soy bean-based infant milk formula. Salt composition and concentration were both shown to affect the polysaccharides' antioxidant activity. It can be postulated that the salt ions intefer with the polysaccharide chains' interactions and alter their structure, leading to a new three-dimensional structure that better exposes antiooxidant sites in comparison to the polysaccharide without salt supplement. Among the cations that were studied, Ca(2+) had the strongest enhancement effect on antioxidant activities of both polysaccharides. Understanding the effect of salts on polysaccharides' stucture, in addition to furthering knowledge on polysaccharide bioactivities, may also shed light on the position of the antioxidant active sites. PMID:26492255

  19. Salt Effect on the Antioxidant Activity of Red Microalgal Sulfated Polysaccharides in Soy-Bean Formula.

    PubMed

    Burg, Ariela; Oshrat, Levy-Ontman

    2015-10-01

    Sulfated polysaccharides produced by microalgae, which are known to exhibit various biological activities, may potentially serve as natural antioxidant sources. To date, only a few studies have examined the antioxidant bioactivity of red microalgal polysaccharides. In this research, the effect of different salts on the antioxidant activities of two red microalgal sulfated polysaccharides derived from Porphyridium sp. and Porphyridium aerugineum were studied in a soy bean-based infant milk formula. Salt composition and concentration were both shown to affect the polysaccharides' antioxidant activity. It can be postulated that the salt ions intefer with the polysaccharide chains' interactions and alter their structure, leading to a new three-dimensional structure that better exposes antiooxidant sites in comparison to the polysaccharide without salt supplement. Among the cations that were studied, Ca(2+) had the strongest enhancement effect on antioxidant activities of both polysaccharides. Understanding the effect of salts on polysaccharides' stucture, in addition to furthering knowledge on polysaccharide bioactivities, may also shed light on the position of the antioxidant active sites.

  20. Monoclonal antibodies, carbohydrate-binding modules, and the detection of polysaccharides in plant cell walls.

    PubMed

    Hervé, Cécile; Marcus, Susan E; Knox, J Paul

    2011-01-01

    Plant cell walls are diverse composites of complex polysaccharides. Molecular probes such as monoclonal antibodies (MABs) and carbohydrate-binding modules (CBMs) are important tools to detect and dissect cell wall structures in plant materials. We provide an account of methods that can be used to detect cell wall polysaccharide structures (epitopes) in plant materials and also describe treatments that can provide information on the masking of sets of polysaccharides that may prevent detection. These masking -phenomena may indicate potential interactions between sets of cell wall polysaccharides, and methods to uncover them are an important aspect of cell wall immunocytochemistry.

  1. Plant Cell Wall Polysaccharides as Potential Resources for the Development of Novel Prebiotics

    PubMed Central

    Kim, Dojung; Paek, Seung-Ho

    2012-01-01

    Prebiotic oligosaccharides, with a degree of polymerization (DP) of mostly less than 10, exhibit diverse biological activities that contribute to human health. Currently available prebiotics are mostly derived from disaccharides and simple polysaccharides found in plants. Subtle differences in the structures of oligosaccharides can cause significant differences in their prebiotic proper-ties. Therefore, alternative substances supplying polysaccharides that have more diverse and complex structures are necessary for the development of novel oligosaccharides that have actions not present in existing prebiotics. In this review, we show that structural polysaccharides found in plant cell walls, such as xylans and pectins, are particularly potential resources supplying broadly diverse polysaccharides to produce new prebiotics. PMID:24009823

  2. The structure of mushroom polysaccharides and their beneficial role in health.

    PubMed

    Huang, Xiaojun; Nie, Shaoping

    2015-10-01

    Mushroom is a kind of fungus that has been popular for its special flavour and renowned biological values. The polysaccharide contained in mushroom is regarded as one of the primary bioactive constituents and is beneficial for health. The structural features and bioactivities of mushroom polysaccharides have been studied extensively. It is believed that the diverse biological bioactivities of polysaccharides are closely related to their structure or conformation properties. In this review, the structural characteristics, conformational features and bioactivities of several mushroom polysaccharides are summarized, and their beneficial mechanisms and the relationships between their structure and bioactivities are also discussed.

  3. Studies of the polysaccharide fraction from the lipopolysaccharide of Pseudomonas alcaligenes

    PubMed Central

    Lomax, James A.; Gray, George W.; Wilkinson, Stephen G.

    1974-01-01

    Studies of the lipopolysaccharide of Pseudomonas alcaligenes strain BR 1/2 were extended to the polysaccharide moiety. The crude polysaccharide, obtained by mild acid hydrolysis of the lipopolysaccharide, was fractionated by gel filtration. The major fraction was the phosphorylated polysaccharide, for which the approximate proportions of residues were; glucose (2), rhamnose (0.7), heptose (2–3), galactosamine (1), alanine (1), 3-deoxy-2-octulonic acid (1), phosphorus (5–6). The heptose was l-glycero-d-manno-heptose. The minor fractions from gel filtration contained free 3-deoxy-2-octulonic acid, Pi and PPi. The purified polysaccharide was studied by periodate oxidation, methylation analysis, partial hydrolysis, and dephosphorylation. All the rhamnose and part of the glucose and heptose occur as non-reducing terminal residues. Other glucose residues are 3-substituted, and most heptose residues are esterified with condensed phosphate residues, possibly in the C-4 position. Free heptose and a heptosylglucose were isolated from a partial hydrolysate of the polysaccharide. The location of galactosamine in the polysaccharide was not established, but either the C-3 or C-4 position appears to be substituted and a linkage to alanine was indicated. In its composition, the polysaccharide from Ps. alcaligenes resembles core polysaccharides from other pseudomonads: no possible side-chain polysaccharide was detected. PMID:4369226

  4. Structure of the polysaccharides from the lipopolysaccharide of Azospirillum brasilense Jm125A2.

    PubMed

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2015-10-30

    Two polysaccharides were obtained by mild acid degradation of the lipopolysaccharide of associative nitrogen-fixing bacteria Azospirillum brasilense Jm125A2 isolated from the rhizosphere of a pearl millet. The following structures of the polysaccharides were established by sugar and methylation analyses, Smith degradation, and (1)H and (13)C NMR spectroscopy: [Formula: see text] Structure 1 has been reported earlier for a polysaccharide from A. brasilense S17 (Fedonenko YP, Konnova ON, Zdorovenko EL, Konnova SA, Zatonsky GV, Shaskov AS, Ignatov VV, Knirel YA. Carbohydr Res 2008;343:810-6), whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides.

  5. Activation of intrinsic apoptotic signaling pathway in cancer cells by Cymbopogon citratus polysaccharide fractions.

    PubMed

    Thangam, Ramar; Sathuvan, Malairaj; Poongodi, Arasu; Suresh, Veeraperumal; Pazhanichamy, Kalailingam; Sivasubramanian, Srinivasan; Kanipandian, Nagarajan; Ganesan, Nalini; Rengasamy, Ramasamy; Thirumurugan, Ramasamy; Kannan, Soundarapandian

    2014-07-17

    Essential oils of Cymbopogon citratus were already reported to have wide ranging medical and industrial applications. However, information on polysaccharides from the plant and their anticancer activities are limited. In the present study, polysaccharides from C. citratus were extracted and fractionated by anion exchange and gel filtration chromatography. Two different polysaccharide fractions such as F1 and F2 were obtained, and these fractions were found to have distinct acidic polysaccharides as characterized by their molecular weight and sugar content. NMR spectral analysis revealed the presence of (1→4) linked b-d-Xylofuranose moiety in these polysaccharides. Using these polysaccharide fractions F1 and F2, anti-inflammatory and anticancer activities were evaluated against cancer cells in vitro and the mechanism of action of the polysaccharides in inducing apoptosis in cancer cells via intrinsic pathway was also proposed. Two different reproductive cancer cells such as Siha and LNCap were employed for in vitro studies on cytotoxicity, induction of apoptosis and apoptotic DNA fragmentation, changes in mitochondrial membrane potential, and profiles of gene and protein expression in response to treatment of cells by the polysaccharide fractions. These polysaccharide fractions exhibited potential cytotoxic and apoptotic effects on carcinoma cells, and they induced apoptosis in these cells through the events of up-regulation of caspase 3, down-regulation of bcl-2 family genes followed by cytochrome c release.

  6. A new natural angelica polysaccharide based colon-specific drug delivery system.

    PubMed

    Zhou, Siyuan; Zhang, Bangle; Liu, Xinyou; Teng, Zenghui; Huan, Menglei; Yang, Tiehong; Yang, Zhifu; Jia, Min; Mei, Qibing

    2009-12-01

    Colon-specific drug delivery systems are clinically necessary to treat colon diseases locally while minimizing systemic side effects. In this study, we extracted angelica polysaccharide from fresh roots of Angelica sinensis Diels and analyzed the monosaccharide components. With succinate as a cross-linker and angelica polysaccharide as a drug carrier, a dexamethasone-polysaccharide conjugate was synthesized. The amount of dexamethasone (Dex) loaded in the dexamethasone-polysaccharide conjugate was 14.13/100 mg. The newly synthesized dexamethasone-polysaccharide conjugate was found to greatly reduce systemic absorption of Dex and effectively deliver Dex to the large intestine. When dexamethasone-polysaccharide conjugate was used to treat TNBS-induced ulcerative colitis in rats by gavage, the ulcerative area of the colon and the colonic myeloperoxidase (MPO) activity was reduced in a dose-dependent manner. There was no effects on spleen weight, thymus weight, or peripheral blood lymphocyte count (0.25 micromol kg(-1) day(-1)). These results indicate that the dexamethasone-polysaccharide conjugate has a therapeutic effect on TNBS-induced ulcerative colitis in rats, while simultaneously reducing the systemic immunosuppression caused by Dex. Thus, the angelica polysaccharide was a promising colon-specific drug carrier, and the new dexamethasone-polysaccharide conjugate may yield a potential drug for the treatment of human inflammatory bowel disease.

  7. Evaluation of Methane from Sisal Leaf Residue and Palash Leaf Litter

    NASA Astrophysics Data System (ADS)

    Arisutha, S.; Baredar, P.; Deshpande, D. M.; Suresh, S.

    2014-12-01

    The aim of this study is to evaluate methane production from sisal leaf residue and palash leaf litter mixed with different bulky materials such as vegetable market waste, hostel kitchen waste and digested biogas slurry in a laboratory scale anaerobic reactor. The mixture was prepared with 1:1 proportion. Maximum methane content of 320 ml/day was observed in the case of sisal leaf residue mixed with vegetable market waste as the feed. Methane content was minimum (47 ml/day), when palash leaf litter was used as feed. This was due to the increased content of lignin and polyphenol in the feedstock which were of complex structure and did not get degraded directly by microorganisms. Sisal leaf residue mixtures also showed highest content of volatile fatty acids (VFAs) as compared to palash leaf litter mixtures. It was observed that VFA concentration in the digester first increased, reached maximum (when pH was minimum) and then decreased.

  8. Wheat leaf photosynthesis loss due to leaf rust, with respect to lesion development and leaf nitrogen status.

    PubMed

    Robert, Corinne; Bancal, Marie-Odile; Ney, Bertrand; Lannou, Christian

    2005-01-01

    In wheat (Triticum aestivum cv. Soissons) plants grown under three different fertilisation treatments, we quantified the effect of leaf rust (Puccinia triticina) on flag leaf photosynthesis during the whole sporulation period. Bastiaans' model: Y = (1 - x)beta was used to characterize the relationship between relative leaf photosynthesis (Y) and disease severity (x). The evolution of the different types of symptoms induced by the pathogen (sporulating, chlorotic and necrosed tissues) was evaluated using image analysis. The beta-values varied from 2 to 11, 1.4-2, and 0.8-1 during the sporulation period, when considering the proportion of sporulating, sporulating + necrotic, and total diseased area, respectively. Leaf nitrogen (N) content did not change the effect of the disease on host photosynthesis. We concluded that leaf rust has no global effect on the photosynthesis of the symptomless parts of the leaves and that the large range in the quantification of leaf rust effect on the host, which is found in the literature, can be accounted for by considering the different symptom types. We discuss how our results could improve disease assessments and damage prediction in a wheat crop.

  9. Independence of stem and leaf hydraulic traits in six Euphorbiaceae tree species with contrasting leaf phenology.

    PubMed

    Chen, Jun-Wen; Zhang, Qiang; Li, Xiao-Shuang; Cao, Kun-Fang

    2009-08-01

    Hydraulic traits and hydraulic-related structural properties were examined in three deciduous (Hevea brasiliensis, Macaranga denticulate, and Bischofia javanica) and three evergreen (Drypetes indica, Aleurites moluccana, and Codiaeum variegatum) Euphorbiaceae tree species from a seasonally tropical forest in south-western China. Xylem water potential at 50% loss of stem hydraulic conductivity (P50(stem)) was more negative in the evergreen tree, but leaf water potential at 50% loss of leaf hydraulic conductivity (P50(leaf)) did not function as P50(stem) did. Furthermore, P50(stem) was more negative than P50(leaf) in the evergreen tree; contrarily, this pattern was not observed in the deciduous tree. Leaf hydraulic conductivity overlapped considerably, but stem hydraulic conductivity diverged between the evergreen and deciduous tree. Correspondingly, structural properties of leaves overlapped substantially; however, structural properties of stem diverged markedly. Consequently, leaf and stem hydraulic traits were closely correlated with leaf and stem structural properties, respectively. Additionally, stem hydraulic efficiency was significantly correlated with stem hydraulic resistance to embolism; nevertheless, such a hydraulic pattern was not found in leaf hydraulics. Thus, these results suggest: (1) that the evergreen and deciduous tree mainly diverge in stem hydraulics, but not in leaf hydraulics, (2) that regardless of leaf or stem, their hydraulic traits result primarily from structural properties, and not from leaf phenology, (3) that leaves are more vulnerable to drought-induced embolism than stem in the evergreen tree, but not always in the deciduous tree and (4) that there exists a trade-off between hydraulic efficiency and safety for stem hydraulics, but not for leaf hydraulics.

  10. The red edge of plant leaf reflectance

    NASA Technical Reports Server (NTRS)

    Horler, D. N. H.; Dockray, M.; Barber, J.

    1983-01-01

    A detailed study of the red edge spectral feature of green vegetation based on laboratory reflectance spectrophotometry is presented. A parameter lambda is defined as the wavelength is defined as the wavelength of maximum slope and found to be dependent on chlorophyll concentration. Species, development stage, leaf layering, and leaf water content of vegetation also influences lambda. The maximum slope parameter is found to be independent of simulated ground area coverage. The results are interpreted in terms of Beer's Law and Kubelka-Munk theory. The chlorophyll concentration dependence of lambda seems to be explained in terms of a pure absorption effect, and it is suggested that the existence of two lambda components arises from leaf scattering properties. The results indicate that red edge measurements will be valuable for assessment of vegetative chlorophyll status and leaf area index independently of ground cover variations, and will be particularly suitable for early stress detection.

  11. Monitoring Air Quality with Leaf Yeasts.

    ERIC Educational Resources Information Center

    Richardson, D. H. S.; And Others

    1985-01-01

    Proposes that leaf yeast serve as quick, inexpensive, and effective techniques for monitoring air quality. Outlines procedures and provides suggestions for data analysis. Includes results from sample school groups who employed this technique. (ML)

  12. Reflectance model of a plant leaf

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L.

    1973-01-01

    A light ray, incident at 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's Equations and Snell's Law. The optical mediums of the leaf considered for ray tracing are: air, cell sap, chloroplast, and cell wall. The above ray is also drawn through the same leaf cross section considering cell wall and air as the only optical mediums. The values of the reflection and transmission found from ray tracing agree closely with the experimental results obtained using a Beckman DK-2A Spectroreflectometer. Similarly a light ray, incident at about 60 deg to the normal, is drawn through the palisade cells of a soybean leaf to illustrate the pathway of light, incident at an oblique angle, through the palisade cells.

  13. Photosynthesis and Respiration in Leaf Slices.

    ERIC Educational Resources Information Center

    Brown, Simon

    1998-01-01

    Demonstrates how leaf slices provide an inexpensive material for illustrating several fundamental points about the biochemistry of photosynthesis and respiration. Presents experiments that illustrate the effects of photon flux density and herbicides and carbon dioxide concentration. (DDR)

  14. Spectroscopic Measurement of Leaf Water Status

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.; Boardman, Joseph W.

    1995-01-01

    A leaf drying experiment was carried out in the laboratory in which simultaneous spectral reflectance in the 350-2450 nm region, and leaf weights, were measured at 10 second intervals over a 40 minute period. As the leaf water weight dropped from approximately 60 to 38%. a nearly-linear rise in reflectance at all wavelengths beyond 1000 nm was observed. A principal components analysis of the time series of spectra in the 2000-2500 nm wavelength region showed that over 99% of the variance in the spectra, that were individually scaled to have a sum equal to that of the mean spectrum and subsequently mean corrected, was in the first component. This result shows that it is feasible to determine leaf water content remotely with an imaging spectrometer independent of the surface irradiance effects caused by topography.

  15. 7 CFR 29.3528 - Leaf surface.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3528 Leaf surface. The roughness or smoothness of the web or lamina of a tobacco...

  16. 7 CFR 29.3528 - Leaf surface.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3528 Leaf surface. The roughness or smoothness of the web or lamina of a tobacco...

  17. 7 CFR 29.3528 - Leaf surface.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3528 Leaf surface. The roughness or smoothness of the web or lamina of a tobacco...

  18. 7 CFR 29.3528 - Leaf surface.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3528 Leaf surface. The roughness or smoothness of the web or lamina of a tobacco...

  19. 7 CFR 29.3528 - Leaf surface.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3528 Leaf surface. The roughness or smoothness of the web or lamina of a tobacco...

  20. 7 CFR 29.3647 - Heavy Leaf (B Group).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., medium body, close leaf structure, rough, lean in oil, dull finish, pale color intensity, inelastic... Leaf. Mature, medium body, close leaf structure, rough, lean in oil, dull finish, pale color intensity.... Underripe, medium body, close leaf structure, rough, lean in oil, dull finish, pale color...

  1. 7 CFR 29.3647 - Heavy Leaf (B Group).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., medium body, close leaf structure, rough, lean in oil, dull finish, pale color intensity, inelastic... Leaf. Mature, medium body, close leaf structure, rough, lean in oil, dull finish, pale color intensity.... Underripe, medium body, close leaf structure, rough, lean in oil, dull finish, pale color...

  2. 7 CFR 29.3647 - Heavy Leaf (B Group).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., medium body, close leaf structure, rough, lean in oil, dull finish, pale color intensity, inelastic... Leaf. Mature, medium body, close leaf structure, rough, lean in oil, dull finish, pale color intensity.... Underripe, medium body, close leaf structure, rough, lean in oil, dull finish, pale color...

  3. Effect of harvest timing and leaf hairiness on fiber quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent concerns over leaf grades have generated questions of how both time of day cotton is harvested, as well as leaf hairiness levels of certain varieties, influence fiber quality. To address this, two smooth leaf varieties and two varieties with higher levels of leaf pubescence were harvested at...

  4. Effect of herbivore damage on broad leaf motion in wind

    NASA Astrophysics Data System (ADS)

    Burnett, Nicholas; Kothari, Adit

    2015-11-01

    Terrestrial plants regularly experience wind that imposes aerodynamic forces on the plants' leaves. Passive leaf motion (e.g. fluttering) and reconfiguration (e.g. rolling into a cone shape) in wind can affect the drag on the leaf. In the study of passive leaf motion in wind, little attention has been given to the effect of herbivory. Herbivores may alter leaf motion in wind by making holes in the leaf. Also, a small herbivore (e.g. snail) on a leaf can act as a point mass, thereby affecting the leaf's motion in wind. Conversely, accelerations imposed on an herbivore sitting on a leaf by the moving leaf may serve as a defense by dislodging the herbivore. In the present study, we investigated how point masses (>1 g) and holes in leaves of the tuliptree affected passive leaf motion in turbulent winds of 1 and 5 m s-1. Leaf motion was unaffected by holes in the leaf surface (about 10% of leaf area), but an herbivore's mass significantly damped the accelerations of fluttering leaves. These results suggest that an herbivore's mass, but not the damage it inflicts, can affect leaf motion in the wind. Furthermore, the damping of leaf fluttering from an herbivore's mass may prevent passive leaf motions from being an effective herbivore defense.

  5. 7 CFR 29.1163 - Smoking Leaf (H Group).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Smoking Leaf (H Group). 29.1163 Section 29.1163... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.1163 Smoking Leaf (H Group). This group consists of... Quality Orange Smoking Leaf Mellow, open leaf structure, medium body, lean in oil, strong color...

  6. 7 CFR 29.1163 - Smoking Leaf (H Group).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Smoking Leaf (H Group). 29.1163 Section 29.1163... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.1163 Smoking Leaf (H Group). This group consists of... Quality Orange Smoking Leaf Mellow, open leaf structure, medium body, lean in oil, strong color...

  7. 7 CFR 29.1163 - Smoking Leaf (H Group).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Smoking Leaf (H Group). 29.1163 Section 29.1163... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.1163 Smoking Leaf (H Group). This group consists of... Quality Orange Smoking Leaf Mellow, open leaf structure, medium body, lean in oil, strong color...

  8. 7 CFR 29.1163 - Smoking Leaf (H Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Smoking Leaf (H Group). 29.1163 Section 29.1163... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.1163 Smoking Leaf (H Group). This group consists of... Quality Orange Smoking Leaf Mellow, open leaf structure, medium body, lean in oil, strong color...

  9. 7 CFR 29.1163 - Smoking Leaf (H Group).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Smoking Leaf (H Group). 29.1163 Section 29.1163... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.1163 Smoking Leaf (H Group). This group consists of... Quality Orange Smoking Leaf Mellow, open leaf structure, medium body, lean in oil, strong color...

  10. 7 CFR 30.31 - Classification of leaf tobacco.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Classification of leaf tobacco. 30.31 Section 30.31... REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.31 Classification of leaf tobacco. For the purpose of this classification leaf tobacco...

  11. 7 CFR 30.31 - Classification of leaf tobacco.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Classification of leaf tobacco. 30.31 Section 30.31... REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.31 Classification of leaf tobacco. For the purpose of this classification leaf tobacco...

  12. 7 CFR 30.31 - Classification of leaf tobacco.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Classification of leaf tobacco. 30.31 Section 30.31... REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.31 Classification of leaf tobacco. For the purpose of this classification leaf tobacco...

  13. 7 CFR 30.31 - Classification of leaf tobacco.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Classification of leaf tobacco. 30.31 Section 30.31... REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.31 Classification of leaf tobacco. For the purpose of this classification leaf tobacco...

  14. 7 CFR 30.31 - Classification of leaf tobacco.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Classification of leaf tobacco. 30.31 Section 30.31... REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.31 Classification of leaf tobacco. For the purpose of this classification leaf tobacco...

  15. 7 CFR 29.3648 - Thin Leaf (C Group).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth, oily, clear finish, deep color intensity, semielastic, spready, 90 percent uniform, and 10 percent injury tolerance. C2L Fine Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth,...

  16. 7 CFR 29.3648 - Thin Leaf (C Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth, oily, clear finish, deep color intensity, semielastic, spready, 90 percent uniform, and 10 percent injury tolerance. C2L Fine Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth,...

  17. 7 CFR 29.3648 - Thin Leaf (C Group).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth, oily, clear finish, deep color intensity, semielastic, spready, 90 percent uniform, and 10 percent injury tolerance. C2L Fine Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth,...

  18. 7 CFR 29.3648 - Thin Leaf (C Group).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth, oily, clear finish, deep color intensity, semielastic, spready, 90 percent uniform, and 10 percent injury tolerance. C2L Fine Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth,...

  19. 7 CFR 29.3648 - Thin Leaf (C Group).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth, oily, clear finish, deep color intensity, semielastic, spready, 90 percent uniform, and 10 percent injury tolerance. C2L Fine Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth,...

  20. 7 CFR 28.512 - Leaf Grade No. 2.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade No. 2. 28.512 Section 28.512 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Pima Cotton § 28.512 Leaf Grade No. 2. Leaf grade No. 2 shall be American Pima cotton which...

  1. 7 CFR 28.511 - Leaf Grade No. 1.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade No. 1. 28.511 Section 28.511 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Pima Cotton § 28.511 Leaf Grade No. 1. Leaf grade No. 1 shall be American Pima cotton which...

  2. What Is a Leaf? An Online Tutorial and Tests

    ERIC Educational Resources Information Center

    Burrows, Geoffrey

    2008-01-01

    A leaf is a fundamental unit in botany and understanding what constitutes a leaf is fundamental to many plant science activities. My observations and subsequent testing indicated that many students could not confidently and consistently recognise a leaf from a leaflet, or recognise basic leaf arrangements and the various types of compound or…

  3. 7 CFR 28.515 - Leaf Grade No. 5.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade No. 5. 28.515 Section 28.515 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Pima Cotton § 28.515 Leaf Grade No. 5. Leaf grade No. 5 shall be American Pima cotton which...

  4. 7 CFR 28.513 - Leaf Grade No. 3.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade No. 3. 28.513 Section 28.513 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Pima Cotton § 28.513 Leaf Grade No. 3. Leaf grade No. 3 shall be American Pima cotton which...

  5. 7 CFR 28.514 - Leaf Grade No. 4.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade No. 4. 28.514 Section 28.514 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Pima Cotton § 28.514 Leaf Grade No. 4. Leaf grade No. 4 shall be American Pima cotton which...

  6. 7 CFR 28.517 - Leaf Grade No. 7.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade No. 7. 28.517 Section 28.517 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Pima Cotton § 28.517 Leaf Grade No. 7. American Pima cotton which in leaf is inferior to...

  7. 7 CFR 28.516 - Leaf Grade No. 6.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf Grade No. 6. 28.516 Section 28.516 Agriculture..., TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for the Leaf Grade of American Pima Cotton § 28.516 Leaf Grade No. 6. Leaf grade No. 6 shall be American Pima cotton which...

  8. 7 CFR 29.3647 - Heavy Leaf (B Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., close leaf structure, rough, lean in oil, dull finish, pale color intensity, inelastic, narrow, 70..., medium body, close leaf structure, rough, lean in oil, dull finish, pale color intensity, inelastic... Leaf. Mature, heavy, close leaf structure, rough, lean in oil, dull finish, pale color...

  9. Actinobacillus actinomycetemcomitans Y4 capsular-polysaccharide-like polysaccharide promotes osteoclast-like cell formation by interleukin-1 alpha production in mouse marrow cultures.

    PubMed Central

    Nishihara, T; Ueda, N; Amano, K; Ishihara, Y; Hayakawa, H; Kuroyanagi, T; Ohsaki, Y; Nagata, K; Noguchi, T

    1995-01-01

    The mechanism of osteoclast-like cell formation induced by periodontopathic bacterium Actinobacillus actinomycetemcomitans Y4 (serotype b) capsular-polysaccharide-like polysaccharide (capsular-like polysaccharide) was examined in a mouse bone marrow culture system. When mouse bone marrow cells were cultured with A. actinomycetemcomitans Y4 capsular-like polysaccharide for 9 days, many multinucleated cells were formed. The multinucleated cells showed several characteristics of osteoclasts, including tartrate-resistant acid phosphatase (TRACP) and the ability to resorb the calcified dentine. In this study, we examined the effects of antisera to interleukins on the formation of osteoclast-like cells induced by A. actinomycetemcomitans Y4 capsular-like polysaccharide. Monospecific anti-mouse recombinant interleukin-1 alpha (rIL-1 alpha) serum completely inhibited the formation of osteoclast-like cells in the presence of A. actinomycetemcomitans Y4 capsular-like polysaccharide. However, anti-mouse rIL-1 beta and anti-mouse rIL-6 sera showed no effect on osteoclast-like cell formation. IL-1 receptor antagonist significantly inhibited the osteoclast-like cell formation mediated by A. actinomycetemcomitans Y4 capsular-like polysaccharide in mouse marrow cultures. The bioactive IL-1 was detected in the culture media of mouse bone marrow cells stimulated with A. actinomycetemcomitans Y4 capsular-like polysaccharide. These results indicate that IL-1 alpha is involved in the mechanism of the formation of osteoclast-like cells induced by A. actinomycetemcomitans Y4 capsular-like polysaccharide. We sought to determine whether osteoclast-like cell formation induced by A. actinomycetemcomitans Y4 capsular-like polysaccharide could be modulated by the protein kinase inhibitors H8 and HA1004. The formation of osteoclast-like cells was suppressed by H8 and HA1004. These findings suggest that the signals by protein kinases may regulate osteoclast-like cell formation induced by A

  10. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation.

    PubMed

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-04-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe asrl2(semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function.SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1(SLL1)/ROLLED LEAF9(RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation.

  11. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation

    PubMed Central

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-01-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe a srl2 (semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function. SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1 (SLL1)/ROLLED LEAF9 (RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation. PMID:26873975

  12. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation.

    PubMed

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-04-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe asrl2(semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function.SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1(SLL1)/ROLLED LEAF9(RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation. PMID:26873975

  13. Antibacterial activity on Citrullus colocynthis Leaf extract

    PubMed Central

    gowri, S. Shyamala; Priyavardhini, S.; Vasantha, K.; Umadevi, M.

    2009-01-01

    Studies on the antibacterial activities of the leaf extract of Citrullus colocynthis (Cucurbitaceae), a medicinal plant used for the treatment of various ailments was carried out using agar disc diffusion technique. The results revealed that the crude acetone extract exhibited antibacterial activities against Pseudomonas aeruginosa with zones of inhibition measuring 14.0mm. The chloroform leaf extract exhibited no antibacterial activity against Staphylococcus aureus. The minimum inhibitory concentration for the chloroform extract was 4.0mm for Escherichia coli. PMID:22557336

  14. Remote sensing of leaf water status

    NASA Technical Reports Server (NTRS)

    Ripple, William J.; Schrumpf, Barry J.

    1987-01-01

    Relative water content (RWC) measurements were made concurrently with spectral reflectance measurements from individual snapbean leaves. The relationships between spectra and RWC were described using second order polynomial equations. The middle infrared bands most sensitive to changes in leaf RWC also had the highest water absorption coefficients, as published by Curcio Petty (1951). The relationship between reflectance at 2100nm and total water potential for a single leaf was found to be linear.

  15. Dried-leaf Artemisia annua: A practical malaria therapeutic for developing countries?

    PubMed Central

    Weathers, Pamela J; Towler, Melissa; Hassanali, Ahmed; Lutgen, Pierre; Engeu, Patrick Ogwang

    2015-01-01

    Artemisinin from the plant Artemisia annua (A. annua) L, and used as artemisinin combination therapy (ACT), is the current best therapeutic for treating malaria, a disease that hits children and adults especially in developing countries. Traditionally, A. annua was used by the Chinese as a tea to treat “fever”. More recently, investigators have shown that tea infusions and oral consumption of the dried leaves of the plant have prophylactic and therapeutic efficacy. The presence of a complex matrix of chemicals within the leaves seems to enhance both the bioavailability and efficacy of artemisinin. Although about 1000-fold less potent than artemisinin in their antiplasmodial activity, these plant chemicals are mainly small molecules that include other artemisinic compounds, terpenes (mainly mono and sesqui), flavonoids, and polyphenolic acids. In addition, polysaccharide constituents of A. annua may enhance bioavailability of artemisinin. Rodent pharmacokinetics showed longer T1/2 and Tmax and greater Cmax and AUC in Plasmodium chabaudi-infected mice treated with A. annua dried leaves than in healthy mice. Pharmacokinetics of deoxyartemisinin, a liver metabolite of artemisinin, was more inhibited in infected than in healthy mice. In healthy mice, artemisinin serum levels were > 40-fold greater in dried leaf fed mice than those fed with pure artemisinin. Human trial data showed that when delivered as dried leaves, 40-fold less artemisinin was required to obtain a therapeutic response compared to pure artemisinin. ACTs are still unaffordable for many malaria patients, and cost estimates for A. annua dried leaf tablet production are orders of magnitude less than for ACT, despite improvements in the production capacity. Considering that for > 2000 years this plant was used in traditional Chinese medicine for treatment of fever with no apparent appearance of artemisinin drug resistance, the evidence argues for inclusion of affordable A. annua dried leaf tablets into

  16. Polysaccharides purified from wild Cordyceps activate FGF2/FGFR1c signaling

    NASA Astrophysics Data System (ADS)

    Zeng, Yangyang; Han, Zhangrun; Yu, Guangli; Hao, Jiejie; Zhang, Lijuan

    2015-02-01

    Land animals as well as all organisms in ocean synthesize sulfated polysaccharides. Fungi split from animals about 1.5 billion years ago. As fungi make the evolutionary journey from ocean to land, the biggest changes in their living environment may be a sharp decrease in salt concentration. It is established that sulfated polysaccharides interact with hundreds of signaling molecules and facilitate many signaling transduction pathways, including fibroblast growth factor (FGF) and FGF receptor signaling pathway. The disappearance of sulfated polysaccharides in fungi and plants on land might indicate that polysaccharides without sulfation might be sufficient in facilitating protein ligand/receptor interactions in low salinity land. Recently, it was reported that plants on land start to synthesize sulfated polysaccharides in high salt environment, suggesting that fungi might be able to do the same when exposed in such environment. Interestingly, Cordyceps, a fungus habituating inside caterpillar body, is the most valued traditional Chinese Medicine. One of the important pharmaceutical active ingredients in Cordyceps is polysaccharides. Therefore, we hypothesize that the salty environment inside caterpillar body might allow the fungi to synthesize sulfated polysaccharides. To test the hypothesis, we isolated polysaccharides from both lava and sporophore of wild Cordyceps and also from Cordyceps militaris cultured without or with added salts. We then measured the polysaccharide activity using a FGF2/FGFR1c signaling-dependent BaF3 cell proliferation assay and found that polysaccharides isolated from wild Cordyceps activated FGF2/FGFR signaling, indicating that the polysaccharides synthesized by wild Cordyceps are indeed different from those by the cultured mycelium.

  17. Wind increases leaf water use efficiency.

    PubMed

    Schymanski, Stanislaus J; Or, Dani

    2016-07-01

    A widespread perception is that, with increasing wind speed, transpiration from plant leaves increases. However, evidence suggests that increasing wind speed enhances carbon dioxide (CO2 ) uptake while reducing transpiration because of more efficient convective cooling (under high solar radiation loads). We provide theoretical and experimental evidence that leaf water use efficiency (WUE, carbon uptake per water transpired) commonly increases with increasing wind speed, thus improving plants' ability to conserve water during photosynthesis. Our leaf-scale analysis suggests that the observed global decrease in near-surface wind speeds could have reduced WUE at a magnitude similar to the increase in WUE attributed to global rise in atmospheric CO2 concentrations. However, there is indication that the effect of long-term trends in wind speed on leaf gas exchange may be compensated for by the concurrent reduction in mean leaf sizes. These unintuitive feedbacks between wind, leaf size and water use efficiency call for re-evaluation of the role of wind in plant water relations and potential re-interpretation of temporal and geographic trends in leaf sizes. PMID:26714739

  18. Wind increases leaf water use efficiency.

    PubMed

    Schymanski, Stanislaus J; Or, Dani

    2016-07-01

    A widespread perception is that, with increasing wind speed, transpiration from plant leaves increases. However, evidence suggests that increasing wind speed enhances carbon dioxide (CO2 ) uptake while reducing transpiration because of more efficient convective cooling (under high solar radiation loads). We provide theoretical and experimental evidence that leaf water use efficiency (WUE, carbon uptake per water transpired) commonly increases with increasing wind speed, thus improving plants' ability to conserve water during photosynthesis. Our leaf-scale analysis suggests that the observed global decrease in near-surface wind speeds could have reduced WUE at a magnitude similar to the increase in WUE attributed to global rise in atmospheric CO2 concentrations. However, there is indication that the effect of long-term trends in wind speed on leaf gas exchange may be compensated for by the concurrent reduction in mean leaf sizes. These unintuitive feedbacks between wind, leaf size and water use efficiency call for re-evaluation of the role of wind in plant water relations and potential re-interpretation of temporal and geographic trends in leaf sizes.

  19. Association of tomato leaf curl Sudan virus with leaf curl disease of tomato in Jeddah, Saudi Arabia.

    PubMed

    Sohrab, Sayed Sartaj; Yasir, Muhammad; El-Kafrawy, Sherif Ali; Abbas, Ayman T; Mousa, Magdi Ali Ahmed; Bakhashwain, Ahmed A

    2016-06-01

    Tomato is an important vegetable crop and its production is adversely affected by leaf curl disease caused by begomovirus. Leaf curl disease is a serious concern for tomato crops caused by begomovirus in Jeddah, Kingdom of Saudi Arabia. Tomato leaf curl disease has been shown to be mainly caused either by tomato leaf curl Sudan virus or tomato yellow leaf curl virus as well as tomato leaf curl Oman virus. Many tomato plants infected with monopartite begomoviruses were also found to harbor a symptom enhancing betasatellites. Here we report the association of tomato leaf curl Sudan virus causing leaf curl disease of tomato in Jeddah, Kingdom of Saudi Arabia. The complete genome sequence analysis showed highest (99.9 %) identity with tomato leaf curl Sudan virus causing leaf curl disease in Arabian Peninsula. In phylogenetic relationships analysis, the identified virus formed closest cluster with tomato leaf curl Sudan virus. In recombination analysis study, the major parent was identified as tomato leaf curl Sudan virus. Findings of this study strongly supports the associated virus is a variant of tomato leaf curl Sudan virus causing disease in Sudan, Yemen and Arabian Peninsula. The betasatellites sequence analysis showed highest identity (99.8 %) with tomato leaf curl betasatellites-Amaranthus-Jeddah. The phylogenetic analysis result based on betasatellites formed closed cluster with tomato yellow leaf curl Oman betasatellites. The importance of these findings and occurrence of begomovirus in new geographic regions causing leaf curl disease of tomato in Jeddah, Kingdom of Saudi Arabia are discussed.

  20. Association of tomato leaf curl Sudan virus with leaf curl disease of tomato in Jeddah, Saudi Arabia.

    PubMed

    Sohrab, Sayed Sartaj; Yasir, Muhammad; El-Kafrawy, Sherif Ali; Abbas, Ayman T; Mousa, Magdi Ali Ahmed; Bakhashwain, Ahmed A

    2016-06-01

    Tomato is an important vegetable crop and its production is adversely affected by leaf curl disease caused by begomovirus. Leaf curl disease is a serious concern for tomato crops caused by begomovirus in Jeddah, Kingdom of Saudi Arabia. Tomato leaf curl disease has been shown to be mainly caused either by tomato leaf curl Sudan virus or tomato yellow leaf curl virus as well as tomato leaf curl Oman virus. Many tomato plants infected with monopartite begomoviruses were also found to harbor a symptom enhancing betasatellites. Here we report the association of tomato leaf curl Sudan virus causing leaf curl disease of tomato in Jeddah, Kingdom of Saudi Arabia. The complete genome sequence analysis showed highest (99.9 %) identity with tomato leaf curl Sudan virus causing leaf curl disease in Arabian Peninsula. In phylogenetic relationships analysis, the identified virus formed closest cluster with tomato leaf curl Sudan virus. In recombination analysis study, the major parent was identified as tomato leaf curl Sudan virus. Findings of this study strongly supports the associated virus is a variant of tomato leaf curl Sudan virus causing disease in Sudan, Yemen and Arabian Peninsula. The betasatellites sequence analysis showed highest identity (99.8 %) with tomato leaf curl betasatellites-Amaranthus-Jeddah. The phylogenetic analysis result based on betasatellites formed closed cluster with tomato yellow leaf curl Oman betasatellites. The importance of these findings and occurrence of begomovirus in new geographic regions causing leaf curl disease of tomato in Jeddah, Kingdom of Saudi Arabia are discussed. PMID:27366765