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Sample records for acyl gellan gum

  1. Rheology of sheared gels based on low acyl-gellan gum.

    PubMed

    García, M Carmen; Alfaro, M Carmen; Muñoz, José

    2016-06-01

    Sheared gels containing 0.2 wt% low-acyl gellan gum were prepared by different processing protocols using Na(+) or Ca(2+) as gel-promoting ions. Rheology and confocal laser scanning microscopy were used to gain information on the sample structure. Confocal laser scanning microscopy revealed the formation of a heterogeneous microstructure consisting of a dispersion of gel-like clusters. Small amplitude oscillatory shear stress results indicated that their viscoelastic properties had a predominant elastic component. Flow curves exhibited very high viscosities at low shear stress, an apparent yield stress and very shear thinning behaviour, supporting their applications as a stabilizer.

  2. Growth arrest of vascular smooth muscle cells in suspension culture using low-acyl gellan gum.

    PubMed

    Natori, Tomomi; Fujiyoshi, Masachika; Uchida, Masashi; Abe, Natsuki; Kanaki, Tatsuro; Fukumoto, Yasunori; Ishii, Itsuko

    2017-03-01

    The proliferation of vascular smooth muscle cells (SMCs) causes restenosis in biomaterial vascular grafts. The purposes of this study were to establish a suspension culture system for SMCs by using a novel substrate, low-acyl gellan gum (GG) and to maintain SMCs in a state of growth inhibition. When SMCs were cultured in suspension with GG, their proliferation was inhibited. Their viability was 70% at day 2, which was maintained at more than 50% until day 5. In contrast, the viability of cells cultured in suspension without GG was 5.6% at day 2. By cell cycle analysis, the ratio of SMCs in the S phase when cultured in suspension with GG was lower than when cultured on plastic plates. In SMCs cultured in suspension with GG, the ratio of phosphorylated retinoblastoma (Rb) protein to Rb protein was decreased and p27(Kip1) expression was unchanged in comparison with SMCs cultured on plastic plates. In addition, SMCs could be induced to proliferate again by changing the culture condition from suspension with GG to plastic plates. These results suggest that our established culturing method for SMCs is useful to maintain SMCs in a state of growth inhibition with high viability.

  3. Gellan gum fluid gels for topical administration of diclofenac.

    PubMed

    Mahdi, Mohammed H; Conway, Barbara R; Mills, Thomas; Smith, Alan M

    2016-12-30

    Diclofenac topical formulations are often preferred for drug administration to patients who experience serious GIT problems. Absorption of the drug through the skin, however, can be challenging due to the natural protective feature of the stratum corneum (SC). In this article, fluid gels prepared from gellan gum were explored as a topical drug delivery vehicle. Rheological analysis of the formulations showed that it was possible to produce a topical gel with a viscosity and the mechanical strength similar to that of the commercially available Voltaren(®) gel using 1% w/w of a 50:50 low acyl/high acyl (LA/HA) gellan blend. Soft-tribology was used to assess the lubrication properties of gellan fluid gels. The lubrication of the gellan gum fluid gel formulations at high rubbing speeds was similar to the lubrication of the Voltaren(®) gel. The use of gellan gum dramatically increased skin permeation of diclofenac when compared with the commercially available formulation and could be controlled by changing the gellan gum concentration and/or sodium ion concentration in the formulation. This study highlights the potential use of fluid gels that can be easily tuned to have physical properties suitable for topical formulations with the added advantage of increasing drug permeation.

  4. High acyl gellan as an emulsion stabilizer.

    PubMed

    Vilela, Joice Aline Pires; da Cunha, Rosiane Lopes

    2016-03-30

    High acyl gellan (0.01-0.2% w/w) was used as stabilizer in oil in water emulsions containing 30% (w/w) of sunflower oil and prepared under different process conditions. Stable emulsions to phase separation could be obtained using high acyl gellan (HA) content above 0.05% (w/w), while low acyl gellan (LA) prepared at the same conditions could not stabilize emulsions. Emulsions properties depended on the process used to mix the oil and gellan dispersion since high pressure homogenization favored stabilization while very high energy density applied by ultrasound led to systems destabilization. Emulsions prepared using high pressure homogenization showed zeta potential values ranging from -50 up to -59 mV, suggesting that electrostatic repulsion could be contributing to the systems stability. Rheological properties of continuous phase were also responsible for emulsions stabilization, since HA gellan dispersions showed high viscosity and gel-like behavior. The high viscosity of the continuous phase could be associated to the presence of high acyl gellan microgels/aggregates. Disentanglement of these aggregates performed by ultrasound strongly decreased the viscosity and consequently affected the emulsions behavior, reducing the stability to phase separation.

  5. Development of mucoadhesive sprayable gellan gum fluid gels.

    PubMed

    Mahdi, Mohammed H; Conway, Barbara R; Smith, Alan M

    2015-07-05

    The nasal mucosa provides a potentially good route for local and systemic drug delivery. However, the protective feature of the nasal cavity make intranasal delivery challenging. The application of mucoadhesive polymers in nasal drug delivery systems enhances the retention of the dosage form in the nasal cavity. Several groups have investigated using low acyl gellan as a drug delivery vehicle but only limited research however, has been performed on high acyl gellan for this purpose, despite its properties being more conducive to mucoadhesion. High acyl gellan produces highly elastic gels below 60°C which make it difficult to spray using a mechanical spray device. Therefore, in this study we have tried to address this problem by making fluid gels by introducing a shear force during gelation of the gellan polymer. These fluid gel systems contain gelled micro-particles suspended in a solution of un-gelled polymer. These systems can therefore behave as pourable viscoelastic fluids. In this study we have investigated the rheological behavior and mucoadhesion of fluid gels of two different types of gellan (high and low acyl) and fluid gels prepared from blends of high and low acyl gellan at a 50:50 ratio. The results demonstrated that by preparing fluid gels of high acyl gellan, the rheological properties were sufficient to spray through a standard nasal spray device. Moreover fluid gels also significantly enhance both high acyl and low acyl gellan mucoadhesion properties.

  6. Preparation and Evaluation of Soft Gellan Gum Gel Containing Paracetamol

    PubMed Central

    Gohel, M. C.; Parikh, R. K.; Nagori, S. A.; Shah, S. N.; Dabhi, M. R.

    2009-01-01

    The objective of this study was to develop soft paracetamol gel using gellan gum as a gelling agent and sodium citrate as a source of cation. Different batches were prepared using three different concentrations of gellan gum (0.1, 0.3, and 0.5%), each with two different sodium citrate concentrations (0.3 and 0.5%). The consistency of the paracetamol gel was dependent on the concentration of gellan gum, sodium citrate and co-solute. The results of dissolution study of soft gel containing 0.3% gellan gum and 0.3% sodium citrate revealed that paracetamol was completely released in 30 min. Polyethylene glycol 400 worked as a solubilizer for paracetamol. All the gels possessed acceptable sensory characteristics when evaluated by human volunteers. Short term stability study carried out for four weeks at different temperatures revealed no considerable changes in performance characteristics of developed optimized formulation. PMID:20336205

  7. Formulation of controlled release gellan gum macro beads of amoxicillin.

    PubMed

    Babu, R Jayachandra; Sathigari, Sateesh; Kumar, M Thilek; Pandit, J K

    2010-01-01

    Gellan gum has been reported to have wide pharmaceutical applications such as tablet binder, disintegrant, gelling agent and as a controlled release polymer. Multiparticulate delivery systems spread out more uniformly in the gastrointestinal tract and reduce the local irritation. The purpose of this study is to explore possible applicability of gellan macro beads as an oral controlled release system of a sparingly soluble drug, amoxicillin. Gellan gum beads were prepared by ionotropic gelation with calcium ions. The effect of drug loading, stirring time, polymer concentration, electrolyte (CaCl2) concentration, curing time etc. influencing the preparation of the gellan gum macro beads and the drug release from gellan gum beads were investigated in this study. Optimal preparation conditions allowed very high incorporation efficiency for amoxicillin (91%) The release kinetics of amoxicillin from gellan beads followed the diffusion model for an inert porous matrix in the order: 0.1 N HCl > phosphate buffer > distilled water. Change in curing time did not significantly affect the release rate constant, but drug concentration, polymer concentration and electrolyte concentration significantly affect the release rate of amoxicillin from the beads. The gellan macro beads may be suitable for gastro retentive controlled delivery of amoxicillin.

  8. Self-structuring foods based on acid-sensitive low and high acyl mixed gellan systems to impact on satiety

    PubMed Central

    Bradbeer, Jennifer F.; Hancocks, Robin; Spyropoulos, Fotios; Norton, Ian T.

    2014-01-01

    This study investigated the in vitro acid-induced gelation of mixed systems of two biopolymers; low acyl and high acyl gellan gum. Rheological and texture analysis showed that these mixed gels displayed textures that lay between the material properties exhibited for the low and high acyl variants. DSC analysis showed that mixtures of the low acyl and high acyl forms exhibit two separate conformational transitions at temperatures coincident with each of the individual biopolymers. Various metabolically relevant pH environments and hydrocolloid concentrations were investigated. These resulted in very different acid gelled structures, which were characterised by texture analysis. The structures of the acid gels were shown to depend upon the pH, hydrocolloid concentration and proportion of each biopolymer used during their production. A selection of these mixed gellan structures were assessed post-production in terms of their response to prolonged exposure to an acidic (pH 1), stomach-like, environment. This resulted in a significant increase in the gel strength, regardless of the biopolymer proportions. The high acyl gellan was less acid-sensitive, and subsequently no evidence of acid gelation was observed with high acyl gellan at a proportion greater than 60% of the total biopolymer. The findings presented here demonstrate that structuring as well as de-structuring of mixed gellan acid gels can be controlled in acidic environments similar to those that are present in the stomach after food consumption. PMID:24882914

  9. Gellan gum: a new biomaterial for cartilage tissue engineering applications.

    PubMed

    Oliveira, J T; Martins, L; Picciochi, R; Malafaya, P B; Sousa, R A; Neves, N M; Mano, J F; Reis, R L

    2010-06-01

    Gellan gum is a polysaccharide manufactured by microbial fermentation of the Sphingomonas paucimobilis microorganism, being commonly used in the food and pharmaceutical industry. It can be dissolved in water, and when heated and mixed with mono or divalent cations, forms a gel upon lowering the temperature under mild conditions. In this work, gellan gum hydrogels were analyzed as cells supports in the context of cartilage regeneration. Gellan gum hydrogel discs were characterized in terms of mechanical and structural properties. Transmissionelectron microscopy revealed a quite homogeneous chain arrangement within the hydrogels matrix, and dynamic mechanical analysis allowed to characterize the hydrogels discs viscoelastic properties upon compression solicitation, being the compressive storage and loss modulus of approximately 40 kPa and 3 kPa, respectively, at a frequency of 1 Hz. Rheological measurements determined the sol-gel transition started to occur at approximately 36 degrees C, exhibiting a gelation time of approximately 11 s. Evaluation of the gellan gum hydrogels biological performance was performed using a standard MTS cytotoxicity test, which showed that the leachables released are not deleterious to the cells and hence were noncytotoxic. Gellan gum hydrogels were afterwards used to encapsulate human nasal chondrocytes (1 x 10(6) cells/mL) and culture them for total periods of 2 weeks. Cells viability was confirmed using confocal calcein AM staining. Histological observations revealed normal chondrocytes morphology and the obtained data supports the claim that this new biomaterial has the potential to serve as a cell support in the field of cartilage regeneration.

  10. Sterile Culture of Rotylenchulus reniformis on Tomato Root with Gellan Gum as a Supporting Medium

    PubMed Central

    Eyre, Melissa J.; Caswell, Edward P.

    1991-01-01

    Rotylenchulus reniformis was repeatedly propagated in sterile excised tomato roots growing on modified White's medium with gellan gum as the support. Gellan gum provided an optically clear support medium that could be liquified by adding 5 mM disodium ethylenediaminetetraacetate (EDTA) to facilitate nematode extraction. Liquefaction of the gellan-gum medium by EDTA allowed efficient recovery of eggs and vermiform stages of R. reniformis. Extraction efficiency was quantified with Radopholus similis as a test organism. The efficiency of extracting R. similis from the gellan gum did not vary with the concentrations of EDTA tested. PMID:19283117

  11. Sterile Culture of Rotylenchulus reniformis on Tomato Root with Gellan Gum as a Supporting Medium.

    PubMed

    Eyre, M J; Caswell, E P

    1991-04-01

    Rotylenchulus reniformis was repeatedly propagated in sterile excised tomato roots growing on modified White's medium with gellan gum as the support. Gellan gum provided an optically clear support medium that could be liquified by adding 5 mM disodium ethylenediaminetetraacetate (EDTA) to facilitate nematode extraction. Liquefaction of the gellan-gum medium by EDTA allowed efficient recovery of eggs and vermiform stages of R. reniformis. Extraction efficiency was quantified with Radopholus similis as a test organism. The efficiency of extracting R. similis from the gellan gum did not vary with the concentrations of EDTA tested.

  12. Optimisation of gellan gum edible coating for ready-to-eat mango (Mangifera indica L.) bars.

    PubMed

    Danalache, Florina; Carvalho, Claudia Y; Alves, Vitor D; Moldão-Martins, Margarida; Mata, Paulina

    2016-03-01

    The optimisation of an edible coating based on low acyl (L)/high acyl (H) gellan gum for ready-to-eat mango bars was performed through a central composite rotatable design (CCRD). The independent variables were the concentration of gellan (L/H90/10) and the concentration of Ca(2+) in the coating solution, as well as the storage time after coating application. The response variables studied were the coating thickness, mango bars firmness, syneresis, and colour alterations. Gellan concentration was the independent variable that most influenced the thickness of the coating. Syneresis was quite low for the conditions tested (<1.64%). Similarly, the colour alterations were low during the entire storage time (ΔE<5). Considering the model predictions, 1.0%wt L/H90/10 with addition of 6 mM Ca(2+) could represent the optimal coating formulation for the mango bars. The release of eight volatile compounds from the uncoated and coated mango bars with the selected formulation was analysed by Headspace - Solid Phase Micro Extraction-Gas Chromatography during 9 days of refrigerated storage. This work showed that the coating can improve mango bars sensory characteristics (appearance and firmness) and stability in terms of syneresis, colour and volatiles content during storage increasing the commercial value of the final product.

  13. An insight into the emerging exopolysaccharide gellan gum as a novel polymer.

    PubMed

    Prajapati, Vipul D; Jani, Girish K; Zala, Bhumi S; Khutliwala, Tohra A

    2013-04-02

    The microbial exopolysaccharides are water-soluble polymers secreted by microorganisms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceutical and chemical industries due to its novel properties. It is commercially produced by C.P. Kelco in Japan and the USA. This article presents a critical review of the available information on the gum synthesized by Sphingomonas paucimobilis with special emphasis on its fermentative production. Factors affecting the fermentative production of gellan gum and problems associated with mass transfer have been addressed. Classification and trade names of gellan gum has been specified. Characteristics of gellan gum with respect to its structure, physicochemical properties are discussed. An attempt has also been made to review the current and potential applications of gellan gum in food, pharmaceutical and other industries.

  14. Chitosan fibers enhanced gellan gum hydrogels with superior mechanical properties and water-holding capacity.

    PubMed

    Liu, Limei; Wang, Binghao; Gao, Yuan; Bai, Tong-Chun

    2013-08-14

    New hydrogels based on acetylated gellan gum (A-gellan) and chitosan fibers (F-chitosan) are prepared and coded as F-chitosan/A-gellan. Compared to A-gellan hydrogel, F-chitosan/A-gellan hydrogels show higher storage moduli and water-holding capacity. Specifically, the storage modulus of 2.0 F-chitosan/A-gellan (mass ratio of chitosan fibers and gellan gum is 2:1) hydrogels at regular frequency of 1 rad/s is 2.2 kPa, approximately 4.6 times more than that of the A-gellan hydrogel. In addition, the fractural morphology analysis of A-gellan and 2.0 F-chitosan/A-gellan hydrogels treated by different dry methods indicates that the 2.0 F-chitosan/A-gellan hydrogel has more stable macrostructure. Moreover, compared to A-gellan gel, 2.0 F-chitosan/A-gellan gel shows higher activation energy and water-holding capacity during dehydration and higher dielectric constant after dehydration. These results can be attributed to the special advantages of chitosan fibers, which are full of polar and hydrophilic amino group and can transfer the load applied on the hydrogels in fiber form.

  15. 21 CFR 172.665 - Gellan gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....50 gram of sodium chloride is added. The solution is heated to 80 °C with stirring, held at 80 °C for..., sodium, calcium, and magnesium salt. The polysaccharide may contain acyl (glyceryl and acetyl) groups as... bore pipet and transferred into a solution of 10-percent calcium chloride. A tough worm-like gel...

  16. 21 CFR 172.665 - Gellan gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... identification test (i), 0.50 gram of sodium chloride is added. The solution is heated to 80 °C with stirring... neutralized to a mixed potassium, sodium, calcium, and magnesium salt. The polysaccharide may contain acyl... solution is drawn into a wide bore pipet and transferred into a solution of 10-percent calcium chloride....

  17. 21 CFR 172.665 - Gellan gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... identification test (i), 0.50 gram of sodium chloride is added. The solution is heated to 80 °C with stirring... neutralized to a mixed potassium, sodium, calcium, and magnesium salt. The polysaccharide may contain acyl... solution is drawn into a wide bore pipet and transferred into a solution of 10-percent calcium chloride....

  18. 21 CFR 172.665 - Gellan gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... identification test (i), 0.50 gram of sodium chloride is added. The solution is heated to 80 °C with stirring... neutralized to a mixed potassium, sodium, calcium, and magnesium salt. The polysaccharide may contain acyl... solution is drawn into a wide bore pipet and transferred into a solution of 10-percent calcium chloride....

  19. Modified Gellan Gum hydrogels with tunable physical and mechanical properties

    PubMed Central

    Coutinho, Daniela F.; Sant, Shilpa; Shin, Hyeongho; Oliveira, João T.; Gomes, Manuela E.; Neves, Nuno M.; Khademhosseini, Ali; Reis, Rui L.

    2010-01-01

    Gellan Gum (GG) has been recently proposed for tissue engineering applications. GG hydrogels are produced by physical crosslinking methods induced by temperature variation or by the presence of divalent cations. However, physical crosslinking methods may yield hydrogels that become weaker in physiological conditions due to the exchange of divalent cations by monovalent ones. Hence, this work presents a new class of GG hydrogels crosslinkable by both physical and chemical mechanisms. Methacrylate groups were incorporated in the GG chain, leading to the production of a methacrylated gellan gum (MeGG) hydrogel with highly tunable physical and mechanical properties. The chemical modification was confirmed by proton nuclear magnetic resonance (1H-NMR) and Fourier transform infrared spectroscopy (FTIR-ATR). The mechanical properties of the developed hydrogel networks, with Young’s modulus values between 0.15 and 148 kPa, showed to be tuned by the different crosslinking mechanisms used. The in vitro swelling kinetics and hydrolytic degradation rate was dependent on the crosslinking mechanisms used to form the hydrogels. Three-dimensional (3D) encapsulation of NIH-3T3 fibroblast cells in MeGG networks demonstrated in vitro biocompatibility confirmed by high cell survival. Given the highly tunable mechanical and degradation properties of MeGG, it may be applicable for a wide range of tissue engineering approaches. PMID:20663552

  20. Optimization of culture medium compositions for gellan gum production by a halobacterium Sphingomonas paucimobilis.

    PubMed

    Zhang, Jun; Dong, Ya-chen; Fan, Lin-lin; Jiao, Zhi-hua; Chen, Qi-he

    2015-01-22

    The effect of culture medium compositions on gellan gum production produced by fermentation with a halobacterium Sphingomonas paucimobilis QHZJUJW CGMCC2428 was studied. In this work, a fractional factorial design was applied to investigate the main factors that affected gellan gum production by S. paucimobilis QHZJUJW CGMCC2428. Sucrose was the best carbon source for gellan gum and peptone displayed better inducing effect. Central composite design and response surface methodology were adopted to derive a statistical model for optimizing submerged culture medium composition. These experimental results showed that the optimum culture medium for producing gellan gum was composed of 40.00 (w/v) sucrose, 3.00% peptone (w/v), MgSO4 (w/v), 9.20% KH2PO4 (w/v), 7.50% Na2HPO4 (w/v), 4.30% K2SO4 (w/v), pH 6.8-7.0. The maximal gellan gum was 19.89±0.68 g/L, which was agreed closely with the predicated value (20.12 g/L). After incubated for 72 h under the optimized culture medium in 5-L bioreactor, the gellan gum fermentation reached about 19.90±0.68 g/L, which was higher than that in the initial cultivation medium.

  1. Multi-modality gellan gum-based tissue-mimicking phantom with targeted mechanical, electrical, and thermal properties

    NASA Astrophysics Data System (ADS)

    Chen, Roland K.; Shih, A. J.

    2013-08-01

    This study develops a new class of gellan gum-based tissue-mimicking phantom material and a model to predict and control the elastic modulus, thermal conductivity, and electrical conductivity by adjusting the mass fractions of gellan gum, propylene glycol, and sodium chloride, respectively. One of the advantages of gellan gum is its gelling efficiency allowing highly regulable mechanical properties (elastic modulus, toughness, etc). An experiment was performed on 16 gellan gum-based tissue-mimicking phantoms and a regression model was fit to quantitatively predict three material properties (elastic modulus, thermal conductivity, and electrical conductivity) based on the phantom material's composition. Based on these material properties and the regression model developed, tissue-mimicking phantoms of porcine spinal cord and liver were formulated. These gellan gum tissue-mimicking phantoms have the mechanical, thermal, and electrical properties approximately equivalent to those of the spinal cord and the liver.

  2. Gellan gum capped silver nanoparticle dispersions and hydrogels: cytotoxicity and in vitro diffusion studies

    NASA Astrophysics Data System (ADS)

    Dhar, S.; Murawala, P.; Shiras, A.; Pokharkar, V.; Prasad, B. L. V.

    2012-01-01

    The preparation of highly stable water dispersions of silver nanoparticles using the naturally available gellan gum as a reducing and capping agent is reported. Further, exploiting the gel formation characteristic of gellan gum silver nanoparticle incorporated gels have also been prepared. The optical properties, morphology, zeta potential and long-term stability of the synthesized silver nanoparticles were investigated. The superior stability of the gellan gum-silver nanoparticle dispersions against pH variation and electrolyte addition is revealed. Finally, we studied the cytotoxicity of AgNP dispersions in mouse embryonic fibroblast cells (NIH3T3) and also evaluated the in vitro diffusion of AgNP dispersions/gels across rat skin.The preparation of highly stable water dispersions of silver nanoparticles using the naturally available gellan gum as a reducing and capping agent is reported. Further, exploiting the gel formation characteristic of gellan gum silver nanoparticle incorporated gels have also been prepared. The optical properties, morphology, zeta potential and long-term stability of the synthesized silver nanoparticles were investigated. The superior stability of the gellan gum-silver nanoparticle dispersions against pH variation and electrolyte addition is revealed. Finally, we studied the cytotoxicity of AgNP dispersions in mouse embryonic fibroblast cells (NIH3T3) and also evaluated the in vitro diffusion of AgNP dispersions/gels across rat skin. Electronic supplementary information (ESI) available: Time dependent UV-Vis spectral studies revealing the stability of AgNP dispersions and agar plate images displaying the antibacterial activity of AgNPs. See DOI: 10.1039/c1nr10957j

  3. Yield stress determines bioprintability of hydrogels based on gelatin-methacryloyl and gellan gum for cartilage bioprinting

    PubMed Central

    Mouser, Vivian H. M.; Melchels, Ferry P.W.; Visser, Jetze; Dhert, Wouter J.A.; Gawlitta, Debby; Malda, Jos

    2016-01-01

    Bioprinting of chondrocyte-laden hydrogels facilitates the fabrication of constructs with controlled organization and shape for e.g. articular cartilage implants. Gelatin-methacryloyl (gelMA) supplemented with gellan gum is a promising bio-ink. However, the rheological properties governing the printing process, and the influence of gellan gum on the mechanical properties and chondrogenesis of the blend, are still unknown. Here, we investigated the suitability of gelMA/gellan for cartilage bioprinting. Multiple concentrations, ranging from 3-25% gelMA with 0-1.5% gellan gum, were evaluated for their printability, defined as the ability to form filaments and to incorporate cells at 15-37°C. To support the printability assessment, yield stress and viscosity of the hydrogels were measured. Stiffness of UV-cured constructs, as well as cartilage-like tissue formation by embedded chondrocytes, were determined in vitro. A large range of gelMA/gellan concentrations were printable with inclusion of cells and formed the bioprinting window. Addition of gellan gum improved filament deposition by inducing yielding behavior, increased construct stiffness, and supported chondrogenesis. High gellan gum concentrations, however, did compromise cartilage matrix production and distribution, and even higher concentrations resulted in too high yield stresses to allow cell encapsulation. This study demonstrates the high potential of gelMA/gellan blends for cartilage bioprinting and identifies yield stress as dominant factor for bioprintability. PMID:27431733

  4. The influence of gellan gum on the transfer of fluorescein dextran across rat nasal epithelium in vivo.

    PubMed

    Jansson, Björn; Hägerström, Helene; Fransén, Nelly; Edsman, Katarina; Björk, Erik

    2005-04-01

    The nasal uptake of a 3000 Da fluorescein dextran (FD3) was investigated in rats, using fluorescence microscopy. The uptake from a formulation containing deacetylated gellan gum, an in situ gelling agent, was compared to that from a mannitol solution. Additionally, the rheological behavior of the gellan gum in water and saline was studied. It was shown that the gellan gum solution was easily administered owing to its low viscosity, and upon contact with the mucosa, a gel was formed. The epithelial uptake and transfer of FD3 appeared to be increased and prolonged using the gellan gum formulation. This increase was not accompanied by qualitative changes of the epithelial FD3 distribution or any visible harmful effects.

  5. Molecular structures of gellan gum imaged with atomic force microscopy in relation to the rheological behavior in aqueous systems in the presence or absence of various cations.

    PubMed

    Funami, Takahiro; Noda, Sakie; Nakauma, Makoto; Ishihara, Sayaka; Takahashi, Rheo; Al-Assaf, Saphwan; Ikeda, Shinya; Nishinari, Katsuyoshi; Phillips, Glyn O

    2008-09-24

    Aqueous solutions of gellan gum with comparable molecular masses but with different acyl contents were investigated by atomic force microscopy and rheological measurements in the presence or absence of various cations. For a high-acyl sample, no continuous network structures were identified microscopically, except in the presence of Ca (2+), where structural inhomogeneity was the highest in terms of the height distribution of molecular assemblies. Rheological thermal hysteresis between sol-gel transitions was detected in the presence of K (+) and Ca (2+), particularly Ca (2+). The storage modulus at 20 degrees C was larger in the order Na (+) < Ca (2+) < K (+). For a low-acyl sample, continuous network structures were identified in the presence of each cation, involving greater thermal hysteresis than the corresponding data for the high-acyl sample. Structural homogeneity was the highest in the presence of K (+). Thermal hysteresis and elasticity of the system were discussed in terms of continuousness and homogeneity of network structures.

  6. In situ gel based on gellan gum as new carrier for nasal administration of mometasone furoate.

    PubMed

    Cao, Shi-lei; Ren, Xiao-wei; Zhang, Qi-zhi; Chen, En; Xu, Feng; Chen, Jun; Liu, Li-Chun; Jiang, Xin-guo

    2009-01-05

    The main purpose of this study was to prepare a novel in situ gel system for nasal delivery of MF and study its efficacy on allergic rhinitis model. An ion-activated in situ gel was developed and characterized with gellan gum as a carrier. The system was stable kept at 40+/-2 degrees C for 6 months, and the micrographic results showed that in situ gel was safety without mucosa irritation when given at 20 microg once daily for 1 month to rats with allergic rhinitis. MF in gellan gum produced obviously effect on allergic rhinitis at the doses of 20 microg/body following intranasal administration, and the efficacy was significantly superior to that of the common suspension (P<0.01). The in situ gel system is a promising approach for the intranasal delivery of MF for the therapeutic effects improvement.

  7. Ion activated in situ gel of gellan gum containing salbutamol sulphate for nasal administration.

    PubMed

    Salunke, Sneha R; Patil, Sanjay B

    2016-06-01

    Nasal delivery is the promising approach for rapid onset of action and avoids the first pass metabolism. The main aim of present study was to develop a novel mucoadhesive in situ gel of salbutamol sulphate using gellan gum and hydroxylpropyl methyl cellulose (HPMC) for nasal administration. The formulations were prepared so as to have gelation at physiological ion content after nasal administration. Developed formulations were evaluated for gelation, viscosity, drug content, in vitro mucoadhesion, in vitro drug release study, ex vivo permeation, and histopathology. Formulations showed pH in the range of nasal cavity and optimum viscosity for nasal administration. The mucoadhesive force depends upon concentration of HPMC and drug release was found to be 97.34% in 11h. The histopathology did not detect any damage during ex vivo permeation studies. Hence, in situ gel system of gellan gum may be a promising approach for nasal delivery of salbutamol sulphate for therapeutic improvement.

  8. Nanoparticulate bioactive-glass-reinforced gellan-gum hydrogels for bone-tissue engineering.

    PubMed

    Gantar, Ana; da Silva, Lucilia P; Oliveira, Joaquim M; Marques, Alexandra P; Correlo, Vitor M; Novak, Saša; Reis, Rui L

    2014-10-01

    This work presents bioactive-glass-reinforced gellan-gum spongy-like hydrogels (GG-BAG) as novel hydrophilic materials for use as the scaffolding in bone-tissue engineering. The reinforcement with bioactive-glass particles resulted in an improvement to the microstructure and to the mechanical properties of the material. These mechanical properties were found to be dependent on the composition and improved with the amount of bioactive glass; however, values necessary to accommodate biomechanical loading were not achieved in this study. Nevertheless, by incorporating the bioactive-glass particles, the composite material acquired the ability to form an apatite layer when soaked in simulated body fluid. Furthermore, human-adipose-derived stem cells were able to adhere and spread within the gellan-gum, spongy-like hydrogels reinforced with the bioactive glass, and remain viable, which is an important result when considering their use in bone-tissue engineering. Thus, hydrogels based on gellan gum and bioactive glass are promising biomaterials for use either alone or with cells, and with the potential for use in osteogenic differentiation.

  9. Fabrication of Porous α-TCP/Gellan Gum Scaffold for Bone Tissue Engineering.

    PubMed

    Wen, Jian; Kim, Ill Yong; Kikuta, Koichi; Ohtsuki, Chikara

    2016-03-01

    α-tricalcium phosphate (α-TCP, α-Ca3(PO4)2) receives great attention for bone repairing due to its biodegradability and capability of transformation to human bone's main inorganic components, hydroxyapatite (HAp). α-TCP porous scaffold is easily procurable by sintering of the low-temperature polymorph of TCP, β-TCR Still, porous body of α-TCP is too brittle to being handled and shaped, limiting its clinical application as implant materials. To improve mechanical properties of α-TCP porous scaffold, the present study focused on coating of a type of polysaccharides on α-TCP scaffolds. Gellan gum was chosen as the polysaccharide for coating because of its biodegradability as well as the potential acting as substrate for HAp deposition during hydration of α-TCP after exposure to body fluid. After coating of gellan gum on α-TCP scaffolds with porosity of 75 vol%, the compressive strength increased from 0.45 MPa to around 2.00 MPa. Among the coated scaffold, the maximum compressive strength, 3.97 MPa, was obtained on the scaffold with porosity of 63 vol%. Improvement of mechanical properties of α-TCP/gellan gum composites was achieved to show easy handling performance for a bone substitute for tissue repairing. The dissolving rate of the coated scaffolds was also controlled by adjusting the concentration of GG solutions.

  10. Controlling the rheology of gellan gum hydrogels in cell culture conditions.

    PubMed

    Moxon, Samuel R; Smith, Alan M

    2016-03-01

    Successful culturing of tissues within polysaccharide hydrogels is reliant upon specific mechanical properties. Namely, the stiffness and elasticity of the gel have been shown to have a profound effect on cell behaviour in 3D cell cultures and correctly tuning these mechanical properties is critical to the success of culture. The usual way of tuning mechanical properties of a hydrogel to suit tissue engineering applications is to change the concentration of polymer or its cross-linking agents. In this study sonication applied at various amplitudes was used to control mechanical properties of gellan gum solutions and gels. This method enables the stiffness and elasticity of gellan gum hydrogels cross-linked with DMEM to be controlled without changing either polymer concentration or cross-linker concentration. Controlling the mechanical behaviour of gellan hydrogels impacted upon the activity of alkaline phosphatase (ALP) in encapsulated MC3T3 pre-osteoblasts. This shows the potential of applying a simple technique to generate hydrogels where tissue-specific mechanical properties can be produced that subsequently influence cell behaviour.

  11. Evaluation of the fluid uptake kinetics and drug release from gellan gum tablets containing metronidazole.

    PubMed

    Emeje, M O; Franklin-Ude, P I; Ofoefule, S I

    2010-08-01

    In this study, the fluid uptake (swelling) kinetics and disintegrant properties of gellan gum in metronidazole tablets were evaluated in both simulated gastric and intestinal fluids (SGF and SIF respectively) without enzymes. The mechanical properties as well as the disintegration and dissolution profile of the tablets were also assessed and compared with those of two standard disintegrants: maize starch and sodium starch glycolate (Primogel). Results show that, swelling was faster and higher in SIF than SGF with the minimum and maximum swelling rates of the gum being 0.365 and 6.900 mm(3)/min respectively in SGF, while the corresponding values in SIF were 0.277 and 7.600 mm(3)/min respectively. The gum was most effective as a disintegrant for metronidazole tablets at an optimum concentration of 0.2% (w/w) when incorporated extra-granularly.

  12. Cloning and knockout of phytoene desaturase gene in Sphingomonas elodea ATCC 31461 for economic recovery of gellan gum.

    PubMed

    Zhu, Liang; Wu, Xuechang; Li, Ou; Chen, Yamin; Qian, Chaodong; Teng, Yi; Tao, Xianglin; Gao, Haichun

    2011-09-01

    A gene encoding phytoene desaturase (crtI) in the carotenoid biosynthetic pathway of Sphingomonas elodea ATCC 31461, an industrial gellan gum-producing strain, was cloned and identified. This gene is predicted to encode a 492-amino acid protein with significant homology to the phytoene desaturase of other carotenogenic organisms. Knockout of crtI gene blocked yellow carotenoid pigment synthesis and resulted in the accumulation of colorless phytoene, confirming that it encodes phytoene desaturase. Further research indicates that the yield of gellan gum production by crtI gene knockout mutants is almost the same as that by the wild-type strain. In addition, a recovery method based on the colorless fermentation broth of the crtI gene knockout mutant was investigated. Compared to the volume of alcohol for the parent strain, much less alcohol (30%) is required in this recovery process; thus, the costs of downstream purification of gellan gum can be substantially reduced.

  13. Gellan gum injectable hydrogels for cartilage tissue engineering applications: in vitro studies and preliminary in vivo evaluation.

    PubMed

    Oliveira, João T; Santos, Tírcia C; Martins, Luís; Picciochi, Ricardo; Marques, Alexandra P; Castro, António G; Neves, Nuno M; Mano, João F; Reis, Rui L

    2010-01-01

    Gellan gum is a polysaccharide that we have previously proposed for applications in the cartilage tissue engineering field. In this work, gellan gum hydrogels were tested for their ability to be used as injectable systems using simple processing methods, able to deliver and maintain chondrocytes by in situ gelation, and support cell viability and production of extracellular matrix (ECM). Rheological measurements determined that the sol-gel transition occurred near the body temperature at 39 degrees C, upon temperature decrease, in approximately 20 s. Gellan gum discs shows a storage compression modulus of around 80 kPa at a frequency of 1 Hz by dynamic mechanical analysis. Human articular chondrocytes were encapsulated in the gels, cultured in vitro for total periods of 56 days, and analyzed for cell viability and ECM production. Calcein AM staining showed that cell kept viable after 14 days and the histological analysis and real-time quantitative polymerase chain reaction revealed that hyaline-like cartilage ECM was synthesized. Finally, the in vivo performance of the gellan gum hydrogels, in terms of induced inflammatory reaction and integration into the host tissue, was evaluated by subcutaneous implantation in Balb/c mice for 21 days. Histological analysis showed a residual fibrotic capsule at the end of the experiments. Dynamic mechanical analysis revealed that the gels were stable throughout the experiments while evidencing a tendency for decreasing mechanical properties, which was consistent with weight measurements. Altogether, the results demonstrate the adequacy of gellan gum hydrogels processed by simple methods for noninvasive injectable applications toward the formation of a functional cartilage tissue-engineered construct and originally report the preliminary response of a living organism to the subcutaneous implantation of the gellan gum hydrogels. These are the two novel features of this work.

  14. Gellan gum based microparticles of metoclopromide hydrochloride for intranasal delivery: development and evaluation.

    PubMed

    Mahajan, Hitendra Shaligram; Gattani, Surendra Ganeshlal

    2009-04-01

    The purpose of this study was to develop nasal microparticles of metoclopromide employing gellan gum as a polymer by spray drying method. This method of microencapsulation is particularly less dependent on the solubility characteristics of the drug and polymer and is simple, reproducible, and easy to scale up. The microparticles were evaluated for characteristics like particle size, incorporation efficiency, swelling ability, zeta potential, mucoadhesion, thermal analysis, X-ray diffraction (XRD) study and in vitro drug release. The microparticles so prepared had irregular shape and smooth but distorted surface morphology. They were negatively charged. The particle size ranged from 9.38 to 10.67 microm. Differential scanning calorimetry (DSC) studies revealed that metoclopromide was molecularly dispersed inside the microparticles. The swelling was increased with increase in amount of polymer. The release of drug from microparticles was moderately sustained without lag time and attributed to formation of hydrogel; ionically cross linked hydrogel was hypothesized. The formulation was found to be non toxic to nasal tissue. These in vitro preliminary results show that spray dried microparticles based on gellan gum could be suitable nasal delivery system for the administration of metoclopromide.

  15. High rate of N2 fixation by East Siberian cryophilic soil bacteria as determined by measuring acetylene reduction in nitrogen-poor medium solidified with gellan gum.

    PubMed

    Hara, Shintaro; Hashidoko, Yasuyuki; Desyatkin, Roman V; Hatano, Ryusuke; Tahara, Satoshi

    2009-05-01

    For evaluating N(2) fixation of diazotrophic bacteria, nitrogen-poor liquid media supplemented with at least 0.5% sugar and 0.2% agar are widely used for acetylene reduction assays. In such a soft gel medium, however, many N(2)-fixing soil bacteria generally show only trace acetylene reduction activity. Here, we report that use of a N(2) fixation medium solidified with gellan gum instead of agar promoted growth of some gellan-preferring soil bacteria. In a soft gel medium solidified with 0.3% gellan gum under appropriate culture conditions, bacterial microbiota from boreal forest bed soils and some free-living N(2)-fixing soil bacteria isolated from the microbiota exhibited 10- to 200-fold-higher acetylene reduction than those cultured in 0.2% agar medium. To determine the N(2) fixation-activating mechanism of gellan gum medium, qualitative differences in the colony-forming bacterial components from tested soil microbiota were investigated in plate cultures solidified with either agar or gellan gum for use with modified Winogradsky's medium. On 1.5% agar plates, apparently cryophilic bacterial microbiota showed strictly distinguishable microbiota according to the depth of soil in samples from an eastern Siberian Taiga forest bed. Some pure cultures of proteobacteria, such as Pseudomonas fluorescens and Burkholderia xenovorans, showed remarkable acetylene reduction. On plates solidified with 1.0% gellan gum, some soil bacteria, including Luteibacter sp., Janthinobacterium sp., Paenibacillus sp., and Arthrobacter sp., uniquely grew that had not grown in the presence of the same inoculants on agar plates. In contrast, Pseudomonas spp. and Burkholderia spp. were apparent only as minor colonies on the gellan gum plates. Moreover, only gellan gum plates allowed some bacteria, particularly those isolated from the shallow organic soil layer, to actively swarm. In consequence, gellan gum is a useful gel matrix to bring out growth potential capabilities of many soil

  16. Physicochemical studies of glucose, gellan gum, and hydroxypropyl cellulose--inhibition of cast iron corrosion.

    PubMed

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy

    2013-06-05

    Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied. The addition of potassium iodide to the corrosion-inhibition system showed both antagonism and synergism toward inhibition efficiency. Polarization studies revealed the mixed-type inhibiting nature of the carbohydrates. The adsorption of inhibitors on the cast iron surface obeys Langmuir adsorption isotherm model, both in presence and absence of KI. Physical interaction between the inhibitor molecules and the iron surface was suggested by the thermochemical parameters, rather than chemical interaction.

  17. 3D printing of layered brain-like structures using peptide modified gellan gum substrates.

    PubMed

    Lozano, Rodrigo; Stevens, Leo; Thompson, Brianna C; Gilmore, Kerry J; Gorkin, Robert; Stewart, Elise M; in het Panhuis, Marc; Romero-Ortega, Mario; Wallace, Gordon G

    2015-10-01

    The brain is an enormously complex organ structured into various regions of layered tissue. Researchers have attempted to study the brain by modeling the architecture using two dimensional (2D) in vitro cell culturing methods. While those platforms attempt to mimic the in vivo environment, they do not truly resemble the three dimensional (3D) microstructure of neuronal tissues. Development of an accurate in vitro model of the brain remains a significant obstacle to our understanding of the functioning of the brain at the tissue or organ level. To address these obstacles, we demonstrate a new method to bioprint 3D brain-like structures consisting of discrete layers of primary neural cells encapsulated in hydrogels. Brain-like structures were constructed using a bio-ink consisting of a novel peptide-modified biopolymer, gellan gum-RGD (RGD-GG), combined with primary cortical neurons. The ink was optimized for a modified reactive printing process and developed for use in traditional cell culturing facilities without the need for extensive bioprinting equipment. Furthermore the peptide modification of the gellan gum hydrogel was found to have a profound positive effect on primary cell proliferation and network formation. The neural cell viability combined with the support of neural network formation demonstrated the cell supportive nature of the matrix. The facile ability to form discrete cell-containing layers validates the application of this novel printing technique to form complex, layered and viable 3D cell structures. These brain-like structures offer the opportunity to reproduce more accurate 3D in vitro microstructures with applications ranging from cell behavior studies to improving our understanding of brain injuries and neurodegenerative diseases.

  18. Improvement in the in situ gelling properties of deacetylated gellan gum by the immobilization of thiol groups.

    PubMed

    Krauland, Alexander H; Leitner, Verena M; Bernkop-Schnürch, Andreas

    2003-06-01

    The rheological properties of an in situ crosslinking thiolated deacetylated gellan gum were examined in vitro. Mediated by a carbodiimide, L-cysteine was covalently bound to deacetylated gellan gum (DGG). The deacetylated gellan gum-cysteine (DGG-Cys) conjugate displayed 216.53 +/- 59.54 micromol thiol groups per gram polymer (means +/- SD, n = 3). The thiolated polymer was capable of forming inter- and/or intramolecular disulfide bonds in aqueous solution (1.5%; m/m) at pH 7. After 6 h of incubation at room temperature, storage modulus, loss modulus, and complex viscosity increased 300-, 6.4-, and 26.6-fold, respectively, relative to the unthiolated polymer. Loss tangent of DGG-Cys was <1, indicating a gel, whereas the corresponding unmodified polymer had a loss tangent of >1, indicating a fluid. Frequency sweep measurements demonstrated an increase in crosslinking of the thiolated polymer as a function of time. DGG-Cys appeared to be superior to the unmodified polymer also in the presence of physiological cation concentrations found (e.g., in tear fluid and nasal secretion), which is referred to rheological properties. The polymer generated within this study represents a promising novel excipient for various drug delivery systems in which in situ gelling properties are favorable.

  19. Degradation of Carbazole by Microbial Cells Immobilized in Magnetic Gellan Gum Gel Beads▿

    PubMed Central

    Wang, Xia; Gai, Zhonghui; Yu, Bo; Feng, Jinhui; Xu, Changyong; Yuan, Yong; Lin, Zhixin; Xu, Ping

    2007-01-01

    Polycyclic aromatic heterocycles, such as carbazole, are environmental contaminants suspected of posing human health risks. In this study, we investigated the degradation of carbazole by immobilized Sphingomonas sp. strain XLDN2-5 cells. Four kinds of polymers were evaluated as immobilization supports for Sphingomonas sp. strain XLDN2-5. After comparison with agar, alginate, and κ-carrageenan, gellan gum was selected as the optimal immobilization support. Furthermore, Fe3O4 nanoparticles were prepared by a coprecipitation method, and the average particle size was about 20 nm with 49.65-electromagnetic-unit (emu) g−1 saturation magnetization. When the mixture of gellan gel and the Fe3O4 nanoparticles served as an immobilization support, the magnetically immobilized cells were prepared by an ionotropic method. The biodegradation experiments were carried out by employing free cells, nonmagnetically immobilized cells, and magnetically immobilized cells in aqueous phase. The results showed that the magnetically immobilized cells presented higher carbazole biodegradation activity than nonmagnetically immobilized cells and free cells. The highest biodegradation activity was obtained when the concentration of Fe3O4 nanoparticles was 9 mg ml−1 and the saturation magnetization of magnetically immobilized cells was 11.08 emu g−1. Additionally, the recycling experiments demonstrated that the degradation activity of magnetically immobilized cells increased gradually during the eight recycles. These results support developing efficient biocatalysts using magnetically immobilized cells and provide a promising technique for improving biocatalysts used in the biodegradation of not only carbazole, but also other hazardous organic compounds. PMID:17827304

  20. Rheological studies of the gelation of deacetylated gellan gum (Gelrite) in physiological conditions.

    PubMed

    Paulsson, M; Hägerström, H; Edsman, K

    1999-10-01

    Gels have been successfully used to increase the mucosal contact time and hence the bioavailability of nasal and ophthalmic formulations. The use of in situ gelling polymers requires a rapid sol-gel transition that produces a strong gel for an optimal contact time. In this study, the rheological behaviour of deacetylated gellan gum (Gelrite) was analysed in order to better understand the reasons for the good performance in humans. Thermal scans were used to study gel formation and other changes in the structure of the samples when the macromolecular and ionic contents were altered. The effect the different ions in tear fluid (Na+, K+, Ca2+) had on the gel strength and the consequences of dilution due to the ocular protective mechanisms were examined. Na+ was found to be the most important gel-promoting ion in vivo. It was also found that gels are formed in tear fluid even when the concentration of Gelrite) is only 0.1%. Samples with concentrations of Gelrite of 0.5-1% do not require more ions than 10-25% of those in tear fluid to form gels. These two findings can partly explain the good performance of Gelrite in vivo. Gels with a high elastic modulus can thus be formed even though dilution of instilled drops takes place.

  1. Artocarpus heterophyllus L. seed starch-blended gellan gum mucoadhesive beads of metformin HCl.

    PubMed

    Nayak, Amit Kumar; Pal, Dilipkumar; Santra, Kousik

    2014-04-01

    Jackfruit (Artocarpus heterophyllus Lam., family: Moraceae) seed starch (JFSS)-gellan gum (GG) mucoadhesive beads containing metformin HCl were developed through ionotropic gelation technique. The effect of GG to JFSS ratio and CaCl2 concentration on the drug encapsulation efficiency (DEE, %) and cumulative drug release at 10h (R10h, %) was optimized and analyzed using response surface methodology based on 3(2) factorial design. The optimized JFSS-GG beads containing metformin HCl showed DEE of 92.67±4.46%, R10h of 61.30±2.37%, and mean diameter of 1.67±0.27 mm. The optimized beads showed pH-dependent swelling and mucoadhesivity with the goat intestinal mucosa. The in vitro drug release from all these JFSS-GG beads containing metformin HCl was followed zero-order pattern (R(2)=0.9907-0.9975) with super case-II transport mechanism over a period of 10 h. The beads were also characterized by SEM and FTIR. The optimized JFSS-GG beads containing metformin HCl exhibited significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration.

  2. Microfabricated photocrosslinkable polyelectrolyte-complex of chitosan and methacrylated gellan gum

    PubMed Central

    Coutinho, Daniela F.; Sant, Shilpa; Shakiba, Mojdeh; Wang, Ben; Gomes, Manuela E.; Neves, Nuno M.; Reis, Rui L.

    2012-01-01

    Chitosan (CHT) based polyelectrolyte complexes (PECs) have been receiving great attention for tissue engineering approaches. These hydrogels are held together by ionic forces and can be disrupted by changes in physiological conditions. In this study, we present a new class of CHT-based PEC hydrogels amenable to stabilization by chemical crosslinking. The photocrosslinkable anionic methacrylated gellan gum (MeGG) was complexed with cationic CHT and exposed to light, forming a PEC hydrogel. The chemical characterization of the photocrosslinkable PEC hydrogel by Fourier transform infrared spectroscopy (FTIR) revealed absorption peaks specific to the raw polymers. A significantly higher swelling ratio was observed for the PEC hydrogel with higher CHT content. The molecular interactions between both polysaccharides were evaluated chemically and microscopically, indicating the diffusion of CHT to the interior of the hydrogel. We hypothesized that the addition of MeGG to CHT solution first leads to a membrane formation around MeGG. Then, migration of CHT inside the MeGG hydrogel occurs to balance the electrostatic charges. The photocrosslinkable feature of MeGG further allowed the formation of cell-laden microscale hydrogel units with different shapes and sizes. Overall, this system is potentially useful for a variety of applications including the replication of microscale features of tissues for modular tissue engineering. PMID:23293429

  3. Preparation of polymer gel dosimeters based on less toxic monomers and gellan gum

    NASA Astrophysics Data System (ADS)

    Hiroki, A.; Sato, Y.; Nagasawa, N.; Ohta, A.; Seito, H.; Yamabayashi, H.; Yamamoto, T.; Taguchi, M.; Tamada, M.; Kojima, T.

    2013-10-01

    New polymer gel dosimeters consisting of 2-hydroxyethyl methacrylate (HEMA), triethylene glycol monoethyl ether monomethacrylate (TGMEMA), polyethylene glycol 400 dimethacrylate (9G), tetrakis (hydroxymethyl) phosphonium chloride as an antioxidant, and gellan gum as a gel matrix were prepared. They were optically analyzed by measuring absorbance to evaluate a dose response. The absorbance of the polymer gel dosimeters that were exposed to 60Co γ-rays increased with increasing dose. The dosimeters comprising HEMA and 9G showed a linear increase in absorbance in the dose range from 0 to 10 Gy. The dose response depended on the 9G concentration. For others comprising HEMA, 9G and TGMEMA, the absorbance of the polymer gel dosimeters drastically increased above a certain dose, and then leveled off up to 10 Gy. The optical variations in these polymer gel dosimeters were also induced by x-irradiation from Cyberknife radiotherapy equipment. Furthermore, the exposed region of the latter polymer gel dosimeter exhibited a thermo-responsive behavior.

  4. Gellan gum microspheres containing a novel α-amylase from marine Nocardiopsis sp. strain B2 for immobilization.

    PubMed

    Chakraborty, Samrat; Jana, Sougata; Gandhi, Arijit; Sen, Kalyan Kumar; Zhiang, Wang; Kokare, Chandrakant

    2014-09-01

    A Nocardiopsis sp. stain B2 with an ability to produce stable α-amylase was isolated from marine sediments. The characterization of microorganism was done by biochemical tests and 16S rDNA sequencing. The α-amylase was purified by gel filtration chromatography by using sephadex G-75. The molecular mass of the amylase was found to be 45 kDa by SDS-PAGE and gel filtration chromatography. The isolated α-amylase was immobilized by ionotropic gelation technique using gellan gum (GG). These microspheres were spherical with average particle size of 375.62±21.76 to 492.54±32.18 μm. The entrapment efficiency of these α-amylase loaded GG microspheres was found 74.76±1.32 to 87.64±1.52%. Characterization of α-amylase-gellan gum microspheres was confirmed using FTIR and SEM analysis. The in vitro amylase release kinetic have been studied by various mathematical models that follow the Korsmeyer-Peppas model (R2=0.9804-0.9831) with anomalous (non-Fickian) diffusion release mechanism.

  5. Baclofen novel gastroretentive extended release gellan gum superporous hydrogel hybrid system: in vitro and in vivo evaluation.

    PubMed

    El-Said, Ibrahim A; Aboelwafa, Ahmed A; Khalil, Rawia M; ElGazayerly, Omaima N

    2016-01-01

    Baclofen is a centrally acting skeletal muscle relaxant with a short elimination half-life, which results in frequent daily dosing and subsequent poor patient compliance. The narrow absorption window of baclofen in the upper gastrointestinal tract limits its formulation as extended release dosage forms. In this study, baclofen extended release superporous hydrogel (SPH) systems, including conventional SPH, SPH composite and SPH hybrid (SPHH), were prepared aiming to increase the residence of baclofen at its absorption window. The applicability of different polymers, namely, gellan gum, guar gum, polyvinyl alcohol and gelatin, was investigated in preparation of SPHH systems. The prepared SPH systems were evaluated regarding weight and volume swelling ratio, porosity, mechanical properties, incorporation efficiency, degree of erosion and drug release. In vivo assessment was performed in dogs to evaluate gastric residence time by X-ray studies. In addition, the oral bioavailability of baclofen relative to commercially available Lioresal® immediate release tablets was also investigated. The novel baclofen gellan SPHH cross linked with calcium chloride was characterized by optimum mechanical properties, acceptable swelling properties as well as extended drug release. It also exhibited a prolonged plasma profile when compared to twice daily administered Lioresal®.

  6. Strain-rate and temperature dependent material properties of Agar and Gellan Gum used in biomedical applications.

    PubMed

    Schiavi, Alessandro; Cuccaro, Rugiada; Troia, Adriano

    2016-01-01

    Agar and Gellan Gum are biocompatible polymers extensively used in several fields of tissue engineering research (e.g. tissue replacement, tissue support, tissue mimicking), due to their mechanical behaviour effectively representative of actual biological tissues. Since mechanical properties of artificial tissues are related to biocompatibility and functionality of medical implants and significantly influence adhesion, growth and differentiation of cells in tissue-engineering scaffolds, an accurate characterization of Young׳s modulus and relaxation time processes is needed. In this study, the strain-rate and temperature dependent material properties of Agarose and one among the numerous kind of Gellan Gum commercially available, known as Phytagel(®), have been investigated. Nine hydrogel samples have been realized with different mechanical properties: the first one Agar-based as a reference material, the further eight samples Gellan Gum based in which the effect of dispersed solid particles like kieselguhr and SiC, as enhancing mechanical properties factors, have been investigated as a function of concentration. Stress-strain has been investigated in compression and relaxation time has been evaluated by means of the Kohlrausch-Williams-Watts time decay function. Mechanical properties have been measured as a function of temperature between 20 °C and 35 °C and at different strain rates, from ~10(-3)s(-1) and ~10(-2)s(-1) (or deformation rate from ~0.01 mms(-1) to ~0.1 mms(-1)). From experimental data, the combined temperature and strain-rate dependence of hydrogels Young׳s modulus is determined on the basis of a constitutive model. In addition to a dependence of Young׳s modulus on temperature, a remarkable influence of strain-rate has been observed, especially in the sample containing solid particles; in same ranges of temperature and strain-rate, also relaxation time variations have been monitored in order to identify a possible dependence of damping

  7. Preparation and characterization of a new gellan gum and sulphated hyaluronic acid hydrogel designed for epidural scar prevention.

    PubMed

    Cencetti, Claudia; Bellini, Davide; Longinotti, Cristina; Martinelli, Andrea; Matricardi, Pietro

    2011-02-01

    Postsurgical adhesions are a common problem in clinical practice, causing nerve compression, pain and discomfort. A new hydrogel based on gellan gum and sulphated hyaluronic acid was synthesized, with the aim to create an effective barrier for epidural scar formation. Physico-chemical properties of the gel were analyzed, and preliminary biocompatibility data (i.e. cytotoxicity) have been collected in view of its potential clinical use. The characterization of the new material demonstrated that the hydrogel, due to its high-viscosity, could effectively act as a barrier with a long in situ residence time. In addition, the hydrogel can be easily extruded from a syringe and its structure exhibits excellent stabilizing properties. Furthermore, biological assays showed that this gel is suitable for further preclinical development.

  8. A novel in situ gel base of deacetylase gellan gum for sustained ophthalmic drug delivery of ketotifen: in vitro and in vivo evaluation.

    PubMed

    Zhu, Lina; Ao, Junping; Li, Peiling

    2015-01-01

    In this study, an ion-activated ketotifen ophthalmic delivery system was developed by using a natural polysaccharide, deacetylase gellan gum. Its rheological characteristics, stability, in vitro gelation, release in vitro, and pharmacodynamic activity in vivo were investigated. The formulation had an optimum viscosity that will allow easy drop as a liquid, which then underwent a rapid sol-gel transition due to ionic interaction. There were negligible alterations in the initial values of viscosity of the formulations over a storage period of 180 days. The in vitro release profiles indicated that the release of ketotifen from in situ gels exhibited a sustained feature. Scintigraphic studies indicated that deacetylase gellan gum could increase the residence time of the formulation. At the same dose, in situ gels demonstrated a typical sustained and prolonged drug-effects behavior compared with the common drops.

  9. A novel in situ gel base of deacetylase gellan gum for sustained ophthalmic drug delivery of ketotifen: in vitro and in vivo evaluation

    PubMed Central

    Zhu, Lina; Ao, Junping; Li, Peiling

    2015-01-01

    In this study, an ion-activated ketotifen ophthalmic delivery system was developed by using a natural polysaccharide, deacetylase gellan gum. Its rheological characteristics, stability, in vitro gelation, release in vitro, and pharmacodynamic activity in vivo were investigated. The formulation had an optimum viscosity that will allow easy drop as a liquid, which then underwent a rapid sol–gel transition due to ionic interaction. There were negligible alterations in the initial values of viscosity of the formulations over a storage period of 180 days. The in vitro release profiles indicated that the release of ketotifen from in situ gels exhibited a sustained feature. Scintigraphic studies indicated that deacetylase gellan gum could increase the residence time of the formulation. At the same dose, in situ gels demonstrated a typical sustained and prolonged drug-effects behavior compared with the common drops. PMID:26251573

  10. Fabrication of Apigenin loaded gellan gum-chitosan hydrogels (GGCH-HGs) for effective diabetic wound healing.

    PubMed

    Shukla, Rajesh; Kashaw, Sushil K; Jain, Alok Pal; Lodhi, Santram

    2016-10-01

    The Apigenin (APN) was isolated from ethanolic extract of M. alba leaves and screened by in-vivo wound models (Diabetic and Dead space) in rats. Apigenin loaded hydrogel (HGs) was prepared using gellan gum-chitosan (GGCH) with PEG as a cross linker and characterized for various parameter like AFM, swelling property, entrapment efficiency and drug release. Further performance of hydrogel was evaluated by wound healing activity tested against wound contraction, collagen content, dried granuloma weights and antioxidant activity. The percent entrapment efficiency of optimized hydrogel found to be 87.15±1.20. APN loaded GGCH-HGs were able to release 96.11% APN in 24h. The level of superoxide dismutase (SOD) and catalase were found increased significantly in granuloma tissue of APN treated group. APN GGCH-HGs found higher wound healing effect in diabetic as well as normal wound tissues with significant antioxidant activity. Results proven the utility of prepared hydrogel (APN loaded GGCH-HGs) seems to be highly suitable for wound healing due to its unique properties of biocompatibility, biodegradability, moist nature and antioxidant effectiveness.

  11. Enzymatic mineralization of gellan gum hydrogel for bone tissue-engineering applications and its enhancement by polydopamine.

    PubMed

    Douglas, T E L; Wlodarczyk, M; Pamula, E; Declercq, H A; de Mulder, E L W; Bucko, M M; Balcaen, L; Vanhaecke, F; Cornelissen, R; Dubruel, P; Jansen, J A; Leeuwenburgh, S C G

    2014-11-01

    Interest is growing in the use of hydrogels as bone tissue-engineering (TE) scaffolds due to advantages such as injectability and ease of incorporation of active substances such as enzymes. Hydrogels consisting of gellan gum (GG), an inexpensive calcium-crosslinkable polysaccharide, have been applied in cartilage TE. To improve GG suitability as a material for bone TE, alkaline phosphatase (ALP), an enzyme involved in mineralization of bone by cleaving phosphate from organic phosphate, was incorporated into GG hydrogels to induce mineralization with calcium phosphate (CaP). Incorporated ALP induced formation of apatite-like material on the submicron scale within GG gels, as shown by FTIR, SEM, EDS, XRD, ICP-OES, TGA and von Kossa staining. Increasing ALP concentration increased amounts of CaP as well as stiffness. Mineralized GG was able to withstand sterilization by autoclaving, although stiffness decreased. In addition, mineralizability and stiffness of GG was enhanced by the incorporation of polydopamine (PDA). Furthermore, mineralization of GG led to enhanced attachment and vitality of cells in vitro while cytocompatibility of the mineralized gels was comparable to one of the most commonly used bone substitute materials. The results proved that ALP-mediated enzymatic mineralization of GG could be enhanced by functionalization with PDA.

  12. Injectable and photocross-linkable gels based on gellan gum methacrylate: a new tool for biomedical application.

    PubMed

    Pacelli, Settimio; Paolicelli, Patrizia; Dreesen, Inge; Kobayashi, Shuichiro; Vitalone, Annabella; Casadei, Maria Antonietta

    2015-01-01

    In this work, a natural polysaccharide gellan gum (GG) has been modified with methacrylic groups (GG-MA) and combined with polyethylene glycol dimethacrylate (PEG-DMA) in order to create novel injectable hydrogels that can be easily delivered through a needle and photocross-linked in the injection site. A novel synthetic procedure for methacrylation of GG has been proposed to better control its derivatization. Different degrees of functionalization have been achieved and their effects on the solubility and mechanical properties of GG-MA were investigated. A good balance in terms of hydrophilicity and elasticity of the corresponding hydrogels was identified, although not suitable enough as injectable material for the treatment of damaged soft tissues. For this reason, several concentrations and different molecular weights of PEG-DMA were investigated to modulate the composition of GG-MA hydrogels and overcome their extreme fragility. Swelling abilities of the hydrogels in different media were studied as a key parameter able to affect the release profile of loaded therapeutic agents. Model molecules having different spherical hindrance (sulindac and vitamin B12) were then chosen to study how the hydrogels were able to modulate their diffusion profiles over time. Finally, the hydrogel's safety was evaluated trough an MTT cytotoxicity test on human fibroblasts.

  13. Influence of the ratio of amphiphilic copolymers used as emulsifiers on the microstructure, physical stability and rheology of α-pinene emulsions stabilized with gellan gum.

    PubMed

    García, Maria Carmen; Alfaro, Maria Carmen; Muñoz, José

    2015-11-01

    α-Pinene is a terpenic solvent whose use in the formulation of emulsions entails a double benefit from the environmental point of view since it is a green solvent, easily biodegradable, which also has certain antimicrobial properties. In this work a combination of Atlas™ G-5000 and Atlox™ 4913 amphiphilic copolymers was used to obtain O/W emulsions formulated with α-pinene and gellan gum. These emulsions may find applications related to the design of complex biotechnological systems with different uses. In order to investigate the microstructure and the physical stability of these emulsions, a combination of different techniques such as rheology, microscopy, laser diffraction and multiple light scattering turn out to be a useful methodology. The results demonstrated the need to include a minimum amount of Atlas™ G-5000 copolymer in the formulation of these emulsions to improve their stability. These results were supported by the information revealed by optical micrographs, according to which Atlas™ G-5000 is directed to the continuous medium to structure water (this surfactant is particularly effective at forming hydrogen bonds with water). On the other hand Atlox™ 4913 is preferentially adsorbed at the α-pinene-water interface, such that a high Atlox™ 4913/Atlas™ G-5000 mass ratio slows down the kinetics of coalescence as shown by multiple light scattering. However, a very low relative concentration of Atlas™ G-5000 causes creaming to become the dominant destabilization mechanism. Increasing the Atlas™ G-5000/Atlox™ 4913 mass ratio yields emulsions with enhanced viscosity and viscoelasticity.

  14. Free radical grafting of gallic acid (GA) on cellulose nanocrystals (CNCS) and evaluation of antioxidant reinforced gellan gum films

    NASA Astrophysics Data System (ADS)

    Criado, P.; Fraschini, C.; Salmieri, S.; Becher, D.; Safrany, A.; Lacroix, M.

    2016-01-01

    Antiradical properties were introduced on cellulose nanocrystals (CNCs) by redox pair (RP) initiator and γ-radiation treatments. Different procedures were tested on CNC, first a 2 h reaction of hydrogen peroxide (H2O2)/ascorbic acid (AA) was performed on CNC solution. γ-Radiation treatment at 20 kGy dose was then applied and immediately after GA was reacted during 24 h with the pretreated CNCs, giving CNC-H2O2-AA-γ-GA. The formation of new carboxylic acids and carbonyl groups were characterized by FT-IR at 1650 and 1730 cm-1 respectively. Carboxylic acid functionalities were also analyzed by conductometric titration where an increase from 49 to 134 mmol COOH kg-1 was found from native to irradiated CNCs. A similar increase in the carboxylic acid content (132 mmol kg-1) was observed for CNC-H2O2-AA-γ-GA, showing the highest radical scavenging properties (8 mM Trolox eq/mg CNC). Thermogravimetric analysis confirmed the structural changes onto CNC. Film packaging containing 20% of CNC-H2O2-AA-γ-GA was then added to a gellan-based film packaging. A significant improvement (p<0.05) of the tensile strength (TS), the tensile modulus (TM) and the elongation at break (EB) and water vapor permeability reduction was observed when CNC-H2O2-AA-γ-GA was added to the film packaging formulation.

  15. Novel injectable, self-gelling hydrogel-microparticle composites for bone regeneration consisting of gellan gum and calcium and magnesium carbonate microparticles.

    PubMed

    Douglas, Timothy E L; Łapa, Agata; Reczyńska, Katarzyna; Krok-Borkowicz, Małgorzata; Pietryga, Krzysztof; Samal, Sangram Keshari; Declercq, Heidi A; Schaubroeck, David; Boone, Marijn; Van der Voort, Pascal; De Schamphelaere, Karel; Stevens, Christian V; Bliznuk, Vitaliy; Balcaen, Lieve; Parakhonskiy, Bogdan V; Vanhaecke, Frank; Cnudde, Veerle; Pamuła, Elżbieta; Skirtach, Andre G

    2016-11-21

    The suitability of hydrogel biomaterials for bone regeneration can be improved by incorporation of an inorganic phase in particle form, thus maintaining hydrogel injectability. In this study, carbonate microparticles containing different amounts of calcium (Ca) and magnesium (Mg) were added to solutions of the anionic polysaccharide gellan gum (GG) to crosslink GG by release of Ca(2+) and Mg(2+) from microparticles and thereby induce formation of hydrogel-microparticle composites. It was hypothesized that increasing Mg content of microparticles would promote GG hydrogel formation. The effect of Mg incorporation on cytocompatibility and cell growth was also studied. Microparticles were formed by mixing Ca(2+) and Mg(2+) and [Formula: see text] ions in varying concentrations. Microparticles were characterized physiochemically and subsequently mixed with GG solution to form hydrogel-microparticle composites. The elemental Ca:Mg ratio in the mineral formed was similar to the Ca:Mg ratio of the ions added. In the absence of Mg, vaterite was formed. At low Mg content, magnesian calcite was formed. Increasing the Mg content further caused formation of amorphous mineral. Microparticles of vaterite and magnesium calcite did not induce GG hydrogel formation, but addition of Mg-richer amorphous microparticles induced gelation within 20 min. Microparticles were dispersed homogeneously in hydrogels. MG-63 osteoblast-like cells were cultured in eluate from hydrogel-microparticle composites and on the composites themselves. All composites were cytocompatible. Cell growth was highest on composites containing particles with an equimolar Ca:Mg ratio. In summary, carbonate microparticles containing a sufficient amount of Mg induced GG hydrogel formation, resulting in injectable, cytocompatible hydrogel-microparticle composites.

  16. Gellan gum-based mucoadhesive microspheres of almotriptan for nasal administration: Formulation optimization using factorial design, characterization, and in vitro evaluation

    PubMed Central

    Abbas, Zaheer; Marihal, Sachin

    2014-01-01

    Background: Almotriptan malate (ALM), indicated for the treatment of migraine in adults is not a drug candidate feasible to be administered through the oral route during the attack due to its associated symptoms such as nausea and vomiting. This obviates an alternative dosage form and nasal drug delivery is a good substitute to oral and parenteral administration. Materials and Methods: Gellan gum (GG) microspheres of ALM, for intranasal administration were prepared by water-in-oil emulsification cross-linking technique employing a 23 factorial design. Drug to polymer ratio, calcium chloride concentration and cross-linking time were selected as independent variables, while particle size and in vitro mucoadhesion of the microspheres were investigated as dependent variables. Regression analysis was performed to identify the best formulation conditions. The microspheres were evaluated for characteristics such as practical percentage yield, particle size, percentage incorporation efficiency, swellability, zeta potential, in vitro mucoadhesion, thermal analysis, X-ray diffraction study, and in vitro drug diffusion studies. Results: The shape and surface characteristics of the microspheres were determined by scanning electron microscopy, which revealed spherical nature and nearly smooth surface with drug incorporation efficiency in the range of 71.65 ± 1.09% – 91.65 ± 1.13%. In vitro mucoadhesion was observed the range of 79.45 ± 1.69% – 95.48 ± 1.27%. Differential scanning calorimetry and X-ray diffraction results indicated a molecular level dispersion of drug in the microspheres. In vitro drug diffusion was Higuchi matrix controlled and the release mechanism was found to be non-Fickian. Stability studies indicated that there were no significant deviations in the drug content, in vitro mucoadhesion and in vitro drug diffusion characteristics. Conclusion: The investigation revealed promising potential of GG microspheres for delivering ALM intranasally for the

  17. Enrichment of enzymatically mineralized gellan gum hydrogels with phlorotannin-rich Ecklonia cava extract Seanol(®) to endow antibacterial properties and promote mineralization.

    PubMed

    Douglas, Timothy E L; Dokupil, Agnieszka; Reczyńska, Katarzyna; Brackman, Gilles; Krok-Borkowicz, Malgorzata; Keppler, Julia K; Božič, Mojca; Van Der Voort, Pascal; Pietryga, Krzysztof; Samal, Sangram Keshari; Balcaen, Lieve; van den Bulcke, Jan; Van Acker, Joris; Vanhaecke, Frank; Schwarz, Karin; Coenye, Tom; Pamuła, Elżbieta

    2016-08-10

    Hydrogels offer several advantages as biomaterials for bone regeneration, including ease of incorporation of soluble substances such as mineralization-promoting enzymes and antibacterial agents. Mineralization with calcium phosphate (CaP) increases bioactivity, while antibacterial activity reduces the risk of infection. Here, gellan gum (GG) hydrogels were enriched with alkaline phosphatase (ALP) and/or Seanol(®), a seaweed extract rich in phlorotannins (brown algae-derived polyphenols), to induce mineralization with CaP and increase antibacterial activity, respectively. The sample groups were unmineralized hydrogels, denoted as GG, GG/ALP, GG/Seanol and GG/Seanol/ALP, and hydrogels incubated in mineralization medium (0.1 M calcium glycerophosphate), denoted as GG/ALP_min, GG/Seanol_min and GG/Seanol/ALP_min. Seanol(®) enhanced mineralization with CaP and also increased compressive modulus. Seanol(®) and ALP interacted in a non-covalent manner. Release of Seanol(®) occurred in a burst phase and was impeded by ALP-mediated mineralization. Groups GG/Seanol and GG/ALP/Seanol exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus. GG/Seanol/ALP_min, but not GG/Seanol_min, retained some antibacterial activity. Eluates taken from groups GG/ALP_min, GG/Seanol_min and GG/ALP/Seanol_min displayed comparable cytotoxicity towards MG-63 osteoblast-like cells. These results suggest that enrichment of hydrogel biomaterials with phlorotannin-rich extracts is a promising strategy to increase mineralizability and antibacterial activity.

  18. Generation of composites for bone tissue-engineering applications consisting of gellan gum hydrogels mineralized with calcium and magnesium phosphate phases by enzymatic means.

    PubMed

    Douglas, Timothy E L; Krawczyk, Grzegorz; Pamula, Elzbieta; Declercq, Heidi A; Schaubroeck, David; Bucko, Miroslaw M; Balcaen, Lieve; Van Der Voort, Pascal; Bliznuk, Vitaliy; van den Vreken, Natasja M F; Dash, Mamoni; Detsch, Rainer; Boccaccini, Aldo R; Vanhaecke, Frank; Cornelissen, Maria; Dubruel, Peter

    2016-11-01

    Mineralization of hydrogels, desirable for bone regeneration applications, may be achieved enzymatically by incorporation of alkaline phosphatase (ALP). ALP-loaded gellan gum (GG) hydrogels were mineralized by incubation in mineralization media containing calcium and/or magnesium glycerophosphate (CaGP, MgGP). Mineralization media with CaGP:MgGP concentrations 0.1:0, 0.075:0.025, 0.05:0.05, 0.025:0.075 and 0:0.1 (all values mol/dm(3) , denoted A, B, C, D and E, respectively) were compared. Mineral formation was confirmed by IR and Raman, SEM, ICP-OES, XRD, TEM, SAED, TGA and increases in the the mass fraction of the hydrogel not consisting of water. Ca was incorporated into mineral to a greater extent than Mg in samples mineralized in media A-D. Mg content and amorphicity of mineral formed increased in the order A < B < C < D. Mineral formed in media A and B was calcium-deficient hydroxyapatite (CDHA). Mineral formed in medium C was a combination of CDHA and an amorphous phase. Mineral formed in medium D was an amorphous phase. Mineral formed in medium E was a combination of crystalline and amorphous MgP. Young's moduli and storage moduli decreased in dependence of mineralization medium in the order A > B > C > D, but were significantly higher for samples mineralized in medium E. The attachment and vitality of osteoblastic MC3T3-E1 cells were higher on samples mineralized in media B-E (containing Mg) than in those mineralized in medium A (not containing Mg). All samples underwent degradation and supported the adhesion of RAW 264.7 monocytic cells, and samples mineralized in media A and B supported osteoclast-like cell formation. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Human skin cell fractions fail to self-organize within a gellan gum/hyaluronic acid matrix but positively influence early wound healing.

    PubMed

    Cerqueira, Mariana T; da Silva, Lucília P; Santos, Tírcia C; Pirraco, Rogério P; Correlo, Vitor M; Marques, Alexandra P; Reis, Rui L

    2014-05-01

    Split-thickness autografts still are the current gold standard to treat skin, upon severe injuries. Nonetheless, autografts are dependent on donor site availability and often associated to poor quality neoskin. The generation of dermal-epidermal substitutes by tissue engineering is seen as a promising strategy to overcome this problematic. However, solutions that can be safely and conveniently transplanted in one single surgical intervention are still very challenging as their production normally requires long culture time, and graft survival is many times compromised by delayed vascularization upon transplantation. This work intended to propose a strategy that circumvents the prolonged and laborious preparation period of skin substitutes and allows skin cells self-organization toward improved healing. Human dermal/epidermal cell fractions were entrapped directly from isolation within a gellan gum/hyaluronic acid (GG-HA) spongy-like hydrogel formed from an off-the-shelf dried polymeric network. Upon transplantation into full-thickness mice wounds, the proposed constructs accelerated the wound closure rate and re-epithelialization, as well as tissue neovascularization. A synergistic effect of the GG-HA matrix and the transplanted cells over those processes was demonstrated at early time points. Despite the human-derived and chimeric blood vessels found, the proposed matrix did not succeed in prolonging cells residence time and in sustaining the self-organization of transplanted human cells possibly due to primitive degradation. Despite this, the herein proposed approach open the opportunity to tackle wound healing at early stages contributing to re-epithelialization and neovascularization.

  20. In vitro and in vivo ocular safety and eye surface permanence determination by direct and Magnetic Resonance Imaging of ion-sensitive hydrogels based on gellan gum and kappa-carrageenan.

    PubMed

    Fernández-Ferreiro, Anxo; González Barcia, Miguel; Gil-Martínez, María; Vieites-Prado, Alba; Lema, Isabel; Argibay, Barbara; Blanco Méndez, José; Lamas, Maria Jesus; Otero-Espinar, Francisco Javier

    2015-08-01

    Gellan gum, kappa-carrageenan and alginates are natural polysaccharides able to interact with different cations that can be used to elaborate ion-activated in situ gelling systems for different uses. The interaction between fluid solutions of these polysaccharides and cations presents into the tear made these biopolymers very interesting to elaborate ophthalmic drug delivery systems. The main purpose of this study is to evaluate the ability of mixtures of these polymers to obtain ion-activated ophthalmic in situ gelling systems with optimal properties for ocular use. To achieve this purpose different proportion of the biopolymers were analyzed using a mixture experimental design evaluating their transparency, mechanical properties and bioadhesion in the absence and presence of simulated tear fluid. Tear induces a rapid sol-to-gel phase transition in the mixtures forming a consistent hydrogel. The solution composed by 80% of gellan gum and 20% kappa-carrageenan showed the best mechanical and mucoadhesive properties. This mixture was evaluated for rheological behavior, microstructure, cytotoxicity, acute corneal irritancy, ex-vivo and in vivo ocular toxicity and in vivo corneal contact time using Magnetic Resonance Images (MRI) techniques. Result indicates that the system is safe at ophthalmic level and produces an extensive ocular permanence higher than 6h.

  1. 21 CFR 172.665 - Gellan gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...://www.nap.edu), or may be examined at the Center for Food Safety and Applied Nutrition's Library, Food... Cosmetic Act do not preclude such use. (f) To assure safe use of the additive: (1) The label of its container shall bear, in addition to other information required by the Federal Food, Drug, and Cosmetic...

  2. Limonene encapsulation in freeze dried gellan systems.

    PubMed

    Evageliou, Vasiliki; Saliari, Dimitra

    2017-05-15

    The encapsulation of limonene in freeze-dried gellan systems was investigated. Surface and encapsulated limonene content was determined by measurement of the absorbance at 252nm. Gellan matrices were both gels and solutions. For a standard gellan concentration (0.5wt%) gelation was induced by potassium or calcium chloride. Furthermore, gellan solutions of varying concentrations (0.25-1wt%) were also studied. Limonene was added at two different concentrations (1 and 2mL/100g sample). Gellan gels encapsulated greater amounts of limonene than solutions. Among all gellan gels, the KCl gels had the greater encapsulated limonene content. However, when the concentration of limonene was doubled in these KCl gels, the encapsulated limonene decreased. The surface limonene content was significant, especially for gellan solutions. The experimental conditions and not the mechanical properties of the matrices were the dominant factor in the interpretation of the observed results.

  3. Gum Disease and Men

    MedlinePlus

    ... Gum Disease Risk Factors Gum Disease Symptoms Gum Disease Prevention Gum Disease and Other Diseases Gum Disease and ... Gum Disease Risk Factors Gum Disease Symptoms Gum Disease Prevention Gum Disease and Other Diseases Gum Disease and ...

  4. Gum Graft Surgery

    MedlinePlus

    ... Gum Disease Risk Factors Gum Disease Symptoms Gum Disease Prevention Gum Disease and Other Diseases Gum Disease and ... Gum Disease Risk Factors Gum Disease Symptoms Gum Disease Prevention Gum Disease and Other Diseases Gum Disease and ...

  5. Gum biopsy

    MedlinePlus

    Biopsy - gingiva (gums) ... the mouth in the area of the abnormal gum tissue. You may also have an injection of numbing medicine. A small piece of gum tissue is removed and checked for problems in ...

  6. Bleeding gums

    MedlinePlus

    ... periodontal exam. DO NOT use tobacco, since it makes bleeding gums worse. Control gum bleeding by applying pressure directly on the gums with a gauze pad soaked in ice water. If you have been diagnosed with a ...

  7. Large deformation analysis of gellan gels

    NASA Astrophysics Data System (ADS)

    Kawai, Shinnosuke; Nitta, Yoko; Nishinari, Katsuyoshi

    2007-08-01

    Gellan gel, a typical polysaccharide gel, is ruptured with different deformation behaviors from gelatin gel or rubber. It exhibits both strain hardening and softening; hardening is observed for moderate strain and softening occurs for larger strain. From the analyses of stress-strain curves of gellan gels, we propose forms of strain energy function. The fit with the proposed equation was excellent, while the existing models fail because they consider only one of hardening or softening effect. Furthermore, these equations are shown to be capable of extracting the hardening and softening effects separately from the observed stress-strain curves. By using these fitting equations, the concentration dependences of hardening and softening are investigated. It is shown that the degrees of hardening and softening both increase with increasing gellan concentration.

  8. Gum Disease

    MedlinePlus

    ... away from the teeth. This is known as periodontitis (pronounced: pair-ee-oh-don-TY-tus), a more advanced form of gum disease. With periodontitis, gums become weakened and form pockets around the ...

  9. Nicotine Gum

    MedlinePlus

    ... gum is used to help people stop smoking cigarettes. Nicotine chewing gum should be used together with ... by your doctor.If you smoke your first cigarette more than 30 minutes after waking up, use ...

  10. Nanometric organisation in blends of gellan/xyloglucan hydrogels.

    PubMed

    de Souza, Clayton F; Riegel-Vidotti, Izabel C; Cardoso, Mateus B; Ono, Lucy; Lucyszyn, Neoli; Lubambo, Adriana F; Sens, Camila V; Grein-Iankovski, Aline; Sierakowski, Maria Rita

    2014-12-19

    Mixtures of gellan gum (GL) and a xyloglucan (XGJ) extracted from Hymenaea courbaril seeds were prepared in a solution of 0.15 mol L(-1) NaCl. Rheology measurements revealed that 2.4 g L(-1) pure GL formed a brittle hydrogel, and GL-XGJ blends showed improved pseudoplastic character with higher XGJ contents. SAXS analyses showed that the Rg dimensions ranged from 1.3 to 4.9 nm, with larger values occurring as the amount of XGJ increased, and diffusion tests indicated that better diffusion of methylene blue dye was obtained in the network with a higher XGJ content. AFM topographic images of the films deposited onto mica revealed fewer heterogeneous surfaces with increased XGJ contents. The water contact angle revealed more hydrophobic character on all of the films, and the wettability decreased with increasing amounts of XGJ. Therefore, the demonstrated benefit of using XGJ blends is the production of a soft material with improved interface properties.

  11. Gum (Periodontal) Disease

    MedlinePlus

    ... of this page please turn Javascript on. Gum (Periodontal) Disease What Is Gum (Periodontal) Disease? An Infection of the Gums and Surrounding Tissues Gum (periodontal) disease is an infection of the gums and surrounding ...

  12. Interpenetrating network formation in gellan--agarose gel composites.

    PubMed

    Amici, E; Clark, A H; Normand, V; Johnson, N B

    2000-01-01

    Thermal, mechanical, turbidity, and microscope evidence is provided which strongly suggests molecular interpenetrating network (IPN) formation by mixtures of the bacterial and seaweed polysaccharides gellan and agarose. There is no evidence for synergistic coupling of the networks, and simple phase separation (demixing) can definitely be ruled out. Some changes in the gellan gelling behavior are suggested, however, by the increased gellan effective concentrations implicit in cure curve data. The dependence of this effect on the agarose nominal concentration seems consistent with a previous model that focused on gelling parameters, and changes in these rather than real concentration effects. In large deformation mechanical tests, the influence of agarose added to gellan is to re-enforce the network (higher compression and shear moduli, higher stresses-to-break) without significantly changing the strain to break, or the gellan brittle failure mechanism.

  13. Gum Disease

    MedlinePlus

    ... gingivitis, to serious damage to the tissue and bone supporting the teeth. In the worst cases, you ... pockets that become infected. If not treated, the bones, gums and connective tissue that support the teeth ...

  14. Oral sustained delivery of paracetamol from in situ-gelling gellan and sodium alginate formulations.

    PubMed

    Kubo, Wataru; Miyazaki, Shozo; Attwood, David

    2003-06-04

    The purpose of this study was to evaluate the potential for the oral sustained delivery of paracetamol of two formulations with in situ gelling properties. Oral administration of aqueous solutions of either gellan gum (1.0%, w/v) or sodium alginate (1.5%, w/v) containing calcium ions in complexed form resulted in the formation of gel depots in rabbit and rat stomachs as a consequence of the release of the calcium ions in the acidic environment. In vitro studies demonstrated diffusion-controlled release of paracetamol from the gels over a period of 6h. The bioavailability of paracetamol from the gels formed in situ in the stomachs of rabbits following oral administration of the liquid formulations was similar to that of a commercially available suspension containing an identical dose of paracetamol.

  15. Gums - swollen

    MedlinePlus

    ... A.D.A.M. Editorial team. Related MedlinePlus Health Topics Gum Disease Browse the Encyclopedia A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare ... for online health information and services. Learn more about A.D. ...

  16. Flow behaviour of gellan sol with selected cations.

    PubMed

    Sharma, Shipra; Bhattacharya, Suvendu

    2015-02-01

    An understanding of the flow behaviour of the sols before gel formation is important for developing nutrient enriched gels. The influence of cations like CaCl2 (0.05 and 0.1 %, w/w) and FeSO4 (0.05 and 0.1 %, w/w) on the rheological properties of 1 % gellan sol (w/w) prior to gelling was investigated. The apparent viscosity, reported at a shear-rate of 100 s(-1), indicated that the gellan dispersion without any cation possessed lower values compared to other samples containing different cations. The Cross model provided the best fit (0.97 ≤ r ≤ 0.99, p ≤ 0.01) compared to moderate fitting to power law model (0.94 ≤ r ≤ 0.98). Among the different Cross model parameters, the zero-shear viscosity (ηo) increased with the addition of CaCl2 and FeSO4, and with an increase in their concentrations. Zero-shear viscosity values were 0.46 Pas for gellan sol, 0.79 Pas for gellan with 0.05 % (w/w) CaCl2, 1.41 Pas for gellan with 0.1 % CaCl2, 3.85 Pas for gellan with 0.05 % FeSO4 and 4.33 Pas for gellan with 0.1 % FeSO4. An increase in cation concentration from 0.05 to 0.10 % (w/w) marginally increased the relaxation time (λ) values indicating the development of more solid characteristics in the sol.

  17. Alkaline phosphatase encapsulated in gellan-chitosan hybrid capsules.

    PubMed

    Fujii, Toshihiro; Ogiwara, Daisuke; Ohkawa, Kousaku; Yamamoto, Hiroyuki

    2005-05-23

    Alkaline phosphatase (ALP) was encapsulated in gellan-chitosan polyion complex (PIC) capsules using a convenient procedure. The recovery of ALP was about 50% when the capsules were prepared by dropping a solution of ALP and gellan mixture (ALP/gellan) into a chitosan solution. When p-nitrophenyl phosphate (p-NPP) and 5-bromo-4-chloro-3-indolyl phosphate (BCIP) were incubated with ALP/gellan-chitosan capsules as substrates for ALP, the transparent colorless capsules changed to yellow and blue, respectively. The encapsulation of ALP into the PIC capsules was also confirmed by SDS-PAGE and immunoblot analyses. The ALP and polypeptides of more than 30 kDa remained without release even after incubation at 4 degrees C for 14 d. The biochemical properties of the encapsulated ALP activity were similar to those of the intact enzyme. When the solution containing p-NPP was loaded on a column packed with ALP/gellan-chitosan capsules at 27 degrees C, approximately 75% of p-NPP was hydrolyzed by passing through the column. No significant leakage of ALP was observed during the procedure, indicating that the capsules were resistant to pressure in the chromatographic operation. Furthermore, 70% of the hydrolytic activity of the packed capsules remained after storage at 4 degrees C for one month. These results suggest that the polyion complex capsules could be useful materials for protein fixation without chemical modification. [Diagram: see text] Encapsulation of ALP into PIC capsules and the morphological changes seen in the absence of the ALP substrate and in the presence of p-NPP and BICP.

  18. 21 CFR 184.1349 - Karaya gum (sterculia gum).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Karaya gum (sterculia gum). 184.1349 Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1349 Karaya gum (sterculia gum). (a) Karaya gum (sterculia gum) is the dried gummy exudate from the trunk of trees of various species of the genus...

  19. Trigonella foenum-graecum L. seed mucilage-gellan mucoadhesive beads for controlled release of metformin HCl.

    PubMed

    Nayak, Amit Kumar; Pal, Dilipkumar

    2014-07-17

    Fenugreek (Trigonella foenum-graecum L.) seed mucilage (FSM)-gellan gum (GG) mucoadhesive beads containing metformin HCl for oral use were developed through ionotropic-gelation technique. Effects of GG to FSM ratio and cross-linker (CaCl2) concentration on the drug encapsulation efficiency (DEE, %), and cumulative drug release after 10h (R10h, %) of ionotropically-gelled FSM-GG mucoadhesive beads containing metformin HCl were optimized by 3(2) factorial design. The optimized mucoadhesive beads showed DEE of 92.53 ± 3.85% and R10h of 55.28 ± 1.58% and mean diameter of 1.62 ± 0.22 mm. The in vitro metformin HCl release from these ionotropically-gelled FSM-GG beads was prolonged over 10h and followed zero-order model with super case-II transport mechanism. The optimized mucoadhesive beads also exhibited pH-dependent swelling, good mucoadhesivity with biological mucosal membrane and significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration.

  20. Gum Disease in Children

    MedlinePlus

    ... Teeth Oral Hygiene Habits and Hypertension Risk Alcohol Consumption and Gum Health Workshop on Regeneration Periodontal Disease More Prevalent among Ethnic Minorities Dental Implants Periodontal Health and Diabetes Periodontal ...

  1. Gum Disease Symptoms

    MedlinePlus

    ... Teeth Oral Hygiene Habits and Hypertension Risk Alcohol Consumption and Gum Health Workshop on Regeneration Periodontal Disease More Prevalent among Ethnic Minorities Dental Implants Periodontal Health and Diabetes Periodontal ...

  2. Gum Disease and Women

    MedlinePlus

    ... Teeth Oral Hygiene Habits and Hypertension Risk Alcohol Consumption and Gum Health Workshop on Regeneration Periodontal Disease More Prevalent among Ethnic Minorities Dental Implants Periodontal Health and Diabetes Periodontal ...

  3. Oxidative acylation using thioacids

    NASA Technical Reports Server (NTRS)

    Liu, R.; Orgel, L. E.

    1997-01-01

    Several important prebiotic reactions, including the coupling of amino acids into polypeptides by the formation of amide linkages, involve acylation. Theae reactions present a challenge to the understanding of prebiotic synthesis. Condensation reactions relying on dehydrating agents are either inefficient in aqueous solution or require strongly acidic conditions and high temperatures. Activated amino acids such as thioester derivatives have therefore been suggested as likely substrates for prebiotic peptide synthesis. Here we propose a closely related route to amide bond formation involving oxidative acylation by thioacids. We find that phenylalanine, leucine and phenylphosphate are acylated efficiently in aqueous solution by thioacetic acid and an oxidizing agent. From a prebiotic point of view, oxidative acylation has the advantage of proceeding efficiently in solution and under mild conditions. We anticipate that oxidative acylation should prove to be a general method for activating carboxylic acids, including amino acids.

  4. Modification of palm kernel oil esters nanoemulsions with hydrocolloid gum for enhanced topical delivery of ibuprofen

    PubMed Central

    Salim, Norazlinaliza; Basri, Mahiran; Rahman, Mohd BA; Abdullah, Dzulkefly K; Basri, Hamidon

    2012-01-01

    Introduction During recent years, there has been growing interest in the use of nanoemulsion as a drug-carrier system for topical delivery. A nanoemulsion is a transparent mixture of oil, surfactant and water with a very low viscosity, usually the product of its high water content. The present study investigated the modification of nanoemulsions with different hydrocolloid gums, to enhanced drug delivery of ibuprofen. The in vitro characterization of the initial and modified nanoemulsions was also studied. Methods A palm kernel oil esters nanoemulsion was modified with different hydrocolloid gums for the topical delivery of ibuprofen. Three different hydrocolloids (gellan gum, xanthan gum, and carrageenan) were selected for use. Ternary phase diagrams were constructed using palm kernel oil esters as the oil, Tween 80 as the surfactant, and water. Nanoemulsions were prepared by phase inversion composition, and were gradually mixed with the freshly prepared hydrocolloids. The initial nanoemulsion and modified nanoemulsions were characterized. The abilities of the nanoemulsions to deliver ibuprofen were assessed in vitro, using a Franz diffusion cell fitted with rat skin. Results No significant changes were observed in droplet size (~16–20 nm) but a significant difference in polydispersity indexes were observed before and after the modification of nanoemulsions using gellan gum, carrageenan, and xanthan gum. The zeta potentials of the initial nanoemulsions (−11.0 mV) increased to −19.6 mV, −13.9 mV, and −41.9 mV, respectively. The abilities of both the initial nanoemulsion (T802) and the modified nanoemulsion to deliver ibuprofen through the skin were evaluated in vitro, using Franz diffusion cells fitted with rat skin. The in vitro permeation data showed that the modified nanoemulsion (Kp value of 55.4 × 10−3 cm · h−1) increased the permeability of ibuprofen 4.40 times over T802 (Kp value of 12.6 × 10−3 cm · h−1) (P < 0.05). Conclusion The

  5. Organization of genes required for gellan polysaccharide biosynthesis in Sphingomonas elodea ATCC 31461.

    PubMed

    Harding, Nancy E; Patel, Yamini N; Coleman, Russell J

    2004-02-01

    Sphingomonas elodea ATCC 31461 produces gellan, a capsular polysaccharide that is useful as a gelling agent for food and microbiological media. Complementation of nonmucoid S. elodea mutants with a gene library resulted in identification of genes essential for gellan biosynthesis. A cluster of 18 genes spanning 21 kb was isolated. These 18 genes are homologous to genes for synthesis of sphingan polysaccharide S-88 from Sphingomonas sp. ATCC 31554, with predicted amino acid identities varying from 61% to 98%. Both polysaccharides have the same tetrasaccharide repeat unit, comprised of [-->4)-alpha- l-rhamnose-(1-->3)-beta- d-glucose-(1-->4)-beta- d-glucuronic acid-(1-->4)-beta- d-glucose-(1-->]. Polysaccharide S-88, however, has mannose or rhamnose in the fourth position and has a rhamnosyl side chain, while gellan has no sugar side chain but is modified by glyceryl and acetyl substituents. Genes for synthesis of the precursor dTDP- l-rhamnose were highly conserved. The least conserved genes in this cluster encode putative glycosyl transferases III and IV and a gene of unknown function, gelF. Three genes ( gelI, gelM, and gelN) affected the amount and rheology of gellan produced. Four additional genes present in the S-88 sphingan biosynthetic gene cluster did not have homologs in the gene cluster for gellan biosynthesis. Three of these gene homologs, gelR, gelS, and gelG, were found in an operon unlinked to the main gellan biosynthetic gene cluster. In a third region, a gene possibly involved in positive regulation of gellan biosynthesis was identified.

  6. What Happens to Swallowed Gum?

    MedlinePlus

    ... made of either natural or synthetic materials (gum resin), preservatives, flavorings, and sweeteners. The body can absorb ... human digestive tract can't digest the gum resin. It's moved through the digestive tract by the ...

  7. What Happens to Swallowed Gum?

    MedlinePlus

    ... gums that are not sugar free can cause cavities . Sugar-free gum sweetened with sorbitol also can be a problem because it can cause diarrhea. Cinnamon-flavored gums of any kind may irritate the mouth lining. They can be hot and spicy in your mouth, as you probably know. A good rule would be to ...

  8. The Gum nebula

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.

    1972-01-01

    The distance from the sun to the center of the star, Gamma Velorium, is determined in an effort to draw a physical model and identify the ionized energy source of the Gum nebula. The distance is calculated from the local hydrogen density of radio astronomy studies and the hydrogen measure.

  9. Acyl-Lipid Metabolism

    PubMed Central

    Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

    2010-01-01

    Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:22303259

  10. Acyl-Lipid Metabolism

    PubMed Central

    Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

    2013-01-01

    Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:23505340

  11. 21 CFR 184.1349 - Karaya gum (sterculia gum).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... conditions: Maximum Usage Levels Permitted Food (as served) Percent Function Frozen dairy desserts and mixes... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Karaya gum (sterculia gum). 184.1349 Section 184.1349 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  12. In Vivo Evaluation of a PEO-Gellan Gum Semi-Interpenetrating Polymer Network for the Oral Delivery of Sulpiride.

    PubMed

    Hoosain, Famida G; Choonara, Yahya E; Kumar, Pradeep; Tomar, Lomas K; Tyagi, Charu; du Toit, Lisa C; Pillay, Viness

    2016-05-16

    In this study, an optimized epichlorohydrin-crosslinked semi-interpenetrating polymer network xerogel matrix system (XePoMas) for the controlled delivery of sulpiride was prepared. The ability of XePoMas to sustain drug release was determined by in vitro and in vivo drug release experiments. Swelling of the xerogel over the 24-h experimental period ranged from 346 to 648%; swelling was observed to increase exponentially over the initial 8 h. In vitro drug release depicted a linear zero order drug release profile with an R (2) value of 0.9956. The ability of the fabricated XePoMas to sustain drug release and enhance bioavailability of sulpiride in vivo was investigated by evaluating the plasma drug concentration over 24 h in the large pig model. The optimized XePoMas formulation was shown to increase intestinal absorption of sulpiride to a greater extent than the marketed product in vivo, with a C max of 830.58 ng/mL after 15 h.

  13. Enzymatically-treated guar gums

    SciTech Connect

    Carter, W.H.; Srivastava, V.K.

    1987-07-28

    A method is described of recovering oil from an oil bearing formation by fracturing the step of inserting into the formation, at high pressure, an aqueous composition comprising guar gum in water. The guar gum is first coated and impregnated, while in the solid particulate state, with an aqueous solution of a hydrolytic enzyme.

  14. The Gum Nebula.

    NASA Technical Reports Server (NTRS)

    Maran, S. P.

    1971-01-01

    A historical review of observations on the Gum Nebula is given together with a survey of knowledge on its size, emission features, and dynamics of expansion. The ultraviolet spectrum of Zeta Puppis is examined in terms of features caused by various absorption lines, and radio emission from Vela X is analyzed, together with the effects of nebular plasma on the propagation of radio pulses from pulsars in the Nebula. The density distribution and the possibility of being produced by the Vela X supernova are discussed.

  15. 21 CFR 172.695 - Xanthan gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 1.02 to 1.45. (3) Positive for xanthan gum when subjected to the following procedure: Locust Bean Gum Gel Test Blend on a weighing paper or in a weighing pan 1.0 gram of powdered locust bean gum with... bean gum). Allow the solution to cool without agitation as before. Formation of a gel on...

  16. 21 CFR 172.695 - Xanthan gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Positive for xanthan gum when subjected to the following procedure: Locust Bean Gum Gel Test Blend on a weighing paper or in a weighing pan 1.0 gram of powdered locust bean gum with 1.0 gram of the powdered... in 200 milliliters of distilled water previously heated to 80 °C (omit the locust bean gum)....

  17. 21 CFR 582.7349 - Sterculia gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sterculia gum. 582.7349 Section 582.7349 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7349 Sterculia gum. (a) Product. Sterculia gum (karaya gum). (b) Conditions of use. This substance is...

  18. Gum chewing during pre-anesthetic fasting.

    PubMed

    Poulton, Thomas J

    2012-03-01

    Many ad hoc fasting guidelines for pre-anesthetic patients prohibit gum chewing. We find no evidence that gum chewing during pre-anesthetic fasting increases the volume or acidity of gastric juice in a manner that increases risk, nor that the occasional associated unreported swallowing of gum risks subsequent aspiration. On the contrary, there is evidence that gum chewing promotes gastrointestinal motility and physiologic gastric emptying. Recommendations against pre-anesthetic gum chewing do not withstand scrutiny and miss an opportunity to enhance comfort and sense of wellbeing for patients awaiting anesthesia. Gum chewing during the pre-anesthetic nil per os (NPO) period would also permit the development of gum-delivered premedications and should be permitted in children old enough to chew gum safely. Gum chewing should cease when sedatives are given and all patients should be instructed to remove any chewing gum from the mouth immediately prior to anesthetic induction.

  19. Acylation of Ferrocene: A Greener Approach

    ERIC Educational Resources Information Center

    Birdwhistell, Kurt R.; Nguyen, Andy; Ramos, Eric J.; Kobelja, Robert

    2008-01-01

    The acylation of ferrocene is a common reaction used in organic laboratories to demonstrate Friedel-Crafts acylation and the purification of compounds using column chromatography. This article describes an acylation of ferrocene experiment that is more eco-friendly than the conventional acylation experiment. The traditional experiment was modified…

  20. Take Care of Your Teeth and Gums

    MedlinePlus

    ... En español Take Care of Your Teeth and Gums Browse Sections The Basics Overview Take Action! Brushing ... only in moderation. What causes tooth decay and gum disease? Plaque (“plak”) is a sticky substance that ...

  1. 21 CFR 573.1010 - Xanthan gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Xanthan gum. 573.1010 Section 573.1010 Food and... Listing § 573.1010 Xanthan gum. The food additive xanthan gum may be safely used in animal feed as follows: (a) The food additive is xanthan gum as defined in § 172.695 of this chapter and meets all of...

  2. 21 CFR 184.1351 - Gum tragacanth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Gum tragacanth. 184.1351 Section 184.1351 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1351 Gum tragacanth. (a) Gum tragacanth is the exudate from one of...

  3. 21 CFR 582.7339 - Guar gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Guar gum. 582.7339 Section 582.7339 Food and Drugs..., AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7339 Guar gum. (a) Product. Guar gum. (b) Conditions of use. This substance is generally recognized as safe when used...

  4. 21 CFR 582.7333 - Gum ghatti.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gum ghatti. 582.7333 Section 582.7333 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7333 Gum ghatti. (a) Product. Gum ghatti. (b) Conditions of use. This substance is generally recognized as safe...

  5. 21 CFR 582.7351 - Gum tragacanth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gum tragacanth. 582.7351 Section 582.7351 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7351 Gum tragacanth. (a) Product. Tragacanth (gum tragacanth). (b) Conditions of use. This substance is...

  6. 21 CFR 582.3336 - Gum guaiac.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gum guaiac. 582.3336 Section 582.3336 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Gum guaiac. (a) Product. Gum guaiac. (b) Tolerance. 0.1 percent (equivalent antioxidant activity...

  7. 21 CFR 573.1010 - Xanthan gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.1010 Xanthan gum. The food additive xanthan gum may be safely used in animal feed as follows: (a) The food additive is xanthan gum as defined in § 172.695 of this chapter and meets all of...

  8. 21 CFR 573.1010 - Xanthan gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.1010 Xanthan gum. The food additive xanthan gum may be safely used in animal feed as follows: (a) The food additive is xanthan gum as defined in § 172.695 of this chapter and meets all of...

  9. 21 CFR 573.1010 - Xanthan gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.1010 Xanthan gum. The food additive xanthan gum may be safely used in animal feed as follows: (a) The food additive is xanthan gum as defined in § 172.695 of this chapter and meets all of...

  10. 21 CFR 573.1010 - Xanthan gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.1010 Xanthan gum. The food additive xanthan gum may be safely used in animal feed as follows: (a) The food additive is xanthan gum as defined in § 172.695 of this chapter and meets all of...

  11. 21 CFR 582.7330 - Gum arabic.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Gum arabic. 582.7330 Section 582.7330 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7330 Gum arabic. (a) Product. Acacia (gum arabic). (b) Conditions of use. This substance is generally recognized...

  12. 21 CFR 582.7330 - Gum arabic.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Gum arabic. 582.7330 Section 582.7330 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7330 Gum arabic. (a) Product. Acacia (gum arabic). (b) Conditions of use. This substance is generally recognized...

  13. 21 CFR 582.7330 - Gum arabic.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gum arabic. 582.7330 Section 582.7330 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7330 Gum arabic. (a) Product. Acacia (gum arabic). (b) Conditions of use. This substance is generally recognized...

  14. 21 CFR 582.7330 - Gum arabic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Gum arabic. 582.7330 Section 582.7330 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7330 Gum arabic. (a) Product. Acacia (gum arabic). (b) Conditions of use. This substance is generally recognized...

  15. 21 CFR 582.7330 - Gum arabic.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gum arabic. 582.7330 Section 582.7330 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7330 Gum arabic. (a) Product. Acacia (gum arabic). (b) Conditions of use. This substance is generally recognized...

  16. Alginate beads of Captopril using galactomannan containing Senna tora gum, guar gum and locust bean gum.

    PubMed

    Pawar, Harshal A; Lalitha, K G; Ruckmani, K

    2015-05-01

    Gastro-retentive Captopril loaded alginate beads were prepared by an ionotropic gelation method using sodium alginate in combination with natural gums containing galactomannans (Senna tora seed gum, guar gum and locust bean gum) in the presence of calcium chloride. The process variables such as concentration of sodium alginate/natural polymer, concentration of calcium chloride, curing time, stirring speed and drying condition were optimized. Prepared beads were evaluated for various parameters such as flow property, drug content and entrapment efficiency, size and shape, and swelling index. Surface morphology of the beads was studied using scanning electron microscopy. In vitro mucoadhesion and in vitro drug release studies were carried out on the prepared beads. From the entrapment efficiency and dissolution study, it was concluded that galactomannans in combination with sodium alginate show sustained release property. The bead formulation F4 prepared using combination of sodium alginate and guar gums in the ratio 2:1 showed satisfactory sustained release for 12h. The release of Captopril from the prepared beads was found to be controlled by the swelling of the polymer followed by drug diffusion through the swelled polymer and slow erosion of the beads.

  17. GumTree: Data reduction

    NASA Astrophysics Data System (ADS)

    Rayner, Hugh; Hathaway, Paul; Hauser, Nick; Fei, Yang; Franceschini, Ferdi; Lam, Tony

    2006-11-01

    Access to software tools for interactive data reduction, visualisation and analysis during a neutron scattering experiment enables instrument users to make informed decisions regarding the direction and success of their experiment. ANSTO aims to enhance the experiment experience of its facility's users by integrating these data reduction tools with the instrument control interface for immediate feedback. GumTree is a software framework and application designed to support an Integrated Scientific Experimental Environment, for concurrent access to instrument control, data acquisition, visualisation and analysis software. The Data Reduction and Analysis (DRA) module is a component of the GumTree framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with GumTree, able to pull experiment data and metadata directly from the instrument control and data acquisition components. The DRA itself uses components common to all instruments at the facility, providing a consistent interface. It features familiar ISAW-based 1D and 2D plotting, an OpenGL-based 3D plotter and peak fitting performed by fityk. This paper covers the benefits of integration, the flexibility of the DRA module, ease of use for the interface and audit trail generation.

  18. Assessing DNA recovery from chewing gum.

    PubMed

    Eychner, Alison M; Schott, Kelly M; Elkins, Kelly M

    2017-01-01

    The purpose of this study was to evaluate which DNA extraction method yields the highest quantity of DNA from chewing gum. In this study, several popular extraction methods were tested, including Chelex-100, phenol-chloroform-isoamyl alcohol (PCIA), DNA IQ, PrepFiler, and QIAamp Investigator, and the quantity of DNA recovered from chewing gum was determined using real-time polymerase chain reaction with Quantifiler. Chewed gum control samples were submitted by anonymous healthy adult donors, and discarded environmental chewing gum samples simulating forensic evidence were collected from outside public areas (e.g., campus bus stops, streets, and sidewalks). As expected, results indicate that all methods tested yielded sufficient amplifiable human DNA from chewing gum using the wet-swab method. The QIAamp performed best when DNA was extracted from whole pieces of control gum (142.7 ng on average), and the DNA IQ method performed best on the environmental whole gum samples (29.0 ng on average). On average, the QIAamp kit also recovered the most DNA from saliva swabs. The PCIA method demonstrated the highest yield with wet swabs of the environmental gum (26.4 ng of DNA on average). However, this method should be avoided with whole gum samples (no DNA yield) due to the action of the organic reagents in dissolving and softening the gum and inhibiting DNA recovery during the extraction.

  19. Colin Gum and the discovery of the Gum nebula

    NASA Technical Reports Server (NTRS)

    Kerr, F. J.

    1971-01-01

    The research of Colin Gum in the field of astronomy is reviewed. It includes a radio survey at 200 MHz, a photographic survey for HII regions in the Southern Milky Way from longitude 220 deg to 20 deg, and a catalogue of 85 physically separate regions. He suggested that certain faint nebulosities were part of a large, nearby H II region excited by gamma Velorum and zeta Puppis. He was also concerned with 21-cm studies.

  20. Occupational asthma caused by guar gum.

    PubMed

    Lagier, F; Cartier, A; Somer, J; Dolovich, J; Malo, J L

    1990-04-01

    Some vegetable gums have been reported to cause asthma. We describe three subjects who were exposed at work to guar gum, which is derived from the outer part of Cyanopsis tetragonolobus, a vegetable that grows in India. The first subject worked for a pharmaceutical company; the second and third subjects worked at a carpet-manufacturing plant. All three subjects developed symptoms of rhinitis and asthma after the onset of exposure to guar gum. All subjects were atopic and demonstrated mild bronchial hyperresponsiveness to inhaled histamine at the time they were observed. Skin prick tests demonstrated an immediate skin reaction to guar gum. All three subjects had high levels of serum IgE antibodies to guar gum. Specific inhalation challenges in which the three subjects were exposed for short intervals (less than or equal to 4 minutes) to powder of guar gum elicited isolated immediate bronchospastic reactions in two subjects and a dual reaction in the other subject.

  1. Keep Gum Disease Away! | NIH MedlinePlus the Magazine

    MedlinePlus

    ... this page please turn Javascript on. Feature: Fighting Gum Disease Keep Gum Disease Away! Past Issues / Fall 2010 Table of ... repair damage resulting from uncared-for teeth and gums. Photo: Frederic Havens "Take care of your teeth, ...

  2. Ghrelin acylation and metabolic control.

    PubMed

    Al Massadi, O; Tschöp, M H; Tong, J

    2011-11-01

    Since its discovery, many physiologic functions have been ascribed to ghrelin, a gut derived hormone. The presence of a median fatty acid side chain on the ghrelin peptide is required for the binding and activation of the classical ghrelin receptor, the growth hormone secretagogue receptor (GHSR)-1a. Ghrelin O-acyl transferase (GOAT) was recently discovered as the enzyme responsible for this acylation process. GOAT is expressed in all tissues that have been found to express ghrelin and has demonstrated actions on several complex endocrine organ systems such as the hypothalamus-pituitary-gonadal, insular and adrenal axis as well as the gastrointestinal (GI) tract, bone and gustatory system. Ghrelin acylation is dependent on the function of GOAT and the availability of substrates such as proghrelin and short- to medium-chain fatty acids (MCFAs). This process is governed by GOAT activity and has been shown to be modified by dietary lipids. In this review, we provided evidence that support an important role of GOAT in the regulation of energy homeostasis and glucose metabolism by modulating acyl ghrelin (AG) production. The relevance of GOAT and AG during periods of starvation remains to be defined. In addition, we summarized the recent literature on the metabolic effects of GOAT specific inhibitors and shared our view on the potential of targeting GOAT for the treatment of metabolic disorders such as obesity and type 2 diabetes.

  3. Preparation and characterization of antimicrobial wound dressings based on silver, gellan, PVA and borax.

    PubMed

    Cencetti, C; Bellini, D; Pavesio, A; Senigaglia, D; Passariello, C; Virga, A; Matricardi, P

    2012-10-15

    Silver-loaded dressings are designed to provide the same antimicrobial activity of topical silver, with the advantages of a sustained silver release and a reduced number of dressing changes. Moreover, such type of dressing must provide a moist environment, avoiding fiber shedding, dehydration and adherence to the wound site. Here we describe the preparation of a novel silver-loaded dressing based on a Gellan/Hyaff(®) (Ge-H) non woven, treated with a polyvinyl alcohol (PVA)/borax system capable to enhance the entrapment of silver in the dressing and to modulate its release. The new hydrophilic non woven dressings show enhanced water uptake capability and slow dehydration rates. A sustained silver release is also achieved. The antibacterial activity was confirmed on Staphylococcus aureus and Pseudomonas aeruginosa.

  4. Preparation and in vitro antibacterial evaluation of gatifloxacin mucoadhesive gellan system

    PubMed Central

    Kesavan, K.; Nath, G.; Pandit, JK.

    2010-01-01

    Background and the purpose of the study The poor bioavailability and therapeutic response exhibited by the conventional ophthalmic solutions due to precorneal elimination of the drug may be overcome by the use of mucoadhesive in situ gel forming systems that are instilled as drops into the eye and undergo a sol-gel transition in the cul-de-sac and have good mucoadhesion with ocular mucus layers. The objective of this study was to formulate ophthalmic mucoadhesive system of gatifloxacin (GTN) and to evaluate its in vitro antibacterial potential against, Staphylococcus aureus and Escherichia coli. Methods : Mucoadhesive systems were prepared using gellan combined with sodium carboxymethylcellulose (NaCMC) or sodium alginate to enhance the gel bioadhesion properties. The prepared formulations were evaluated for their gelation, and rheological behaviors, mucoadhesion force, in vitro drug release, and antibacterial activity. Results All formulations in non-physiological or physiological conditions showed pseudoplastic behaviors. Increase in the concentration of mucoadhesive agent enhanced the mucoadhesive force significantly. In vitro release of gatifloxacin from the mucoadhesive system in simulated tear fluid (STF, pH of 7.4) was influenced significantly by the properties and concentration of gellan, sodium carboxymethyl cellulose and sodium alginate. Significant reduction in the total bacterial count was observed between drug solution (control) and mucoadhesive batches against both tested organisms. Major conclusion The developed mucoadhesive system is a viable alternative to conventional eye drops of GTN due to its ability to enhance bioavailability through its longer precorneal residence time and ability to sustain the release of the drug. PMID:22615622

  5. Chemical Reporters for Exploring Protein Acylation

    PubMed Central

    Thinon, Emmanuelle; Hang, Howard C.

    2015-01-01

    Proteins are acylated by a variety of metabolites that regulates many important cellular pathways in all kingdoms of life. Acyl groups in cells can vary in structure from the smallest unit, acetate, to modified long chain fatty acids, all of which can be activated and covalently attached to diverse amino acid side chains and consequently modulate protein function. For example, acetylation of Lys residues can alter the charge state of proteins and generate new recognition elements for protein–protein interactions. Alternatively, long chain fatty-acylation targets proteins to membranes and enables spatial control of cell signalling. To facilitate the analysis of protein acylation in biology, acyl analogues bearing alkyne or azide tags have been developed that enable fluorescent imaging and proteomic profiling of modified proteins using bioorthogonal ligation methods. Herein, we summarize the currently available acylation chemical reporters and highlight their utility to discover and quantify the roles of protein acylation in biology. PMID:25849926

  6. Rheological and interfacial properties at the equilibrium of almond gum tree exudate (Prunus dulcis) in comparison with gum arabic.

    PubMed

    Mahfoudhi, Nesrine; Sessa, Mariarenata; Ferrari, Giovanna; Hamdi, Salem; Donsi, Francesco

    2016-06-01

    Almond gum contains an arabinogalactan-type polysaccharide, which plays an important role in defining its interfacial and rheological properties. In this study, rheological and interfacial properties of almond gum and gum arabic aqueous dispersions were comparatively investigated. The interfacial tension of almond gum and gum arabic aqueous dispersions was measured using the pendant drop method in hexadecane. The asymptotic interfacial tension values for almond gum were significantly lower than the corresponding values measured for gum arabic, especially at high concentration. Rheological properties were characterized by steady and oscillatory tests using a coaxial geometry. Almond gum flow curves exhibited a shear thinning non-Newtonian behavior with a tendency to a Newtonian plateau at low shear rate, while gum arabic flow curves exhibited such behavior only at high shear rate. The influence of temperature (5-50  ℃) on the flow curves was studied at 4% (m/m) gum concentration and the Newtonian viscosities at infinite and at zero shear rate, for gum arabic and almond gum, respectively, were accurately fitted by an Arrhenius-type equation. The dynamic properties of the two gum dispersions were also studied. Both gum dispersions exhibited viscoelastic properties, with the viscous component being predominant in a wider range of concentrations for almond gum, while for gum arabic the elastic component being higher than the elastic one especially at higher concentrations.The rheological and interfacial tension properties of almond gum suggest that it may represent a possible substitute of gum arabic in different food applications.

  7. Structural, thermal and rheological characterization of modified Dalbergia sissoo gum--A medicinal gum.

    PubMed

    Munir, Hira; Shahid, Muhammad; Anjum, Fozia; Mudgil, Deepak

    2016-03-01

    Dalbergia sissoo gum was purified by ethanol precipitation. The purified gum was modified and hydrolyzed. Gum was modified by performing polyacrylamide grafting and carboxymethylation methods. The hydrolysis was carried out by using mannanase, barium hydroxide and trifluoroacetic acid. The modified and hydrolyzed gums were characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The decrease in viscosity was studied by performing the flow test. The modified and hydrolyzed gums were thermally stable as compared to crude gum. There was increase in crystallinity after modification and hydrolysis, determined through XRD. FTIR analysis exhibits no major transformation of functional group, only there was change in the intensity of transmittance. It is concluded that the modified and hydrolyzed gum can be used for pharmaceutical and food industry.

  8. Poly(acrylonitrile) grafted Ipomoea seed-gums: a renewable reservoir to industrial gums.

    PubMed

    Singh, Vandana; Tiwari, Ashutosh; Tripathi, Devendra Narayan; Sanghi, Rashmi

    2005-01-01

    Plants of Ipomoea genus are widely distributed in India as wild vegetation and are reported source for the seed gums. Seed gums from Ipomoea dasysperma, Ipomoea hederacea, and Ipomoea palmata plants were grafted with polyacrylonitrile (PAN) using potassium persulfate/ascorbic acid redox initiator for modifying their properties for potential industrial applications. Under identical grafting conditions, the extent of the grafting was observed to be dependent on the galactose-to-mannose ratio and the degree of the branching in the galactomannans. Viscosity, gel formation, film formation, and the shelf life of the grafted gum solutions and water and saline retention capacity of the grafted seed gums were determined and compared with the parent gums. Water retention of the alkalie hydrolyzed grafted seed gums were also studied. Grafted gums were characterized using FTIR, NMR, and XRD analysis.

  9. Gum chewing affects academic performance in adolescents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chewing gum may have an impact on improved memory during specific tasks of recognition and sustained attention. Research objective was to determine the effect of gum chewing on standardized test scores and math class grades of eighth grade students. Four math classes, 108 students, were randomized i...

  10. Brief Report: Gum Chewing Affects Standardized Math Scores in Adolescents

    ERIC Educational Resources Information Center

    Johnston, Craig A.; Tyler, Chermaine; Stansberry, Sandra A.; Moreno, Jennette P.; Foreyt, John P.

    2012-01-01

    Gum chewing has been shown to improve cognitive performance in adults; however, gum chewing has not been evaluated in children. This study examined the effects of gum chewing on standardized test scores and class grades of eighth grade math students. Math classes were randomized to a gum chewing (GC) condition that provided students with gum…

  11. Nicotine Gum and Behavioral Treatment: A Placebo Controlled Trial.

    ERIC Educational Resources Information Center

    Hall, Sharon M.; And Others

    1987-01-01

    Assigned 139 subjects to intensive behavioral or to low-contact smoking treatment and to 2-milligram nicotine gum or to placebo gum in a 2x2 factorial design. Nicotine gum produced higher abstinence rates than did placebo. Subjects receiving low-contact condition plus nicotine gum had excellent abstinence rates at both 26 weeks and 52 weeks.…

  12. Chewing gum moderates the vigilance decrement.

    PubMed

    Morgan, Kate; Johnson, Andrew J; Miles, Christopher

    2014-05-01

    We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in post-task self-rated alertness scores. The declines in both performance and subjective alertness were attenuated in the chewing-gum group. In particular, correct RTs were significantly shorter following the chewing of gum in the latter stages of the task. Additionally, the gradients of decline for target detection and incline for correct RTs were both attenuated for the chewing-gum group. These findings are consistent with the data of Tucha and Simpson (2011), Appetite, 56, 299-301, who showed beneficial effects of chewing gum in the latter stages of a 30 min visual attention task, and extend their data to a task that necessitates the continuous updating of order memory. It is noteworthy that our data contradict the claim (Kozlov, Hughes, & Jones, 2012, Q. J. Exp. Psychology, 65, 501-513) that chewing gum negatively impacts short-term memory task performance.

  13. The Physiology of Protein S-acylation

    PubMed Central

    Chamberlain, Luke H.; Shipston, Michael J.

    2015-01-01

    Protein S-acylation, the only fully reversible posttranslational lipid modification of proteins, is emerging as a ubiquitous mechanism to control the properties and function of a diverse array of proteins and consequently physiological processes. S-acylation results from the enzymatic addition of long-chain lipids, most typically palmitate, onto intracellular cysteine residues of soluble and transmembrane proteins via a labile thioester linkage. Addition of lipid results in increases in protein hydrophobicity that can impact on protein structure, assembly, maturation, trafficking, and function. The recent explosion in global S-acylation (palmitoyl) proteomic profiling as a result of improved biochemical tools to assay S-acylation, in conjunction with the recent identification of enzymes that control protein S-acylation and de-acylation, has opened a new vista into the physiological function of S-acylation. This review introduces key features of S-acylation and tools to interrogate this process, and highlights the eclectic array of proteins regulated including membrane receptors, ion channels and transporters, enzymes and kinases, signaling adapters and chaperones, cell adhesion, and structural proteins. We highlight recent findings correlating disruption of S-acylation to pathophysiology and disease and discuss some of the major challenges and opportunities in this rapidly expanding field. PMID:25834228

  14. Interstellar gas in the Gum Nebula

    NASA Technical Reports Server (NTRS)

    Wallerstein, G.; Jenkins, E. B.; Silk, J.

    1980-01-01

    A survey of the interstellar gas near the Gum Nebula by optical observation of 67 stars at Ca II, 42 stars at Na I, and 14 stars in the UV with the Copernicus satellite provided radial velocities and column densities for all resolved absorption components. Velocity dispersions for gas in the Gum Nebula are not significantly larger than in the general interstellar medium; the ionization structure is predominantly that of an H II region with moderately high ionization. Denser, more highly ionized clouds are concentrated toward the Gum Nebula; these clouds do not show the anomalously high ionization observed in the Vela remnant clouds.

  15. Modified acyl-ACP desaturase

    DOEpatents

    Cahoon, E.B.; Shanklin, J.; Lindgvist, Y.; Schneider, G.

    1998-01-06

    Disclosed is a method for modifying the chain length and double bond positional specificities of a soluble plant fatty acid desaturase. More specifically, the method involves modifying amino acid contact residues in the substrate binding channel of the soluble fatty acid desaturase which contact the fatty acid. Specifically disclosed is the modification of an acyl-ACP desaturase. Amino acid contact residues which lie within the substrate binding channel are identified, and subsequently replaced with different residues to effect the modification of activity. 1 fig.

  16. Locust bean gum: a versatile biopolymer.

    PubMed

    Prajapati, Vipul D; Jani, Girish K; Moradiya, Naresh G; Randeria, Narayan P; Nagar, Bhanu J

    2013-05-15

    Biopolymers or natural polymers are an attractive class of biodegradable polymers since they are derived from natural sources, easily available, relatively cheap and can be modified by suitable reagent. Locust bean gum is one of them that have a wide potentiality in drug formulations due to its extensive application as food additive and its recognized lack of toxicity. It can be tailored to suit its demands of applicants in both the pharmaceutical and biomedical areas. Locust bean gum has a wide application either in the field of novel drug delivery system as rate controlling excipients or in tissue engineering as scaffold formation. Through keen references of reported literature on locust bean gum, in this review, we have described critical aspects of locust bean gum, its manufacturing process, physicochemical properties and applications in various drug delivery systems.

  17. Diabetes, Gum Disease, and Other Dental Problems

    MedlinePlus

    ... Radio Broadcast Clinical Trials For Health Care Professionals Community Outreach and Health Fairs Health Communication Programs FAQs ... sugars or starches. Some types of plaque cause tooth decay or cavities. Other types of plaque cause gum ...

  18. 21 CFR 172.695 - Xanthan gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... polysaccharide gum derived from Xanthomonas campestris by a pure-culture fermentation process and purified by... hexose units and is manufactured as the sodium, potassium, or calcium salt. (b) The strain of...

  19. 21 CFR 172.695 - Xanthan gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... polysaccharide gum derived from Xanthomonas campestris by a pure-culture fermentation process and purified by... hexose units and is manufactured as the sodium, potassium, or calcium salt. (b) The strain of...

  20. ESR spectroscopic properties of irradiated gum Arabic.

    PubMed

    Leonor, S J; Gómez, J A; Kinoshita, A; Calandreli, I; Tfouni, E; Baffa, O

    2013-12-01

    Electron spin resonance (ESR) spectra of irradiated gum Arabic with doses between 0.5 and 5 kGy were studied. A linear relationship between the absorbed dose and the intensities of the ESR spectra was observed. ESR spectra of irradiated gum Arabic showed a decay of relative concentrations of free radicals originated by radiation and the production of at least two species of free radicals with half-times: 3.3 and 125.4 h. The results of spectral simulations for these radical groups were giso=2.0046; A=1.2 mT and gx=gy=2.0062, gz=2.0025. Hydration and dehydration of irradiated gum Arabic returns the ESR spectrum to its initial state before irradiation. The results show that ESR can be used as simple and reliable method to detect irradiated gum Arabic up to 60 days after initial radiation with doses on the order of 5 kGy.

  1. Synergistic gel formation of xyloglucan/gellan mixtures as sudied by rheology, DSC, and circular dichroism.

    PubMed

    Nitta, Yoko; Kim, Bo S; Nishinari, Katsuyoshi; Shirakawa, Mayumi; Yamatoya, Kazuhiko; Oomoto, Toshio; Asai, Iwao

    2003-01-01

    The gelation behavior of mixtures of tamarind seed xyloglucan (TSX) and sodium form gellan (Na-G) was investigated. The storage and loss shear moduli, G' and G'', of the mixtures showed that a thermoreversible gel was obtained although each polysaccharide alone did not form a gel at experimental conditions. The viscoelastic behavior of the mixtures showed a gel formation of TSX and Na-G induced by synergistic interaction. This synergistic interaction was also revealed by differential scanning calorimetry (DSC) and circular dichroism. Although TSX alone did not show any peak in DSC curves, mixtures with only a small amount of Na-G, which by itself did not show any peak, showed a single peak. With increasing Na-G content, another peak began to appear at the same temperature at which a peak of Na-G alone appeared. Thermally induced changes in circular dichroism of the mixtures were different from those expected from the individual behavior of TSX and Na-G.

  2. The appearance of the Gum nebula

    NASA Technical Reports Server (NTRS)

    Bok, B. J.

    1971-01-01

    The dimensions of the Gum nebula complex appear to be overestimated. The distance of 460 parsecs to the central pulsar is rather on the large side, and likely contributions from gamma Velorum and zeta Puppis were underestimated. The multiorigin character of the Gum nebula is reaffirmed. The parts produced by traditional ultraviolet thermal radiation and by processes directly related to the supernova outburst must be defined.

  3. Hydrolytic fragmentation of seed gums under microwave irradiation.

    PubMed

    Singh, V; Tiwari, A

    2009-03-01

    The seed gum solutions of Ipomoea purga, Ipomoea palmata, Ipomoea dasysperma, Cyanaposis tetragonolobus (Guar gum) and Crotolaria medicaginea were microwave (MW) irradiated and their degradation to oligo and monosaccharides was investigated. The gum solutions were fragmented into oligosaccharides/constituent monosaccharides depending upon the length of MW exposure in presence of catalytic amount of mineral acid or even when no acid was used. A mechanism for the microwave induced hydrolytic degradation of the seed gums has been proposed. The MW exposure time required for the partial and complete degradation of the gums was found dependent on the types of the linkages and degree of the branching present in the gums.

  4. Medicated chewing gum, a novel drug delivery system

    PubMed Central

    Aslani, Abolfazl; Rostami, Farnaz

    2015-01-01

    New formulations and technologies have been developed through oral drug delivery systems’ researches. Such researches display significance of oral route amongst patients. We’ve reviewed all the features associated with medicated chewing gum as a modern drug delivery by introducing the history, advantages and disadvantages, methods of manufacturing, composition differences, evaluation tests and examples of varieties of medicated chewing gums. Acceptance of medicated chewing gum has been augmented through years. The advantages and therapeutic benefits of chewing gum support its development as we can see new formulations with new drugs contained have been produced from past and are going to find a place in market by formulation of new medicated chewing gums. Potential applications of medicated chewing gums are highly widespread as they will be recognized in future. Nowadays standards for qualifying chewing gums are the same as tablets. Patient-centered studies include medicated chewing gums as a delivery system too which creates compliance for patients. PMID:26109999

  5. More Evidence Ties Gum Health to Stroke Risk

    MedlinePlus

    ... 163755.html More Evidence Ties Gum Health to Stroke Risk Study shows increasing risk of brain blockage ... as people with healthy gums to suffer a stroke, new research suggests. It's not the first study ...

  6. Could a Germ Link Gum Disease, Rheumatoid Arthritis?

    MedlinePlus

    ... 162571.html Could a Germ Link Gum Disease, Rheumatoid Arthritis? Study may offer new insight into the cause ... the long-noticed connection between gum disease and rheumatoid arthritis, a new study suggests. The discovery might also ...

  7. Assessment of physical and structural characteristics of almond gum.

    PubMed

    Bashir, Mudasir; Haripriya, Sundaramoorthy

    2016-12-01

    Almond gum was investigated for its physical and structural characteristics in comparison to gum arabic. Among physical properties, bulk density was found to be 0.600±0.12g/mL and 0.502±0.20g/mL for almond and gum arabic respectively. Almond gum (0.820±0.13g/mL) displayed the maximum value for tapped density. Compressibility index of exudate gum powders varied from 26.79±1.47 to 37.46±0.50% and follow the order gum arabic>almond gum. Almond gum demonstrated good flow characteristics when compared to gum arabic. True density showed significant difference (p<0.05) among the exudate samples and it was recorded higher for gum arabic. The maximum value of porosity recorded in case of gum arabic indicates the presence of large number of interstitial spaces among its particles. Almond gum had fair flow character while good for the other exudate gum powder. Almond gum had relatively higher mineral content than gum arabic. The oil holding capacity of exudate gums varied from 0.87±0.05 to 0.92±0.02g/g. Exudate powder samples were found to lie in the first quadrant of the hue angle (0-90°) corresponding to the range of reddish-purple to yellow. The absence of peaks in the X-ray diffractograms of exudate samples reflects their amorphous nature. SEM micrographs revealed a lot of variability in shape and size of the exudate particles.

  8. Rheological Differences of Waxy Barley Flour Dispersions Mixed with Various Gums

    PubMed Central

    Kim, Chong-Yeon; Yoo, Byoungseung

    2017-01-01

    Rheological properties of waxy barley flour (WBF) dispersions mixed with various gums (carboxyl methyl celluleose, guar gum, gum arabic, konjac gum, locust bean gum, tara gum, and xanthan gum) at different gum concentrations were examined in steady and dynamic shear. WBF-gum mixture samples showed a clear trend of shear-thinning behavior and had a non-Newtonian nature with yield stress. Rheological tests indicated that the flow and dynamic rheological parameter (apparent viscosity, consistency index, yield stress, storage modulus, and loss modulus) values of WBF dispersions mixed with gums, except for gum arabic, were significantly higher than those of WBF with no gum, and also increased with an increase in gum concentration. In particular, konjac gum at 0.6% among other gums showed the highest rheological parameter values. Tan δ values of WBF-xanthan gum mixtures were lower than those of other gums, showing that there is a more pronounced synergistic effect on the elastic properties of WBF in the presence of xanthan gum. Such synergistic effect was hypothesized by considering thermodynamic compatibility between xanthan gum and WBF. These rheological results suggest that in the WBF-gum mixture systems, the addition of gums modified the flow and viscoelastic properties of WBF, and that these modifications were dependent on the type of gum and gum concentration.

  9. Acyl hydrolases from trans-AT polyketide synthases target acetyl units on acyl carrier proteins.

    PubMed

    Jenner, Matthew; Afonso, Jose P; Kohlhaas, Christoph; Karbaum, Petra; Frank, Sarah; Piel, Jörn; Oldham, Neil J

    2016-04-18

    Acyl hydrolase (AH) domains are a common feature of trans-AT PKSs. They have been hypothesised to perform a proofreading function by removing acyl chains from stalled sites. This study determines the substrate tolerance of the AH PedC for a range of acyl-ACPs. Clear preference towards short, linear acyl-ACPs is shown, with acetyl-ACP the best substrate. These results imply a more targeted housekeeping role for PedC: namely the removal of unwanted acetyl groups from ACP domains caused by erroneous transfer of acetyl-CoA, or possibly by decarboxylation of malonyl-ACP.

  10. 78 FR 43226 - Xanthan Gum From Austria and China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... COMMISSION Xanthan Gum From Austria and China Determinations On the basis of the record \\1\\ developed in the... with material injury by reason of imports from China of xanthan gum provided for in subheading 3913.90... imports from China of xanthan gum. Background The Commission instituted these investigations...

  11. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  12. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia siliqua (Linne), a leguminous...

  13. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  14. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  15. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  16. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  17. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  18. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  19. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  20. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  1. 7 CFR 160.7 - Gum spirits of turpentine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Gum spirits of turpentine. 160.7 Section 160.7... STANDARDS FOR NAVAL STORES General § 160.7 Gum spirits of turpentine. The designation “gum spirits of turpentine” shall refer to the kind of spirits of turpentine obtained by distillation of the oleoresin...

  2. Sugar substitutes, chewing gum and dental caries--a review.

    PubMed

    Edgar, W M

    1998-01-10

    The prevalent use of chewing gum has prompted interest in its dental effects. Important defining aspects are the ability to use sugar substitutes in gum manufacture and the prolonged stimulation of a protective flow of saliva. The main sugar substitutes used are sorbitol and xylitol. Because it is not fermented by oral bacteria, xylitol is considered to be non-cariogenic, and while sorbitol in solution can be fermented slowly by mutants streptococci, chewing sorbitol-sweetened gum does not cause a fall in plaque pH. Effects of chewing sugar-free gum on the ability of plaque to form acid from sucrose are equivocal, although the tendency is for the plaque acidogenicity to be reduced with the use of xylitol gum for 2-3 weeks, due to its inhibitory effects on mutants streptococci. Gum-chewing also stimulates a protective salivary flow when used after an acidogenic stimulus, and may enhance salivary function, especially in subjects with low flow rates. Sorbitol and xylitol gums have similar beneficial effects in promoting enamel remineralisation in short-term in-situ experiments. Clinical trials indicate that xylitol gum has a useful anticaries role, superior to the effects of sorbitol gum. In conclusion, both sorbitol and xylitol chewing gums are non-cariogenic in contrast to sugared gum, and exhibit beneficial anticaries properties through salivary stimulation. In addition, xylitol's antibacterial properties seem likely to lead to caries reductions superior to the more modest reductions with sorbitol gum.

  3. Biobased alternatives to guar gum as tackifiers for hydromulch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guar gum, obtained from guar [Cyamopsis tetragonoloba (L.) Taub.] seeds, is currently the principal gum used as a tackifier (binder) for hydraulically-applied mulches (hydromulches) used in erosion control. The oil industry’s increased use of guar gum in hydraulic fracturing together with lower glo...

  4. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food....780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried gummy exudate from stems and branches of trees...

  5. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the...

  6. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food... Other Specific Usage Additives § 172.780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried...

  7. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the dried gummy exudate from stems...

  8. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic)...

  9. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic)...

  10. 21 CFR 184.1330 - Acacia (gum arabic).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acacia (gum arabic). 184.1330 Section 184.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic)...

  11. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food... Other Specific Usage Additives § 172.780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried...

  12. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acacia (gum arabic). 172.780 Section 172.780 Food... Other Specific Usage Additives § 172.780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried...

  13. 21 CFR 172.780 - Acacia (gum arabic).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acacia (gum arabic). 172.780 Section 172.780 Food... Other Specific Usage Additives § 172.780 Acacia (gum arabic). The food additive may be safely used in food in accordance with the following prescribed conditions: (a) Acacia (gum arabic) is the dried...

  14. Compositional analysis and rheological properties of gum kondagogu (Cochlospermum gossypium): a tree gum from India.

    PubMed

    Vinod, V T P; Sashidhar, R B; Sarma, V U M; Vijaya Saradhi, U V R

    2008-03-26

    Gum kondagogu ( Cochlospermum gossypium) is a tree exudate gum that belongs to the family Bixaceae. Compositional analysis of the gum by HPLC and LC-MS revealed uronic acids to be the major component of the polymer ( approximately 26 mol %). Furthermore, analysis of the gum by GC-MS indicated the presence of sugars such as arabinose (2.52 mol %), mannose (8.30 mol %), alpha- d-glucose (2.48 mol %), beta- d-glucose (2.52 mol %), rhamnose (12.85 mol %), galactose (18.95 mol %), d-glucuronic acid (19.26 mol %), beta- d-galactouronic acid (13.22 mol %), and alpha- d-galacturonic acid (11.22 mol %). Gum kondagogu, being rich in rhamnose, galactose, and uronic acids, can be categorized on the basis of its sugar composition as a rhamnogalacturonan type of gum. The rheological measurements performed on the gum suggest that above 0.6% (w/v) it shows a Newtonian behavior and shear rate thinning behavior as a function of gum concentration. The viscoelastic behavior of gum kondagogu solutions (1 and 2%) in aqueous as well as in 100 mM NaCl solution exhibits a typical gel-like system. The G' (viscous modulus)/ G'' (elastic modulus) ratios of native gum kondagogu (1 and 2%) in aqueous solution were found to be 1.89 and 1.85 and those in 100 mM NaCl to be 1.54 and 2.2, respectively, suggesting a weak gel-like property of the polymer. Crossover values of G' and G'' were observed to be at frequencies of 0.432 Hz for 1% and 1.2 Hz for 2% for native gum in aqueous condition, indicating a predominantly liquid- to solid-like behavior, whereas crossover values of 2.1 Hz for 1% and 1.68 Hz for 2% gum in 100 mM NaCl solution suggest a larger elastic contribution.

  15. Fatty acyl-CoA reductase

    SciTech Connect

    Reiser, Steven E.; Somerville, Chris R.

    1998-12-01

    The present invention relates to bacterial enzymes, in particular to an acyl-CoA reductase and a gene encoding an acyl-CoA reductase, the amino acid and nucleic acid sequences corresponding to the reductase polypeptide and gene, respectively, and to methods of obtaining such enzymes, amino acid sequences and nucleic acid sequences. The invention also relates to the use of such sequences to provide transgenic host cells capable of producing fatty alcohols and fatty aldehydes.

  16. The size and shape of Gum's nebula

    NASA Technical Reports Server (NTRS)

    Johnson, H. M.

    1971-01-01

    The ionizing light of the supernova which produced the Gum nebula is now fossilized in the still live, though failing, H II region. The main body of the nebula suggests a hollow center or shell form, with a characteristic radius of about half the distance to the outlying fragments. The edges of the main body patches are typically sharp and often bright. The structure of the Gum nebula appears to be dependent on the event of ionization and possibly on the details of heating. It is not now an unstructured ambient medium, as it may have been before the recent ionization. Several hypotheses are presented for a structured ambient medium.

  17. The Gum Nebula and Related Problems

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Proceedings of a symposium concerning the Gum Nebula (GN) and related topics are reported. Papers presented include: Colin Gum and the discovery of the GN; identification of the GN as the fossil Stromgren sphere of Vela X Supernova; size and shape of GN; formation of giant H-2 regions following supernova explosions; radio astronomy Explorer 1 observations of GN; cosmic ray effects in the GN; low intensity H beta emission from the interstellar medium; and how to recognize and analyze GN. Astronomical charts and diagrams are included.

  18. Design, formulation and evaluation of caffeine chewing gum

    PubMed Central

    Aslani, Abolfazl; Jalilian, Fatemeh

    2013-01-01

    Background: Caffeine which exists in drinks such as coffee as well as in drug dosage forms in the global market is among the materials that increase alertness and decrease fatigue. Compared to other forms of caffeine, caffeine gum can create faster and more prominent effects. In this study, the main goal is to design a new formulation of caffeine gum with desirable taste and assess its physicochemical properties. Materials and Methods: Caffeine gum was prepared by softening of gum bases and then mixing with other formulation ingredients. To decrease the bitterness of caffeine, sugar, aspartame, liquid glucose, sorbitol, manitol, xylitol, and various flavors were used. Caffeine release from gum base was investigated by mechanical chewing set. Content uniformity test was also performed on the gums. The gums were evaluated in terms of organoleptic properties by the Latin-Square design at different stages. Results: After making 22 formulations of caffeine gums, F11 from 20 mg caffeine gums and F22 from 50 mg caffeine gums were chosen as the best formulation in organoleptic properties. Both types of gum released about 90% of their own drug content after 30 min. Drug content of 20 and 50 mg caffeine gum was about 18.2-21.3 mg and 45.7-53.6 mg respectively. Conclusion: In this study, 20 and 50 mg caffeine gums with suitable and desirable properties (i.e., good taste and satisfactory release) were formulated. The best flavor for caffeine gum was cinnamon. Both kinds of 20 and 50 mg gums succeeded in content uniformity test. PMID:24223387

  19. 21 CFR 184.1333 - Gum ghatti.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (total). Not more than 6.0 percent; (iv) Heavy metals (as Pb). Not more than 40 parts per million (0.004... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Gum ghatti. 184.1333 Section 184.1333 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT...

  20. 21 CFR 184.1333 - Gum ghatti.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... than 1.75 percent; (iii) Ash (total). Not more than 6.0 percent; (iv) Heavy metals (as Pb). Not more... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Gum ghatti. 184.1333 Section 184.1333 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  1. 21 CFR 184.1333 - Gum ghatti.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... than 1.75 percent; (iii) Ash (total). Not more than 6.0 percent; (iv) Heavy metals (as Pb). Not more... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Gum ghatti. 184.1333 Section 184.1333 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  2. 21 CFR 184.1333 - Gum ghatti.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... than 1.75 percent; (iii) Ash (total). Not more than 6.0 percent; (iv) Heavy metals (as Pb). Not more... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Gum ghatti. 184.1333 Section 184.1333 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  3. 21 CFR 184.1333 - Gum ghatti.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... than 1.75 percent; (iii) Ash (total). Not more than 6.0 percent; (iv) Heavy metals (as Pb). Not more... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Gum ghatti. 184.1333 Section 184.1333 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  4. Relationships Between Gum-Chewing and Stress.

    PubMed

    Konno, Michiyo; Takeda, Tomotaka; Kawakami, Yoshiaki; Suzuki, Yoshihiro; Kawano, Yoshiaki; Nakajima, Kazunori; Ozawa, Takamitsu; Ishigami, Keiichi; Takemura, Naohiro; Sakatani, Kaoru

    2016-01-01

    Studies have shown that chewing is thought to affect stress modification in humans. Also, studies in animals have demonstrated that active chewing of a wooden stick during immobilization stress ameliorates the stress-impaired synaptic plasticity and prevents stress-induced noradrenaline release in the amygdala. On the other hand, studies have suggested that the right prefrontal cortex (PFC) dominates the regulation of the stress response system, including the hypothalamic-pituitary-adrenal (HPA) axis. The International Affective Digitized Sounds-2 (IADS) is widely used in the study of emotions and neuropsychological research. Therefore, in this study, the effects of gum-chewing on physiological and psychological (including PFC activity measured by NIRS) responses to a negative stimulus selected from the IADS were measured and analyzed. The study design was approved by the Ethics Committee of Tokyo Dental College (No. 436). We studied 11 normal adults using: cerebral blood oxygenation in the right medial PFC by multi-channel NIRS; alpha wave intensity by EEG; autonomic nervous function by heart rate; and emotional conditions by the State-Trait Anxiety Inventory (STAI) test and the 100-mm visual analogue scale (VAS). Auditory stimuli selected were fewer than 3.00 in Pleasure value. Sounds were recorded in 3 s and reproduced at random using software. Every task session was designed in a block manner; seven rests: Brown Noise (30 s) and six task blocks: auditory stimuli or auditory stimuli with gum-chewing (30 s). During the test, the participants' eyes were closed. Paired Student's t-test was used for the comparison (P<0.05). Gum-chewing showed a significantly greater activation in the PFC, alpha wave appearance rate and HR. Gum-chewing also showed a significantly higher VAS score and a smaller STAI level indicating 'pleasant'. Gum-chewing affected physiological and psychological responses including PFC activity. This PFC activation change might influence the HPA axis

  5. ROMPgel beads in IRORI format: acylations revisited.

    PubMed

    Roberts, Richard S

    2005-01-01

    Functionalized "designer" polymers derived from ring-opening metathesis polymerization (ROMPgels) are attractive for their high loading, high purity, and ease of synthesis. Their physical state may vary from liquid to gel to granular solid, making a general method of handling these polymers difficult. By incorporating a suitable norbornene-substituted linker on standard Wang beads, ROMPgels can be easily grafted onto the resin, adding the convenience of a bead format while still maintaining the high loading and excellent site accessibility. This advantage is demonstrated by the use of an N-hydroxysuccinimide ROMPgel (3.3 mmol g(-1), a 3-fold increase from the parent linker resin) in IRORI Kan format. Conditions for the acylation of these IRORI-formatted ROMPgels are reported, along with the scope and limitations of the choice of acylating reagents. Yields are greatly improved by the use of perfluorinated solvents as a nonparticipating cosolvent in the acylation process. A simple titration method for the quantification of the acylated ROMPgels is also reported. Spent Kans are regenerated after each use without apparent loss of activity or purity after several cycles. Due to the high loading and reduced swelling of the ROMPgel resin, up to 0.39 mmol acyl group has successfully been recovered from a single IRORI miniKan, demonstrating the high capacity of the resin and applicability to both lead discovery and optimization programs.

  6. Effect of GutsyGum(tm), A Novel Gum, on Subjective Ratings of Gastro Esophageal Reflux Following A Refluxogenic Meal.

    PubMed

    Brown, Rachel; Sam, Cecilia H Y; Green, Tim; Wood, Simon

    2015-06-01

    Chewing gum alleviates symptoms of gastro-esophageal reflux (GER) following a refluxogenic meal. GutsyGum(tm), a chewing gum developed to alleviate the symptoms of GER contains calcium carbonate, with a proprietary blend of licorice extract, papain, and apple cider vinegar (GiGs®). The efficacy of GutsyGum(tm) was determined in alleviating the symptoms of GER after a refluxogenic meal compared to placebo gum. This double-blind, placebo-controlled-crossover trial with a one-week washout between treatments had 24 participants with a history of GER consume a refluxogenic meal and then chew GutsyGum(tm) or placebo gum. Participants completed GER symptom questionnaires, consisting of symptom based 10 cm Visual Analogue Scales, immediately following the meal and then at regular intervals out to four hours postmeal. Adjusted mean ± SEM heartburn score (15-min postmeal to 240 min) was significantly lower in GutsyGum(tm) than in placebo gum treatment (0.81 ± 0.20 vs. 1.45 ± 0.20 cm; p = 0.034). Mean acid reflux score was significantly lower in GutsyGum(tm) than in placebo treatment (0.72 ± 0.19 vs. 1.46 ± 0.19 cm; p = 0.013). There were no significant differences for any of the secondary outcomes. However, pain approached significance with less pain reported in GutsyGum(tm) versus placebo treatment (0.4 ± 0.2 vs. 0.9 ± 0.2 cm; p = 0.081). Although nausea (p = 0.114) and belching (p = 0.154) were lower following GutsyGum(tm), the difference was not statistically significant. GutsyGum(tm) is more effective than a placebo gum in alleviating primary symptoms of heartburn and acid reflux (Clinical Trial Registration: ACTRN12612000973819).

  7. Effects of the conjugation of whey proteins with gellan polysaccharides on surfactant-induced competitive displacement from the air-water interface.

    PubMed

    Cai, B; Ikeda, S

    2016-08-01

    Whey proteins can be used to stabilize foams and emulsions against coalescence because of their ability to form viscoelastic films at the interface that resist film rupture on collision between colloidal particles. However, whey proteins are competitively displaced from the interface if small-molecule surfactants are added, leading to destabilization of the entire system. This is because surfactants are more effective in molecular packing at the interface, and they lower interfacial tension to a greater degree than whey proteins do, but their interfacial films are poor in viscoelasticity. We hypothesized that whey proteins would become more resistant to surfactant-induced competitive displacement if they were conjugated with network-forming polysaccharides. The protein moiety of the conjugate would be expected to enable its adsorption to the interface, and the polysaccharide moiety would be expected to form self-assembled networks, strengthening the interfacial film as a whole. In this study, whey proteins were conjugated with gellan polysaccharides using the Maillard reaction. Atomic force microscopy images of interfacial films formed by the whey protein-gellan conjugate at the air-water interface and transferred onto mica sheets using the Langmuir-Blodgett method revealed that gellan did form self-assembled networks at the interface and that interfacial films also contained a large number of unconjugated whey protein molecules. Following the addition of a small-molecule surfactant (Tween 20) to the sub-phase, surface pressure increased, indicating spontaneous adsorption of surfactants to the interface. Atomic force microscopy images showed decreases in interfacial area coverage by whey proteins as surface pressure increased. At a given surface pressure, the interfacial area coverage by whey protein-gellan conjugates was greater than coverage by unconjugated whey proteins, confirming that whey proteins became more resistant to surfactant-induced displacement after

  8. An association between temporomandibular disorder and gum chewing.

    PubMed

    Correia, Diana; Real Dias, Maria Carlos; Castanho Moacho, Antonio; Crispim, Pedro; Luis, Henrique; Oliveira, Miguel; Carames, Joao

    2014-01-01

    This single center, randomized, small study sought to investigate the prevalence and frequency of chewing gum consumption, and whether there is a relationship between these factors and the presence of symptoms associated with temporomandibular disorder (TMD). Subjects were divided into 7 groups based on their parafunctional oral habits. Of these, subjects who chewed gum were divided into 5 subgroups (A-E) based on their gum chewing habits. Group A chewed gum <1 hour/day (n = 12), Group B chewed gum 1-2 hours/day (n = 11), Group C chewed gum 3 hours/day (n = 6), and Group D chewed gum >3 hours at a time (n = 8); the frequency of gum chewing in Groups A-D was once a week. Group E subjects chewed gum 1-3 times/week for at least 1 hour each occurrence (n = 2). Sixty-three percent of the subjects in Group D reported TMD symptoms of arthralgia and myofascial pain. Thirty-three percent of the subjects in Group C showed symptoms of arthralgia. Eighty-three percent of the subjects in Group A and 27% in Group B reported myofascial pain. All subjects in Group E reported masseter hypertrophy. The remaining 2 groups were Group F, subjects that didn't chew gum but had other parafunctional oral habits (n = 2), and Group G, subjects who didn't have parafunctional oral habits (n = 12).

  9. In silico prediction of acyl glucuronide reactivity

    NASA Astrophysics Data System (ADS)

    Potter, Tim; Lewis, Richard; Luker, Tim; Bonnert, Roger; Bernstein, Michael A.; Birkinshaw, Timothy N.; Thom, Stephen; Wenlock, Mark; Paine, Stuart

    2011-11-01

    Drugs and drug candidates containing a carboxylic acid moiety, including many widely used non-steroidal anti-inflammatory drugs (NSAIDs) are often metabolized to form acyl glucuronides (AGs). NSAIDs such as Ibuprofen are amongst the most widely used drugs on the market, whereas similar carboxylic acid drugs such as Suprofen have been withdrawn due to adverse events. Although the link between these AG metabolites and toxicity is not proven, there is circumstantial literature evidence to suggest that more reactive acyl glucuronides may, in some cases, present a greater risk of exhibiting toxic effects. We wished therefore to rank the reactivity of potential new carboxylate-containing drug candidates, and performed kinetic studies on synthetic acyl glucuronides to benchmark our key compounds. Driven by the desire to quickly rank the reactivity of compounds without the need for lengthy synthesis of the acyl glucuronide, a correlation was established between the degradation half-life of the acyl glucuronide and the half life for the hydrolysis of the more readily available methyl ester derivative. This finding enabled a considerable broadening of chemical property space to be investigated. The need for kinetic measurements was subsequently eliminated altogether by correlating the methyl ester hydrolysis half-life with the predicted 13C NMR chemical shift of the carbonyl carbon together with readily available steric descriptors in a PLS model. This completely in silico prediction of acyl glucuronide reactivity is applicable within the earliest stages of drug design with low cost and acceptable accuracy to guide intelligent molecular design. This reactivity data will be useful alongside the more complex additional pharmacokinetic exposure and distribution data that is generated later in the drug discovery process for assessing the overall toxicological risk of acidic drugs.

  10. Acyl-coenzyme A:cholesterol acyltransferases

    PubMed Central

    Chang, Ta-Yuan; Li, Bo-Liang; Chang, Catherine C. Y.; Urano, Yasuomi

    2009-01-01

    The enzymes acyl-coenzyme A (CoA):cholesterol acyltransferases (ACATs) are membrane-bound proteins that utilize long-chain fatty acyl-CoA and cholesterol as substrates to form cholesteryl esters. In mammals, two isoenzymes, ACAT1 and ACAT2, encoded by two different genes, exist. ACATs play important roles in cellular cholesterol homeostasis in various tissues. This chapter summarizes the current knowledge on ACAT-related research in two areas: 1) ACAT genes and proteins and 2) ACAT enzymes as drug targets for atherosclerosis and for Alzheimer's disease. PMID:19141679

  11. Acyl silicates and acyl aluminates as activated intermediates in peptide formation on clays

    NASA Technical Reports Server (NTRS)

    White, D. H.; Kennedy, R. M.; Macklin, J.

    1984-01-01

    Glycine reacts with heating on dried clays and other minerals to give peptides in much better yield than in the absence of mineral. This reaction was proposed to occur by way of an activated intermediate such as an acyl silicate or acyl aluminate analogous to acyl phosphates involved in several biochemical reactions including peptide bond synthesis. The proposed mechanism has been confirmed by trapping the intermediate, as well as by direct spectroscopic observation of a related intermediate. The reaction of amino acids on periodically dried mineral surfaces represents a widespead, geologically realistic setting for prebiotic peptide formation via in situ activation.

  12. Acyl anion free N-heterocyclic carbene organocatalysis.

    PubMed

    Ryan, Sarah J; Candish, Lisa; Lupton, David W

    2013-06-21

    Reaction discovery using N-heterocyclic carbene organocatalysis has been dominated by the chemistry of acyl anion equivalents. Recent studies demonstrate that NHCs are far more diverse catalysts, with a variety of reactions discovered that proceed without acyl anion equivalent formation. In this tutorial review selected examples of acyl anion free NHC catalysis using carbonyl compounds are presented.

  13. Direct photography of the Gum Nebula

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Roosen, R. G.; Thompson, J.; Ludden, D. J.

    1976-01-01

    The paper discusses a series of wide-angle photographs taken of the Gum Nebula in the traditional region including H-alpha with the aid of a 40-cm and an 80-cm lens in both the red and the green. The photographs support the large dimensions (75 deg in galactic longitude by 40 deg in galactic latitude) of the Gum Nebula suggested earlier, and the appearance is consistent with an origin due to photons from a supernova outburst. The relatively high-density gas has cooled and is visible on the red plates. The low-density gas has remained at a high temperature and may be visible as diffuse emission on the green plates.

  14. [Effect of chewing sugar-free gum on dental caries].

    PubMed

    Szóke, Judit; Proskin, Howard M; Bánóczy, Jolán

    2002-02-01

    Previous in vivo studies have demonstrated that chewing sugar-free gum after eating reduces the development of dental caries. To investigate the extrapolation of these findings, a two-year clinical study was conducted on 547 schoolchildren in Budapest. Subjects in the "gum" (test) group were instructed to chew one stick of commercially available sorbitol-sweetened chewing gum for 15-20 minutes after meals, three times daily. The "control" group was not provided with chewing gum. After two years, excluding white spots, the "gum" group exhibited a 38.7% caries increment reduction compared to the "control" group. Including white spots, a corresponding 33.1% reduction was indicated. These results clearly suggest that even in a population with moderate caries prevalence and normal oral hygiene habits (including the use of fluoride dentifrices), an after-meal gum chewing regimen can significantly reduce the rate of caries development.

  15. The Gum nebula and related problems

    NASA Technical Reports Server (NTRS)

    Maran, S. P.; Brandt, J. C.; Stecher, T. P.

    1971-01-01

    Papers were presented in conference sessions on the Gum nebula, the Vela X remnant, the hot stars gamma Velorum and zeta Puppis, the B associations in the Vela-Puppis complex, and pulsars. Ground-based optical and radio astronomy; rocket and satellite observations in the radio, visible, ultraviolet, and X-ray regions; and theoretical problems in the physical state of the interstellar medium, stellar evolution, and runaway star dynamics were considered.

  16. Validating the applicability of the GUM procedure

    NASA Astrophysics Data System (ADS)

    Cox, Maurice G.; Harris, Peter M.

    2014-08-01

    This paper is directed at practitioners seeking a degree of assurance in the quality of the results of an uncertainty evaluation when using the procedure in the Guide to the Expression of Uncertainty in Measurement (GUM) (JCGM 100 : 2008). Such assurance is required in adhering to general standards such as International Standard ISO/IEC 17025 or other sector-specific standards. We investigate the extent to which such assurance can be given. For many practical cases, a measurement result incorporating an evaluated uncertainty that is correct to one significant decimal digit would be acceptable. Any quantification of the numerical precision of an uncertainty statement is naturally relative to the adequacy of the measurement model and the knowledge used of the quantities in that model. For general univariate and multivariate measurement models, we emphasize the use of a Monte Carlo method, as recommended in GUM Supplements 1 and 2. One use of this method is as a benchmark in terms of which measurement results provided by the GUM can be assessed in any particular instance. We mainly consider measurement models that are linear in the input quantities, or have been linearized and the linearization process is deemed to be adequate. When the probability distributions for those quantities are independent, we indicate the use of other approaches such as convolution methods based on the fast Fourier transform and, particularly, Chebyshev polynomials as benchmarks.

  17. Acylated pregnane glycosides from Caralluma russeliana.

    PubMed

    Abdel-Sattar, Essam; Ahmed, Ahmed A; Hegazy, Mohamed-Elamir F; Farag, Mohamed A; Al-Yahya, Mohammad Abdul-Aziz

    2007-05-01

    The chloroform extract of the aerial parts of Caralluma russeliana yielded four acylated pregnane glycosides, namely russeliosides E-H, three were found now. The structures of the compounds were elucidated using MS, 1H NMR, 13C NMR, 1H-1H COSY, HMQC, NOESY and HMBC experiments.

  18. Quantification and Qualification of Bacteria Trapped in Chewed Gum

    PubMed Central

    Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.

    2015-01-01

    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-chewed into gum and chewed gums were molded to standard dimensions, sonicated and plated to determine numbers of colony-forming-units incorporated, yielding calibration curves of colony-forming-units retrieved versus finger-chewed in. In a second method, calibration curves were created by finger-chewing known numbers of bacteria into gum and subsequently dissolving the gum in a mixture of chloroform and tris-ethylenediaminetetraacetic-acid (TE)-buffer. The TE-buffer was analyzed using quantitative Polymerase-Chain-Reaction (qPCR), yielding calibration curves of total numbers of bacteria versus finger-chewed in. Next, five volunteers were requested to chew gum up to 10 min after which numbers of colony-forming-units and total numbers of bacteria trapped in chewed gum were determined using the above methods. The qPCR method, involving both dead and live bacteria yielded higher numbers of retrieved bacteria than plating, involving only viable bacteria. Numbers of trapped bacteria were maximal during initial chewing after which a slow decrease over time up to 10 min was observed. Around 108 bacteria were detected per gum piece depending on the method and gum considered. The number of species trapped in chewed gum increased with chewing time. Trapped bacteria were clearly visualized in chewed gum using scanning-electron-microscopy. Summarizing, using novel methods to quantify and qualify oral bacteria trapped in chewed gum, the hypothesis is confirmed that chewing of gum can trap

  19. Quantification and qualification of bacteria trapped in chewed gum.

    PubMed

    Wessel, Stefan W; van der Mei, Henny C; Morando, David; Slomp, Anje M; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J

    2015-01-01

    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-chewed into gum and chewed gums were molded to standard dimensions, sonicated and plated to determine numbers of colony-forming-units incorporated, yielding calibration curves of colony-forming-units retrieved versus finger-chewed in. In a second method, calibration curves were created by finger-chewing known numbers of bacteria into gum and subsequently dissolving the gum in a mixture of chloroform and tris-ethylenediaminetetraacetic-acid (TE)-buffer. The TE-buffer was analyzed using quantitative Polymerase-Chain-Reaction (qPCR), yielding calibration curves of total numbers of bacteria versus finger-chewed in. Next, five volunteers were requested to chew gum up to 10 min after which numbers of colony-forming-units and total numbers of bacteria trapped in chewed gum were determined using the above methods. The qPCR method, involving both dead and live bacteria yielded higher numbers of retrieved bacteria than plating, involving only viable bacteria. Numbers of trapped bacteria were maximal during initial chewing after which a slow decrease over time up to 10 min was observed. Around 10(8) bacteria were detected per gum piece depending on the method and gum considered. The number of species trapped in chewed gum increased with chewing time. Trapped bacteria were clearly visualized in chewed gum using scanning-electron-microscopy. Summarizing, using novel methods to quantify and qualify oral bacteria trapped in chewed gum, the hypothesis is confirmed that chewing of gum can trap

  20. Acylation of the Type 3 Secretion System Translocon Using a Dedicated Acyl Carrier Protein

    PubMed Central

    Agrebi, Rym; Canestrari, Mickaël J.; Mignot, Tâm; Lebrun, Régine; Bouveret, Emmanuelle

    2017-01-01

    Bacterial pathogens often deliver effectors into host cells using type 3 secretion systems (T3SS), the extremity of which forms a translocon that perforates the host plasma membrane. The T3SS encoded by Salmonella pathogenicity island 1 (SPI-1) is genetically associated with an acyl carrier protein, IacP, whose role has remained enigmatic. In this study, using tandem affinity purification, we identify a direct protein-protein interaction between IacP and the translocon protein SipB. We show, by mass spectrometry and radiolabelling, that SipB is acylated, which provides evidence for a modification of the translocon that has not been described before. A unique and conserved cysteine residue of SipB is identified as crucial for this modification. Although acylation of SipB was not essential to virulence, we show that this posttranslational modification promoted SipB insertion into host-cell membranes and pore-forming activity linked to the SPI-1 T3SS. Cooccurrence of acyl carrier and translocon proteins in several γ- and β-proteobacteria suggests that acylation of the translocon is conserved in these other pathogenic bacteria. These results also indicate that acyl carrier proteins, known for their involvement in metabolic pathways, have also evolved as cofactors of new bacterial protein lipidation pathways. PMID:28085879

  1. Molar absorptivity and color characteristics of acylated and non-acylated pelargonidin-based anthocyanins.

    PubMed

    Giusti, M M; Rodríguez-Saona, L E; Wrolstad, R E

    1999-11-01

    The effects of glycosylation and acylation on the spectral characteristics, molar absorptivity, and color attributes of purified acylated and non-acylated pelargonidin derivatives were compared. Pigments were obtained from strawberries, radishes, red-fleshed potatoes, and partially hydrolyzed radish pigments. Individual pigments were isolated by using semipreparative HPLC. Spectral and color (CIELch) attributes of purified pigments were measured. Molar absorptivity ranged from 15 600 to 39 590 for pelargonidin-3-glucoside (pg-3-glu) and pg-3-rutinoside-5-glucoside acylated with p-coumaric acid, respectively. The presence of cinnamic acid acylation had a considerable impact on spectral and color characteristics, causing a bathochromic shift of lambda(max). Sugar substitution also played an important role, with a hypsochromic shift caused by the presence of glycosylation. Pg-3, 5-diglu and pg-3,5-triglu possessed a higher hue angle (>40 degrees ) than the other pg derivatives at pH 1.0, corresponding to the yellow-orange region of the color solid. Acylation with malonic acid did not affect lambda(max) and showed little effect on color characteristics. The solvent system had an effect not only on the molar absorptivity, but also on the visual color characteristic of the pigments.

  2. Immunological and functional properties of the exudate gum from northwestern Mexican mesquite (Prosopis spp.) in comparison with gum arabic.

    PubMed

    Goycoolea, F M; Calderón de la Barca, A M; Balderrama, J R; Valenzuela, J R

    1997-08-01

    A comparison between the fine structural features of exudate gum from mesquite (Prosopis spp.) indigenous to NW Mexico and commercial gum arabic from Acacia spp. was achieved by means of immunological techniques. Their functional properties were compared from the ability to form oil-in-water emulsions and encapsulate cold press orange peel essential oil by spray drying. Fine comparison of the antigenic compounds in both materials against polyclonal rabbit antibodies, showed that the carbohydrate-rich components with slow mobility of mesquite gum are closely related to the faster ones of gum arabic. Also, close identity was observed for the components in the proteic fraction of both gums. Similar tannin concentrations were found in both materials (approximately 0.43%) with only dark coloured samples bearing higher amounts (approximately 1.9%). Gum arabic retained nearly 100% of the quantity of orange peel essential oil emulsified in water before spray drying, while mesquite gum did so for 90.6% of the citrus oil. From these results it is believed that mesquite gum might be a suitable replacement of gum arabic in arid regions of the world were Prosopis trees have widespread occurrence.

  3. A chewing gum containing 7.5% sodium hexametaphosphate inhibits stain deposition compared with a placebo chewing gum.

    PubMed

    Biesbrock, Aaron R; Walters, Patricia; Bartizek, Robert D

    2004-04-01

    The 2-period, randomized, double-blind, placebo-controlled, crossover study compared the stain-prevention and stain-removal benefit of a chewing gum containing 7.5% sodium hexametaphosphate (measured by digital image analysis) with a placebo chewing gum. The results of this study support that sodium hexametaphosphate delivered from a chewing gum prevents dental stain formation and facilitates stain removal, which leads to a perceptible whitening benefit. The long-term clinical benefits of sodium hexametaphosphate delivered from chewing gum have not been reported in the literature.

  4. Effect of gums on the rheological characteristics and microstructure of acid-induced SPI-gum mixed gels.

    PubMed

    Chang, Yuan-Yuan; Li, Dong; Wang, Li-Jun; Bi, Chong-Hao; Adhikari, Benu

    2014-08-08

    The effect of addition of xanthan gum (XG) and guar gum (GG) on the rheological properties and microstructure of glucono-δ-lactone induced soy protein isolate (SPI)-XG gels and SPI-GG gels was investigated using steady and dynamic rheological tests, creep-recovery and confocal laser scanning microscopy (CLSM). Results showed that the apparent viscosity of SPI-gum (XG, GG) mixed solutions increased with the increase in the gum (XG, GG) concentration. The storage (G') and loss (G″) moduli of SPI-gum (XG, GG) mixed gels increased in the presence and increase in the gum (XG, GG) concentration. The Burger's model fitted the creep recovery data well (R(2)>0.919) and showed that both the instantaneous and equilibrium (retarded) elastic components of this model increased with the increase in SPI and gum concentrations. The proportion occupied by gum in mixed gels was found to increase with the increase in the concentration of gums which increased the density of protein aggregates in the mixed gels.

  5. Head-group acylation of monogalactosyldiacylglycerol is a common stress response, and the acyl-galactose acyl composition varies with the plant species and applied stress.

    PubMed

    Vu, Hieu Sy; Roth, Mary R; Tamura, Pamela; Samarakoon, Thilani; Shiva, Sunitha; Honey, Samuel; Lowe, Kaleb; Schmelz, Eric A; Williams, Todd D; Welti, Ruth

    2014-04-01

    Formation of galactose-acylated monogalactosyldiacylglycerols has been shown to be induced by leaf homogenization, mechanical wounding, avirulent bacterial infection and thawing after snap-freezing. Here, lipidomic analysis using mass spectrometry showed that galactose-acylated monogalactosyldiacylglycerols, formed in wheat (Triticum aestivum) and tomato (Solanum lycopersicum) leaves upon wounding, have acyl-galactose profiles that differ from those of wounded Arabidopsis thaliana, indicating that different plant species accumulate different acyl-galactose components in response to the same stress. Additionally, the composition of the acyl-galactose component of Arabidopsis acMGDG (galactose-acylated monogalactosyldiacylglycerol) depends on the stress treatment. After sub-lethal freezing treatment, acMGDG contained mainly non-oxidized fatty acids esterified to galactose, whereas mostly oxidized fatty acids accumulated on galactose after wounding or bacterial infection. Compositional data are consistent with acMGDG being formed in vivo by transacylation with fatty acids from digalactosyldiacylglycerols. Oxophytodienoic acid, an oxidized fatty acid, was more concentrated on the galactosyl ring of acylated monogalactosyldiacylglycerols than in galactolipids in general. Also, oxidized fatty acid-containing acylated monogalactosyldiacylglycerols increased cumulatively when wounded Arabidopsis leaves were wounded again. These findings suggest that, in Arabidopsis, the pool of galactose-acylated monogalactosyldiacylglycerols may serve to sequester oxidized fatty acids during stress responses.

  6. Characterization and in vitro drug release studies of a natural polysaccharide Terminalia catappa gum (Badam gum).

    PubMed

    Meka, Venkata Srikanth; Nali, Sreenivasa Rao; Songa, Ambedkar Sunil; Kolapalli, Venkata Ramana Murthy

    2012-12-01

    The main objective of the present study is the physicochemical characterization of naturally available Terminalia catappa gum (Badam gum [BG]) as a novel pharmaceutical excipient and its suitability in the development of gastroretentive floating drug delivery systems (GRFDDS) to retard the drug for 12 h when the dosage form is exposed to gastrointestinal fluids in the gastric environment. As BG was being explored for the first time for its pharmaceutical application, physicochemical, microbiological, rheological, and stability studies were carried out on this gum. In the present investigation, the physicochemical properties, such as micromeritic, rheological, melting point, moisture content, pH, swelling index, water absorption, and volatile acidity, were evaluated. The gum was characterized by scanning electron microscopy, differential scanning calorimetry (DSC), powder X-ray diffraction studies (PXRD), and Fourier transform infrared spectroscopy (FTIR). Gastroretentive floating tablets of BG were prepared with the model drug propranolol HCl by direct compression methods. The prepared tablets were evaluated for all their physicochemical properties, in vitro buoyancy, in vitro drug release, and rate order kinetics. PBG 04 was selected as an optimized formulation based on its 12-h drug release and good buoyancy characteristics. The optimized formulation was characterized with FTIR, DSC, and PXRD studies, and no interaction between the drug and BG was found. Thus, the study confirmed that BG might be used in the gastroretentive drug delivery system as a release-retarding polymer.

  7. Gum Sensor: A Stretchable, Wearable, and Foldable Sensor Based on Carbon Nanotube/Chewing Gum Membrane.

    PubMed

    Darabi, Mohammad Ali; Khosrozadeh, Ali; Wang, Quan; Xing, Malcolm

    2015-12-02

    Presented in this work is a novel and facile approach to fabricate an elastic, attachable, and cost-efficient carbon nanotube (CNT)-based strain gauge which can be efficiently used as bodily motion sensors. An innovative and unique method is introduced to align CNTs without external excitations or any complicated procedure. In this design, CNTs are aligned and distributed uniformly on the entire chewing gum by multiple stretching and folding technique. The current sensor is demonstrated to be a linear strain sensor for at least strains up to 200% and can detect strains as high as 530% with a high sensitivity ranging from 12 to 25 and high durability. The gum sensor has been used as bodily motion sensors, and outstanding results are achieved; the sensitivity is quite high, capable of tracing slow breathing. Since the gum sensor can be patterned into various forms, it has wide applications in miniaturized sensors and biochips. Interestingly, we revealed that our gum sensor has the ability to monitor humidity changes with high sensitivity and fast resistance response capable of monitoring human breathing.

  8. The identification of Combretum gums which are not permitted food additives, II.

    PubMed

    Anderson, D M; Morrison, N A

    1990-01-01

    Combretum gums, readily available at low prices in East and West Africa, may be offered for sale as 'gum arabic'. Vigilance is necessary to detect such misrepresentations because Combretum gums differ greatly from gum arabic (Acacia senegal (L.) Willd.) in terms of quality, solution properties and value. Moreover, because there is no toxicological evidence for their safety in use, Combretum gums are not included in any of the international lists of permitted food additives. Food manufacturers and regulatory authorities therefore require data that characterize Combretum gums so that their use in foodstuffs can be prevented. This paper presents such data for the gums from a further six Combretum species. All of these have negative optical rotations similar to that of food grade gum arabic. It is no longer sufficient, therefore, to rely solely on an optical rotation measurement to confirm the identity of gum arabic. The additional analyses necessary to differentiate between Combretum gums and gum arabic are discussed.

  9. 77 FR 43857 - Xanthan Gum From Austria and China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-26

    ... COMMISSION Xanthan Gum From Austria and China Determinations On the basis of the record \\1\\ developed in the... Austria and China of xanthan gum, provided for in subheading 3913.90.20 of the Harmonized Tariff Schedule... and China. Accordingly, effective June 5, 2012, the Commission instituted antidumping...

  10. [Constituents of essential oil of imported myrrh and gum opoponax].

    PubMed

    Tian, J; Shi, S

    1996-04-01

    The constitutents of essential oil in two kinds of Myrrha were analyzed by GC-MS. Fifteen compounds in Myrrh and thirty-three compounds in Gum opoponax were identified with their percent contents given. The main constituent of Myrrh is furanoeudesma-1,3-diene, and the main constituent of Gum opoponax is beta-trans-ocimene.

  11. Deformation Mechanisms of Gum Metals Under Nanoindentation

    NASA Astrophysics Data System (ADS)

    Sankaran, Rohini Priya

    Gum Metal is a set of multi-component beta-Ti alloys designed and developed by Toyota Central R&D Labs in 2003 to have a nearly zero shear modulus in the direction. After significant amounts of cold-work (>90%), these alloys were found to have yield strengths at a significant fraction of the predicted ideal strengths and exhibited very little work hardening. It has been speculated that this mechanical behavior may be realized through an ideal shear mechanism as opposed to conventional plastic deformation mechanisms, such as slip, and that such a mechanism may be realized through a defect structure termed "nanodisturbance". It is furthermore theorized that for near ideal strength to be attained, dislocations need to be pinned at sufficiently high stresses. It is the search for these defects and pinning points that motivates the present study. However, the mechanism of plastic deformation and the true origin of specific defect structures unique to gum metals is still controversial, mainly due to the complexity of the beta-Ti alloy system and the heavily distorted lattice exhibited in cold worked gum metals, rendering interpretation of images difficult. Accordingly, the first aim of this study is to clarify the starting as-received microstructures of gum metal alloys through conventional transmission electron microscopy (TEM) and aberration-corrected high resolution scanning transmission electron microscopy with high-angle annular dark field detector (HAADF-HRSTEM) imaging. To elucidate the effects of beta-stability and starting microstructure on the deformation behavior of gum metals and thus to provide adequate context for potentially novel deformation structures, we investigate three alloy conditions: gum metal that has undergone solution heat treatment (STGM), gum metal that has been heavily cold worked (CWGM), and a solution treated alloy of nominal gum metal composition, but leaner in beta-stabilizing content (ST Ref-1). In order to directly relate observed

  12. Acyl glucuronides: the good, the bad and the ugly.

    PubMed

    Regan, Sophie L; Maggs, James L; Hammond, Thomas G; Lambert, Craig; Williams, Dominic P; Park, B Kevin

    2010-10-01

    Acyl glucuronidation is the major metabolic conjugation reaction of most carboxylic acid drugs in mammals. The physiological consequences of this biotransformation have been investigated incompletely but include effects on drug metabolism, protein binding, distribution and clearance that impact upon pharmacological and toxicological outcomes. In marked contrast, the exceptional but widely disparate chemical reactivity of acyl glucuronides has attracted far greater attention. Specifically, the complex transacylation and glycation reactions with proteins have provoked much inconclusive debate over the safety of drugs metabolised to acyl glucuronides. It has been hypothesised that these covalent modifications could initiate idiosyncratic adverse drug reactions. However, despite a large body of in vitro data on the reactions of acyl glucuronides with protein, evidence for adduct formation from acyl glucuronides in vivo is limited and potentially ambiguous. The causal connection of protein adduction to adverse drug reactions remains uncertain. This review has assessed the intrinsic reactivity, metabolic stability and pharmacokinetic properties of acyl glucuronides in the context of physiological, pharmacological and toxicological perspectives. Although numerous experiments have characterised the reactions of acyl glucuronides with proteins, these might be attenuated substantially in vivo by rapid clearance of the conjugates. Consequently, to delineate a relationship between acyl glucuronide formation and toxicological phenomena, detailed pharmacokinetic analysis of systemic exposure to the acyl glucuronide should be undertaken adjacent to determining protein adduct concentrations in vivo. Further investigation is required to ascertain whether acyl glucuronide clearance is sufficient to prevent covalent modification of endogenous proteins and consequentially a potential immunological response.

  13. Multiple acyl-CoA dehydrogenation deficiency as decreased acyl-carnitine profile in serum.

    PubMed

    Wen, Bing; Li, Duoling; Li, Wei; Zhao, Yuying; Yan, Chuanzhu

    2015-06-01

    We report a case with late onset riboflavin-responsive multiple acyl-CoA dehydrogenation deficiency (MADD) characterized by decreased acyl-carnitine profile in serum which is consistent with primary systemic carnitine deficiency (CDSP) while just the contrary to a typical MADD. This patient complained with muscle weakness, muscle pain and intermittent vomiting, and was diagnosed as polymyositis, received prednisone therapy before consulted with us. Muscle biopsy revealed mild lipid storage. The findings of serum acyl-carnitines were consistent with CDSP manifesting as decreased free and total carnitines in serum. But oral L-carnitine supplementation was not very effective to this patient and mutation analysis of the SLC22A5 gene for CDSP was normal. Later, another acyl-carnitine analysis revealed a typical MADD profile in serum, which was characterized by increased multiple acyl-carnitines. Compound heterozygous mutations were identified in electron transferring-flavoprotein dehydrogenase (ETFDH) gene which confirmed the diagnosis of MADD. After administration of riboflavin, he improved dramatically, both clinically and biochemically. Thus, late onset riboflavin-responsive MADD should be included in the differential diagnosis for adult carnitine deficiency.

  14. Fatty Acyl Chains of Mycobacterium marinum Lipooligosaccharides

    PubMed Central

    Rombouts, Yoann; Alibaud, Laeticia; Carrère-Kremer, Séverine; Maes, Emmanuel; Tokarski, Caroline; Elass, Elisabeth; Kremer, Laurent; Guérardel, Yann

    2011-01-01

    We have recently established the fine structure of the glycan backbone of lipooligosaccharides (LOS-I to LOS-IV) isolated from Mycobacterium marinum, a close relative of Mycobacterium tuberculosis. These studies culminated with the description of an unusual terminal N-acylated monosaccharide that confers important biological functions to LOS-IV, such as macrophage activation, that may be relevant to granuloma formation. It was, however, also suggested that the lipid moiety was required for LOSs to exert their immunomodulatory activity. Herein, using highly purified LOSs from M. marinum, we have determined through a combination of mass spectrometric and NMR techniques, the structure and localization of the fatty acids composing the lipid moiety. The occurrence of two distinct polymethyl-branched fatty acids presenting specific localizations is consistent with the presence of two highly related polyketide synthases (Pks5 and Pks5.1) in M. marinum and presumably involved in the synthesis of these fatty acyl chains. In addition, a bioinformatic search permitted us to identify a set of enzymes potentially involved in the biosynthesis or transfer of these lipids to the LOS trehalose unit. These include MMAR_2343, a member of the Pap (polyketide-associated protein) family, that acylates trehalose-based glycolipids in M. marinum. The participation of MMAR_2343 to LOS assembly was demonstrated using a M. marinum mutant carrying a transposon insertion in the MMAR_2343 gene. Disruption of MMAR_2343 resulted in a severe LOS breakdown, indicating that MMAR_2343, hereafter designated PapA4, fulfills the requirements for LOS acylation and assembly. PMID:21803773

  15. Microbead design for sustained drug release using four natural gums.

    PubMed

    Odeku, Oluwatoyin A; Okunlola, Adenike; Lamprecht, Alf

    2013-07-01

    Four natural gums, namely albizia, cissus, irvingia and khaya gums have been characterized and evaluated as polymers for the formulation of microbeads for controlled delivery of diclofenac sodium. The natural gums were characterized for their material properties using standard methods. Diclofenac microbeads were prepared by ionotropic gelation using gel blends of the natural gums and sodium alginate at different ratios and zinc chloride solution (10%w/v) as the crosslinking agent. The microbeads were assessed using SEM, swelling characteristics, drug entrapment efficiencies and release properties. Data obtained from in vitro dissolution studies were fitted to various kinetic equations to determine the kinetics and mechanisms of drug release, and the similarity factor, f2, was used to compare the different formulations. The results showed that the natural gum polymers varied considerably in their material properties. Spherical and discrete microbeads with particle size of 1.48-2.41 μm were obtained with entrapment efficiencies of 44.0-71.3%w/w. Drug release was found to depend on the type and concentration of polymer gum used with formulations containing gum:alginate ratio of 3:1 showing the highest dissolution times. Controlled release of diclofenac was obtained over for 5h. Drug release from the beads containing the polymer blends of the four gums and sodium alginate fitted the Korsmeyer-Peppas model which appeared to be dependent on the nature of natural gum in the polymer blend while the beads containing alginate alone fitted the Hopfenberg model. Beads containing albizia and cissus had comparable release profiles to those containing khaya (f2>50). The results suggest that the natural gums could be potentially useful for the formulation controlled release microbeads.

  16. 21 CFR 201.319 - Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not limited to...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya... including, but not limited to, agar, alginic acid, calcium polycarbophil, carboxymethylcellulose...

  17. 21 CFR 201.319 - Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not limited to...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya... including, but not limited to, agar, alginic acid, calcium polycarbophil, carboxymethylcellulose...

  18. 21 CFR 201.319 - Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not limited to...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya... including, but not limited to, agar, alginic acid, calcium polycarbophil, carboxymethylcellulose...

  19. 21 CFR 201.319 - Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not limited to...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya... including, but not limited to, agar, alginic acid, calcium polycarbophil, carboxymethylcellulose...

  20. 21 CFR 201.319 - Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not limited to...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya..., carboxymethylcellulose sodium, carrageenan, chondrus, glucomannan ((B-1,4 linked) polymannose acetate), guar gum, karaya... active ingredients; required warnings and directions. (a) Reports in the medical literature and...

  1. Effects of basil seed gum, Cress seed gum and Quince seed gum on the physical, textural and rheological properties of whipped cream.

    PubMed

    Farahmandfar, Reza; Asnaashari, Maryam; Salahi, Mohammad Reza; Khosravi Rad, Tandis

    2017-05-01

    This study focuses on the physical, textural and rheological properties of low fat (LF) whipped cream with 30% fat content developed with Basil seed gum (BSG), Cress seed gum (CSG) and Quince seed gum (QSG) at the concentration of 0.1 and 0.3% (w/w) and comparison with high fat (HF) whipped cream sample (55%) as control. Flow curves were analyzed using Herschel bulkey and Carreau models through a fitting procedure. The rheological investigations confirmed that all samples were shear thinning fluid exhibiting a yield stress and thixotropy properties. The frequency sweep test showed that at the same gum concentration, mixes containing BSG have higher G', G″ and η(*) than those of mixes with QSG and CSG, and all mixes containing gum displayed weak gel-like behavior. Analysis showed that adding and increasing gums concentration caused to increased viscosity, hardness and overrun, leading to a better quality in the final products. Moreover, textural properties showed that the effect of BSG on hardness and adhesiveness was significantly greater than QSG and CSG at the same concentration. Based on obtained result, 0.3% concentration of added BSG had a much greater effects on the whipped cream properties than those of mixes with QSG and CSG.

  2. Physiological Consequences of Compartmentalized Acyl-CoA Metabolism*

    PubMed Central

    Cooper, Daniel E.; Young, Pamela A.; Klett, Eric L.; Coleman, Rosalind A.

    2015-01-01

    Meeting the complex physiological demands of mammalian life requires strict control of the metabolism of long-chain fatty acyl-CoAs because of the multiplicity of their cellular functions. Acyl-CoAs are substrates for energy production; stored within lipid droplets as triacylglycerol, cholesterol esters, and retinol esters; esterified to form membrane phospholipids; or used to activate transcriptional and signaling pathways. Indirect evidence suggests that acyl-CoAs do not wander freely within cells, but instead, are channeled into specific pathways. In this review, we will discuss the evidence for acyl-CoA compartmentalization, highlight the key modes of acyl-CoA regulation, and diagram potential mechanisms for controlling acyl-CoA partitioning. PMID:26124277

  3. The rheological properties of tara gum (Caesalpinia spinosa).

    PubMed

    Wu, Yanbei; Ding, Wei; Jia, Lirong; He, Qiang

    2015-02-01

    The rheological properties of tara gum, as affected by concentration, temperature, pH and the presence of salts and sucrose, were investigated by using steady and dynamic shear measurements and atomic force microscope observation. Tara gum exhibited non-Newtonian, pseudoplastic behaviour without thixotropy at tested concentrations (0.2-1.0%, w/v). Salts (CaCl2 and NaCl) led to a viscosity reduction, which was more sensitive to Ca(2+) than to Na(+). The gum had stable viscosity over a wide pH range (pH 3-11), and the influence of sucrose was concentration dependent. Increasing temperature from 20°C to 80°C decreased the gum viscosity. Frequency sweeps indicated that tara gum (1.0% w/v) behaved as a liquid at low frequency, and acted more like a gel at high frequency. With the decrease of concentration, tara gum may show a viscous property rather than an elastic one. These results are potentially useful for the application of tara gum in food processing.

  4. Effect of Angum gum in combination with tragacanth gum on rheological and sensory properties of ketchup.

    PubMed

    Komeilyfard, Ahmadreza; Fazel, Mohammad; Akhavan, Hamidreza; Mousakhani Ganjeh, Alireza

    2017-04-01

    The aim of this study was to evaluate the effect of Angum gum (AnG) alone and in combination with tragacanth gum (TG) on the stability, texture, sensory, and rheological properties of tomato ketchup. AnG, TG, and Angum gum and tragacanth gum mixture (AnGT; 1:1 ratio) were added at levels of 0.5, 1, and 1.5%. Ten tomato ketchup formulations were produced: control (without hydrocolloid), AnG (0.5-1.5%), TG (0.5-1.5%), AnGT (0.5-1.5%). It was observed that the hydrocolloids addition to tomato ketchup significantly decreased the Bostwick consistency value and serum separation at 2200, 5000, and 8800 g. Textural properties of tomato ketchup by using back extrusion test and particle size analysis were significantly increased with hydrocolloid addition. All tomato ketchup formulations showed shear thinning behavior and the addition of hydrocolloids increased apparent viscosity. The power law and Herschel-Bulkley models were successfully fitted with experimental data. The flow behavior indices of Herschel-Bulkley and power law models were changed in the range of 0.19-0.24 and 0.14-0.30, respectively. The consistency coefficients of these models were in the range of 16.31-79.57 and 11.19-146.06 Pa s(n) , respectively. The storage modulus (G') of all tomato ketchups was higher than the loss modulus (G″). Hydrocolloid addition showed no significant effect on the color indices (L*, a*, b*, hue angle, chroma, and total color differences) of tomato ketchup. The overall acceptability of 1.5% AnG, 0.5% TG, 1 and 1.5% AnGT were significantly higher than other samples. Therefore, AnG can be used alone and in combination with TG as stabilizer in tomato ketchup.

  5. Bactericidal activity of Pistacia lentiscus mastic gum against Helicobacter pylori.

    PubMed

    Marone, P; Bono, L; Leone, E; Bona, S; Carretto, E; Perversi, L

    2001-12-01

    In this study we evaluated the antibacterial activity of mastic gum, a resin obtained from the Pistacia lentiscus tree, against clinical isolates of Helicobacter pylori. The minimal bactericidal concentrations (MBCs) were obtained by a microdilution assay. Mastic gum killed 50% of the strains tested at a concentration of 125 microg/ml and 90% at a concentration of 500 microg/ml. The influence of sub-MBCs of mastic gum on the morphologies of H. pylori was evaluated by transmission electron microscopy. The lentiscus resin induced blebbing, morphological abnormalities and cellular fragmentation in H. pylori cells.

  6. In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva

    PubMed Central

    Moore, Michael; Hasler-Nguyen, Nathalie; Saroea, Geoffrey

    2008-01-01

    Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B) on stain removal in an in vitro experiment, when compared with a confectionary whitening chewing gum (C) and human saliva (D). Methods Bovine incisors were stained by alternating air exposure and immersion in a broth containing natural pigments such as coffee, tea and oral microorganisms for 10 days. Stained enamel samples were exposed to saliva alone or to the test chewing gums under conditions simulating human mastication. The coloration change of the enamel samples was measured using a spectrophotometer. Measurements were obtained for each specimen (average of three absorbances) using the L*a*b scale: lightness (L*), red-green (a) and yellow-blue (b). Results Medicated chewing gums (A and B) removed a greater amount of visible extrinsic stain, while the confectionary chewing gum with a whitening claim (C) had a milder whitening effect as evaluated by quantitative and qualitative assessment. Conclusion The tested Nicotine Replacement Therapy (NRT) chewing gums were more effective in the removal of the extrinsic tooth stain. This visible improvement in tooth whitening appearance could strengthen the smokers' motivation to quit smoking. PMID:18694488

  7. What do GUM physicians think should be taught in a modern undergraduate GUM module? A qualitative inquiry.

    PubMed

    Fernando, I

    2015-10-01

    Traditional undergraduate Genitourinary Medicine (GUM) teaching in the UK concentrated on the management of individual sexually transmitted infections. There is significant variation, however, in the GUM teaching provided by different medical schools today. I undertook a qualitative interview study to gather views of GUM and other sexual health clinicians regarding what should be taught within a modern undergraduate GUM module. Nine GUM clinicians and two Sexual and Reproductive Health (SRH) clinicians participated in the study; all were directly involved in undergraduate teaching. Semi-structured interviews were conducted with study participants by a single interviewer, focusing on three key topics: their individual opinions regarding important learning outcomes (LOs) for a modern model GUM curriculum, their preferred teaching methods and the total recommended teaching time required. Interviews were audio-recorded with consent and professionally transcribed. Data were analysed by the content analysis method. Interviewees frequently stressed skill and attitudinal LOs, even above knowledge. Recommended important skills included sexual history taking, HIV risk assessment and testing, and male and female genital examination. Recommended attitudinal LOs were developing an open and non-judgemental approach to sexual health issues and understanding sexual well-being to be an important component of general health. Respondents were keen for a mixture of teaching methods, but generally agreed that clinic attendance and experiential learning were beneficial. They preferred that GUM teaching should be delivered in the latter years of the undergraduate curriculum.

  8. Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed.

    PubMed

    Cahoon, E B; Coughlan, S J; Shanklin, J

    1997-04-01

    A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1delta9)* and cis-vaccenic (18:1delta11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed delta9 desaturation of acyl-ACP substrates, and the recombinant enzyme exhibited seven- to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known delta9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized delta9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a delta9-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

  9. Acyl-acyl carrier protein as a source of fatty acids for bacterial bioluminescence

    SciTech Connect

    Byers, D.M.; Meighen, E.A.

    1985-09-01

    Pulse-chase experiments with (/sup 3/H)tetradecanoic acid and ATP showed that the bioluminescence-related 32-kDa acyltransferase from Vibrio harveyi can specifically catalyze the deacylation of a /sup 3/H-labeled 18-kDa protein observed in extracts of this bacterium. The 18-kDa protein has been partially purified and its physical and chemical properties strongly indicate that it is fatty acyl-acyl carrier protein (acyl-ACP). Both this V. harveyi (/sup 3/H)acylprotein and (/sup 3/H)palmitoyl-ACP from Escherichia coli were substrates in vitro for either the V. harveyi 32-kDa acyltransferase or the analogous enzyme (34K) from Photobacterium phosphoreum. TLC analysis indicated that the hexane-soluble product of the reaction is fatty acid. No significant cleavage of either E. coli or V. harveyi tetradecanoyl-ACP was observed in extracts of these bacteria unless the 32-kDa or 34K acyltransferase was present. Since these enzymes are believed to be responsible for the supply of fatty acids for reduction to form the aldehyde substrate of luciferase, the above results suggest that long-chain acyl-ACP is the source of fatty acids for bioluminescence.

  10. Acylated flavonol glycoside from Platanus orientalis.

    PubMed

    Tantry, Mudasir A; Akbar, Seema; Dar, Javid A; Irtiza, Syed; Galal, Ahmed; Khuroo, Mohammad A; Ghazanfar, Khalid

    2012-03-01

    The ethylacetate and n-butanol fractions of ethanolic extract of Platanus orientalis leaves led to the isolation of new acylated flavonol glycoside as 3',5,7-trihydroxy-4'-methoxyflavonol 3-[O-2-O-(2,4-Dihydroxy)-E-cinnamoyl-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl (1→2)]-β-D-glucopyranoside, along with seven known compounds. All the compounds were characterized by NMR including 2D NMR techniques. The isolates were evaluated for NF-κB, nitric oxide (NO), aromatase and QR2 chemoprevention activities and some of them appeared to be modestly active.

  11. Oxidation and Gum Formation in Diesel Fuels.

    DTIC Science & Technology

    2014-09-26

    AD A157 41@ OX<IDATION AND GUM FORMATION IN DIESEL FUELS(U) SRI i/i INTERNATIONAL MENLO PARK CA CHEMISTRY LAB F R MAYO 0MAY 85 ARO-2i65 2-EG DRA29-84...A333 Ravenswood Ave., Menlo Park, CA 94025 11. CONTROLLING OFFICE NAMIE AND ADDRESS 12. REPORT OATS U. S. Army Research Office May 3, 1985 Post Office...0e ’-’’ŕ %m. Ř P 0I 0 Da Ř a 0 0 C; C4 C4 𔃾 0 000 00 -e -0 It@ ~~~9 %a ca 04 0I 4%D ’ t. X0 .0 .~ .0.9 .9.A A .0 ... 0 A 00. Z f%4~ 8 0 ; 4 a N

  12. Evaluation of a Treatment Approach Combining Nicotine Gum with Self-Guided Behavioral Treatments for Smoking Relapse Prevention.

    ERIC Educational Resources Information Center

    Killen, Joel D.; And Others

    1990-01-01

    Randomly assigned 1,218 smokers to cells in 4 (nicotine gum delivered ad lib, fixed regimen nicotine gum, placebo gum, no gum) x 3 (self-selected relapse prevention modules, randomly administered modules, no modules) design. Subjects receiving nicotine gum were more likely to be abstinent at 2- and 6-month followups. Fixed regimen accounted for…

  13. A patient with congenital hypertrichosis, gum hyperplasia and macromastia.

    PubMed

    Sood, A; Garg, R K; Saily, R; Dash, R J

    2000-05-01

    A syndrome of congenital hypertrichosis, hirsutism, gum hyperplasia and macromastia is described. The patient was demonstrated to have mild hyperinsulinemia with normal oral glucose tolerance test. This is the second such patient reported in the literature.

  14. Ask a Periodontist (Frequently Asked Questions about Gum Disease)

    MedlinePlus

    ... Teeth Oral Hygiene Habits and Hypertension Risk Alcohol Consumption and Gum Health Workshop on Regeneration Periodontal Disease More Prevalent among Ethnic Minorities Dental Implants Periodontal Health and Diabetes Periodontal ...

  15. Use of Natural Gums and Mucilages as Pharmaceutical Excipients.

    PubMed

    Hamman, Hannlie; Steenekamp, Jan; Hamman, Josias

    2015-01-01

    Polysaccharide rich gums and mucilages are produced by different natural sources such as plants, animals and microbial organisms to fulfil structural and physiological functions. Their diverse structural compositions with a broad range of physicochemical properties make them useful for inclusion in dosage forms for different purposes such as to improve manufacturing processes and/or to facilitate drug delivery. A number of natural gums and mucilages have been investigated for inclusion in pharmaceutical formulations for a variety of reasons. The search for new excipients continues to be an active topic in dosage form design and drug delivery research. The aim of this review article is to give an overview of the chemical nature of natural gums and mucilages and to discuss their applications in the formulation of pharmaceutical dosage forms. Special emphasis will be placed on the use of gums and mucilages in novel drug delivery systems, such as modified release dosage forms and delivery systems that target specific sites of delivery.

  16. Progress toward Understanding Protein S-acylation: Prospective in Plants.

    PubMed

    Li, Yaxiao; Qi, Baoxiu

    2017-01-01

    S-acylation, also known as S-palmitoylation or palmitoylation, is a reversible post-translational lipid modification in which long chain fatty acid, usually the 16-carbon palmitate, covalently attaches to a cysteine residue(s) throughout the protein via a thioester bond. It is involved in an array of important biological processes during growth and development, reproduction and stress responses in plant. S-acylation is a ubiquitous mechanism in eukaryotes catalyzed by a family of enzymes called Protein S-Acyl Transferases (PATs). Since the discovery of the first PAT in yeast in 2002 research in S-acylation has accelerated in the mammalian system and followed by in plant. However, it is still a difficult field to study due to the large number of PATs and even larger number of putative S-acylated substrate proteins they modify in each genome. This is coupled with drawbacks in the techniques used to study S-acylation, leading to the slower progress in this field compared to protein phosphorylation, for example. In this review we will summarize the discoveries made so far based on knowledge learnt from the characterization of protein S-acyltransferases and the S-acylated proteins, the interaction mechanisms between PAT and its specific substrate protein(s) in yeast and mammals. Research in protein S-acylation and PATs in plants will also be covered although this area is currently less well studied in yeast and mammalian systems.

  17. Progress toward Understanding Protein S-acylation: Prospective in Plants

    PubMed Central

    Li, Yaxiao; Qi, Baoxiu

    2017-01-01

    S-acylation, also known as S-palmitoylation or palmitoylation, is a reversible post-translational lipid modification in which long chain fatty acid, usually the 16-carbon palmitate, covalently attaches to a cysteine residue(s) throughout the protein via a thioester bond. It is involved in an array of important biological processes during growth and development, reproduction and stress responses in plant. S-acylation is a ubiquitous mechanism in eukaryotes catalyzed by a family of enzymes called Protein S-Acyl Transferases (PATs). Since the discovery of the first PAT in yeast in 2002 research in S-acylation has accelerated in the mammalian system and followed by in plant. However, it is still a difficult field to study due to the large number of PATs and even larger number of putative S-acylated substrate proteins they modify in each genome. This is coupled with drawbacks in the techniques used to study S-acylation, leading to the slower progress in this field compared to protein phosphorylation, for example. In this review we will summarize the discoveries made so far based on knowledge learnt from the characterization of protein S-acyltransferases and the S-acylated proteins, the interaction mechanisms between PAT and its specific substrate protein(s) in yeast and mammals. Research in protein S-acylation and PATs in plants will also be covered although this area is currently less well studied in yeast and mammalian systems. PMID:28392791

  18. Understanding Acyl Chain and Glycerolipid Metabolism in Plants

    SciTech Connect

    Ohlrogge, John B.

    2013-11-05

    Progress is reported in these areas: acyl-editing in initial eukaryotic lipid assembly in soybean seeds; identification and characterization of two Arabidopsis thaliana lysophosphatidyl acyltransferases with preference for lysophosphatidylethanolamine; and characterization and subcellular distribution of lysolipid acyl transferase activity of pea leaves.

  19. Characterization of the "Escherichia Coli" Acyl Carrier Protein Phosphodiesterase

    ERIC Educational Resources Information Center

    Thomas, Jacob

    2009-01-01

    Acyl carrier protein (ACP) is a small essential protein that functions as a carrier of the acyl intermediates of fatty acid synthesis. ACP requires the posttranslational attachment of a 4'phosphopantetheine functional group, derived from CoA, in order to perform its metabolic function. A Mn[superscript 2+] dependent enzymatic activity that removes…

  20. Design, formulation and evaluation of green tea chewing gum

    PubMed Central

    Aslani, Abolfazl; Ghannadi, Alireza; Khalafi, Zeinab

    2014-01-01

    Background: The main purpose of this study is to design, formulate and evaluate the green tea gums with a suitable taste and quality in order to produce an anti-oxidant chewing gum. Materials and Methods: Fresh green tea leaves obtained from Northern Iran for extraction. Maceration is the extraction method that is used in this study. The contents of caffeine, catechin and flavonoids of the hydro alcoholic extract were measured. Various formulations of the 120 mg green tea extract chewing gums with different sweeteners, flavoring agents and various gum bases were prepared afterward release pattern, content uniformity, organoleptic results and other properties were characterized. Results: The contents of caffeine, catechin and flavonoid of the hydro alcoholic extraction were 207.32 mg/g, 130.00 mg/g and 200.82 mg/g, respectively. Release pattern of green tea chewing gum with different gum base ratios and various sweeteners in phosphate buffer were prepared. A total of 60 persons who were 20-30 years of age, participated in our panel test for organoleptic properties such as taste, stiffness, stickiness, etc., Acceptable gum was the one with the same ratio of the used rubber bases. Cinnamon selected as the preferred taste by volunteers. Combination of aspartame, sugar and maltitol has appropriate taste. The effect of various sweetener on release pattern was negligible, on the other hand rubber bases ratio variation, changed the release pattern obviously. Conclusion: The green tea chewing gum with sugar, maltitol and aspartame sweeteners and cinnamon flavor, using the same rubber bases ratio may be a desirable antioxidant product. PMID:25161989

  1. Natural polymers, gums and mucilages as excipients in drug delivery.

    PubMed

    Kumar, Shobhit; Gupta, Satish Kumar

    2012-01-01

    Use of natural polymers, gums and mucilages in drug delivery systems has been weighed down by the synthetic materials. Natural based excipients offered advantages such as non-toxicity, less cost and abundantly availablity. Aqueous solubility of natural excipients plays an important role in their selection for designing immediate, controlled or sustained release formulations. This review article provide an overview of natural gum, polymers and mucilages as excipients in dosage forms as well as novel drug delivery systems.

  2. Acyl peptidic siderophores: structures, biosyntheses and post-assembly modifications.

    PubMed

    Kem, Michelle P; Butler, Alison

    2015-06-01

    Acyl peptidic siderophores are produced by a variety of bacteria and possess unique amphiphilic properties. Amphiphilic siderophores are generally produced in a suite where the iron(III)-binding headgroup remains constant while the fatty acid appendage varies by length and functionality. Acyl peptidic siderophores are commonly synthesized by non-ribosomal peptide synthetases; however, the method of peptide acylation during biosynthesis can vary between siderophores. Following biosynthesis, acyl siderophores can be further modified enzymatically to produce a more hydrophilic compound, which retains its ferric chelating abilities as demonstrated by pyoverdine from Pseudomonas aeruginosa and the marinobactins from certain Marinobacter species. Siderophore hydrophobicity can also be altered through photolysis of the ferric complex of certain β-hydroxyaspartic acid-containing acyl peptidic siderophores.

  3. GumTree—An integrated scientific experiment environment

    NASA Astrophysics Data System (ADS)

    Lam, Tony; Hauser, Nick; Götz, Andy; Hathaway, Paul; Franceschini, Fredi; Rayner, Hugh; Zhang, Lidia

    2006-11-01

    GumTree is an open source and multi-platform graphical user interface for performing neutron scattering and X-ray experiments. It handles the complete experiment life cycle from instrument calibration, data acquisition, and real time data analysis to results publication. The aim of the GumTree Project is to create a highly Integrated Scientific Experiment Environment (ISEE), allowing interconnectivity and data sharing between different distributed components such as motors, detectors, user proposal database and data analysis server. GumTree is being adapted to several instrument control server systems such as TANGO, EPICS and SICS, providing an easy-to-use front-end for users and simple-to-extend model for software developers. The design of GumTree is aimed to be reusable and configurable for any scientific instrument. GumTree will be adapted to six neutron beam instruments for the OPAL reactor at ANSTO. Other European institutes including ESRF, ILL and PSI have shown interest in using GumTree as their workbench for instrument control and data analysis.

  4. Chewing gum and impasse-induced self-reported stress.

    PubMed

    Torney, Laura K; Johnson, Andrew J; Miles, Christopher

    2009-12-01

    An insoluble anagram task [Zellner, D., Loaiza, S., Gonzalez, Z., Pita, J., Morales, J., Pecora, D., et al. (2006). Food selection changes under stress. Physiology and Behaviour, 87, 789-793] was used to investigate the proposition that chewing gum reduces self-rated stress [Scholey, A., Haskell, C., Robertson, B., Kennedy, D., Milne, A., & Wetherell, M. (2009). Chewing gum alleviates negative mood and reduces cortisol during acute laboratory psychological stress. Physiology and Behaviour, 97, 304-312]. Using a between-participants design, 40 participants performed an insoluble anagram task followed by a soluble anagram task. These tasks were performed with or without chewing gum. Self-rated measures were taken at baseline, post-stressor, and post-recovery task. The insoluble anagram task was found to amplify stress in terms of increases in self-rated stress and reductions in both self-rated calmness and contentedness. However, chewing gum was found not to mediate the level of stress experienced. Furthermore, chewing gum did not result in superior performance on the soluble anagram task. The present study fails to generalise the findings of Scholey et al. to an impasse-induced stress that has social components. The explanation for the discrepancy with Scholey et al. is unclear; however, it is suggested that the impossibility of the insoluble anagram task may negate any secondary stress reducing benefits arising from chewing gum-induced task improvement.

  5. Effect of guar and xanthan gums on functional properties of mango (Mangifera indica) kernel starch.

    PubMed

    Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Hasnain, Abid

    2016-12-01

    The effects of different concentrations of guar and xanthan gums on functional properties of mango kernel starch (MKS) were studied. Both guar and xanthan gum enhanced the water absorption of MKS. The addition of xanthan gum appeared to reduce the SP (swelling power) and solubility at higher temperatures while guar gum significantly enhanced the SP as well as solubility of MKS. The addition of both gums produced a reinforcing effect on peak viscosity of MKS as compared to control. Pasting temperature of MKS was higher than that of starch modified by gums indicating ease of gelatinization. Guar gum played an accelerative effect on setback but xanthan gum delayed the setback phenomenon during the cooling of the starch paste. Both gums were found to be effective in reducing the syneresis while gel firmness was markedly improved.

  6. Application of cashew tree gum on the production and stability of spray-dried fish oil.

    PubMed

    Botrel, Diego Alvarenga; Borges, Soraia Vilela; Fernandes, Regiane Victória de Barros; Antoniassi, Rosemar; de Faria-Machado, Adelia Ferreira; Feitosa, Judith Pessoa de Andrade; de Paula, Regina Celia Monteiro

    2017-04-15

    Evaluation of cashew gum compared to conventional materials was conducted regarding properties and oxidative stability of spray-dried fish oil. Emulsions produced with cashew gum showed lower viscosity when compared to Arabic gum. The particle size was larger (29.9μm) when cashew gum was used, and the encapsulation efficiency reached 76%, similar to that of modified starch but higher than that for Arabic gum (60%). The oxidation process for the surface oil was conducted and a relative lower formation of oxidation compounds was observed for the cashew gum treatment. GAB model was chosen to describe the moisture adsorption isotherm behaviours. Microparticles produced using Arabic and cashew gums showed greater water adsorption when exposed to higher relative humidities. Microparticles produced using cashew gum were more hygroscopic however encapsulation efficiency were higher and surface oil oxidation were less pronounced. Cashew gum can be further explored as an encapuslant material for spray drying processes.

  7. Acyl-CoA binding proteins: multiplicity and function.

    PubMed

    Gossett, R E; Frolov, A A; Roths, J B; Behnke, W D; Kier, A B; Schroeder, F

    1996-09-01

    The physiological role of long-chain fatty acyl-CoA is thought to be primarily in intermediary metabolism of fatty acids. However, recent data show that nM to microM levels of these lipophilic molecules are potent regulators of cell functions in vitro. Although long-chain fatty acyl-CoA are present at several hundred microM concentration in the cell, very little long-chain fatty acyl-CoA actually exists as free or unbound molecules, but rather is bound with high affinity to membrane lipids and/or proteins. Recently, there is growing awareness that cytosol contains nonenzymatic proteins also capable of binding long-chain fatty acyl-CoA with high affinity. Although the identity of the cytosolic long-chain fatty acyl-CoA binding protein(s) has been the subject of some controversy, there is growing evidence that several diverse nonenzymatic cytosolic proteins will bind long-chain fatty acyl-CoA. Not only does acyl-CoA binding protein specifically bind medium and long-chain fatty acyl-CoA (LCFA-CoA), but ubiquitous proteins with multiple ligand specificities such as the fatty acid binding proteins and sterol carrier protein-2 also bind LCFA-CoA with high affinity. The potential of these acyl-CoA binding proteins to influence the level of free LCFA-CoA and thereby the amount of LCFA-CoA bound to regulatory sites in proteins and enzymes is only now being examined in detail. The purpose of this article is to explore the identity, nature, function, and pathobiology of these fascinating newly discovered long-chain fatty acyl-CoA binding proteins. The relative contributions of these three different protein families to LCFA-CoA utilization and/or regulation of cellular activities are the focus of new directions in this field.

  8. Cysteine-286 as the site of acylation of the Lux-specific fatty acyl-CoA reductase.

    PubMed

    Lee, C Y; Meighen, E A

    1997-04-04

    The channelling of fatty acids into the fatty aldehyde substrate for the bacterial bioluminescence reaction is catalyzed by a fatty acid reductase multienzyme complex, which channels fatty acids through the thioesterase (LuxD), synthetase (LuxE) and reductase (LuxC) components. Although all three components can be readily acylated in extracts of different luminescent bacteria, this complex has been successfully purified only from Photobacterium phosphoreum and the sites of acylation identified on LuxD and LuxE. To identify the acylation site on LuxC, the nucleotide sequence of P. phosphoreum luxC has been determined and the gene expressed in a mutant Escherichia coli strain. Even in crude extracts, the acylated reductase intermediate as well as acyl-CoA reductase activity could be readily detected, providing the basis for analysis of mutant reductases. Comparison of the amino-acid sequences of LuxC from P. phosphoreum, P. leiognathi and other luminescent bacteria, showed that only three cysteine residues (C171, C279, and C286) were conserved. As a cysteine residue on LuxC has been implicated in fatty acyl transfer, each of the conserved cysteine residues of the P. phosphoreum and P. leiognathi reductases was converted to a serine residue, and the properties of the mutant proteins examined. Only mutation of C286-blocked reductase activity and prevented formation of the acylated reductase intermediate, showing that C286 is the site of acylation on LuxC.

  9. Correlation between caries incidence and frequency of chewing gum sweetened with sucrose or xylitol.

    PubMed

    Rekola, M

    1989-01-01

    The effect on caries incidence of the daily consumption of chewing gum sweetened with sucrose or xylitol was measured in 100 subjects included in the 1-year chewing gum study (Scheinin et al. 1975, Turku sugar Studies XVIII). The subjects were divided retrospectively into groups consuming 2-8 chewing gum pieces per day and their caries incidence was compared. With chewing gum sweetened with sucrose, the caries incidence increased in relation to the daily consumption of gum. In contrast, chewing gum sweetened with xylitol reduced the incidence of caries with increasing consumption.

  10. Ultrasound assisted enzymatic depolymerization of aqueous guar gum solution.

    PubMed

    Prajapat, Amrutlal L; Subhedar, Preeti B; Gogate, Parag R

    2016-03-01

    The present work investigates the effectiveness of application of low intensity ultrasonic irradiation for the intensification of enzymatic depolymerization of aqueous guar gum solution. The extent of depolymerization of guar gum has been analyzed in terms of intrinsic viscosity reduction. The effect of ultrasonic irradiation on the kinetic and thermodynamic parameters related to the enzyme activity as well as the intrinsic viscosity reduction of guar gum using enzymatic approach has been evaluated. The kinetic rate constant has been found to increase with an increase in the temperature and cellulase loading. It has been observed that application of ultrasound not only enhances the extent of depolymerization but also reduces the time of depolymerization as compared to conventional enzymatic degradation technique. In the presence of cellulase enzyme, the maximum extent of depolymerization of guar gum has been observed at 60 W of ultrasonic rated power and ultrasonic treatment time of 30 min. The effect of ultrasound on the kinetic and thermodynamic parameters as well as the molecular structure of cellulase enzyme was evaluated with the help of the chemical reaction kinetics model and fluorescence spectroscopy. Application of ultrasound resulted in a reduction in the thermodynamic parameters of activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) by 47%, 50%, 65% and 1.97%, respectively. The changes in the chemical structure of guar gum treated using ultrasound assisted enzymatic approach in comparison to the native guar gum were also characterized by FTIR. The results revealed that enzymatic depolymerization of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency index without any change in the core chemical structure which could make it useful for incorporation in food products.

  11. Efficacy of chewing gum in preventing extrinsic tooth staining.

    PubMed

    Yankell, S L; Emling, R C

    1997-01-01

    The purpose of this six-week clinical study was to determine the efficacy of sugar-free chewing gum versus no chewing on preventing Peridex (0.12% chlorhexidine)-associated stain. One-hundred and fifty healthy adult subjects, categorized by tea or coffee intake and smoking, were randomly assigned to a chewing or no chewing gum group. All subjects were given Peridex and an ADA-approved toothbrush and fluoride toothpaste to use twice a day. Gum was chewed for 20 minutes five times each day, after toothbrushing and Peridex rinse in the morning and evening, and after each meal. At baseline, all subjects received a professional cleaning to remove all supragingival deposits and extrinsic strain. At three and six weeks, safety and stain intensity and area were monitored on the anterior teeth and posterior Ramfjord teeth using the Lobene stain scoring method. Seventy-two subjects in each group completed the study. Attrition was unrelated to product use. No untoward reactions were reported or observed at any time in the study. At the six-week evaluations, the chewing gum group exhibited significantly lower (p < 0.05-0.001) total stain scores on both anterior and posterior areas evaluated compared to the no chewing group scores. In addition to the stain evaluations, a randomly selected subset of 60 subjects was evaluated for gingivitis at baseline prior to cleaning, and at three and six weeks, on the buccal and lingual surfaces of the Ramfjord teeth. Both the chewing gum and no chewing gum subset subjects had a significant decrease in gingivitis scores from baseline to three weeks (p < 0.001) and from baseline to six weeks (p < 0.05-0.001). There were no significant statistical differences between the two groups at anytime during the study on gingivitis levels. Chewing gum, after product use, did not reduce the efficacy of chlorhexidine on gingivitis scores.

  12. Macromolecular dimensions and mechanical properties of monolayer films of Sonorean mesquite gum.

    PubMed

    López-Franco, Yolanda L; Valdez, Miguel A; Hernández, Javier; Calderón de la Barca, Ana M; Rinaudo, Marguerite; Goycoolea, Francisco M

    2004-09-16

    Mesquite gum sourced from Prosopis velutina trees and gum arabic (Acacia spp.) were characterized using light scattering and Langmuir isotherms. Both gum materials were fractionated by hydrophobic interaction chromatography, yielding four fractions for both gums: FI, FIIa, FIIb and FIII in mesquite gum and FI, FII, FIIIa and FIIIb in gum arabic. In mesquite gum, the obtained fractions had different protein content (7.18-38.60 wt.-%) and macromolecular dimensions (M approximately 3.89 x 10(5)-8.06 x 10(5) g.mol(-1), RG approximately 48.83-71.11 nm, RH approximately 9.61-24.06 nm) and architecture given by the structure factor (RG/RH ratio approximately 2.96-5.27). The mechanical properties of Langmuir monolayers at the air-water interface were very different on each gum and their fractions. For mesquite gum, the most active species at the interface were those comprised in Fractions IIa and IIb and III, while Fraction I the pi/A isotherm lied below that of the whole gum. In gum arabic only Fraction III developed greater surface pressure at the same surface per milligram of material than whole gum. This is rationalized in terms of structural differences in both materials. Mesquite gum tertiary structure seems to fit best with an elongated polydisperse macrocoil in agreement with the "twisted hairy rope" proposal for arabinogalactan proteoglycans.

  13. Smell and taste of chewing gum affect frequency domain EEG source localizations.

    PubMed

    Yagyu, T; Kondakor, I; Kochi, K; Koenig, T; Lehmann, D; Kinoshita, T; Hirota, T; Yagyu, T

    1998-04-01

    We investigated brain electric field signatures of subjective feelings after chewing regular gum or gum base without flavor. 19-channel eyes-closed EEG from 20 healthy males before and after 5 minutes of chewing the two gum types in random sequence was source modeled in the frequency domain using the FFT-Dipole-Approximation. 3-dimensional brain locations and strengths (Global Field Power, GFP) of the equivalent sources of five frequency bands were computed as changes from pre-chewing baseline. Gum types differed (ANOVA) in pre-post changes of source locations for the alpha-2 band (to anterior and right after regular gum, opposite after gum base) and beta-2 band (to anterior and inferior after regular gum, opposite after gum base), and of GFP for delta-theta, alpha-2 and beta-1 (regular gum: increase. gum base: decrease). Subjective feeling changed to more positive values after regular gum than gum base (ANOVA).--Thus, chewing gum with and without taste-smell activates different brain neuronal populations.

  14. Differential turnover of phospholipid acyl groups in mouse peritoneal macrophages

    SciTech Connect

    Kuwae, T.; Schmid, P.C.; Johnson, S.B.; Schmid, H.H. )

    1990-03-25

    Phospholipid acyl turnover was assessed in mouse peritoneal exudate cells which consisted primarily of macrophages. The cells were incubated for up to 5 h in media containing 40% H218O, and uptake of 18O into ester carbonyls of phospholipids was determined by gas chromatography-mass spectrometry of hydrogenated methyl esters. The uptake was highest in choline phospholipids and phosphatidylinositol, less in ethanolamine phospholipids, and much less in phosphatidylserine. Acyl groups at the sn-1 and sn-2 positions of diacyl glycerophospholipids, including arachidonic and other long-chain polyunsaturated fatty acids, acquired 18O at about the same rate. Acyl groups of alkylacyl glycerophosphocholine exhibited lower rates of 18O uptake, and acyl groups of ethanolamine plasmalogens (alkenylacyl glycerophosphoethanolamines) acquired only minimal amounts of 18O within 5 h, indicating a low average acyl turnover via free fatty acids. Pulse experiments with exogenous 3H-labeled arachidonic acid supported the concept that acylation of alkenyl glycerophosphoethanolamine occurs by acyl transfer from other phospholipids rather than via free fatty acids and acyl-CoA. The 18O content of intracellular free fatty acids increased gradually over a 5-h period, whereas in extracellular free fatty acids it reached maximal 18O levels within the first hour. Arachidonate and other long-chain polyunsaturated fatty acids were found to participate readily in deacylation-reacylation reactions but were present only in trace amounts in the free fatty acid pools inside and outside the cells. We conclude that acyl turnover of macrophage phospholipids through hydrolysis and reacylation is rapid but tightly controlled so that appreciable concentrations of free arachidonic acid do not occur.

  15. The origin of the Gum nebula

    NASA Technical Reports Server (NTRS)

    Bruhweiler, F. C.; Kafatos, M.; Brandt, J. C.

    1983-01-01

    Obsrvations and theoretical investigations of the Gum nebula (GN) since about 1971 are reviewed. Direct observations of the GN, the Vela X supernova remnant (SNR), the Vela pulsar, and other stars in or near the GN are discussed with those of related phenomena such as the radio loops and known SNRs; the emphasis is on studies of the interstellar absorption lines, the evidence for hot gas in the GN, and the extended diffuse emission. The four basic models proposed for the GN are considered: a fossil Stromgren sphere, an old SNR, an H II region, or a superbubble. The GN physical parameters predicted by each model are listed in a table and compared. A minimum explanation which attributes the 36 x 36-deg filamentary structure and the 125-pc radius structure to the action of the stellar winds from Zeta Pup and Gamma-2 Vel (and perhaps the effect of a Vel X supernova explosion 20,000 years ago) is found most appropriate, at least until the questions of the net expansion rate of the GN (about 20 km/sec or about zero?) and the existence of the diffuse emission beyond the filamentary structure are resolved by observations.

  16. Runaway stars in the Gum Nebula

    NASA Technical Reports Server (NTRS)

    Got, J. R., III; Ostriker, J. P.

    1971-01-01

    It is proposed that the two pulsars PSR 0833-45 (the Vela pulsar) and MP 0835 are runaways from a common binary system originally located in the B association around gamma Velorum. Arguments are presented for a simple model of the Gum nebula in which two distinct ionized regions are present. The first consists of the Stromgren spheres of gamma Velorum and zeta Puppis, while the second is a larger, more filamentary region ionized by the supernova explosion associated with PSR 0833-45. Using this model and the available dispersion measures, the distances to the two pulsars were estimated and found to be compatible with a runaway origin. The position angle of the rotation axis of PSR 0833-45 is also compatible with this origin. The masses of the parent stars of the two pulsars can be deduced from the runaway star dynamics and an assumed age for MP 0835. It is concluded that the masses were in excess of 10 solar masses. The dynamically-determined parent star masses are in agreement with the values expected for evolved members of the B association around gamma Velorum.

  17. A NEW SPECIES OF INVASIVE GALL WASP (HYMENOPTERA: EULOPHIDAE: TETRASTICHINAE) ON BLUE GUM (EUCALYPTUS GLOBULUS) IN CALIFORNIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The blue gum gall wasp, Selitrichodes globulus La Salle & Gates (Hymenoptera: Eulophidae: Tetrastichinae), is described as an invasive gall inducer on blue gum, Eucalyptus globulus (Myrtaceae), in California....

  18. Role of acyl carrier protein isoforms in plant lipid metabolism

    SciTech Connect

    Not Available

    1990-01-01

    Although acyl carrier protein (ACP) is the best studied protein in plant fatty acid biosynthesis, the in vivo forms of ACPs and their steady state pools have not been examined previously in either seed or leaf. Information about the relative pool sizes of free ACP and its acyl-ACP intermediates is essential for understanding regulation of de novo fatty acid biosynthesis in plants. In this study we utilized antibodies directed against spinach ACP as a sensitive assay to analyze the acyl groups while they were still covalently attached to ACPs. 4 refs., 4 figs.

  19. Synthesis of coenzyme A thioesters using methyl acyl phosphates in an aqueous medium.

    PubMed

    Pal, Mohan; Bearne, Stephen L

    2014-12-28

    Regioselective S-acylation of coenzyme A (CoA) is achieved under aqueous conditions using various aliphatic and aromatic carboxylic acids activated as their methyl acyl phosphate monoesters. Unlike many hydrophobic activating groups, the anionic methyl acyl phosphate mixed anhydride is more compatible with aqueous solvents, making it useful for conducting acylation reactions in an aqueous medium.

  20. Microencapsulation of saffron petal anthocyanins with cress seed gum compared with Arabic gum through freeze drying.

    PubMed

    Jafari, Seid-Mahdi; Mahdavi-Khazaei, Katayoun; Hemmati-Kakhki, Abbas

    2016-04-20

    In this research, encapsulation efficiency of cress seed gum (CSG) as a native hydrocolloid was compared with Arabic gum (AG) and maltodextrin (dextrose equivalent of 20 (M20), and 7 (M7)) for saffron (Crocus sativus) petal's extract by freeze drying method. Combinations of CSG-M20, AG-M20, and M7-M20 with ratios of 50:50 and M20 alone (100%) were used as wall materials. A mixture of 1:5 (based on dry matter) between core (concentrated anthocyanin extract of saffron petal) and wall materials were freeze dried and stability of encapsulated anthocyanins along with color parameters (a*, b*, L*, C, H° and TCD) of final powders were measured during 10 weeks of storage (at 35°C as an accelerated method). Total anthocyanins were determined through pH differential method every week. Four prepared formulations of encapsulated powders didn't show any significant differences (P>0.01) in terms of total anthocyanin content measured immediately after production and after 10 weeks storage. AG-M20 mixture and M20 alone showed the highest and lowest TCD, respectively. The mixture of CSG-M20 in comparison with AG-M20 and M20 had the same protecting effect (P<0.01) but showed a relatively high TCD (9.33).

  1. Evaluation of Release Retarding Property of Gum Damar and Gum Copal in Combination with Hydroxypropyl Methylcellulose

    PubMed Central

    Fulbandhe, V. M.; Jobanputra, C. R.; Wadher, K. J.; Umekar, M. J.; Bhoyar, G. S.

    2012-01-01

    The formulations consisting of a hydrophilic and hydrophobic material were investigated for effect on drug-release pattern from the matrices. Gum damar and gum copal being water-insoluble were used to study the efficiency of combined matrices to sustain the release of drug. Hydroxypropyl methylcellulose K100M and diclofenac sodium were used as the hydrophilic material and model drug, respectively. The influence of concentration of hydroxypropyl methylcellulose on drug release pattern of hydrophobic material was determined. The optimum ratio of drug: polymer was found to be 1:1. The hydrophobic:hydrophilic polymer ratio of 75:25 was found to have a similar release pattern as that of marketed formulation. At this ratio, the initial burst-release that occurred in individual hydrophobic matrices was lowered to a great extent. The release of drug was found to follow Higuchi's equation as the concentration of hydrophobic material was increased. The formulations were compared with marketed formulation Voveran SR, and a correlation was drawn accordingly. PMID:23440630

  2. Evaluation of release retarding property of gum damar and gum copal in combination with hydroxypropyl methylcellulose.

    PubMed

    Fulbandhe, V M; Jobanputra, C R; Wadher, K J; Umekar, M J; Bhoyar, G S

    2012-05-01

    The formulations consisting of a hydrophilic and hydrophobic material were investigated for effect on drug-release pattern from the matrices. Gum damar and gum copal being water-insoluble were used to study the efficiency of combined matrices to sustain the release of drug. Hydroxypropyl methylcellulose K100M and diclofenac sodium were used as the hydrophilic material and model drug, respectively. The influence of concentration of hydroxypropyl methylcellulose on drug release pattern of hydrophobic material was determined. The optimum ratio of drug: polymer was found to be 1:1. The hydrophobic:hydrophilic polymer ratio of 75:25 was found to have a similar release pattern as that of marketed formulation. At this ratio, the initial burst-release that occurred in individual hydrophobic matrices was lowered to a great extent. The release of drug was found to follow Higuchi's equation as the concentration of hydrophobic material was increased. The formulations were compared with marketed formulation Voveran SR, and a correlation was drawn accordingly.

  3. The activity of Rhizomuchor miehei lipase as a biocatalyst in enzymatic acylation of cyclic alcohol

    NASA Astrophysics Data System (ADS)

    Iftitah, Elvina Dhiaul; Srihardyastuti, Arie; Ariefin, Mokhamat

    2017-03-01

    We report the activity of Rhizomuchor miehei lipase (RML) as a biocatalyst, in particular the investigations concerning the effort of substrate-structure reactivity on the enzymatic acylation. The acylation was studied using acetic anhydride as an acyl donor and performed in n-hexane as a solvent. The selectivity of the enzymatic acylation was revealed by Gas Chromatography-Mass Spectra. We observed that, RML has shown different behavior when catalyzing the acylation of isopulegol and mixture of isopulegol and citronellal (ratio 1:1). The chemoselectivity for the O-acylation was improved when the acyl acceptor included mixture of isopulegol and citronellal

  4. Studies on some physicochemical properties of leucaena leucocephala bark gum.

    PubMed

    Pendyala, Vijetha; Baburao, Chandu; Chandrasekhar, K B

    2010-04-01

    Gum exudates from Leucaena Leucocephala (Family: Fabaceae) plants grown all over India were investigated for its physicochemical properties such as pH, swelling capacity and viscosities at different temperatures using standard methods. Leucaena Leucocephala bark gum appeared to be colorless to reddish brown translucent tears. 5 % w/v mucilage has pH of 7.5 at 28°C. The gum is slightly soluble in water and practically insoluble in ethanol, acetone and chloroform. It swells to about 5 times its original weight in water. A 5 %w/ v mucilage concentration gave a viscosity value which was unaffected at temperature ranges (28-40°C). At concentrations of 2 and 5 %w/v, the gum exhibited pseudo plastic flow pattern while at 10 %w/v concentration the flow behaviour was thixotropic. The results indicate that the swelling ability of Leucaena Leucocephala (LL) bark gum may provide potentials for its use as a disintegrant in tablet formulation, as a hydro gel in modified release dosage forms and the rheological flow properties may also provide potentials for its use as suspending and emulsifying agents owing to its pseudo plastic and thixotropic flow patterns.

  5. Jaw-movement smoothness during empty chewing and gum chewing.

    PubMed

    Minami, Ichiro; Akhter, Rahena; Luraschi, Julien; Oogai, Kazuhiro; Nemoto, Tetsu; Peck, Christopher C; Murray, Gregory M

    2012-06-01

    A major goal of motor coordination is the production of a smooth movement. Jerk-cost, which is an inverse measure of movement smoothness, has been evaluated during gum chewing in previous studies. However, the effect of the gum bolus is still unclear. The aims of this study were to compare the jerk-cost values of normal gum chewing with those of empty chewing. Thirteen subjects undertook, empty chewing, then chewing of gum, and then a second empty chewing. Jerk-cost was calculated from an accelerometer attached to the skin of the mentum. There was a significantly higher smoothness (i.e. lower jerk-cost, P < 0.05) during the opening and second-half closing phases in empty chewing compared with gum chewing. There were no significant differences in jerk-costs (i.e. opening or closing) between the first and the second empty-chewing sequences. These results suggest that the influence of the mechanical effects of tooth contact on jerk-cost is not restricted just to the occlusal phase of chewing, but rather the effect influences the entire opening and closing phases of chewing.

  6. The impact of chewing gum resistance on immediate free recall.

    PubMed

    Rickman, Sarah; Johnson, Andrew; Miles, Christopher

    2013-08-01

    Although the facilitative effects of chewing gum on free recall have proved contentious (e.g., Tucha, Mecklinger, Maier, Hammerl, & Lange, 2004; Wilkinson, Scholey, & Wesnes, 2002), there are strong physiological grounds, for example, increased cerebral activity and blood flow following the act of mastication, to suppose facilitation. The present study manipulated resistance to mastication, that is, chewing four pellets versus one pellet of gum, with the assumption that increased resistance will accentuate cerebral activity and blood flow. Additionally, chewing rate was recorded for all participants. In a within-participants design, participants performed a series of immediate free recall tasks while chewing gum at learning (one or four pellets) and recall (one or four pellets). Increased chewing resistance was not associated with increased memory performance, despite consistent chewing rates for both the one and four pellet conditions at both learning and recall. However, a pattern of recall consistent with context-dependent memory was observed. Here, participants who chewed the equivalent number of gum pellets at both learning and recall experienced significantly superior word recall compared to those conditions where the number of gum pellets differed.

  7. Circulatory response and autonomic nervous activity during gum chewing.

    PubMed

    Hasegawa, Yoko; Sakagami, Joe; Ono, Takahiro; Hori, Kazuhiro; Zhang, Min; Maeda, Yoshinobu

    2009-08-01

    Mastication has been proven to enhance the systemic circulation, with circulatory responses seeming to be largely regulated by autonomic nervous activity via a more complex regulatory system than those of other activities. However, few studies have examined the relationships between changes in autonomic nervous activity and the systemic circulation that are induced by masticatory movement. We investigated changes in the systemic circulation and autonomic nervous activity during gum chewing to clarify the influence of mastication. Electrocardiograms, arterial blood pressure, and masseter electromyograms were taken while chewing gum continuously as indicators of systemic circulation in 10 healthy subjects with normal dentition. Cardiac sympathetic activity and vagus nervous activity, as well as vasomotor sympathetic nervous activity, were evaluated by fluctuation analysis of heart rate and blood pressure. Repeated analysis of variance and multiple comparisons were performed to determine chronological changes in each indicator during gum chewing. Gum chewing increased the heart rate and the mean arterial pressure. Although cardiac sympathetic activity and vagus nervous activity showed significant changes, vasomotor sympathetic nervous activity did not. These results suggest that changes in the autonomic nervous activity of the heart are mainly involved in the enhancement of systemic circulation with gum chewing. This explains some characteristics of autonomic nervous regulation in masticatory movement.

  8. Identification of intestinal bacteria responsible for fermentation of gum arabic in pig model.

    PubMed

    Kishimoto, Akio; Ushida, Kazunari; Phillips, Glyn O; Ogasawara, Takashi; Sasaki, Yasushi

    2006-09-01

    Acacia spp. produce gum exudates, traditionally called gum arabic or gum acacia, which are widely used in the food industry such as emulsifiers, adhesives, and stabilizers. The traditional gum arabic is highly variable with average molecular weights varying from 300,000-800,000. For this reason a standardized sample was used for the present experiments, based on a specific species of gum arabic (Acacia(sen)SUPER GUMEM2). The literature indicates that gum arabic can be fermented by the intestinal bacteria to short chain fatty acid, particularly propionate. However, the bacteria responsible for the fermentation have not been determined. In this study, we used enrichment culture of pig cecal bacteria from the selected high molecular weight specific gum arabic of (M(W )1.77 x 10(6)). We found Prevotella ruminicola-like bacterium as a predominant bacterium that is most likely to be responsible for fermentation of the gum arabic used to propionate.

  9. Application of antibodies for the identification of polysaccharide gum additives in processed foods.

    PubMed

    Pazur, J H; Li, N-Q

    2004-11-01

    Anti-carbohydrate antibodies with specificities for polysaccharide gums were isolated from the serum of rabbits that were immunized with a solution of the gums and Freund's complete adjuvant. The primary objective was to test an immunological method for the detection of the polysaccharide gums as additives to processed foods. Analysis involved the extraction of food with phosphate buffer and the testing of the extract for a reaction with anti-gum antibodies by the agar diffusion method. Reaction by a specific gum with the homologous antibodies establishes the presence of the gum in the food. The method is a novel application of antibodies. The antibody method is highly specific for a gum and thus possesses advantages over other methods of analysis for polysaccharide gums as additives in processed foods.

  10. Acylated cyanidin 3-sambubioside-5-glucosides in Matthiola incana.

    PubMed

    Saito, N; Tatsuzawa, F; Nishiyama, A; Yokoi, M; Shigihara, A; Honda, T

    1995-03-01

    Four acylated cyanidin 3-sambubioside-5-glucosides were isolated from purple-violet flowers of Matthiola incana and their structures were determined by chemical and spectroscopic methods. Three acylated anthocyanins were cyanidin 3-O-(6-O-acyl-2-O-(2-O-sinapyl-beta-D-xylopyranosyl)-beta-D- glucopyranosides)-5-O-(6-O-malonyl-beta-D-glucopyranosides), in which the acyl group is p-coumaryl, caffeyl or ferulyl, respectively. The remaining pigment is free from malonic acid and was identified as cyanidin 3-O-(6-O-trans-ferulyl-2-O-(2- O-trans-sinapyl-beta-D-xylopyranosyl)-beta-D-glucopyranoside)-5-O- (beta-D-glucopyranoside). Analysis of the anthocyanin constituents in 16 purple-violet cultivars revealed that they contained the above triacylated anthocyanins in variable amounts as main pigments. An aromatic pair of pigments containing sinapic and ferulic acids are considered to produce an important intramolecular effect, making bluish colours in these flowers.

  11. Acyl Meldrum's acid derivatives: application in organic synthesis

    NASA Astrophysics Data System (ADS)

    Janikowska, K.; Rachoń, J.; Makowiec, S.

    2014-07-01

    This review is focused on an important class of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleophiles. The possible mechanisms of these transformations are analyzed. The bibliography includes 134 references.

  12. Oxidative activation of dihydropyridine amides to reactive acyl donors.

    PubMed

    Funder, Erik Daa; Trads, Julie B; Gothelf, Kurt V

    2015-01-07

    Amides of 1,4-dihydropyridine (DHP) are activated by oxidation for acyl transfer to amines, alcohols and thiols. In the reduced form the DHP amide is stable towards reaction with amines at room temperature. However, upon oxidation with DDQ the acyl donor is activated via a proposed pyridinium intermediate. The activated intermediate reacts with various nucleophiles to give amides, esters, and thio-esters in moderate to high yields.

  13. Iodine derivatives of chemically modified gum Arabic microspheres.

    PubMed

    Ganie, Showkat A; Ali, Akbar; Mazumdar, Nasreen

    2015-09-20

    Acetylated gum Arabic (AGA) derivatives with different degrees of substitution (DS 0.97-2.74) were synthesized using acetyl chloride and a base under varying reaction conditions. The AGA derivatives were obtained in the form of microspheres and thereafter stable iodine products were prepared by doping the microspheres with an iodinating agent, iodine monochloride (ICl). The reaction between electrophilic iodine and polar carbonyl groups was studied by FT-IR, (1)H-NMR, and UV-VIS spectroscopies. The products were also characterized by DSC, TGA and SEM studies. The incorporated iodine was released in aqueous medium as iodide ions (I(-)). A reaction scheme has been proposed for the iodination and de-iodination of the gum derivatives. This work suggests that the iodine derivatives of modified gum Arabic could be used as a source of iodide ions which is the nutritional form of iodine.

  14. Hybrid modeling of xanthan gum bioproduction in batch bioreactor.

    PubMed

    Zabot, Giovani L; Mecca, Jaqueline; Mesomo, Michele; Silva, Marceli F; Prá, Valéria Dal; de Oliveira, Débora; Oliveira, J Vladimir; Castilhos, Fernanda; Treichel, Helen; Mazutti, Marcio A

    2011-10-01

    This work is focused on hybrid modeling of xanthan gum bioproduction process by Xanthomonas campestris pv. mangiferaeindicae. Experiments were carried out to evaluate the effects of stirred speed and superficial gas velocity on the kinetics of cell growth, lactose consumption and xanthan gum production in a batch bioreactor using cheese whey as substrate. A hybrid model was employed to simulate the bio-process making use of an artificial neural network (ANN) as a kinetic parameter estimator for the phenomenological model. The hybrid modeling of the process provided a satisfactory fitting quality of the experimental data, since this approach makes possible the incorporation of the effects of operational variables on model parameters. The applicability of the validated model was investigated, using the model as a process simulator to evaluate the effects of initial cell and lactose concentration in the xanthan gum production.

  15. The impact of chewing gum on halitosis parameters: a systematic review.

    PubMed

    Muniz, Francisco Wilker Mustafa Gomes; Friedrich, Stephanie Anagnostopoulos; Silveira, Carina Folgearini; Rösing, Cassiano Kuchenbecker

    2017-02-17

    This study aimed to analyze the impact of chewing gum on halitosis parameters. Three databases were searched with the following focused question: 'Can chewing gum additionally reduce halitosis parameters, such as organoleptic scores and volatile sulfur compounds (VSC), when compared to a control treatment'? Controlled clinical trials presenting at least two halitosis measurements (organoleptic scores and/or VSC) were included. Ten studies were included, and different active ingredients were used. One study was performed using a chewing gum without any active ingredient. Chewing gum containing probiotic bacterium was shown to significantly reduce the organoleptic scores. Chewing gums containing zinc acetate and magnolia bark extract as well as allylisothiocyanate (AITC) with zinc lactate significantly reduced the levels of VSC in comparison to a placebo chewing gum. Furthermore, a sodium bicarbonate-containing chewing gum significantly reduced the VSC levels in comparison to rinsing with water. Furthermore, eucalyptus-extract chewing gum showed significant reductions in both organoleptic scores and VSC when compared with a control chewing gum. Chewing gum containing sucrose was able to reduce the VSC levels, in comparison to xylitol and zinc citrate chewing gum, but only for 5 min. It was concluded that chewing gums containing probiotics Lactobaccilus, zinc acetate and magnolia bark extract, eucalyptus-extract, and AITC with zinc lactate may be suitable for halitosis management. However, the low number of included studies and the high heterogeneity among the selected studies may limit the clinical applications of these findings.

  16. 78 FR 33354 - Xanthan Gum From Austria: Final Determination of Sales at Less Than Fair Value

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... International Trade Administration Xanthan Gum From Austria: Final Determination of Sales at Less Than Fair... final determination in the antidumping (``AD'') investigation of xanthan gum from Austria.\\1\\ On March 4... the Preliminary Determination. The Department has determined that xanthan gum from Austria is...

  17. 77 FR 65361 - Xanthan Gum From Austria and the People's Republic of China: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... International Trade Administration Xanthan Gum From Austria and the People's Republic of China: Postponement of... xanthan gum from Austria and the People's Republic of China.\\1\\ The notice of initiation stated that the... antidumping duty investigations are currently due no later than November 12, 2012. \\1\\ See Xanthan Gum...

  18. Metabolic Effects of Nicotine Gum and Cigarette Smoking: Potential Implications for Postcessation Weight Gain?

    ERIC Educational Resources Information Center

    Klesges, Robert C.; And Others

    1991-01-01

    Twenty smoking women participated in nicotine gum and smoking administration, after which resting energy expenditures (REEs) were measured. Results indicated acute increase in REE for both nicotine gum and cigarettes. Metabolic rates for nicotine gum slowly returned to baseline; rates for cigarettes quickly fell significantly below baseline.…

  19. 76 FR 44811 - Carboxymethyl Guar Gum Sodium Salt and Carboxymethyl-Hydroxypropyl Guar; Exemption From the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ...-0531; FRL-8880-5] Carboxymethyl Guar Gum Sodium Salt and Carboxymethyl- Hydroxypropyl Guar; Exemption... carboxymethyl guar gum sodium salt (CAS Reg. No. 39346-76-4) and carboxymethyl-hydroxypropyl guar (CAS Reg. No... residues of carboxymethyl guar gum sodium salt and carboxymethyl- hydroxypropyl guar. DATES:...

  20. Acute and chronic effects of gum chewing on food reinforcement and energy intake.

    PubMed

    Swoboda, Christine; Temple, Jennifer L

    2013-04-01

    Although chewing gum has been considered a potential method for reducing energy intake, little empirical data exist to support this idea. The purpose of this study was to test the hypothesis that chewing gum before eating reduces motivation to eat, hunger, and energy intake. In order to test this hypothesis, we conducted two experiments in which participants chewed gum prior to completing a food reinforcement task or before all eating occasions for two of three weeks. In Experiment 1, we found that chewing gum had no influence on the reinforcing value of food, but chewing mint gum reduced liking of and energy intake from fruit. In addition, chewing gum reduced self-reported hunger immediately after gum chewing and after eating compared with the no gum condition. In Experiment 2, gum chewing had no significant effect on total energy intake, but participants consumed fewer meals, consumed more energy per meal, and had a lower nutrient adequacy ratio during the gum chewing weeks. These studies provide no evidence that acute or chronic gum chewing reduces hunger or energy intake. In fact, chewing mint-flavored gum may deter consumption of fruit and reduce diet quality.

  1. Design, formulation and evaluation of Aloe vera chewing gum

    PubMed Central

    Aslani, Abolfazl; Ghannadi, Alireza; Raddanipour, Razieh

    2015-01-01

    Background: Aloe vera has antioxidant, antiinflammatory, healing, antiseptic, anticancer and antidiabetic effects. The aim of the present study was to design and evaluate the formulation of Aloe vera chewing gum with an appropriate taste and quality with the indications for healing oral wounds, such as lichen planus, mouth sores caused by cancer chemotherapy and mouth abscesses as well as reducing mouth dryness caused by chemotherapy. Materials and Methods: In Aloe vera powder, the carbohydrate content was determined according to mannose and phenolic compounds in terms of gallic acid. Aloe vera powder, sugar, liquid glucose, glycerin, sweeteners and different flavors were added to the soft gum bases. In Aloe vera chewing gum formulation, 10% of dried Aloe vera extract entered the gum base. Then the chewing gum was cut into pieces of suitable sizes. Weight uniformity, content uniformity, the organoleptic properties evaluation, releasing the active ingredient in the phosphate buffer (pH, 6.8) and taste evaluation were examined by Latin square method. Results: One gram of Aloe vera powder contained 5.16 ± 0.25 mg/g of phenolic compounds and 104.63 ± 4.72 mg/g of carbohydrates. After making 16 Aloe vera chewing gum formulations, the F16 formulation was selected as the best formulation according to its physicochemical and organoleptic properties. In fact F16 formulation has suitable hardness, lack of adhesion to the tooth and appropriate size and taste; and after 30 min, it released more than 90% of its drug content. Conclusion: After assessments made, the F16 formulation with maltitol, aspartame and sugar sweeteners was selected as the best formulation. Among various flavors used, peppermint flavor which had the most acceptance between consumers was selected. PMID:26605214

  2. Design, formulation, and evaluation of ginger medicated chewing gum

    PubMed Central

    Aslani, Abolfazl; Ghannadi, Alireza; Rostami, Farnaz

    2016-01-01

    Background: Various ginger compounds improve gastrointestinal problems and motion sickness. The main effects of ginger allocate to some phenolics such as gingerols and shogaols that act as their active agents. Chewing gums are among convenient dosage forms which patients prefer due to their advantages. Hence, this study tried to design, formulate, and evaluate ginger chewing gum of favorable taste and texture to avoid motion sickness and have gastro-protective and anti-oxidant effect. Materials and Methods: Dried ginger rhizomes were percolated to extract ginger compounds. Total phenolics were measured in 70% hydro-alcoholic extract of ginger by gallic and tannic acid standards using Folin–Ciocalteu’s reagent. Chewing gums containing 50 mg of concentrated extract were prepared. Content uniformity, weight variation, release pattern, organoleptic, and mechanical properties were evaluated. Results: Phenolic content was measured 61.50 ± 5.27 mg/g and 76.75 ± 5.45 mg/g of concentrated extract as gallic acid and tannic acid equivalents, respectively. Release pattern of formulations with different gum bases and sweeteners demonstrated almost 100% release of drug. Evaluation of organoleptic properties was on 10 healthy volunteers and later prepared formulations exhibited better characteristics. Formulations without any flavorants have higher acceptability. Evaluation of mechanical properties showed higher stiffness of F15. Conclusion: Ginger chewing gum comprises admissible properties to be used as a modern drug delivery system due to its advantageous results in motion sickness. It passed all the specified tests for an acceptable chewing gum. Thus, it may be successfully produced to help GI problems. PMID:27563640

  3. The Efficacy of Green Tea Chewing Gum on Gingival Inflammation

    PubMed Central

    Behfarnia, Parichehr; Aslani, Ahmad; Jamshidian, Foroogh; Noohi, Soheil

    2016-01-01

    Statement of the Problem According to previous studies, the components of green tea extracts can inhibit the growth of a wide range of gram-pos-itive and -negative bacterial species and might be useful in controlling oral infections. Purpose The aim of this study was to determine the effect of green tea chewing gum on the rate of plaque and gingival inflammation in subjects with gingivitis. Materials and Method In this double-blind randomize controlled clinical trial, 45 patients with generalized marginal gingivitis were selected and divided into two groups of green tea (23) and placebo (22) chewing gum. The patients chewed two gums for 15 minutes daily for three weeks. Sulcus bleeding index (SBI) and approximal plaque index (API) were studied at the baseline, 7 and 21 days later. Saliva sampling was conducted before and after 21 days for evaluation of IL-1β. The results were analyzed and compared by using repeated measures ANOVA, paired t test, and independent two-sample t test (α=0.05). Result The results showed that chewing gum significantly affected the SBI and API (p< 0.001). Paired t test showed that the two groups were significantly different regarding the mean changes of SBI and API at different periods of 1-7, 1-21, and 7-21 (p< 0.001). Concerning IL-1β, the repeated measures ANOVA revealed that the effect of chewing gum was significant (p<0.001). Moreover, paired t-test represented no significant difference between the mean changes of IL-1β within 1-21 day (p= 0.086). Conclusion The green tea chewing gum improved the SBI and API and effectively reduced the level of IL-1β. PMID:27284561

  4. Locust bean gum: Exploring its potential for biopharmaceutical applications.

    PubMed

    Dionísio, Marita; Grenha, Ana

    2012-07-01

    Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua). This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed.

  5. [Chewing gum influence upon blood supply of mastication muscles].

    PubMed

    Loginova, N K; Logatskaia, E V

    2006-01-01

    A total of 27 volunteers 16-26 years of age participated in the study of the influence of chewing gum use in different regimens upon velocity parameters of blood supply of mastication muscles at dopplerography (MM-D-K dopplerograph made in Russia). It was established that regular and continuous (30 min) chewing the gum and also of big volume (in two) but short-term chewing (5 min) equalizes blood supply of mastication muscles on both working and non-working sides.

  6. A case report: metastatic choriocarcinoma to the gum.

    PubMed

    Shafiee, Mohamad Nasir; Ismail, Norazlin Mohamed; Shan, Lim Pei; Kampan, Nirmala; Omar, Mohd Hashim; Dali, Hatta Mohd

    2011-04-01

    Choriocarcinoma is a rare neoplasia with a tendency of distant metastasis although highly sensitive to chemotherapy renders a good prognosis and outcome. Lungs, liver and cerebral metastasis are commonly implicated with maxillofacial region rarely involved. We illustrate a case of overwhelming metastatic choriocarcinoma to lungs, liver, brain and to the extreme of gum metastasis. Decompressive craniectomy for intracranial bleeding, multiple transfusions to correct anaemia and coagulopathy were done before high-risk-regime chemotherapy. Despite this, due to fulminant multi-organs involvement she finally succumbed to death. In conclusion, gum bleeding in choriocarcinoma may suggest metastasis and poor prognosis.

  7. Acylated pregnane glycosides from Caralluma quadrangula.

    PubMed

    Abdallah, Hossam M; Osman, Abdel-Moneim M; Almehdar, Hussein; Abdel-Sattar, Essam

    2013-04-01

    In a previous study, the methanolic extract as well as the chloroform fraction of the aerial parts of Caralluma quadrangula (Forssk.) N.E.Br. indigenous to Saudi Arabia showed significant in vitro cytotoxic activity against breast cancer (MCF7) cell line. In a biologically-guided fractionation approach, four acylated pregnane glycosides were isolated from the chloroform fraction of C. quadrangula. The structures of the isolated compounds were elucidated by the analysis of their MS and NMR data. The compounds were identified as 12,20-di-O-benzoylboucerin 3-O-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (1), 12,20-di-O-benzoylboucerin 3-O-β-D-cymaropyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (2), 12,20-di-O-benzoylboucerin 3-O-β-D-glucopyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (3) and 12,20-di-O-benzoyl-3β,5α,12β,14β,20-pentahydroxy-(20R)-pregn-6-ene 3-O-β-D-glucopyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (4). The isolated compounds were tested for their cytotoxic activity against breast cancer (MCF7) cell line.

  8. Grewia gum as a potential aqueous film coating agent. I: Some physicochemical characteristics of fractions of grewia gum

    PubMed Central

    Ogaji, Ikoni J.; Okafor, Ignatius S.; Hoag, Stephen W.

    2013-01-01

    Background: Grewia gum has received attention as a polymeric pharmaceutical excipient in the recent times, being employed as a suspending, film coating, mucoadhesive, and binding agent. The low aqueous solubility, however, has limited its characterization and application. Objective: The purpose of this study was to fractionate and evaluate some physicochemical properties of the gum. Materials and Methods: Aqueous dispersion of the gum was treated at 80°C for 30 min in the presence of sodium chloride and was subsequently fractionated by successively centrifuging it at 3445 rpm for 30 min. Skeletal density, solubility, particle size, and rheological as well as thermal characteristics of the fractions were evaluated. The 1H nuclear magnetic resonance (NMR) and near infrared (NIR) profiles of the fractions were also investigated. The solubility of the gum increased up to fourfold while the viscosity decreased from 244 to as low as70 cP at 40 rpm with some fractions. Results: Grewia gum and the fractions showed good thermal stability exhibiting no thermal events, but charred irreversibly at 297°C irrespective of the fraction. The molecular weight averages by weight and by number of the fractions were between 233,100 and 235,000. The 1H nuclear magnetic resonance (NMR) spectra showed broad peaks. The NMR and NIR spectra suggested the presence of –OH and –OCH3 functional groups in this gum. Conclusion: The fractionation improved solubility and facilitated further investigations on its characteristics that may have implication on its processing, application, and optimization as a potential pharmaceutical excipient. PMID:23559825

  9. Differentiation of carbohydrate gums and mixtures using fourier transform infrared spectroscopy and chemometrics.

    PubMed

    Prado, Belén M; Kim, Sol; Ozen, Banu F; Mauer, Lisa J

    2005-04-20

    Guar gum, a nonionic galactomannan, is used as an economical thickener and stabilizer in the food industry and is often combined with xanthan, locust bean gum (LBG), or carboxymethylcellulose (CMC) to promote synergistic changes in viscosity or gelling behavior via intermolecular interactions; however, the adulteration of LBG with guar gum is a well-known industrial problem. The ability to identify the purity of gums and concentrations of individual gums in mixtures would be advantageous for quality control in the food industry. Fourier transform infrared spectroscopy (FTIR) methods are rapid and require minimum sample preparation. The objectives of this study were to evaluate the ability of FTIR techniques to (1) differentiate LBG with a variety of mannose/galactose (M/G) ratios, (2) differentiate guar, LBG, tara, and fenugreek gums, (3) differentiate pure guar gum from guar gum mixed with LBG, xanthan gum, or CMC, (4) quantify LBG, xanthan gum, and CMC in guar gum, and (5) quantify guar gum in LBG. Two FTIR methods were used: diffuse reflectance (DRIFT) on powdered gum samples added to KBr at 5%, w/w, and attenuated total reflectance (ATR) on 1%, w/w, gum solutions. Spectra were collected and then analyzed by multivariate statistical procedures (chemometrics). The DRIFT method provided better discrimination and quantitative results than the ATR method. Canonical variate analysis (CVA) of DRIFT spectra (1200-700 cm(-1)) was able to classify LBG with various M/G ratios, pure galactomannans, and pure versus mixtures of gums with 100% accuracy. Quantification of an individual gum in gum mixtures (0.5-15%, w/w) was possible using partial least-squares (PLS) analysis of DRIFT spectra with R2 > 0.93 and using this approach for quantifying guar gum added to LBG resulted in an R2 > 0.99, RMSEC = 0.29, and RMSEP = 3.31. Therefore, the DRIFT FTIR method could be a useful analytical tool for quality control of select gums and gum mixtures used in the food industry.

  10. Mango kernel starch-gum composite films: Physical, mechanical and barrier properties.

    PubMed

    Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Lutfi, Zubala; Hasnain, Abid

    2017-05-01

    Composite films were developed by the casting method using mango kernel starch (MKS) and guar and xanthan gums. The concentration of both gums ranged from 0% to 30% (w/w of starch; db). Mechanical properties, oxygen permeability (OP), water vapor permeability (WVP), solubility in water and color parameters of composite films were evaluated. The crystallinity and homogeneity between the starch and gums were also evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The scanning electron micrographs showed homogeneous matrix, with no signs of phase separation between the components. XRD analysis demonstrated diminished crystalline peak. Regardless of gum type the tensile strength (TS) of composite films increased with increasing gum concentration while reverse trend was noted for elongation at break (EAB) which found to be decreased with increasing gum concentration. The addition of both guar and xanthan gums increased solubility and WVP of the composite films. However, the OP was found to be lower than that of the control with both gums. Furthermore, addition of both gums led to changes in transparency and opacity of MKS films. Films containing 10% (w/w) xanthan gum showed lower values for solubility, WVP and OP, while film containing 20% guar gum showed good mechanical properties.

  11. Effects and after-effects of chewing gum on vigilance, heart rate, EEG and mood.

    PubMed

    Allen, Andrew P; Jacob, Tim J C; Smith, Andrew P

    2014-06-22

    Research has shown that chewing gum improves attention, although the mechanism for this effect remains unclear. This study investigated the effects and after-effects of chewing gum on vigilance, mood, heart rate and EEG. Participants completed a vigilance task four times; at baseline, with or without chewing gum, and twice post-chewing. EEG alpha and beta power at left frontal and temporal lobes, subjective mood and heart rate were assessed. Chewing gum shortened reaction time and increased the rate of hits, although hits fell during the second post-chewing task. Chewing gum heightened heart rate, but only during chewing. Gum also increased beta power at F7 and T3 immediately post-chewing, but not following the post-chewing tasks. The findings show that chewing gum affects several different indicators of alertness.

  12. Gelation and thermal characteristics of microwave extracted fish gelatin-natural gum composite gels.

    PubMed

    Binsi, P K; Nayak, Natasha; Sarkar, P C; Joshy, C G; Ninan, George; Ravishankar, C N

    2017-02-01

    In this study, the gelation and thermal characteristics of microwave extracted fish scale gelatin blended with natural gums such as gum arabic (AG), xanthan gum (XG), guar gum (GG), and tragacanth gum (TG) was evaluated. The nature of interaction and behavior of gelatin in presence of various gums was confirmed by particle size analysis, viscosity profile, FT-IR analysis and turbidity measurements. DSC data revealed that addition of AG, TG and GG remarkably improved the thermal stability of fish gelatin gel. The composite gels of TG, AG, and XG exhibited higher hardness and bloom strength values as compared to pure fish gelatin implying its textural synergy. Based on qualitative descriptive analysis, TG was found to be superior in improving the stability of fish gelatin gel, closely followed by AG. The results suggest that addition of these gums can reduce syneresis and retard melting of gelatin gels at ambient temperature, which are otherwise soft and thermally unstable.

  13. Rheological properties and thickening mechanism of aqueous diutan gum solution: Effects of temperature and salts.

    PubMed

    Xu, Long; Gong, Houjian; Dong, Mingzhe; Li, Yajun

    2015-11-05

    Rheological properties of a new microbial polysaccharide, diutan gum in aqueous solution have been systematically investigated. It is found that molecular aggregates of diutan gum can be formed at a very low concentration (0.12 g/L), and the mechanism of thickening by diutan gum is proposed. The viscosity retention rate of diutan gum changes little when increasing the temperature from 298 K to 348 K or in a high salinity solution (55.5 g L(-1)). Gel structure can be formed in the diutan gum solution, owing to the finding that the dynamic modulus has an exponential relationship with the concentration. The gel properties of diutan gum are not sensitive to temperature, and are virtually independent of cationic environment (Na(+) and Ca(2+)). The temperature/salt tolerance of the diutan gum solution is mainly attributed to its perfect double helix molecular conformation, the location of the side chains of its molecules, and its water retention capacity.

  14. Effects of chewing gum on the stress and work of university students.

    PubMed

    Smith, Andrew P; Woods, Martin

    2012-06-01

    Recent research has indicated that chewing gum can relieve perceptions of stress in an occupational sample (Smith, 2009). In the present study, 72 students completed 2 weeks of either chewing gum or refraining from chewing gum. They completed scales measuring perceived stress, anxiety, depression, and single item measures of work levels and tiredness. These were completed both pre- and post-treatment. Perceived stress decreased as a function of the amount of gum chewed. The chewing gum condition was also associated with a decrease in not getting enough academic work done. There were no significant effects of chewing gum on mental health outcomes. These results confirm some of findings from previous studies of chewing gum and stress in other samples.

  15. Effects of high hydrostatic pressure and chemical reduction on the emulsification properties of gum arabic.

    PubMed

    Ma, Fanyi; Bell, Alan E; Davis, Fred J; Chai, Yunxi

    2015-04-15

    Gum arabic is widely used in the food industry as an additive, both as a thickener and an emulsifier. This study has compared the emulsification properties of two types of gums, KLTA (Acacia senegal) and GCA (Acacia seyal), both in their native/untreated forms and after exposure to high pressure (800 MPa). Further studies were undertaken to chemically modify the disulphide linkages present and to investigate the effects of their reduction on the diffusion of the carbohydrate materials. The emulsification properties of the gum samples were examined by determining the droplet size distribution in a "model" oil-in-water system. Results showed that high pressure treatment and chemical reduction of gums changed the emulsification properties of both gums. The high molecular weight component in arabinogalactan-proteins (AGP/GP), and more "branched" carbohydrates present in gum arabic, may be responsible for the emulsification properties of GCA gum, indicating that the emulsification mechanisms for KLTA and GCA were different.

  16. 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...

  17. Nicotine Gum and Behavioral Treatment in Smoking Cessation.

    ERIC Educational Resources Information Center

    Hall, Sharon M.; And Others

    1985-01-01

    Assigned 120 smoking cessation subjects to either intensive behavioral treatment, nicotine gum in low-contact treatment, or to combined treatment. Combined treatment produced higher abstinence rates than other conditions at all assessments. Differences were significant at 3, 12, and 26 weeks, but not at 52 weeks. (NRB)

  18. Cosmic-ray effects in the Gum nebula

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Boldt, E. A.

    1971-01-01

    The effects of low energy heavy nuclei from the supernova explosion on nearby interstellar space were investigated. In addition to the ionization and heating of the Gum nebula, these particles may produce detectable fluxes of X-rays and gamma rays, both as continuum radiation and line emission.

  19. Improved emulsification performance of corn fiber gum following maturation treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn fiber gum (CFG) in the solid state (milled powder form) was subjected to a maturation treatment by heating under atmospheric pressure at 110 degrees C for 5 (CFG5) and 24 hours (CFG24). The treatment reduced the solubility and aggregation of the proteinaceous component with increased heating t...

  20. DEPOSITS ON FLAME IONIZATION DETECTORS WITH SILICONE GUM RUBBER COLUMNS,

    DTIC Science & Technology

    During the preparative gas chromatography of some organophosphorus esters using a silicone gum rubber column, a copious white deposit was formed on...detector deposits were mainly silicon phosphate (2SiO2.P2O5), and the injection port samples were alpha cristobalite (SiO2).

  1. 75 FR 44251 - Wood Oils and Gums, and Streptomyces

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ... is believed to act against disease-causing fungi in at least two ways: By colonizing plant roots to... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY EPA-HQ-OPP-2010-0441; FRL-8829-8 Wood Oils and Gums, and Streptomyces Strain K61;...

  2. Components responsible for the emulsification properties of corn fibre gum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An emulsion was prepared using corn fibre gum (CFG) and the resulting oil and aqueous phases were separated by centrifugation. The material adsorbed onto the surface of the oil droplets in the oil phase was desorbed using surfactant. The desorbed CFG and the non adsorbed CFG that remained present in...

  3. Cashew gum and gelatin blend for food packaging application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cashew gum (CG) and gelatin (G) films were developed using the casting method and response surface methodology. The objective was produce packaging films from CG/G blends that exhibit effective barrier properties. A study of zeta potential versus pH was first carried out to determine the isoelectric...

  4. Head-group acylation of monogalactosyldiacylglycerol is a common stress response, but the acyl-galactose acyl composition varies with the plant species and applied stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Head group acylation of monogalactosyldiacylglycerol is a plant lipid modification occurring during bacterial infection. Little is known about the range of stresses that induce this lipid modification, the molecular species induced, and the function of the modification. Lipidomic analysis using trip...

  5. Chewing gum increases energy expenditure before and after controlled breakfasts.

    PubMed

    Kresge, Daniel L; Melanson, Kathleen

    2015-04-01

    Chewing has been associated with improved satiation and satiety, but little is known about the metabolic impact of gum chewing. We tested the hypothesis that gum chewing would increase energy expenditure (EE) and reduce respiratory exchange ratio (RER) before and after a controlled test meal. Seventeen males and 13 females (age 21.5 ± 6.6 years, body mass index 23.9 ± 2.8 kg/m(2)) participated in a randomized crossover study in which subjects chewed sugar-free gum for a total of 1 h (3 sessions of 20 min) on the test day (GC) and did not chew gum on a control day (NG). EE and RER were measured by indirect calorimetry after an overnight fast. Subjects consumed a breakfast shake containing 30% of their measured energy needs, and then postprandial EE and RER were measured for 3 h. Blood glucose (GLC) was measured in the fasting and postprandial states at regular intervals. Fasting EE was higher during GC (1.23 ± 0.04 kcal/min; 1 kcal = 4.2 kJ) than during NG (1.17 ± 0.04 kcal/min; p = 0.016). Postprandial EE was also higher during GC (1.46 ± 0.05 kcal/min) than during NG (1.42 ± 0.05 kcal/min; p = 0.037). Fasting and postprandial RER and GLC did not differ between GC and NG. The findings demonstrate that GC is associated with higher fasting and postprandial EE without altering blood glucose or substrate oxidation as measured by RER. These data suggest that gum chewing potentially could influence short-term energy balance in this population; however, longer-term research is needed.

  6. Cetirizine release from cyclodextrin formulated compressed chewing gum.

    PubMed

    Stojanov, Mladen; Larsen, Kim L

    2012-09-01

    Beside the efficient effect on masking cetirizine bitter taste, the cyclodextrins (CDs) as well could have influence on the release from the formulation. In vitro release profiles of cetirizine from compressed chewing gums containing α-, β- and γ-CD were investigated using a three cell chewing apparatus. Different cetirizine/CD formulations were produced and analysed with respect to type of CD (α-, β- and γ-CD), the molar ratio between cetirizine and CD and the formulation of cetirizine (complex or physical mixture). Release experiments from all compressed chewing gum formulations gave similar release patterns, but with variations in the total amount released. Chewing gum formulated with cetirizine alone, demonstrated a release of 75% after 8 min of chewing. The presence of CDs resulted in increased cetirizine release. The analysis of variance (ANOVA) demonstrated that parameters with the most important influence on the release were the molar ratio of cetirizine/CD (P < 0.05) and the formulation of cetirizine/CD (complex or physical mixture) (P < 0.05). The compressed chewing gum formulations with 1:5 molar ratio of cetirizine/CD in complexed form demonstrated the highest release. Even though the statistical analysis (ANOVA) demonstrated significance in the release (P < 0.05) for the complex/physical mixture factor, this difference was negligible compared to the release from chewing gums containing cetirizine without CD. This makes physical mixtures suitable for use in cetirizine/CD formulations instead the complexes with respect to release yield. Thus unnecessary expenses for the complex preformulation may be avoided.

  7. Gum chewing and jaw muscle fatigue and pains.

    PubMed

    Christensen, L V; Tran, K T; Mohamed, S E

    1996-06-01

    To study possible associations between gum chewing and fatigue and pains in the jaw muscles, eight healthy adults performed prolonged idling, prolonged unilateral chewing of gum, and brief vigorous clenching of the teeth (MVC). Through surface electromyography (EMG), the authors monitored the cumulative (microV.s) as well as the average rates (microV.s-1) of contractile activities in the right and left masseter muscles. During 10 min of idling there was an absence of muscle fatigue and muscle pains when the EMG rates of the right and left masseter muscles were 2% and 3%, respectively, of those required to elicit isometric muscle pains through MVC. During 10 min of right-sided gum chewing at a rate of 1.2 Hz, the majority of subjects (75%) experienced weak jaw muscle fatigue-not jaw muscle pains-when the EMG rates of the right and left masseter muscles were 38% and 19%, respectively, of those required to elicit isometric pains through MVC. In comparison with 10 min of idling, the weak muscle fatigue of 10 min of unilateral gum chewing appeared when the total contractile activities of the right and left masseter muscles were increased by 1664% and 519%, respectively. It seemed as if prolonged unilateral gum chewing and previous pain-releasing MVC caused some sensitization of muscle nociceptors which, in turn, aggravated subsequent isometric jaw muscle pains elicited through MVC. Even though the right masseter muscle was the most frequent site of clinical fatigue and pains, the authors found no evidence supporting the theoretical foundation of the myofascial pain/dysfunction syndrome.

  8. Evaluation of accelerated stability test conditions for medicated chewing gums.

    PubMed

    Maggi, Lauretta; Conte, Ubaldo; Nhamias, Alain; Grenier, Pascal; Vergnault, Guy

    2013-10-01

    The overall stability of medicated chewing gums is investigated under different storage conditions. Active substances with different chemical stabilities in solid state are chosen as model drugs. The dosage form is a three layer tablet obtained by direct compression. The gum core contains the active ingredient while the external layers are formulated to prevent gum adhesion to the punches of the tableting machine. Two accelerated test conditions (40°C/75% RH and 30°C/65% RH) are performed for 6 months. Furthermore, a long-term stability test at room conditions is conducted to verify the predictability of the results obtained from the stress tests. Some drugs are stable in all the conditions tested, but other drugs, generally considered stable in solid dosage forms, have shown relevant stability problems particularly when stress test conditions are applied to this particular semi-solid dosage forms. For less stable drugs, the stress conditions of 40°C/75% RH are not always predictable of chewing gum stability at room temperature and may produce false negative; intermediate conditions, 30°C/65% RH, are more predictive for this purpose, the results of drug content found after 6 months at intermediate stress conditions and 12 months at room conditions are generally comparable. But the results obtained show that only long-term conditions stability tests gave consistent results. During aging, the semi solid nature of the gum base itself, may also influence the drug delivery rate during chewing and great attention should be given also to the dissolution stability.

  9. Two fatty acyl reductases involved in moth pheromone biosynthesis

    PubMed Central

    Antony, Binu; Ding, Bao-Jian; Moto, Ken’Ichi; Aldosari, Saleh A.; Aldawood, Abdulrahman S.

    2016-01-01

    Fatty acyl reductases (FARs) constitute an evolutionarily conserved gene family found in all kingdoms of life. Members of the FAR gene family play diverse roles, including seed oil synthesis, insect pheromone biosynthesis, and mammalian wax biosynthesis. In insects, FAR genes dedicated to sex pheromone biosynthesis (pheromone-gland-specific fatty acyl reductase, pgFAR) form a unique clade that exhibits substantial modifications in gene structure and possesses unique specificity and selectivity for fatty acyl substrates. Highly selective and semi-selective ‘single pgFARs’ produce single and multicomponent pheromone signals in bombycid, pyralid, yponomeutid and noctuid moths. An intriguing question is how a ‘single reductase’ can direct the synthesis of several fatty alcohols of various chain lengths and isomeric forms. Here, we report two active pgFARs in the pheromone gland of Spodoptera, namely a semi-selective, C14:acyl-specific pgFAR and a highly selective, C16:acyl-specific pgFAR, and demonstrate that these pgFARs play a pivotal role in the formation of species-specific signals, a finding that is strongly supported by functional gene expression data. The study envisages a new area of research for disclosing evolutionary changes associated with C14- and C16-specific FARs in moth pheromone biosynthesis. PMID:27427355

  10. Regioselective self-acylating cyclodextrins in organic solvent

    PubMed Central

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D.; Choi, Youngjin; Jung, Seunho

    2016-01-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods. PMID:27020946

  11. An annotated database of Arabidopsis mutants of acyl lipid metabolism

    SciTech Connect

    McGlew, Kathleen; Shaw, Vincent; Zhang, Meng; Kim, Ryeo Jin; Yang, Weili; Shorrosh, Basil; Suh, Mi Chung; Ohlrogge, John

    2014-12-10

    Mutants have played a fundamental role in gene discovery and in understanding the function of genes involved in plant acyl lipid metabolism. The first mutant in Arabidopsis lipid metabolism (fad4) was described in 1985. Since that time, characterization of mutants in more than 280 genes associated with acyl lipid metabolism has been reported. This review provides a brief background and history on identification of mutants in acyl lipid metabolism, an analysis of the distribution of mutants in different areas of acyl lipid metabolism and presents an annotated database (ARALIPmutantDB) of these mutants. The database provides information on the phenotypes of mutants, pathways and enzymes/proteins associated with the mutants, and allows rapid access via hyperlinks to summaries of information about each mutant and to literature that provides information on the lipid composition of the mutants. Mutants for at least 30 % of the genes in the database have multiple names, which have been compiled here to reduce ambiguities in searches for information. Furthermore, the database should also provide a tool for exploring the relationships between mutants in acyl lipid-related genes and their lipid phenotypes and point to opportunities for further research.

  12. An annotated database of Arabidopsis mutants of acyl lipid metabolism

    DOE PAGES

    McGlew, Kathleen; Shaw, Vincent; Zhang, Meng; ...

    2014-12-10

    Mutants have played a fundamental role in gene discovery and in understanding the function of genes involved in plant acyl lipid metabolism. The first mutant in Arabidopsis lipid metabolism (fad4) was described in 1985. Since that time, characterization of mutants in more than 280 genes associated with acyl lipid metabolism has been reported. This review provides a brief background and history on identification of mutants in acyl lipid metabolism, an analysis of the distribution of mutants in different areas of acyl lipid metabolism and presents an annotated database (ARALIPmutantDB) of these mutants. The database provides information on the phenotypes ofmore » mutants, pathways and enzymes/proteins associated with the mutants, and allows rapid access via hyperlinks to summaries of information about each mutant and to literature that provides information on the lipid composition of the mutants. Mutants for at least 30 % of the genes in the database have multiple names, which have been compiled here to reduce ambiguities in searches for information. Furthermore, the database should also provide a tool for exploring the relationships between mutants in acyl lipid-related genes and their lipid phenotypes and point to opportunities for further research.« less

  13. Regioselective self-acylating cyclodextrins in organic solvent

    NASA Astrophysics Data System (ADS)

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D.; Choi, Youngjin; Jung, Seunho

    2016-03-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods.

  14. Contribution of lipids, phenolic acids, and protein rich components to emulsifying properties of corn fiber gum and acacia gum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn fiber gum (CFG) is an arabinoxylan enriched fraction obtained by the extraction of corn bran/fiber using a proprietary alkaline hydrogen peroxide process. When purified CFG prepared by this process was hydrolyzed with concentrated base (1.5 N methanolic KOH at 70 °C for one hour) considerable ...

  15. Saffron and beetroot extracts encapsulated in maltodextrin, gum Arabic, modified starch and chitosan: Incorporation in a chewing gum system.

    PubMed

    Chranioti, Charikleia; Nikoloudaki, Aspasia; Tzia, Constantina

    2015-08-20

    Maltodextrin (MD-21DE), gum Arabic (GA), gum Arabic-modified starch (GA-MS), modified starch-chitosan (MS-CH) and modified starch-maltodextrin-chitosan (MS-MD-CH) were used as agents for beetroot and saffron coloring-extracts microencapsulation by freeze drying. The produced powders were evaluated in terms of coloring strength (E) during storage at 40°C for 10 weeks and a first-order kinetic was applied. Color parameters (L(*), a(*), b(*), C(*) and ΔE(*)) and water sorption behavior was also studied. Moreover, incorporation of the powders in a chewing gum model system was conducted. The type of encapsulating agent significantly (P<0.05) affected the studied parameters with the order of protection in both extracts being as follows: MD>GA>GA-MS>MS-CH>MS-MD-CH. The water sorption study revealed that MD and GA kept their structural integrity up to water activities of 0.66 and 0.82, respectively. The chewing gum samples produced with coloring extracts encapsulated in GA-MS showed the greatest a(*)(for beetroot) and b(*) (for saffron) values indicating a better protection.

  16. Trapping of the Enoyl-Acyl Carrier Protein Reductase–Acyl Carrier Protein Interaction

    PubMed Central

    Tallorin, Lorillee; Finzel, Kara; Nguyen, Quynh G.; Beld, Joris; La Clair, James J.; Burkart, Michael D.

    2016-01-01

    An ideal target for metabolic engineering, fatty acid biosynthesis remains poorly understood on a molecular level. These carrier protein-dependent pathways require fundamental protein–protein interactions to guide reactivity and processivity, and their control has become one of the major hurdles in successfully adapting these biological machines. Our laboratory has developed methods to prepare acyl carrier proteins (ACPs) loaded with substrate mimetics and cross-linkers to visualize and trap interactions with partner enzymes, and we continue to expand the tools for studying these pathways. We now describe application of the slow-onset, tight-binding inhibitor triclosan to explore the interactions between the type II fatty acid ACP from Escherichia coli, AcpP, and its corresponding enoyl-ACP reductase, FabI. We show that the AcpP–triclosan complex demonstrates nM binding, inhibits in vitro activity, and can be used to isolate FabI in complex proteomes. PMID:26938266

  17. A Comparative Analysis of Acyl-Homoserine Lactone Synthase Assays.

    PubMed

    Shin, Daniel; Frane, Nicole D; Brecht, Ryan M; Keeler, Jesse; Nagarajan, Rajesh

    2015-12-01

    Quorum sensing is cell-to-cell communication that allows bacteria to coordinate attacks on their hosts by inducing virulent gene expression, biofilm production, and other cellular functions, including antibiotic resistance. AHL synthase enzymes synthesize N-acyl-l-homoserine lactones, commonly referred to as autoinducers, to facilitate quorum sensing in Gram-negative bacteria. Studying the synthases, however, has proven to be a difficult road. Two assays, including a radiolabeled assay and a colorimetric (DCPIP) assay are well-documented in literature to study AHL synthases. In this paper, we describe additional methods that include an HPLC-based, C-S bond cleavage and coupled assays to investigate this class of enzymes. In addition, we compare and contrast each assay for both acyl-CoA- and acyl-ACP-utilizing synthases. The expanded toolkit described in this study should facilitate mechanistic studies on quorum sensing signal synthases and expedite discovery of antivirulent compounds.

  18. Asymmetric Allylboration of Acyl Imines Catalyzed by Chiral Diols

    PubMed Central

    Lou, Sha; Moquist, Philip N.; Schaus, Scott E.

    2008-01-01

    Chiral BINOL-derived diols catalyze the enantioselective asymmetric allylboration of acyl imines. The reaction requires 15 mol% of (S)-3,3′-Ph2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (75 – 94%) and high enantiomeric ratios (95:5 – 99.5:0.5) for aromatic and aliphatic imines. High diastereoselectivities (dr > 98:2) and enantioselectivities (er > 98:2) are obtained in the reactions of acyl imines with crotyldiisopropoxyboranes. This asymmetric transformation is directly applied to the synthesis of maraviroc, the selective CCR5 antagonist with potent activity against HIV-1 infection. Mechanistic investigations of the allylboration reaction including IR, NMR, and mass spectrometry study indicate that acyclic boronates are activated by chiral diols via exchange of one of the boronate alkoxy groups with activation of the acyl imine via hydrogen bonding. PMID:18020334

  19. Identification of Unusual Phospholipid Fatty Acyl Compositions of Acanthamoeba castellanii

    PubMed Central

    Palusinska-Szysz, Marta; Kania, Magdalena; Turska-Szewczuk, Anna; Danikiewicz, Witold; Russa, Ryszard; Fuchs, Beate

    2014-01-01

    Acanthamoeba are opportunistic protozoan pathogens that may lead to sight-threatening keratitis and fatal granulomatous encephalitis. The successful prognosis requires early diagnosis and differentiation of pathogenic Acanthamoeba followed by aggressive treatment regimen. The plasma membrane of Acanthamoeba consists of 25% phospholipids (PL). The presence of C20 and, recently reported, 28- and 30-carbon fatty acyl residues is characteristic of amoeba PL. A detailed knowledge about this unusual PL composition could help to differentiate Acanthamoeba from other parasites, e.g. bacteria and develop more efficient treatment strategies. Therefore, the detailed PL composition of Acanthamoeba castellanii was investigated by 31P nuclear magnetic resonance spectroscopy, thin-layer chromatography, gas chromatography, high performance liquid chromatography and liquid chromatography-mass spectrometry. Normal and reversed phase liquid chromatography coupled with mass spectrometric detection was used for detailed characterization of the fatty acyl composition of each detected PL. The most abundant fatty acyl residues in each PL class were octadecanoyl (18∶0), octadecenoyl (18∶1 Δ9) and hexadecanoyl (16∶0). However, some selected PLs contained also very long fatty acyl chains: the presence of 28- and 30-carbon fatty acyl residues was confirmed in phosphatidylethanolamine (PE), phosphatidylserine, phosphatidic acid and cardiolipin. The majority of these fatty acyl residues were also identified in PE that resulted in the following composition: 28∶1/20∶2, 30∶2/18∶1, 28∶0/20∶2, 30∶2/20∶4 and 30∶3/20∶3. The PL of amoebae are significantly different in comparison to other cells: we describe here for the first time unusual, very long chain fatty acids with Δ5-unsaturation (30∶35,21,24) and 30∶221,24 localized exclusively in specific phospholipid classes of A. castellanii protozoa that could serve as specific biomarkers for the presence of these

  20. Sphingomyelin interfacial behavior: the impact of changing acyl chain composition.

    PubMed Central

    Li, X M; Smaby, J M; Momsen, M M; Brockman, H L; Brown, R E

    2000-01-01

    Sphingomyelins (SMs) containing homogeneous acyl chains with 12, 14, 16, 18, 24, or 26 carbons were synthesized and characterized using an automated Langmuir-type film balance. Surface pressure was monitored as a function of lipid molecular area at constant temperatures between 10 degrees C and 30 degrees C. SM containing lauroyl (12:0) acyl chains displayed only liquid-expanded behavior. Increasing the length of the saturated acyl chain (e.g., 14:0, 16:0, or 18:0) resulted in liquid-expanded to condensed two-dimensional phase transitions at many temperatures in the 10-30 degrees C range. Similar behavior was observed for SMs with lignoceroyl (24:0) or (cerotoyl) 26:0 acyl chains, but isotherms showed only condensed behavior at 10 and 15 degrees C. Insights into the physico-mechanical in-plane interactions occurring within the different SM phases and accompanying changes in SM phase state were provided by analyzing the interfacial area compressibility moduli. At similar surface pressures, SM fluid phases were less compressible than those of phosphatidylcholines with similar chain structures. The area per molecule and compressibility of SM condensed phases depended upon the length of the saturated acyl chain and upon spreading temperature. Spreading of SMs with very long saturated acyl chains at temperatures 30-35 degrees below T(m) resulted in condensed films with lower in-plane compressibilities, but consistently larger cross-sectional molecular areas than the condensed phases achieved by spreading at temperatures only 10-20 degrees below T(m). This behavior is discussed in terms of the enhancement of SM lateral aggregation by temperature reduction, a common approach used during domain isolation from biomembranes. PMID:10733971

  1. Socio-economic aspects of Gum Arabic production in Dalanj area, South Korodofan, Sudan.

    PubMed

    Koli, A O; Eltayeb, A M; Sanjak, E M; Mohammed, M H

    2013-11-01

    Acacia senegal (locally: Hashab tree) is one of the most important tree species in Sudan as it considers the main Gum Arabic producing tree. The objective of this study is to investigate the socio-economic aspects of gum Arabic production and to assess contribution of gum Arabic to sustainable livelihood of local people in Dalanj Locality, South Kordofan State-Sudan. Social survey was carried out by using structured questionnaire for 80 respondents (gum producers) on random sample basis in eight villages, 10 respondents from each village. Issues pertaining to socio-economic factors affecting gum Arabic production and contribution of gum Arabic to sustainable livelihood of local people, in Dalanj Locality, were assessed. Results of the study revealed that expansion of agriculture lands at the expense of hashab trees, fires and illegal felling are the most important factors constraining gum production in the area. The results also indicated that agriculture is the main source of income and gum Arabic is a supplementary source of income. The importance of gum Arabic becomes apparent during (off farm season) the period between crops harvest and the preparation of the next agricultural season. Establishment of producers' associations and provision of loans to producers are highly recommended to ensure sustainability of gum production.

  2. Quantum chemical study of penicillin: Reactions after acylation

    NASA Astrophysics Data System (ADS)

    Li, Rui; Feng, Dacheng; Zhu, Feng

    The density functional theory methods were used on the model molecules of penicillin to determine the possible reactions after their acylation on ?-lactamase, and the results were compared with sulbactam we have studied. The results show that, the acylated-enzyme tetrahedral intermediate can evolves with opening of ?-lactam ring as well as the thiazole ring; the thiazole ring-open products may be formed via ?-lactam ring-open product or from tetrahedral intermediate directly. Those products, in imine or enamine form, can tautomerize via hydrogen migration. In virtue of the water-assisted, their energy barriers are obviously reduced.

  3. Theoretical background and clinical use of nicotine chewing gum.

    PubMed

    Russell, M A; Jarvis, M J

    1985-01-01

    In our view, nicotine chewing gum is the most significant single advance achieved so far in the whole field of smoking cessation. It is the only treatment that has yet been shown to have a specific effect over and above that of attention-placebo factors, and this has been demonstrated repeatedly by several research groups in different countries. It is suitable for use as an adjunct both to intensive psychological methods of treatment and to minimal and largely self-help types of intervention. In either case, it approximately doubles the success rates achieved by intervention without the use of gum. It can be administered effectively by psychologists and family physicians and no doubt by other adequately trained health professionals too. The efficacy of nicotine chewing gum is not limited to the smokers who use it. Its incorporation into a treatment or intervention programme revitalises and maintains the morale of therapists. Until the advent of nicotine gum it has required either a research interest, financial reward, or a degree of masochism to remain for long at the sharp end of the business of helping people to give up smoking. Without a treatment capable of reducing withdrawal symptoms, therapists become drained by having constantly to give out encouragement and support to help their clients to tolerate withdrawal long enough for the difficulties gradually to wane. The rapid and tangible effect of the gum in relieving withdrawal symptoms is a boost to the morale and confidence of client and therapist alike. It is perceived as helpful even by those who fail. This encourages people who relapse to return for further therapy. A discouraging feature with other treatments has been the tendency for those who relapse to avoid contact with their therapists even to the extent of not responding to data collection at long-term follow up. In view of its efficacy, its potential for use in many settings, its minimal demands on therapists' time, and its synergistic effect in

  4. Novel approach in LC-MS/MS using MRM to generate a full profile of acyl-CoAs: discovery of acyl-dephospho-CoAs[S

    PubMed Central

    Li, Qingling; Zhang, Shenghui; Berthiaume, Jessica M.; Simons, Brigitte; Zhang, Guo-Fang

    2014-01-01

    A metabolomic approach to selectively profile all acyl-CoAs was developed using a programmed multiple reaction monitoring (MRM) method in LC-MS/MS and was employed in the analysis of various rat organs. The programmed MRM method possessed 300 mass ion transitions with the mass difference of 507 between precursor ion (Q1) and product ion (Q3), and the precursor ion started from m/z 768 and progressively increased one mass unit at each step. Acyl-dephospho-CoAs resulting from the dephosphorylation of acyl-CoAs were identified by accurate MS and fragmentation. Acyl-dephospho-CoAs were also quantitatively scanned by the MRM method with the mass difference of 427 between Q1 and Q3 mass ions. Acyl-CoAs and dephospho-CoAs were assayed with limits of detection ranging from 2 to 133 nM. The accuracy of the method was demonstrated by assaying a range of concentrations of spiked acyl-CoAs with the results of 80–114%. The distribution of acyl-CoAs reflects the metabolic status of each organ. The physiological role of dephosphorylation of acyl-CoAs remains to be further characterized. The methodology described herein provides a novel strategy in metabolomic studies to quantitatively and qualitatively profile all potential acyl-CoAs and acyl-dephospho-CoAs. PMID:24367045

  5. Copper(II)/amine synergistically catalyzed enantioselective alkylation of cyclic N-acyl hemiaminals with aldehydes.

    PubMed

    Sun, Shutao; Mao, Ying; Lou, Hongxiang; Liu, Lei

    2015-07-07

    The first catalytic asymmetric alkylation of N-acyl quinoliniums with aldehydes has been described. A copper/amine synergistic catalytic system has been developed, allowing the addition of functionalized aldehydes to a wide range of electronically varied N-acyl quinoliniums in good yields with excellent enantiocontrol. The synergistic catalytic system was also effective for N-acyl dihydroisoquinoliniums and β-caboliniums, demonstrating the general applicability of the protocol in the enantioselective alkylation of diverse cyclic N-acyl hemiaminals.

  6. The Level of Circulating Octanoate Does Not Predict Ghrelin O-Acyl Transferase (GOAT)-Mediated Acylation of Ghrelin During Fasting

    PubMed Central

    Nikolayev, Alexander; Liu, Jianhua; Pezzoli, Suzan S.; Farhy, Leon S.; Patrie, James; Gaylinn, Bruce D.; Heiman, Mark; Thorner, Michael O.

    2015-01-01

    Background: Acyl-ghrelin is a 28-amino acid peptide released from the stomach. Ghrelin O-acyl transferase (GOAT) attaches an 8-carbon medium-chain fatty acid (MCFA) (octanoate) to serine 3 of ghrelin. This acylation is necessary for the activity of ghrelin. Animal data suggest that MCFAs provide substrate for GOAT and an increase in nutritional octanoate increases acyl-ghrelin. Objectives: To address the question of the source of substrate for acylation, we studied whether the decline in ghrelin acylation during fasting is associated with a decline in circulating MCFAs. Methods: Eight healthy young men (aged 18–28 years, body mass index range, 20.6–26.2 kg/m2) had blood drawn every 10 minutes for acyl- and desacyl-ghrelin and every hour for free fatty acids (FFAs) during the last 24 hours of a 61.5-hour fast and during a fed day. FFAs were measured by a highly sensitive liquid chromatography-mass spectroscopy method. Acyl- and desacyl-ghrelin were measured in an in-house assay; the results were published previously. Ghrelin acylation was assessed by the ratio of acyl-ghrelin to total ghrelin. Results: With the exception of MCFAs C8 and C10, all other FFAs, the MCFAs (C6 and C12), and the long-chain fatty acids (C14–C18) significantly increased with fasting (P < .05). There was no significant association between the fold change in ghrelin acylation and circulating FFAs. Conclusions: These results suggest that changes in circulating MCFAs are not linked to the decline in ghrelin acylation during fasting and support the hypothesis that acylation of ghrelin depends at least partially on the availability of gastroluminal MCFAs or the regulation of GOAT activity. PMID:25337923

  7. A Cerulenin Insensitive Short Chain 3-Ketoacyl-Acyl Carrier Protein Synthase in Spinacia oleracea Leaves

    PubMed Central

    Jaworski, Jan G.; Clough, Richard C.; Barnum, Susan R.

    1989-01-01

    A cerulenin insensitive 3-ketoacyl-acyl carrier protein synthase has been assayed in extracts of spinach (Spinacia oleracea) leaf. The enzyme was active in the 40 to 80% ammonium sulfate precipitate of whole leaf homogenates and catalyzed the synthesis of acetoacetyl-acyl carrier protein. This condensation reaction was five-fold faster than acetyl-CoA:acyl carrier protein transacylase, and the initial rates of acyl-acyl carrier protein synthesis were independent of the presence of cerulenin. In the presence of fatty acid synthase cofactors and 100 micromolar cerulenin, the principal fatty acid product of de novo synthesis was butyric and hexanoic acids. Using conformationally sensitive native polyacrylamide gel electrophoresis for separation, malonyl-, acetyl-, butyryl-, hexanoyl, and long chain acyl-acyl carrier proteins could be detected by immunoblotting and autoradiography. In the presence of 100 micromolar cerulenin, the accumulation of butyryl- and hexanoyl-acyl carrier protein was observed, with no detectable long chain acyl-acyl carrier proteins or fatty acids being produced. In the absence of cerulenin, the long chain acyl-acyl carrier proteins also accumulated. Images Figure 2 Figure 3 PMID:16666765

  8. Locust bean gum: Exploring its potential for biopharmaceutical applications

    PubMed Central

    Dionísio, Marita; Grenha, Ana

    2012-01-01

    Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua). This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed. PMID:22923958

  9. Preparation and characterization of tragacanth-locust bean gum edible blend films.

    PubMed

    Mostafavi, Fatemeh Sadat; Kadkhodaee, Rassoul; Emadzadeh, Bahareh; Koocheki, Arash

    2016-03-30

    The present work introduces the structure and physicomechanical properties of a novel blend film made from binary solutions of gum tragacanth (GT) and locust bean gum (LBG) at different mixing ratios. Apparent viscosities and surface tensions of individual and blend gum solutions were also investigated. The viscosity data indicated that there was a distinct synergism between the two gums at all mixing ratios. FTIR spectra showed the existence of noncovalent intermolecular interactions between gums. The surface tensions of binary solutions were significantly lower than those of individual gums which is advantageous for coating applications. All films had homogenous and smooth surface morphology and their transparency, water vapour barrier and mechanical properties were improved by incorporating LBG in blend. The results of this study suggest that GT-LBG blend film, owing to its desirable properties, has the potential to be used as a new degradable food packaging material.

  10. Functionality of maize, wheat, teff and cassava starches with stearic acid and xanthan gum.

    PubMed

    Maphalla, Thabelang Gladys; Emmambux, Mohammad Naushad

    2016-01-20

    Consumer concerns to synthetic chemicals have led to strong preference for 'clean' label starches. Lipid and hydrocolloids are food friendly chemicals. This study determines the effects of stearic acid and xanthan gum alone and in combination on the functionality of maize, wheat, teff and cassava starches. An increase in viscosity was observed for all starches with stearic acid and xanthan gum compared to the controls with cassava having the least increase. A further increase in viscosity was observed for the cereal starches with combination of stearic acid and xanthan gum. Stearic acid reduced retrogradation, resulting in soft textured pastes. Combination of stearic acid and xanthan gum reduced the formation of type IIb amylose-lipid complexes, syneresis, and hysteresis in cereal starches compared to stearic acid alone. A combination of stearic acid and xanthan gum produce higher viscosity non-gelling starches and xanthan gum addition increases physical stability to freezing and better structural recovery after shear.

  11. Influence of tragacanth gum in egg white based bioplastics: Thermomechanical and water uptake properties.

    PubMed

    López-Castejón, María Luisa; Bengoechea, Carlos; García-Morales, Moisés; Martínez, Inmaculada

    2016-11-05

    This study aims to extend the range of applications of tragacanth gum by studying its incorporation into bioplastics formulation, exploring the influence that different gum contents (0-20wt.%) exert over the thermomechanical and water uptake properties of bioplastics based on egg white albumen protein (EW). The effect of plasticizer nature was also evaluated through the modification of the water/glycerol ratio within the plasticizer fraction (fixed at 40wt.%). The addition of tragacanth gum generally yielded an enhancement of the water uptake capacity, being doubled at the highest content. Conversely, presence of tragacanth gum resulted in a considerable decrease in the bioplastic mechanical properties: both tensile strength and maximum elongation were reduced up to 75% approximately when compared to the gum-free system. Ageing of selected samples was also studied, revealing an important effect of storage time when tragacanth gum is present, possibly due to its hydrophilic character.

  12. The effect of chewing sugar-free gum after meals on clinical caries incidence.

    PubMed

    Beiswanger, B B; Boneta, A E; Mau, M S; Katz, B P; Proskin, H M; Stookey, G K

    1998-11-01

    To determine the effect of chewing sugar-free gum on caries incidence, the authors conducted a randomized clinical study. A total of 1,402 children in Puerto Rico, in grades 5 through 7 at baseline, completed the study. They were randomized by classroom into a control group or chewing gum group; those in the gum group were instructed to chew sugar-free gum for 20 minutes after each of three meals a day. Clinical and radiographic evaluations were performed at baseline and after two and three years. The results show that all subjects and high-risk subjects, respectively, in the gum group developed 7.9 percent and 11.0 percent fewer decayed, missing or filled surfaces than subjects in the control group. Based on these findings, the authors concluded that chewing sorbitol-based sugar-free gum after eating significantly reduces the incidence of dental caries.

  13. Effects of ultraviolet irradiation on the physicochemical and functional properties of gum arabic.

    PubMed

    Kuan, Yau-Hoong; Bhat, Rajeev; Senan, Chandra; Williams, Peter A; Karim, Alias A

    2009-10-14

    The impact of ultraviolet (UV) irradiation on the physicochemical and functional properties of gum arabic was investigated. Gum arabic samples were exposed to UV irradiation for 30, 60, 90, and 120 min; gum arabic was also treated with formaldehyde for comparison. Molecular weight analysis using gel permeation chromatography indicated that no significant changes occurred on the molecular structure on the samples exposed to UV irradiation. Free amino group analysis indicated that mild UV irradiation (30 min) could induce cross-linking on gum arabic; this result was comparable with that of samples treated with formaldehyde. However, viscosity break down was observed for samples exposed to UV irradiation for longer times (90 and 120 min). All irradiated and formaldehyde-treated samples exhibited better emulsification properties than unirradiated samples. These results indicate that UV-irradiated gum arabic could be a better emulsifier than the native (unmodified) gum arabic and could be exploited commercially.

  14. Characterization of gum ghatti (Anogeissus latifolia): a structural and rheological approach.

    PubMed

    Kaur, Lovedeep; Singh, Jaspreet; Singh, Harjinder

    2009-08-01

    Gatifolia, a commercial gum ghatti (Anogeissus latifolia) product was studied for its structural, thermal, and rheological characteristics. This study may prove helpful for the use of gum ghatti in a diverse range of food applications. The molecular weight (M(W)) and R(g) (radius of gyration) for gum ghatti were calculated to be approximately 8.94 x 10(7) g/mol and 140 nm, respectively, using high-performance size exclusion chromatography (HPSEC) system combined with multi-angle laser light scattering (MALLS). Gum ghatti solutions exhibited pseudoplastic behavior (as determined by flow experiments), which became more prevalent with increasing concentrations. Gum ghatti also displayed time-dependent shear-thickening behavior and showed negative hysteresis during up-down flow measurements. Under the measurement conditions at the range of frequencies and temperatures studied, the gum did not behave as a typical viscoelastic gel.

  15. X-ray diffraction, IR spectroscopy and thermal characterization of partially hydrolyzed guar gum.

    PubMed

    Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

    2012-05-01

    Guar gum was hydrolyzed using cellulase from Aspergillus niger at 5.6 pH and 50°C temperature. Hydrolyzed guar gum sample was characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, dilute solution viscometry and rotational viscometry. Viscometry analysis of native guar gum showed a molecular weight of 889742.06, whereas, after enzymatic hydrolysis, the resultant product had a molecular weight of 7936.5. IR spectral analysis suggests that after enzymatic hydrolysis of guar gum there was no major transformation of functional group. Thermal analysis revealed no major change in thermal behavior of hydrolyzed guar gum. It was shown that partial hydrolysis of guar gum could be achieved by inexpensive and food grade cellulase (Aspergillus niger) having commercial importance and utilization as a functional soluble dietary fiber for food industry.

  16. In situ remineralization of subsurface enamel lesion after the use of a fluoride chewing gum.

    PubMed

    Lamb, W J; Corpron, R E; More, F G; Beltran, E D; Strachan, D S; Kowalski, C J

    1993-01-01

    In situ remineralization of early enamel lesions by a fluoride chewing gum was studied. Human enamel specimens with subsurface lesions were mounted in removable lower appliances for 6 adults. Subjects used a F-free dentifrice 3x/day and chewed five sticks/day for the F gum group (0.1 mg F/stick) or five sticks of sugarless gum. No gum was chewed for controls. Surface microhardness was performed on: (1) sound enamel; (2) lesions; (3) after intraoral exposure, and (4) after acid-resistance testing (ART). Separate specimens were etched and measured for F uptake and image analyses on microradiographs were performed for all regimens. delta Z values were calculated and converted to percent of mineralization. Values for F gum were significantly higher (p > 0.05) than non-F gum and controls for ART, percent remineralization, and F uptake up to 70 microns depth.

  17. Effect of after-meal sucrose-free gum-chewing on clinical caries.

    PubMed

    Szöke, J; Bánóczy, J; Proskin, H M

    2001-08-01

    Previous in situ and in vitro studies have demonstrated that the chewing of sucrose-free gum after eating reduces the development of dental caries. To investigate the extrapolation of these findings to the clinical setting, we conducted a two-year study on 547 schoolchildren in Budapest, Hungary. Subjects in the "Gum" group were instructed to chew one stick of a commercially available sorbitol-sweetened chewing gum for 20 minutes after meals, three times daily. The "Control" group was not provided with chewing gum. After two years, the "Gum" group exhibited a 38.7% reduction in incremental caries, excluding white spots, compared with the "Control" group. Including white spots, a corresponding 33.1% reduction was indicated. These results clearly suggest that even in a moderate caries population practicing normal oral hygiene, including the use of fluoride dentifrices, an after-meal gum-chewing regimen can significantly reduce the rate of caries development.

  18. Effect of after-meal sucrose-free gum-chewing on clinical caries.

    PubMed

    Szöke, J; Bánóczy, J

    2005-07-01

    Previous in situ and in vitro studies have demonstrated that the chewing of sucrose-free gum after eating reduces the development of dental caries. To investigate the extrapolation of these findings to the clinical setting, we conducted a two-year study on 547 schoolchildren in Budapest, Hungary. Subjects in the "Gum" group were instructed to chew one stick of a commercially available sorbitol-sweetened chewing gum for 20 minutes after meals, three times daily. The "Control" group was not provided with chewing gum. After two years, the "Gum" group exhibited a 38.7% reduction in incremental caries, excluding white spots, compared with the "Control" group. Including white spots, a corresponding 33.1% reduction was indicated. These results clearly suggest that even in a moderate caries population practicing normal oral hygiene, including the use of fluoride dentifrices, an after-meal gum-chewing regimen can significantly reduce the rate of caries development.

  19. Radiation induced degradation of xanthan gum in the solid state

    NASA Astrophysics Data System (ADS)

    Şen, Murat; Hayrabolulu, Hande; Taşkın, Pınar; Torun, Murat; Demeter, Maria; Cutrubinis, Mihalis; Güven, Olgun

    2016-07-01

    In this study, the effect of ionizing radiation on xanthan gum was investigated. Xanthan samples were irradiated with gamma rays in air at ambient temperature in the solid state at different dose rates and doses. Change in their molecular weights was followed by size exclusion chromatography (SEC). Chain scission yield (G(S)), and degradation rate constants (k) were calculated. The calculated G(S) values are 0.0151±0.0015, 0.0144±0.0020, 0.0098±0.0010 μmol/J and k values are 1.4×10-8±1.4×10-9, 1.3×10-8±2.0×10-9, 8.7×10-9±1.0×10-9 Gy-1 for 0.1, 3.3 and 7.0 kGy/h dose rates, respectively. It was observed that the dose rate was an important factor controlling the G(S) and degradation rate of xanthan gum. Considering its use in food industry, the effect of irradiation on rheological properties of xanthan gum solutions was also investigated and flow model parameters were determined for all dose rates and doses. Rheological analysis showed that xanthan solution showed non-Newtonian shear thinning behaviour and ionizing radiation does not change the non-Newtonian and shear thinning flow behaviour of xanthan gum solutions in concentration ranges of this work. It was determined that, Power Law model well described the flow behaviour of unirradiated and irradiated xanthan solutions.

  20. Alternative Fuels Compatibility with Army Equipment Testing - Existent Gum

    DTIC Science & Technology

    2012-02-01

    Nitrile synthetic rubber RMA Class A (High Oil Resistance) CONSTRUCTION: COVER: Red Chemivic™ (white spiral stripe) synthetic rubber (oil resistant...the widest swings in physical properties after exposure to fuel blends ; see polyurethane % change in volume (Figure 3) versus nitrile (Figure 4...various aspects of the ASTM D381 method as a means to determine gum contamination of fuel in contact elastomeric and rubber materials. 15. SUBJECT TERMS

  1. Hepatoprotective triterpenes from the gum resin of Boswellia carterii.

    PubMed

    Wang, Yan-Gai; Ma, Qin-Ge; Tian, Jin; Ren, Jin; Wang, Ai-Guo; Ji, Teng-Fei; Yang, Jian-Bo; Su, Ya-Lun

    2016-03-01

    Ten tirucallane-type triterpenes named boscartene A-J and a nor-tetracyclic triterpene boscartene K, together with ten known compounds were isolated from the gum resin of Boswellia carterii Birdw. Their structures and absolute configurations were elucidated by extensive spectroscopic analysis. In vitro assay, some of these compounds (10 μM) showed moderate hepatoprotective activities against d-galactosamine-induced HL-7702 cell damage.

  2. Synergistic gelation of xanthan gum with locust bean gum: a rheological investigation.

    PubMed

    Copetti, G; Grassi, M; Lapasin, R; Pricl, S

    1997-12-01

    Many industrial products often include in their formulation more than one polysaccharide to achieve the desired properties during and after processing. Many such mixed systems behave as would be expected from the known properties of the individual polymers. In others, however, their properties are superior to those of either component alone, or may be qualitatively different. In many polysaccharide systems, the combination of a gelling polymer with a nongelling one gives rise to strong synergistic effects, as a consequence of interaction among different chain polymers and formation of mixed junction zones. Probably, the most exploited mixed gels, especially by the food industry, are those involving the microbial polysaccharide xanthan gum (XG) and the plant galactomannans, like locust bean gum (LBG). Concentrated aqueous systems of LBG and XG display quite different rheological properties: the former show the behaviour typical of hyperentangled macromolecular solutions, whereas the flow and viscoelastic properties of XG systems correspond to those of tenuous, weak-gel networks. Interestingly, when mixed together these macromolecules interact to form a firm, thermoreversible gel with synergistic effects. In the present paper we report the results of a thorough investigation of both polymer concentration and temperature effects on the rheological properties of mixed LBG-XG systems in 20 mM KCl under continuous and oscillatory flow conditions. Under continuous shear at 25 degrees C, pure LBG shows the flow properties of a macromolecular solution, with a shear-thinning behaviour and a Newtonian region at low shear rates, whereas the rheological behaviour of XG and all LX mixed systems is that typical of weak-gels. Furthermore, in the mixed systems the viscosity values do not increase monotonically with increasing xanthan concentration, but the synergistic effect has a maximum in accordance with the XG:LBG ratio 1:1. As the temperature is increased from 25 degrees C to

  3. Acyl migration kinetics of vegetable oil 1,2-diacylglycerols

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The acyl migration kinetics of long-chain 1,2-diacylglycerol (1,2-DAG) to form 1,3-diacylglycerol (1,3-DAG) over the temperature range of 25 to 80 degrees Celsius were examined using proton NMR spectroscopy. The 1,2-DAG mole fraction of 0.32 at equilibrium was found to be insensitive to temperature...

  4. One-Step Conversion of Methyl Ketones to Acyl Chlorides.

    PubMed

    Zaragoza, Florencio

    2015-10-16

    Treatment of aromatic and heteroaromatic methyl ketones with sulfur monochloride and catalytic amounts of pyridine in refluxing chlorobenzene leads to the formation of acyl chlorides. Both electron-rich and electron-poor aryl methyl ketones can be used as starting materials. The resulting C1-byproduct depends on the precise reaction conditions chosen.

  5. Lubricity characteristics of seed oils modified by acylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemically modified seed oils via acylation of epoxidized and polyhydroxylated derivatives were investigated for their potential as candidates for lubrication. The native oil was preliminarily epoxidized and ring-opened in a one-pot reaction using formic acid-H2O2 followed by aqueous HCl treatment t...

  6. Mechanistic studies of malonic acid-mediated in situ acylation.

    PubMed

    Chandra, Koushik; Naoum, Johnny N; Roy, Tapta Kanchan; Gilon, Chaim; Gerber, R Benny; Friedler, Assaf

    2015-09-01

    We have previously introduced an easy to perform, cost-effective and highly efficient acetylation technique for solid phase synthesis (SPPS). Malonic acid is used as a precursor and the reaction proceeds via a reactive ketene that acetylates the target amine. Here we present a detailed mechanistic study of the malonic acid-mediated acylation. The influence of reaction conditions, peptide sequence and reagents was systematically studied. Our results show that the methodology can be successfully applied to different types of peptides and nonpeptidic molecules irrespective of their structure, sequence, or conformation. Using alkyl, phenyl, and benzyl malonic acid, we synthesized various acyl peptides with almost quantitative yields. The ketenes obtained from the different malonic acid derived precursors were characterized by in situ (1) H-NMR. The reaction proceeded in short reaction times and resulted in excellent yields when using uronium-based coupling agents, DIPEA as a base, DMF/DMSO/NMP as solvents, Rink amide/Wang/Merrifield resins, temperature of 20°C, pH 8-12 and 5 min preactivation at inert atmosphere. The reaction was unaffected by Lewis acids, transition metal ions, surfactants, or salt. DFT studies support the kinetically favorable concerted mechanism for CO2 and ketene formation that leads to the thermodynamically stable acylated products. We conclude that the malonic acid-mediated acylation is a general method applicable to various target molecules.

  7. Synthesis and characterization of monodisperse copper nanoparticles using gum acacia

    NASA Astrophysics Data System (ADS)

    Dong, Chunfa; Cai, Hao; Zhang, Xianglin; Cao, Chuanliang

    2014-03-01

    A simple method was put forward in this paper for preparing colloidal copper nanoparticles in aqueous solutions using copper sulfate, gum acacia and hydrazine hydrate as copper precursor, capping agents and reducing agents, respectively, without any inert gas. The formation of nanosized copper was confirmed by its characteristic surface plasmon absorption peak at 604 nm in UV-vis spectra. The transmission electron microscopic (TEM) and scanning electron microscope (SEM) images show that the as-synthesized copper fine spherical particles are distributed uniformly with a narrow distribution from 3 nm to 9 nm. The X-ray diffraction (XRD) and high resolution transmission electron microscopic (HRTEM) demonstrated that the obtained metallic nanoparticles are single crystalline copper nanoparticles. Fourier transform infra-red (FT-IR) spectroscopic data suggested that the copper nanoparticles are coated with gum acacia. The effects of the quantity of gum acacia on the particle size were investigated by the UV-vis spectra and TEM images. The growth process of the nanoparticles was monitored by the UV-vis spectra. The mechanism of the formation copper nanoparticles was discussed. The process raised in this study can be served as an excellent candidate for the preparation of copper nanoparticles in a large scale production.

  8. Low viscosity hydrogel of guar gum: preparation and physicochemical characterization.

    PubMed

    Cunha, Pablyana L R; Castro, Rondinelle R; Rocha, Francisco A C; de Paula, Regina C M; Feitosa, Judith P A

    2005-10-30

    Guar gum was cross-linked with glutaraldehyde and characterized by GPC, rheology, WADX, SEM and TGA. This guar gum is a galactomannan polysaccharide, that contains small amount of arabinose, glucose and uronic acid, besides galactose and mannose. The polymer has high molar mass, with Mw, Mn and Mv values of 2.0x10(6), 1.2x10(6) and 1.9x10(6)g/mol, respectively. The reticulation follows a slow process and lead to a viscosity increase of 40 times compared with the original gum solution. The final viscosity was similar to that of Hylan G-F 20, a hyaluronate derivative, commercially used in viscosupplementation treatment. The gel contains 95.6% of water and the amount of residual glutaraldehyde is much lower than the LD-50. Porous structure was detected by SEM and thermal stability was improved by the cross-linking. The low viscosity, the small amount of remained glutaraldehyde, and the thermal stability indicates that the guar hydrogel has potential to be applied as biomaterial with specific rheological requirements.

  9. The cortical effect of chewing gum during hand movements: A functional MRI study.

    PubMed

    Jang, Sung Ho; Kwon, Hyuk Cheol; Kwon, Hyeok Gyu; Jang, Woo Hyuk

    2015-01-01

    Nine right-handed normal subjects were recruited for this study. We compared the cortical activation during execution of hand movements (right finger flexion-extension) with that during execution of hand movements while chewing gum (right side chewing). We found that execution of hand movements while chewing gum induced less activation in the contralateral SM1 than hand movements alone. Based on our findings, it appears chewing gum during execution of hand movements enhanced the efficiency of hand movements.

  10. Chewing gum, occupational stress, work performance and wellbeing. An intervention study.

    PubMed

    Smith, Andrew P; Chaplin, Katherine; Wadsworth, Emma

    2012-06-01

    An intervention study was carried out to examine the effects of chewing gum on occupational stress and related outcomes. 101 volunteers from Cardiff University completed the study. The results showed that chewing gum reduced stress (both at work and outside work), reduced fatigue, reduced anxiety and depression and led to a more positive mood. Chewing gum was also associated with perceptions of better performance (both at work and outside).

  11. Structural, Thermal, Physical, Mechanical, and Barrier Properties of Chitosan Films with the Addition of Xanthan Gum.

    PubMed

    de Morais Lima, Maria; Carneiro, Lucia Cesar; Bianchini, Daniela; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa; Prentice, Carlos; Moreira, Angelita da Silveira

    2017-03-01

    Films based on chitosan and xanthan gum were prepared using casting technique aiming to investigate the potential of these polymers as packaging materials. Six formulations of films were studied varying the proportion of chitosan and xanthan gum: 100:0 (chitosan:xanthan gum, w/w, C100XG0 film); 90:10 (chitosan:xanthan gum, w/w, C90XG10 film); 80:20 (chitosan:xanthan gum, w/w, C80XG20 film); 70:30 (chitosan:xanthan gum, w/w, C70XG30 film); 60:40 (chitosan:xanthan gum, w/w, C60XG40 film); and 50:50 (chitosan:xanthan gum, w/w, C50XG50 film). The total quantity of solids (chitosan and xanthan gum) in the filmogenic solution was 1.5 g per 100 mL of aqueous solution for all treatments, according to the proportion of each polymer. The films were evaluated by their functional groups, structural, thermal, morphological, physical, mechanical, and barrier properties. All films have presented endothermic peaks in the range of 122 to 175 °C and broad exothermic peaks above 200 °C, which were assigned to the melting temperature and thermal decomposition, respectively. These results demonstrated that films with xanthan gum have the highest Tm and Δm H. The films containing higher content of xanthan gum show also the highest tensile strength and the lowest elongation. Xanthan gum addition did not affect the water vapor permeability, solubility, and moisture of films. This set of data suggests the formation of chitosan-xanthan complexes in the films.

  12. Fluorescently labelled bovine acyl-CoA-binding protein acting as an acyl-CoA sensor: interaction with CoA and acyl-CoA esters and its use in measuring free acyl-CoA esters and non-esterified fatty acids.

    PubMed Central

    Wadum, Majken C T; Villadsen, Jens K; Feddersen, Søren; Møller, Rikke S; Neergaard, Thomas B F; Kragelund, Birthe B; Højrup, Peter; Faergeman, Nils J; Knudsen, Jens

    2002-01-01

    Long-chain acyl-CoA esters are key metabolites in lipid synthesis and beta-oxidation but, at the same time, are important regulators of intermediate metabolism, insulin secretion, vesicular trafficking and gene expression. Key tools in studying the regulatory functions of acyl-CoA esters are reliable methods for the determination of free acyl-CoA concentrations. No such method is presently available. In the present study, we describe the synthesis of two acyl-CoA sensors for measuring free acyl-CoA concentrations using acyl-CoA-binding protein as a scaffold. Met24 and Ala53 of bovine acyl-CoA-binding protein were replaced by cysteine residues, which were covalently modified with 6-bromoacetyl-2-dimethylaminonaphthalene to make the two fluorescent acyl-CoA indicators (FACIs) FACI-24 and FACI-53. FACI-24 and FACI-53 showed fluorescence emission maximum at 510 and 525 nm respectively, in the absence of ligand (excitation 387 nm). Titration of FACI-24 and FACI-53 with hexadecanoyl-CoA and dodecanoyl-CoA increased the fluorescence yield 5.5-and 4.7-fold at 460 and 495 nm respectively. FACI-24 exhibited a high, and similar increase in, fluorescence yield at 460 nm upon binding of C14-C20 saturated and unsaturated acyl-CoA esters. Both indicators bind long-chain (>C14) acyl-CoA esters with high specificity and affinity (K(d)=0.6-1.7 nM). FACI-53 showed a high fluorescence yield for C8-C12 acyl chains. It is shown that FACI-24 acts as a sensitive acyl-CoA sensor for measuring the concentration of free acyl-CoA, acyl-CoA synthetase activity and the concentrations of free fatty acids after conversion of the fatty acid into their respective acyl-CoA esters. PMID:12071849

  13. Locust bean gum: processing, properties and food applications--a review.

    PubMed

    Barak, Sheweta; Mudgil, Deepak

    2014-05-01

    Locust bean gum or carob gum is a galactomannan obtained from seed endosperm of carob tree i.e. Ceratonia siliqua. It is widely utilized as an additive in various industries such as food, pharmaceuticals, paper, textile, oil well drilling and cosmetics. Industrial applications of locust bean gum are due to its ability to form hydrogen bonding with water molecule. It is also beneficial in the control of many health problems like diabetes, bowel movements, heart disease and colon cancer due to its dietary fiber action. This article focuses on production, processing, composition, properties, food applications and health benefits of locust bean gum.

  14. Remineralizing potential, antiplaque and antigingivitis effects of xylitol and sorbitol sweetened chewing gum.

    PubMed

    Steinberg, L M; Odusola, F; Mandel, I D

    1992-01-01

    The objective of this study was to investigate the effects of xylitol and sorbitol sweetened chewing gums on plaque accumulation, gingival inflammation and remineralizing potential of plaque following six weeks of use. Twenty-eight consenting individuals were randomly assigned to each of three phases (six weeks in duration) consisting of chewing xylitol gum, chewing sorbitol gum and a non-chewing phase. Subjects chewed one stick after every meal and at two other times for a total of five sticks per day. At the completion of each treatment phase, plaque and gingival indexes were performed and plaque was later collected. Calcium concentration in plaque was determined by atomic absorption spectophotometry. Reductions in plaque indexes were significant for both xylitol gum (p < 0.001) and sorbitol gum (p < 0.05) when compared to the no chewing period. The gingival indexes reflected a decrement in gingival inflammation with both xylitol and sorbitol, though only sorbitol values were statistically significant (p < 0.05). Chewing xylitol and sorbitol gums reduced plaque accumulation and gingival inflammation. In addition, both gums enhanced the remineralization potential of plaque. Xylitol gum showed a superior effect with respect to remineralization potential and plaque reduction. Sorbitol gum had a superior effect on gingival health but not significantly so.

  15. Effect of masticating chewing gum on postural stability during upright standing.

    PubMed

    Kushiro, Keisuke; Goto, Fumiyuki

    2011-01-07

    The purpose of this study was to investigate the effect of masticating chewing gum on postural stability during upright standing. To address this issue, 12 healthy subjects performed quiet standing on a force platform for the posturography study. The subjects were instructed to stand as stable as possible on the force platform in order to record the trajectory of the center-of-pressure (COP). After measuring the postural sway in the initial condition (pre-condition), the subjects were asked to stand while masticating chewing gum (gum-condition). Following the gum-condition, quiet standing without mastication was evaluated (post-condition) to ensure the effect of masticating chewing gum on postural stability. The trajectory and velocity of the COP were analyzed for each condition. We found that the postural stability tended to enhance during mastication of chewing gum. The rectangle area of the COP trajectory significantly diminished in the gum-condition and significantly enlarged in the post-condition. A similar effect was observed in the maximum velocity and standard deviation (SD) of the fore-aft amplitude of the COP trajectory. The values were significantly smaller in the gum-condition compared to those in the post-condition. These findings suggest that mastication of chewing gum affects the postural control by enhancing the postural stability during upright standing.

  16. Formulation of Eco-friendly Medicated Chewing Gum to Prevent Motion Sickness.

    PubMed

    Shete, Rahul B; Muniswamy, Vimalkumar J; Pandit, Ashlesha P; Khandelwal, Kishanchandra R

    2015-10-01

    An attempt was made to formulate medicated chewing gum to prevent motion sickness using natural gum base for faster onset of action and easy administration, anywhere and anytime, without access to water. To avoid the discard issue of gum cud, natural gum base of Triticum aestivum (wheat grain) was explored because of its biodegradable and biocompatible nature and easy availability. Prolamin, extracted from wheat, showed good chewing capacity, elasticity, high water retention capacity, antifungal activity, and compatibility with the drug. Formulations were prepared based on a two-factor and three-level factorial design. Amount of calcium carbonate (texturizer) and gum base were selected as independent variables. Elasticity and drug release were considered as the dependent variables. All batches were evaluated for the content uniformity, elasticity study, texture study, in vitro drug release study, and chewiness study. Results revealed that medicated chewing gum containing 80 mg of calcium carbonate and 500 mg of gum base showed good elasticity and more than 90% drug release within 16 min. Thus, this study suggested that both good elasticity and chew ability and abundant availability of wheat grain can act as a potential gum base for medicated chewing gum.

  17. Gum chewing reduces the time to first defaecation after pelvic surgery: A randomised controlled study.

    PubMed

    Tazegül Pekin, A; Kerimoğlu, O Seçilmiş; Doğan, N U; Yılmaz, S A; Kebapcılar, A G; Gençoğlu Bakbak, B B; Çelik, Ç

    2015-01-01

    Post-operative ileus is a major complication that increases the morbidity in patients who had abdominal surgery. Several different procedures have been used to manage bowel function, including adequate pain control, prokinetic drugs and supportive strategies. The present study aimed to assess the effect of chewing gum on bowel recovery in patients undergoing gynaecologic abdominal surgeries. A total of 137 patients were randomised into gum-chewing and control groups. Patients in the gum-chewing group began chewing gum at post-operative 3rd h and chewed gum thereafter every 4 h daily, for 30 min each time. All patients received the same post-operative treatment. Primary outcome measures were the time to first passage of flatus and time to first passage of stool. The secondary outcome measures included the first hearing of normal bowel sounds, nausea and the time until discharge from the hospital. Compared with the control group, the time interval between operation and first flatus was shorter in the gum-chewing group (median, 33 h vs 30 h). However, the difference was not significant (p = 0.381). The first defaecation time was significantly shorter in the gum-chewing group. The median time to first defaecation was 67 (20-105) h in the control group and 45 (12-97) h in the gum-chewing group (p < 0.01). Gum chewing is safe, well tolerated and it allows early defaecation after gynaecologic abdominal surgery.

  18. Fabrication of electrospun almond gum/PVA nanofibers as a thermostable delivery system for vanillin.

    PubMed

    Rezaei, Atefe; Tavanai, Hossein; Nasirpour, Ali

    2016-10-01

    In this study, the fabrication of vanillin incorporated almond gum/polyvinyl alcohol (PVA) nanofibers through electrospinning has been investigated. Electrospinning of only almond gum was proved impossible. It was found that the aqueous solution of almond gum/PVA (80:20, concentration=7% (w/w)) containing 3% (w/w) vanillin could have successfully electrospun to uniform nanofibers with diameters as low as 77nm. According to the thermal analysis, incorporated vanillin in almond gum/PVA nanofibers showed higher thermal stability than free vanillin, making this composite especially suitable for high temperature applications. XRD and FTIR analyses proved the presence of vanillin in the almond gum/PVA nanofibers. It was also found that vanillin was dispersed as big crystallites in the matrix of almond gum/PVA nanofibers. FTIR analysis showed almond gum and PVA had chemical cross-linking by etheric bonds between COH groups of almond gum and OH groups of PVA. Also, in the nanofibers, there were no major interaction between vanillin and either almond gum or PVA.

  19. Pharmacognostic studies of gums collected from aprocot trees growing in Armenia and perspectives of their use.

    PubMed

    Chichoyan, N

    2009-11-01

    Plant polysaccharides are widely used in the food and confectionary industries, as an emulsifier, flavour encapsulator, and thickening agent. The apricot tree has a gum that oozes out in the spring and it seems to be a lot like gum Arabic. Gums collected from apricot trees growing in Armenia (RA) are considered as exudates of ecological significance. Besides, in food industry it can entirely replace the more expensive gum Arabic as well as its synthetic derivatives. Periodically organized resource potential studies in the regions of RA gives the opportunity to have an exact notion of biological and utilized resources of gums as a natural exudates of cultivated apricot trees of the country. The study was conducted on gums collected from the apricot trees of Armavir region (Armavir, Edjmiatsin, Baghramyan) that were purified by general physical methods without any chemical or enzymatic influence. According to obtained results--from one apricot tree was collected 54.15+/- 4.41 g/m(2), the biological resource of apricot gum was 45 ton. We also determined the quantities of Mg, K and Ca in apricot gum by atomic--absorptive method (Mg - 18 mg/kg; Ca - 5.8 mg/kg; K - 15.7 mg/kg). The study results also revealed that addition of gummi armeniaca increases the yeast biomass up to 55%. According to above mentioned and the great resources of raw material of apricot tree gum it can be approved its usage in the food industry in Armenia.

  20. Ethanol Metabolism Modifies Hepatic Protein Acylation in Mice

    PubMed Central

    Fritz, Kristofer S.; Green, Michelle F.; Petersen, Dennis R.; Hirschey, Matthew D.

    2013-01-01

    Mitochondrial protein acetylation increases in response to chronic ethanol ingestion in mice, and is thought to reduce mitochondrial function and contribute to the pathogenesis of alcoholic liver disease. The mitochondrial deacetylase SIRT3 regulates the acetylation status of several mitochondrial proteins, including those involved in ethanol metabolism. The newly discovered desuccinylase activity of the mitochondrial sirtuin SIRT5 suggests that protein succinylation could be an important post-translational modification regulating mitochondrial metabolism. To assess the possible role of protein succinylation in ethanol metabolism, we surveyed hepatic sub-cellular protein fractions from mice fed a control or ethanol-supplemented diet for succinyl-lysine, as well as acetyl-, propionyl-, and butyryl-lysine post-translational modifications. We found mitochondrial protein propionylation increases, similar to mitochondrial protein acetylation. In contrast, mitochondrial protein succinylation is reduced. These mitochondrial protein modifications appear to be primarily driven by ethanol metabolism, and not by changes in mitochondrial sirtuin levels. Similar trends in acyl modifications were observed in the nucleus. However, comparatively fewer acyl modifications were observed in the cytoplasmic or the microsomal compartments, and were generally unchanged by ethanol metabolism. Using a mass spectrometry proteomics approach, we identified several candidate acetylated, propionylated, and succinylated proteins, which were enriched using antibodies against each modification. Additionally, we identified several acetyl and propionyl lysine residues on the same sites for a number of proteins and supports the idea of the overlapping nature of lysine-specific acylation. Thus, we show that novel post-translational modifications are present in hepatic mitochondrial, nuclear, cytoplasmic, and microsomal compartments and ethanol ingestion, and its associated metabolism, induce specific

  1. Activation of Exogenous Fatty Acids to Acyl-Acyl Carrier Protein Cannot Bypass FabI Inhibition in Neisseria*

    PubMed Central

    Yao, Jiangwei; Bruhn, David F.; Frank, Matthew W.; Lee, Richard E.; Rock, Charles O.

    2016-01-01

    Neisseria is a Gram-negative pathogen with phospholipids composed of straight chain saturated and monounsaturated fatty acids, the ability to incorporate exogenous fatty acids, and lipopolysaccharides that are not essential. The FabI inhibitor, AFN-1252, was deployed as a chemical biology tool to determine whether Neisseria can bypass the inhibition of fatty acid synthesis by incorporating exogenous fatty acids. Neisseria encodes a functional FabI that was potently inhibited by AFN-1252. AFN-1252 caused a dose-dependent inhibition of fatty acid synthesis in growing Neisseria, a delayed inhibition of growth phenotype, and minimal inhibition of DNA, RNA, and protein synthesis, showing that its mode of action is through inhibiting fatty acid synthesis. Isotopic fatty acid labeling experiments showed that Neisseria encodes the ability to incorporate exogenous fatty acids into its phospholipids by an acyl-acyl carrier protein-dependent pathway. However, AFN-1252 remained an effective antibacterial when Neisseria were supplemented with exogenous fatty acids. These results demonstrate that extracellular fatty acids are activated by an acyl-acyl carrier protein synthetase (AasN) and validate type II fatty acid synthesis (FabI) as a therapeutic target against Neisseria. PMID:26567338

  2. Rates of thrombin acylation and deacylation upon reaction with low molecular weight acylating agents, carbamylating agents and carbonylating agents.

    PubMed

    Brown, A D; Powers, J C

    1995-08-01

    Acylated derivatives of thrombin have been made using low molecular weight acylating agents, carbamylating agents and carbonylating agents. The compounds used to acylate the active site serine include isatoic anhydrides, benzoxazinones, benzylisocyanate, N-(benzylcarbonyloxy)succinimide and p-(dimethylamino)benzoylimidazolide. The rates of acylation and deacylation were determined. The best overall inhibitors of thrombin are 2-ethoxy-4H-3,1-benzoxazin-4-one, isatoic anhydride and tert-butyl-2,4-dioxo-2H-3,1-benzoxazine-1(4H)-acetate, which have k2/Ki values of 52,700 M-1s-1, 48,900 M-1s-1 and 5400 M-1s-1, respectively. The carbamyl derivative of thrombin formed with benzylisocyanate had the slowest rate of deacylation (2.3 x 10(-7) s-1), while the ester derivative formed with 2-(N,N-dimethylamino)methylimino-4H-3,1-benzoxazin-4-one had the fastest rate of deacylation (1.9 x 10(-4) s-1).

  3. Palmitoyl-acyl carrier protein (ACP) thioesterase and the evolutionary origin of plant acyl-ACP thioesterases.

    PubMed Central

    Jones, A; Davies, H M; Voelker, T A

    1995-01-01

    Acyl-acyl carrier protein (ACP) thioesterases play an essential role in chain termination during de novo fatty acid synthesis and in the channeling of carbon flux between the two lipid biosynthesis pathways in plants. We have discovered that there are two distinct but related thioesterase gene classes in higher plants, termed FatA and FatB, whose evolutionary divergence appears to be ancient. FatA encodes the already described 18:1-ACP thioesterase. In contrast, FatB representatives encode thioesterases preferring acyl-ACPs having saturated acyl groups. We unexpectedly obtained a 16:0-ACP thioesterase cDNA from Cuphea hookeriana seed, which accumulate predominantly 8:0 and 10:0. The 16:0 thioesterase transcripts were found in non-seed tissues, and expression in transgenic Brassica napus led to the production of a 16:0-rich oil. We present evidence that this type of FatB gene is ancient and ubiquitous in plants and that specialized plant medium-chain thioesterases have evolved independently from such enzymes several times during angiosperm evolution. Also, the ubiquitous 18:1-ACP thioesterase appears to be a derivative of a 16:0 thioesterase. PMID:7734968

  4. Self-healing guar gum and guar gum-multiwalled carbon nanotubes nanocomposite gels prepared in an ionic liquid.

    PubMed

    Sharma, Mukesh; Mondal, Dibyendu; Mukesh, Chandrakant; Prasad, Kamalesh

    2013-10-15

    Guar gum is a galactomannan extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba. It was found to form a soft viscoelastic gel in 1-butyl-3-methylimidazolium chloride, an ionic liquid at an optimized concentration of 10%w/v. A nanocomposite gel of the gum with enhanced strength could be prepared with 0.2%w/v of multiwalled carbon nanotubes (MWCNTs) in the ionic liquid. When the gels thus prepared were subjected to surface fractures or bisected completely, they found to self-heal at room temperature without any external interventions. The self-healing process could be repeated several times. These viscoelastic gel systems showed thixotropic nature and recovery of the storage modulus with time for several cycles was observed upon rheological investigations. The interaction took place between ionic liquid, guar gum and MWCNT was studied by SEM, TEM, FT-IR, powder XRD and rheometry. The results suggested that, upon standing at room temperature development of electrostatic interactions and the van der Waals interactions among the ionic liquid molecules facilitated the formation of reversible noncovalent bonds and eventually activated the self-healing in the gel systems through appropriate chain entanglements.

  5. Production of a Brassica napus low-molecular mass acyl-coenzyme A-binding protein in Arabidopsis alters the acyl-coenzyme A pool and acyl composition of oil in seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low-molecular mass (10 kD) cytosolic acyl-coenzyme A-binding protein (ACBP) has a substantial influence over fatty acid (FA) composition in oilseeds, possibly via an effect on the partitioning of acyl groups between elongation and desaturation pathways. Previously, we demonstrated that the expressio...

  6. Acylation of Glucagon-Like Peptide-2: Interaction with Lipid Membranes and In Vitro Intestinal Permeability

    PubMed Central

    Trier, Sofie; Linderoth, Lars; Bjerregaard, Simon; Andresen, Thomas Lars; Rahbek, Ulrik Lytt

    2014-01-01

    Background Acylation of peptide drugs with fatty acid chains has proven beneficial for prolonging systemic circulation as well as increasing enzymatic stability without disrupting biological potency. Acylation has furthermore been shown to increase interactions with the lipid membranes of mammalian cells. The extent to which such interactions hinder or benefit delivery of acylated peptide drugs across cellular barriers such as the intestinal epithelia is currently unknown. The present study investigates the effect of acylating peptide drugs from a drug delivery perspective. Purpose We hypothesize that the membrane interaction is an important parameter for intestinal translocation, which may be used to optimize the acylation chain length for intestinal permeation. This work aims to characterize acylated analogues of the intestinotrophic Glucagon-like peptide-2 by systematically increasing acyl chain length, in order to elucidate its influence on membrane interaction and intestinal cell translocation in vitro. Results Peptide self-association and binding to both model lipid and cell membranes was found to increase gradually with acyl chain length, whereas translocation across Caco-2 cells depended non-linearly on chain length. Short and medium acyl chains increased translocation compared to the native peptide, but long chain acylation displayed no improvement in translocation. Co-administration of a paracellular absorption enhancer was found to increase translocation irrespective of acyl chain length, whereas a transcellular enhancer displayed increased synergy with the long chain acylation. Conclusions These results show that membrane interactions play a prominent role during intestinal translocation of an acylated peptide. Acylation benefits permeation for shorter and medium chains due to increased membrane interactions, however, for longer chains insertion in the membrane becomes dominant and hinders translocation, i.e. the peptides get ‘stuck’ in the cell

  7. Influence of gum-chewing on postoperative bowel activity after laparoscopic surgery for gastric cancer

    PubMed Central

    Ge, Bujun; Zhao, Hongmei; Lin, Rui; Wang, Jialiang; Chen, Quanning; Liu, Liming; Huang, Qi

    2017-01-01

    Abstract Background: In some studies, gum-chewing was demonstrated to have a beneficial effect on resumption of bowel function; however, other contradictory findings in other studies refute the effects of gum-chewing on peristaltic movements and digestive system stimulation. In addition, most previous studies were after colorectal or gynecology surgery, whereas few reports focused on the effect of gum-chewing after gastrectomy. The aim of this randomized controlled trial was to assess the effectiveness of gum-chewing on postoperative bowel function in patients who had undergone laparoscopic gastrectomy. Methods: From March 2014 to March 2016, 75 patients with gastric cancer received elective laparoscopic surgery in Shanghai Tongji hospital and were postoperatively randomly divided into 2 groups: 38 in a gum-chewing (Gum) group and 37 in a control (No gum) group. The patients in the Gum group chewed sugarless gum 3 times daily, each time for at least 15 minutes, until the day of postoperative exhaust defecation. Results: The mean time to first flatus (83.4 ± 35.6 vs. 79.2 ± 24.2 hours; P = 0.554) and the mean time to first defecation (125.7 ± 41.2 vs. 115.4 ± 34.2 hours; P = 0.192) were no different between the no gum and Gum groups. There was also no significant difference in the incidence of postoperative ileus (P = 0.896) and postoperative hospital stay (P = 0.109) between the 2 groups. The postoperative pain score at 48 hours (P = 0.032) in the Gum group was significantly higher than in the no gum group. There was no significant difference between the 2 groups in regards to patient demographics, comorbidities, duration of surgery, complications, and nausea/vomiting score. Conclusion: Gum-chewing after laparoscopic gastrectomy did not hasten the return of gastrointestinal function. In addition, gum-chewing may increase patient pain on the second postoperative day. PMID:28353600

  8. Enhancement of welan gum production in Sphingomonas sp. HT-1 via heterologous expression of Vitreoscilla hemoglobin gene.

    PubMed

    Liu, Xiaoliu; Zhu, Ping; Jiang, Ruifan; Wu, Lingtian; Feng, Xiaohai; Li, Sha; Xu, Hong

    2017-01-20

    Welan gum is a microbial polysaccharide produced by Sphingomonas sp. Its production is limited by the dissolved oxygen levels in the highly viscous fermentation. A strategy of heterologous expression of the Vitreoscilla hemoglobin gene in Sphingomonas sp. HT-1 was investigated to alleviate oxygen limitation and improve the yield of welan gum. Ultimately, the welan gum production increased from 25.3g/L to 34.6g/L, whereas the rheological behavior of welan gum solutions remained virtually unchanged. The transcriptional levels of the key genes in the electron transfer chain, TCA cycle and welan gum synthesis pathway, as well as ATP level revealed that the VHb expression in Sphingomonas sp. HT-1 enhanced welan gum biosynthesis by improving respiration and ATP supply. This study would pave the genetic manipulation way for enhancing welan gum yield, and it's also of great importance for the industrial applications of welan gum under harsh conditions.

  9. Physical and chemical stability of gum arabic-stabilized conjugated linoleic acid oil-in-water emulsions.

    PubMed

    Yao, Xiaolin; Xu, Qiong; Tian, Dazhi; Wang, Nana; Fang, Yapeng; Deng, Zhongyang; Phillips, Glyn O; Lu, Jiang

    2013-05-15

    Oil-in-water (O/W) emulsions have been used as a delivery system to protect conjugated linoleic acid (CLA), a polyunsaturated fatty acid, from oxidation. Conventional gum arabic (GA) and two matured gum arabic samples (EM2 and EM10) were used as emulsifiers to prepare CLA-in-water emulsions. The emulsions have optimal physical and chemical stability at gum concentrations of 5% for all three gums. Emulsions with higher gum concentrations are more susceptible to lipid oxidation. This is attributed to reduced physical stability at higher gum concentrations because of the coalescence and depletion-induced flocculation of the emulsion droplets. The prooxidants iron and copper intrinsically contained in the gums could also contribute to this instability. Among the three gums, EM10 provides the most effective protection for CLA both physically and chemically, because of its superior interfacial properties over GA and EM2.

  10. Modification of the substrate specificity of an acyl-acyl carrier protein thioesterase by protein engineering.

    PubMed

    Yuan, L; Voelker, T A; Hawkins, D J

    1995-11-07

    The plant acyl-acyl carrier protein (ACP) thioesterases (TEs) are of biochemical interest because of their roles in fatty acid synthesis and their utilities in the bioengineering of plant seed oils. When the FatB1 cDNA encoding a 12:0-ACP TE (Uc FatB1) from California bay, Umbellularia californica (Uc) was expressed in Escherichia coli and in developing oilseeds of the plants Arabidopsis thaliana and Brassica napus, large amounts of laurate (12:0) and small amounts of myristate (14:0) were accumulated. We have isolated a TE cDNA from camphor (Cinnamomum camphorum) (Cc) seeds that shares 92% amino acid identity with Uc FatB1. This TE, Cc FatB1, mainly hydrolyzes 14:0-ACP as shown by E. coli expression. We have investigated the roles of the N- and C-terminal regions in determining substrate specificity by constructing two chimeric enzymes, in which the N-terminal portion of one protein is fused to the C-terminal portion of the other. Our results show that the C-terminal two-thirds of the protein is critical for the specificity. By site-directed mutagenesis, we have replaced several amino acids in Uc FatB1 by using the Cc FatB1 sequence as a guide. A double mutant, which changes Met-197 to an Arg and Arg-199 to a His (M197R/R199H), turns Uc FatB1 into a 12:0/14:0 TE with equal preference for both substrates. Another mutation, T231K, by itself does not effect the specificity. However, when it is combined with the double mutant to generate a triple mutant (M197R/R199H/T231K), Uc FatB1 is converted to a 14:0-ACP TE. Expression of the double-mutant cDNA in E. coli K27, a strain deficient in fatty acid degradation, results in accumulation of similar amounts of 12:0 and 14:0. Meanwhile the E. coli expressing the triple-mutant cDNA produces predominantly 14:0 with very small amounts of 12:0. Kinetic studies indicate that both wild-type Uc FatB1 and the triple mutant have similar values of Km,app with respect to 14:0-ACP. Inhibitory studies also show that 12:0-ACP is a good

  11. Potentials of gum from Detarium microcarpum (DM) and Mucuna flagellipes (MF) seeds as raw beef burger stabilizers.

    PubMed

    Onweluzo, J C; Obanu, Z A; Okwandu, M C

    2004-01-01

    Raw beef burgers containing graded levels (0.25, 0.5, 0.75. and 1.0%) of polysaccharide gums extracted from Detarium microcarpum (DM) and Mucuna flagellipes (MF) were produced. Unstabilized beef burgers and beef burgers containing gum tragacanth (TR) were also produced simultaneously to serve as control. The raw beef burgers were evaluated for selected physicochemical and sensory properties so as to assess the stabilization potentials of DM and MF polysaccharide gums relative to the conventional TR. Beef burgers containing the polysaccharide gums had significantly (P < 0.05) lower shrinkage, higher water holding capacity (WHC), and better stability under ambient conditions (27 +/- 1 degrees C and RH 90.6%) then the unstabilized burgers. Among the stabilized burgers, DM gum burgers had lower (P < or = 0.05) shrinkage and higher WHC than MF and TR gums burgers. All the gum-stabilized beef burgers required 9-26% higher compression force indicating a less friable product than the unstabilized burgers. At 0.25 and 0.5% levels of gum incorporation DM gum burgers had comparable compression force with TR gum burgers and this was lower (P < or = 0.05) than the compression force of MF gum burgers. Sensory panel results indicated a lower score for finger feel in gum-stablized burgers than the unstabilized burgers. DM and TR gum burgers had comparable scores with TR gum burgers in all the sensory attributes tested. Overall acceptability score showed that all the gum-stabilized beef burgers were acceptable. It was evident from the study that polysaccharide gums from DM and MF seeds can serve as effective stabilizers in beef burgers without adverse effect on the quality of the product.

  12. Characterisation and molecular association of Nigerian and Sudanese Acacia gum exudates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chemical and physicochemical characteristics of gum exudate samples harvested from mature trees of Acacia senegal at two specific locations in Nigeria have been investigated together with gum samples harvested from Acacia senegal and Acacia seyal originating from Sudan. The monosaccharide sugar ...

  13. Recent advances in Rosaceae gum exudates: From synthesis to food and non-food applications.

    PubMed

    Bouaziz, Fatma; Koubaa, Mohamed; Ellouz Ghorbel, Raoudha; Ellouz Chaabouni, Semia

    2016-05-01

    In recent years, great interest has been devoted to the development of new applications for natural gums. These molecules were used for a variety of purposes since they are chemically inert, non-toxic, less expensive, biodegradable and widely available. They represent one of the most abundant raw materials used not only in commercial food products, but also in cosmetic and pharmaceutical products. Plant gums take their advantages compared to other gums (e.g., from animal and microbial sources) mainly because of their acceptance by consumers. Despite of the well description given in literature for the features of plant gum exudates, there is a lack distinguishing the different families that are producing gums, and their potential applications. Among these gums, the ones produced by Rosaceae family (e.g., almond, apricot, cherry, peach, and plum plants) have been taking special attention. Thus, the aim of this review is to report the recent advances in Rosaceae gum exudates. An emphasis is given for the formation mechanisms of these gums, their chemical composition, functional properties and structures, beneficial properties, as well as their food/non-food applications.

  14. Small scale production and characterization of xanthan gum synthesized by local isolates of Xanthomonas campestris.

    PubMed

    Barua, Rajesh; Alam, Md Jahangir; Salim, Mohammad; Ashrafee, Tamzida Shamim

    2016-02-01

    Xanthan gum is a commercially important microbial exopolysaccharide (EPS) produced by Xanthomonas campestris. X. campestris is a plant pathogen causing various plant diseases such as black rot of crucifers, bacterial leaf blight and citrus canker disease resulting in crop damage. In this study, we isolated efficient local bacterial isolates which are capable to produce xanthan gum utilizing different sources of carbon (maltose, sucrose and glucose). Bacterial isolates from different plant leaves and fruits were identified as Xanthomonas campestris based on their morphological and biochemical characteristics. Among the 23 isolates, 70% were capable of producing gum. Taro plant, considered as new bacterial host, also have the capability to produce xanthan gum. Production conditions of xanthan gum and their relative viscosity by these bacterial isolates were optimized using basal medium containing commercial carbon and nitrogen sources and various temperature and rotation. Highest level of xanthan gum (18.286 g/l) with relative viscosity (7.2) was produced (Host, Citrus macroptera) at 28 degrees C, pH 7.0, 150 rpm using sucrose as a carbon source at orbital shaker. Whereas, in lab fermenter, same conditions gave best result (19.587 g/l gum) with 7.8 relative viscosity. Chilled alcohol (96%) was used to recover the xanthan gum. FTIR studies also carried out for further confirmation of compatibility by detecting the chemical groups.

  15. Gum cordia as carrier of antioxidants: effects on lipid oxidation of peanuts.

    PubMed

    Haq, Muhammad Abdul; Azam, Mahmood; Hasnain, Abid

    2015-04-01

    Performance of antioxidants is improved by incorporating them into polymer matrix such as polysaccharides based edible coatings. Gum cordia, an anionic polysaccharide extracted from the fruits of Cordia.myxa could be used as carrier of antioxidants by virtue of its strong adhering and emulsifying properties. This study aimed to explore the potential of gum cordia as carrier of antioxidants when applied as edible coating on peanuts. Gum Cordia was compared with carboxymethyl cellulose (CMC) in delivering of antioxidants: butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and ascorbic acid (AA). Coated and uncoated peanuts were stored at 35 °C for 126 days and coating carrier effectiveness was measured by following lipid oxidation using chemical parameters (peroxide value and thiobarbituric acid reactive species) and sensory evaluation (oxidized flavor). Significant differences (p < 0.05) between coated and uncoated samples were observed. Gum cordia was found better than CMC to deliver the antioxidants. Gum cordia based coating in combination with BHA/BHT exhibited highest protection (290 % higher shelf life than control) based on peroxide value (40 meq.O2 kg(-1)) followed by gum codia plus BHT (244 %), gum cordia plus BHA (232 %), CMC plus BHA/BHT (184 %), CMC plus BHA (139 %), CMC plus BHT (119 %), gum cordia plus AA (96 %) and CMC plus AA (46 %).

  16. Adverse Reaction to Nicotine Gum in Malay Female Smoker: A Case Report

    ERIC Educational Resources Information Center

    Noorzurani, Md Haris Robson; Bond, Alyson; Wolff, Kim

    2008-01-01

    Nicotine replacement therapies (NRT) are prescribed in smoking cessation programmes to help smokers stop smoking. The ideal dosage of NRT should control cravings and withdrawal symptoms but avoid adverse reactions. This report describes a case of adverse reaction to nicotine gum in a female Malay smoker. Assays taken 2 h after the gum, showed that…

  17. Rheological and Quality Characteristics of Taftoon Bread as Affected by Salep and Persian Gums

    PubMed Central

    Mohammadi, R.; Hamidi Esfehani, Z.

    2014-01-01

    Effects of salep gum at concentrations of 0.5%, 1%, 3%, and 5% (w/w flour basis) and the Persian gum at concentrations of 0.5%, 1%, and 3% (w/w flour basis) and combination of the two gums at concentrations of 0.5% + 0.5%, 0.75% + 0.25%, and 0.25% + 0.75% on rheological properties of the wheat flour dough and quality of Taftoon bread were studied with regard to retardation of staling. Rheological (farinograph and extensograph) characteristics, staling, and organoleptic evaluations were performed on the dough and the resulting Taftoon bread. Statistical results showed that the salep gum at 5% and Persian gum at 3% (w/w flour basis) had a significant effect on the dough properties. Salep and Persian gums when each separately added increased and decreased dough water absorption, respectively. Both hydrocolloids increased the dough resistance to extension and decreased its extensibility. Persian gum shows dual nature in water absorption and some other baking properties. Textural studies revealed that addition of 5% salep gum (w/w flour basis) reduced the bread crumb firmness and delayed the staling process of the Taftoon bread. X-ray diffraction study also confirmed this result. PMID:26904649

  18. 40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454.20 Section 454.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GUM AND WOOD...

  19. 40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454.20 Section 454.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD...

  20. 40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454.20 Section 454.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD...

  1. 40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454.20 Section 454.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD...

  2. 40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454.20 Section 454.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GUM AND WOOD...

  3. Compliance with Xylitol and Sorbitol Chewing Gum Regimens in Clinical Trials

    PubMed Central

    BRETZ, WALTER A.; ROSA, ODILA P. S.; SILVA, SALETE M. B.; CORBY, PATRICIA M. A.; MILANDA, MARCELO; LOESCHE, WALTER J.

    2011-01-01

    Objective The purpose of this study was to investigate compliance of long-term xylitol and sorbitol chewing gum regimens in adult women participating in a double-blind randomized controlled clinical trial. Design The participants included 122 mothers (age range: 16–35 years) residing in the city of Bauru, São Paulo, Brazil. Compliance with the xylitol and sorbitol chewing gum regimens was assessed by weighing, with a precision balance, all used gums returned in zip-lock bags during the study period of 33 months. The total number of returned bags in both chewing gum groups was computed and the differences between groups were determined by one-way ANOVA. Compliance was further categorized into excellent, good, fair or poor based on the distribution of the combined data for both groups by quartiles. These distributions for the xylitol and sorbitol groups were subjected to chi-square analysis. Results Compliance was always superior for the xylitol group in all categories. These distributions were, however, not significantly different in statistical terms. Average compliance in the xylitol chewing gum group was significantly higher when compared to the sorbitol chewing gum group (p=0.0481). Conclusions The results suggest that compliance, and possibly acceptance in this population, was superior for xylitol chewing gum than for sorbitol chewing gum. PMID:22241940

  4. Reduction of lipid oxidation by formation of caseinate-oil-oat gum emulsions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concentration of oat gum, though important for formation of stable emulsion, has no effect on oxidation of Omega 3 oil; this is most prominent in fish-oil based Omega 3 oil. The optimal concentration of oat gum is about 0.2% wt for emulsion stability and visual appearance. We found that concentr...

  5. [S-Acyl derivatives of thiosalicylamides having antifungal activity. II].

    PubMed

    Mazza, M; Modena, T; Montanari, L; Pavanetto, F

    1978-07-01

    Some S-acyl derivatives of N-alkylthiosalicylamides [Table I: substances (I leads to XXXI)] were prepared and tested for antifungal activity. The substances, most of which had not been previously reported, were prepared by condensation of 2-mercapto-N-alkylbenzamides with suitable acylating agents. The antifungal activity of the compounds was tested in vitro against Candida albicans and Trichophyton mentagrophytes. For some compounds the was tested activity against the above strains fungicidal, Candida tropicalis and Saccharomyces cerevisiae. Many of the compounds proved to have high antifungal activity comparable with that of Clotrimazol. The results extended knowledge on the structure-antifungal activity relationships of this class of compounds. The compounds with the highest antifungal activity were: 2-acetylmercapto-N,n-heptylbenzamide (XXVIII); 2-acetylmercapto-5-Cl-N,n-propylbenzamide (XIV); 2-acetylmercapto-N,n-octylbenzamide (XXXI); 2-acetylmercapto-N,n-pentylbenzamide (XXV); 2-acetylmercapto-N,n-hexylbenzamide (XXVII).

  6. Metabolic Glycoengineering with N-Acyl Side Chain Modified Mannosamines.

    PubMed

    Wratil, Paul R; Horstkorte, Rüdiger; Reutter, Werner

    2016-08-08

    In metabolic glycoengineering (MGE), cells or animals are treated with unnatural derivatives of monosaccharides. After entering the cytosol, these sugar analogues are metabolized and subsequently expressed on newly synthesized glycoconjugates. The feasibility of MGE was first discovered for sialylated glycans, by using N-acyl-modified mannosamines as precursor molecules for unnatural sialic acids. Prerequisite is the promiscuity of the enzymes of the Roseman-Warren biosynthetic pathway. These enzymes were shown to tolerate specific modifications of the N-acyl side chain of mannosamine analogues, for example, elongation by one or more methylene groups (aliphatic modifications) or by insertion of reactive groups (bioorthogonal modifications). Unnatural sialic acids are incorporated into glycoconjugates of cells and organs. MGE has intriguing biological consequences for treated cells (aliphatic MGE) and offers the opportunity to visualize the topography and dynamics of sialylated glycans in vitro, ex vivo, and in vivo (bioorthogonal MGE).

  7. Pressure production in oral vestibule during gum chewing.

    PubMed

    Nishiura, M; Ono, T; Yoshinaka, M; Fujiwara, S; Yoshinaka, M; Maeda, Y

    2015-12-01

    The aim of this study was to record oral vestibule pressure (OVP) by the lip and cheek contraction during gum chewing, to examine the characteristics of these pressures and coordination between the OVP and jaw movement. The subjects were eight healthy adult men (mean age of 29·3 ± 3·3 years). An experimental plate that incorporated four pressure sensors on the midline of the upper jaw (Ch. 1), upper right canine (Ch. 2), upper right first molar (Ch. 3) and upper left first molar (Ch. 4) was used for measuring OVP. The right masseter electromyogram (EMG) was recorded simultaneously. Subjects chewed gum on the right side 20 times, and eight consecutive strokes were used for the analysis of the sequential order, maximal magnitude and duration of each OVP. Onset of OVP was observed at the molar on the non-chewing side (Ch. 4) before chewing side (Ch. 3), and offset was largely simultaneous at each site. On the chewing side (Chs. 1-3), OVP onset during the interval of EMG activity reached to the peak around the end of interval and offset in the duration of EMG activity. The maximal pressure was significantly larger at Chs. 1-3 than at Ch. 4, but no significant differences were observed in duration of pressure among each site. These results suggest that OVP is coordinated with jaw movement during gum chewing, and larger pressure is produced on the chewing side than on the non-chewing side. Our findings are quantitative indices for the evaluation of lip and cheek function during mastication.

  8. Manilkara zapota (Linn.) Seeds: A Potential Source of Natural Gum.

    PubMed

    Singh, Sudarshan; Bothara, Sunil B

    2014-01-01

    Mucilage isolated from seeds of Manilkara zapota (Linn.) P. Royen syn. is a plant growing naturally in the forests of India. This mucilage is yet to be commercially exploited, and characterized as polymer. Various physicochemical methods like particle size analysis, scanning electron microscopy, thermal analysis, gel permeation chromatography, X-ray diffraction spectrometry, zeta potential, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy have been employed to characterize this gum in the present study. Particle size analyses suggest that mucilage has particle size in nanometer. Scanning electron microscopy analysis suggests that the mucilage has irregular particle size. The glass transition temperature of the gum was observed to be 138°C and 136°C by differential scanning calorimetry and differential thermal analysis, respectively. The thermogravimetric analysis suggested that mucilage had good thermal stability. The average molecular weight of mucilage was determined to be 379180, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The X-ray diffraction spectrometry pattern of the mucilage indicates a completely amorphous structure. Elemental analysis of the gum revealed the contents of carbon, hydrogen, nitrogen, and sulfur to be 80.9 (%), 10.1 (%), 1.58 (%), and 512 (mg/kg), respectively. Mucilage had specific content of calcium, magnesium, potassium, lower concentrations of aluminum, cadmium, cobalt, lead, and nickel. The major functional groups identified from FT-IR spectrum include 3441 cm(-1) (-OH), 1660 cm(-1) (Alkenyl C-H & C=C Stretch), 1632 cm(-1) (-COO-), 1414 cm(-1) (-COO-), and 1219 cm(-1) (-CH3CO). Analysis of mucilage by paper chromatography and 1D NMR, indicated the presence of rhamnose, xylose, arabinose, mannose, and fructose.

  9. Manilkara zapota (Linn.) Seeds: A Potential Source of Natural Gum

    PubMed Central

    Singh, Sudarshan; Bothara, Sunil B.

    2014-01-01

    Mucilage isolated from seeds of Manilkara zapota (Linn.) P. Royen syn. is a plant growing naturally in the forests of India. This mucilage is yet to be commercially exploited, and characterized as polymer. Various physicochemical methods like particle size analysis, scanning electron microscopy, thermal analysis, gel permeation chromatography, X-ray diffraction spectrometry, zeta potential, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy have been employed to characterize this gum in the present study. Particle size analyses suggest that mucilage has particle size in nanometer. Scanning electron microscopy analysis suggests that the mucilage has irregular particle size. The glass transition temperature of the gum was observed to be 138°C and 136°C by differential scanning calorimetry and differential thermal analysis, respectively. The thermogravimetric analysis suggested that mucilage had good thermal stability. The average molecular weight of mucilage was determined to be 379180, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The X-ray diffraction spectrometry pattern of the mucilage indicates a completely amorphous structure. Elemental analysis of the gum revealed the contents of carbon, hydrogen, nitrogen, and sulfur to be 80.9 (%), 10.1 (%), 1.58 (%), and 512 (mg/kg), respectively. Mucilage had specific content of calcium, magnesium, potassium, lower concentrations of aluminum, cadmium, cobalt, lead, and nickel. The major functional groups identified from FT-IR spectrum include 3441 cm−1 (–OH), 1660 cm−1 (Alkenyl C–H & C=C Stretch), 1632 cm−1 (–COO–), 1414 cm−1 (–COO–), and 1219 cm−1 (–CH3CO). Analysis of mucilage by paper chromatography and 1D NMR, indicated the presence of rhamnose, xylose, arabinose, mannose, and fructose. PMID:24729907

  10. Interaction of calcium sulfate with xanthan gum: effect on in vitro bioadhesion and drug release behavior from xanthan gum based buccal discs of buspirone.

    PubMed

    Jaipal, A; Pandey, M M; Abhishek, A; Vinay, S; Charde, S Y

    2013-11-01

    Bioadhesive polymers in buccal drug delivery systems play an important role in delivery of therapeutic drug molecules for local and systemic action. Xanthan gum, a GRAS listed natural polymer was used to design buccal discs of buspirone hydrochloride by direct compression method. Effect of calcium sulfate on bioadhesive and drug release behavior of xanthan gum buccal discs was studied. Varying amount of calcium sulfate (0%, 5%, 10%, 20%, 30%, 40% and 50%, w/w) in combination with xanthan gum was used to prepare buccal bioadhesive discs. Increase in calcium sulfate concentration resulted in faster drug release and decreased the bioadhesive strength of the designed discs. Further, in rheological evaluation it was observed that viscosity of xanthan gum gel reduces with increasing concentration of calcium sulfate. Compatibility of drug with various excipients was assessed using DSC and FTIR techniques.

  11. Psychological and Pharmacological Influences in Cigarette Smoking Withdrawal: Effects of Nicotine Gum and Expectancy on Smoking Withdrawal Symptoms and Relapse.

    ERIC Educational Resources Information Center

    Gottlieb, Andrew M.; And Others

    1987-01-01

    Examined effects of expectancy and nicotine depletion on withdrawal symptoms by giving 109 smokers nicotine gum or placebo. Subjects who believed they had nicotine gum reported fewer physical symptoms of withdrawal, showed less arousal, and smoked fewer cigarettes than did those who thought they had placebo. Actual nicotine content of gum had no…

  12. 78 FR 13379 - Xanthan Gum from Austria and China; Scheduling of the Final Phase of an Antidumping Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... COMMISSION Xanthan Gum from Austria and China; Scheduling of the Final Phase of an Antidumping Investigation... imports from Austria and/or China of xanthan gum, provided for in subheading 3913.90.20 of the Harmonized... Commerce has defined the subject merchandise as Adry xanthan gum, whether or not coated or blended...

  13. Evaluation of alternatives to guar gum as tackifiers for hydromulch and as clumping agents for biodegradable cat litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guar gum is currently the principal gum used as a tackifier for hydromulch used in erosion control, and as a clumping agent in biodegradable cat litters. Due to recent severe price increases for guar gum, cheaper alternatives are being investigated. We examined several alternatives, including xanth...

  14. 78 FR 73434 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Acacia (Gum Arabic)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    ... to Food for Human Consumption; Acacia (Gum Arabic) AGENCY: Food and Drug Administration, HHS. ACTION... regulations to provide for the expanded safe use of acacia (gum arabic) in foods. This action is in response... ] additive regulations in Sec. 172.780, Acacia (gum arabic) (21 CFR 172.780) to provide for the expanded...

  15. Thiourea-Catalyzed Aminolysis of N-acyl Homoserine Lactones

    DTIC Science & Technology

    2013-01-01

    of N-acyl homoserine lactones (AHLs), molecules integral to bacterial quorum sensing . The catalysts afford rate enhancement of up to 10 times the...SUBJECT TERMS quorum sensing Michael A. Bertucci, Stephen J. Lee, Michel R. Gagné University of North Carolina - Chapel Hill Office of Sponsored... quorum sensing . The catalysts afford rate enhancement of up to 10 times the control in CD3CN. Mild catalysis in other polar aprotic solvents is

  16. Antinociceptive property of new 4-acyl-arylhydrazone pyrazole compounds.

    PubMed

    Matheus, M E; Oliveira, L F; Freitas, A C; Carvalho, A M; Barreiro, E J

    1991-01-01

    A series of new 4-acyl-arylhydrazone pyrazole compounds were tested for antinociceptive activity using the inhibition of abdominal contortions induced by acetylcholine (4 mg/kg, ip) in the mouse. Dipyrone was used for comparison of the antinociceptive potency of the compounds being tested. All drugs were administered po in saline (dipyrone) or in propylene glycol (4-acyl-arylhydrazones). The maximum response induced by dipyrone (86% inhibition) was assigned an efficacy index of 1.0. Although none of the compounds had an efficacy index greater than 1.0, all three reached 1.0. The two most potent compounds, W1d and W1g, which also had an efficacy similar to that of dipyrone, contain a p-N(CH3)2 and m-OH,p-OCH3 group in the aromatic ring of the acyl-hydrazone, respectively. W1d presented the lowest antinociceptive ED50 in the series (1.41 mg/kg) and was eleven times more potent than dipyrone (ED50 = 15.80 mg/kg). Other substitutions at the para position had lower potency than W1d. The present results indicate that the introduction of a group at the para position of the acyl-arylhydrazone ring increases the antinociceptive activity of these compounds to provide compounds of the same efficacy but greater potency than dipyrone to which these new compounds are structurally related. Other assays of nociceptive activity are being used to characterize the mechanism of action of the potential new drugs.

  17. Acylation type determines ghrelin's effects on energy homeostasis in rodents.

    PubMed

    Heppner, Kristy M; Chaudhary, Nilika; Müller, Timo D; Kirchner, Henriette; Habegger, Kirk M; Ottaway, Nickki; Smiley, David L; Dimarchi, Richard; Hofmann, Susanna M; Woods, Stephen C; Sivertsen, Bjørn; Holst, Birgitte; Pfluger, Paul T; Perez-Tilve, Diego; Tschöp, Matthias H

    2012-10-01

    Ghrelin is a gastrointestinal polypeptide that acts through the ghrelin receptor (GHSR) to promote food intake and increase adiposity. Activation of GHSR requires the presence of a fatty-acid (FA) side chain on amino acid residue serine 3 of the ghrelin molecule. However, little is known about the role that the type of FA used for acylation plays in the biological action of ghrelin. We therefore evaluated a series of differentially acylated peptides to determine whether alterations in length or stability of the FA side chain have an impact on the ability of ghrelin to activate GHSR in vitro or to differentially alter food intake, body weight, and body composition in vivo. Fatty acids principally available in the diet (such as palmitate C16) and therefore representing potential substrates for the ghrelin-activating enzyme ghrelin O-acyltransferase (GOAT) were used for dose-, time-, and administration/route-dependent effects of ghrelin on food intake, body weight, and body composition in rats and mice. Our data demonstrate that altering the length of the FA side chain of ghrelin results in the differential activation of GHSR. Additionally, we found that acylation of ghrelin with a long-chain FA (C16) delays the acute central stimulation of food intake. Lastly, we found that, depending on acylation length, systemic and central chronic actions of ghrelin on adiposity can be enhanced or reduced. Together our data suggest that modification of the FA side-chain length can be a novel approach to modulate the efficacy of pharmacologically administered ghrelin.

  18. Glycosyltransferases from oat (Avena) implicated in the acylation of avenacins.

    PubMed

    Owatworakit, Amorn; Townsend, Belinda; Louveau, Thomas; Jenner, Helen; Rejzek, Martin; Hughes, Richard K; Saalbach, Gerhard; Qi, Xiaoquan; Bakht, Saleha; Roy, Abhijeet Deb; Mugford, Sam T; Goss, Rebecca J M; Field, Robert A; Osbourn, Anne

    2013-02-08

    Plants produce a huge array of specialized metabolites that have important functions in defense against biotic and abiotic stresses. Many of these compounds are glycosylated by family 1 glycosyltransferases (GTs). Oats (Avena spp.) make root-derived antimicrobial triterpenes (avenacins) that provide protection against soil-borne diseases. The ability to synthesize avenacins has evolved since the divergence of oats from other cereals and grasses. The major avenacin, A-1, is acylated with N-methylanthranilic acid. Previously, we have cloned and characterized three genes for avenacin synthesis (for the triterpene synthase SAD1, a triterpene-modifying cytochrome P450 SAD2, and the serine carboxypeptidase-like acyl transferase SAD7), which form part of a biosynthetic gene cluster. Here, we identify a fourth member of this gene cluster encoding a GT belonging to clade L of family 1 (UGT74H5), and show that this enzyme is an N-methylanthranilic acid O-glucosyltransferase implicated in the synthesis of avenacin A-1. Two other closely related family 1 GTs (UGT74H6 and UGT74H7) are also expressed in oat roots. One of these (UGT74H6) is able to glucosylate both N-methylanthranilic acid and benzoic acid, whereas the function of the other (UGT74H7) remains unknown. Our investigations indicate that UGT74H5 is likely to be key for the generation of the activated acyl donor used by SAD7 in the synthesis of the major avenacin, A-1, whereas UGT74H6 may contribute to the synthesis of other forms of avenacin that are acylated with benzoic acid.

  19. Six new acylated anthocyanins from red radish (Raphanus sativus).

    PubMed

    Tamura, Satoru; Tsuji, Kouji; Yongzhen, Piao; Ohnishi-Kameyama, Mayumi; Murakami, Nobutoshi

    2010-09-01

    Six new acylated anthocyanins (1-6) were isolated along with the three known congeners (7-9) from the fresh roots of red radishes (Raphanus sativus L.) cultivated by our group. Their chemical structures were elucidated by spectroscopic properties. Among the six new anthocyanins, the five constituents (1, 2, 4-6) were shown to contain the malonyl function at 6-OH in the glucopyranosyl residue linked to C-5 in the pelargonidin nucleus.

  20. A new cytotoxic acylated apigenin glucoside from Phyllanthus emblica L.

    PubMed

    El-Desouky, S K; Ryu, Shi Young; Kim, Young-Kyoon

    2008-01-10

    A new acylated apigenin glucoside (apigenin-7-O-(6''-butyryl-beta-glucopyranoside) (1) was isolated from the methanolic extract of the leaves of Phyllanthus emblica L. (Euphorbiaceae) together with the known compounds; gallic acid (2), methyl gallate (3), 1,2,3,4,6-penta-O-galloylglucose (4) and luteolin-4'-O-neohesperiodoside (5). Their chemical structures were elucidated on the basis of spectroscopic studies ((1)H NMR, (13)C NMR, DEPT, HSQC, HMBC).

  1. Genotoxicity studies of the food additive ester gum.

    PubMed

    Mukherjee, A; Agarwal, K; Chakrabarti, J

    1992-07-01

    Ester gum (EG) is used in citrus oil-based beverage flavourings as a weighting or colouring agent. In the present study, concentrations of 50, 100 and 150 mg/kg body weight were administered orally to male Swiss albino mice, and sister chromatid exchange and chromosomal aberration were used as the cytogenetic endpoints to determine the genotoxic and clastogenic potential of the food additive. Although EG was weakly clastogenic and could induce a marginal increase in sister chromatid exchange frequencies, it was not a potential health hazard at the doses tested.

  2. Radio astronomy Explorer-1 observations of the Gum nebula

    NASA Technical Reports Server (NTRS)

    Alexander, J. K.

    1971-01-01

    Complicating factors in the spectrum analysis of the Gum nebula are discussed. These include accounting for the spectrum of supernova remnants in the direction of the nebula, the different absorption laws for radiation from beyond and within the nebula, and the Razin effect. This last results in a low frequency cutoff to the spectrum of synchrotron radiation by particles in a thermal plasma. These factors cause the observer to overestimate the amount of absorption occurring in the nebula. Data from the Explorer 38 satellite are presented for 3.93 and 6.55 MHz. Average optical depth for the nebula at 4 MHz was calculated.

  3. Young stars of low mass in the Gum nebula

    NASA Technical Reports Server (NTRS)

    Graham, J. A.; Heyer, Mark H.

    1989-01-01

    Observations are presented for four recently formed stars in the vicinity of the Gum nebula which are heavily obscured by surrounding dust and are associated with small reflection nebulae. HH46 is the only currently active star of the sample, and it is found to have a spectral type in the range of late G-early K, with superimposed emission lines of H-alpha, Ca II, Fe I, Fe II, and weak He I at near zero velocities. It is suggested that the observed scenario of low-mass stars in an older massive star environment may be analogous to the circumstances surrounding the birth of the sun.

  4. Microwave assisted synthesis of acrylamide grafted locust bean gum and its application in drug delivery.

    PubMed

    Kaity, Santanu; Isaac, Jinu; Kumar, P Mahesh; Bose, Anirbandeep; Wong, Tin Wui; Ghosh, Animesh

    2013-10-15

    Acrylamide grafted copolymer of locust bean gum was prepared by microwave irradiation using ceric ammonium nitrate as redox initiator. The grafting process was optimized in terms of irradiation time, amount of initiator and acrylamide by using constant amount of native locust bean gum. The grafted gum was characterized by Fourier transform infrared spectroscopy (FT-IR), (13)C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), X-ray diffraction study (XRD), differential scanning calorimetry (DSC), elemental analysis, contact angle, viscosity, molecular weight, swelling and biodegradability studies. The grafted gum was found to be biodegradable and non-toxic. It was further used to prepare controlled-release matrix tablet of buflomedil hydrochloride. The in vitro release profile of the tablet showed the rate controlling property of acrylamide grafted locust bean gum was similar to that of hydroxypropyl methylcellulose (HPMC-K15M).

  5. Characterization of xanthan gum produced from glycerol by a mutant strain Xanthomonas campestris CCTCC M2015714.

    PubMed

    Wang, Zichao; Wu, Jianrong; Zhu, Li; Zhan, Xiaobei

    2017-02-10

    Xanthan gum was produced by a mutant strain X. campestris CCTCC M2015714 with glycerol as the sole carbon source. The monosaccharide composition and molar ratio of xanthan gum produced from glycerol are glucose: mannose: glucuronic acid=2.0:1.65:1.0. Meanwhile, chemical structure of xanthan gum produced from glycerol is similar to that of the commercial xanthan through FT-IR and NMR. Remarkably, the molecular weight of xanthan gum produced using our method (3.0±0.14×10(6)Da) is about half that of the commercial one (5.8±0.25×10(6)Da), and the consistency index (K) of which is less than 1/10 that of the commercial xanthan. This work paves the way for xanthan production from glycerol and is useful for studying the structure/application of xanthan gum.

  6. Sulfation of Aegle marmelos gum: synthesis, physico-chemical and functional characterization.

    PubMed

    Jindal, Manish; Rana, Vikas; Kumar, Vineet; Singh, Ram S; Kennedy, John F; Tiwary, Ashok K

    2013-02-15

    The present investigation was aimed at optimizing the conditions for preparing sulfated derivative of gum obtained from partially ripe fruits of Aegle marmelos. Elemental analysis, FTIR-ATR and NMR studies confirmed successful sulfation. The ratio of chlorosulfonic acid to pyridine exerted maximum influence on the degree of substitution followed by reaction temperature and reaction time. The sulfated derivative showed higher swelling in both acidic and alkaline pH as compared to unmodified gum. It also possessed higher negative zeta potential, higher viscosity, work of shear, firmness, consistency, cohesiveness and index of viscosity as compared to both unmodified gum as well as sodium alginate. Sulfated derivative was superior to unmodified gum and sodium alginate in terms of antimicrobial and anticoagulant activity. The sulfated sample appears to be a potential substitute over the unmodified gum sample and sodium alginate for modulating physicochemical properties of food and drug release dosage forms.

  7. [Integrated evaluation of chewing gums and candies influence in oral cavity].

    PubMed

    Rumiantsev, V A; Namestnikova, I V; Mitrofanov, V I; Zakulenkova, E M

    2005-01-01

    In a blind study on 210 medical students during 3 months the influence of 5 types of chewing gums with sugar substitutes (Orbit, Dirol, Stimorol) and 1 type of candy with sucrose upon saliva properties, saliva flow and oral microflora activity were examined. Flow rate of saliva, its pH (mixed saliva), influence upon test sugar and carbamide pH curves, concentrations of carbamide, Ca and phosphate in saliva were determined. It is shown than frequent and prolong use of chewing gums reduced stimulated and unstimulated saliva flow. Frequent use of chewing gums with carbamide provoked increased activity of ureapositive oral microflora. Degree of alkaline changes of mixed saliva pH in case of 3-month use of chewing gums Orbit and Stimorol pro Z was reduced. Chewing gums had weak hygienic efficacy.

  8. Influence of gamma radiation on the physicochemical and rheological properties of sterculia gum polysaccharides

    NASA Astrophysics Data System (ADS)

    Singh, Baljit; Sharma, Vikrant

    2013-11-01

    Keeping in view the influence of gamma radiation on the physiochemical properties of the polysaccharides and their importance in the food and pharmaceutical industry, in the present study attempt has been made to investigate the effects of absorbed dose on FTIR, XRD, SEMs, absorbance, pH, solubility, water absorption capacity, emulsion stability and rheology of sterculia gum. Increase in solubility and decrease in swellability of gum has been observed on increasing the absorbed dose. The emulsion stability has improved for the gum sample irradiated with total dose of 8.1±0.2 kGy. Apparent viscosity of gum solution first increased with increase in dose from 0 to 8.1±0.2 kGy than decreased with regular trends with further increase in total absorbed dose. Flow behavior of gum solution shifted to Newtonian from non-Newtonian with increasing the dose.

  9. Gas chromatographic determination of polysaccharide gums in foods after hydrolysis and derivatization.

    PubMed

    Lawrence, J F; Iyengar, J R

    1985-12-20

    A gas chromatographic method was evaluated for the determination of food grade gums in dairy products, salad dressings and meat sauces. The gums studied were tragacanth, karaya, ghatti, carob, guar, arabic and xanthan gum. The extraction method included removal of fat followed by starch degradation then precipitation of protein. The isolated gums were hydrolysed with trifluoroacetic acid and the resulting neutral monosaccharides converted to their aldonitrile acetate derivatives for determination by gas chromatography. Recoveries from thirteen different commodities averaged 85%. However, the recovery of guar gum from ice cream and cold pack cheese was 42 and 50%, respectively. In a comparison of enzyme hydrolysis and iodine complexation for the removal of starch the former was simpler and provided cleaner extracts than the iodine treatment. Both gave similar results.

  10. Modified gum arabic cross-linked gelatin scaffold for biomedical applications.

    PubMed

    Sarika, P R; Cinthya, Kuriakose; Jayakrishnan, A; Anilkumar, P R; James, Nirmala Rachel

    2014-10-01

    The present work deals with development of modified gum arabic cross-linked gelatin scaffold for cell culture. A new biocompatible scaffold was developed by cross-linking gelatin (Gel) with gum arabic, a polysaccharide. Gum arabic was subjected to periodate oxidation to obtain gum arabic aldehyde (GAA). GAA was reacted with gelatin under appropriate pH to prepare the cross-linked hydrogel. Cross-linking occurred due to Schiff's base reaction between aldehyde groups of oxidized gum arabic and amino groups of gelatin. The scaffold prepared from the hydrogel was characterized by swelling properties, degree of cross-linking, in vitro degradation and scanning electron microscopy (SEM). Cytocompatibility evaluation using L-929 and HepG2 cells confirmed non-cytotoxic and non-adherent nature of the scaffold. These properties are essential for generating multicellular spheroids and hence the scaffold is proposed to be a suitable candidate for spheroid cell culture.

  11. Guar gum solutions for improved delivery of iron particles in porous media (part 1): porous medium rheology and guar gum-induced clogging.

    PubMed

    Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

    2014-10-01

    The present work is the first part of a comprehensive study on the use of guar gum to improve delivery of microscale zero-valent iron particles in contaminated aquifers. Guar gum solutions exhibit peculiar shear thinning properties, with high viscosity in static conditions and lower viscosity in dynamic conditions: this is beneficial both for the storage of MZVI dispersions, and also for the injection in porous media. In the present paper, the processes associated with guar gum injection in porous media are studied performing single-step and multi-step filtration tests in sand-packed columns. The experimental results of single-step tests performed by injecting guar gum solutions prepared at several concentrations and applying different dissolution procedures evidenced that the presence of residual undissolved polymeric particles in the guar gum solution may have a relevant negative impact on the permeability of the porous medium, resulting in evident clogging. The most effective preparation procedure which minimizes the presence of residual particles is dissolution in warm water (60°C) followed by centrifugation (procedure T60C). The multi-step tests (i.e. injection of guar gum at constant concentration with a step increase of flow velocity), performed at three polymer concentrations (1.5, 3 and 4g/l) provided information on the rheological properties of guar gum solutions when flowing through a porous medium at variable discharge rates, which mimic the injection in radial geometry. An experimental protocol was defined for the rheological characterization of the fluids in porous media, and empirical relationships were derived for the quantification of rheological properties and clogging with variable injection rate. These relationships will be implemented in the second companion paper (Part II) in a radial transport model for the simulation of large-scale injection of MZVI-guar gum slurries.

  12. Guar gum solutions for improved delivery of iron particles in porous media (Part 1): Porous medium rheology and guar gum-induced clogging

    NASA Astrophysics Data System (ADS)

    Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

    2014-10-01

    The present work is the first part of a comprehensive study on the use of guar gum to improve delivery of microscale zero-valent iron particles in contaminated aquifers. Guar gum solutions exhibit peculiar shear thinning properties, with high viscosity in static conditions and lower viscosity in dynamic conditions: this is beneficial both for the storage of MZVI dispersions, and also for the injection in porous media. In the present paper, the processes associated with guar gum injection in porous media are studied performing single-step and multi-step filtration tests in sand-packed columns. The experimental results of single-step tests performed by injecting guar gum solutions prepared at several concentrations and applying different dissolution procedures evidenced that the presence of residual undissolved polymeric particles in the guar gum solution may have a relevant negative impact on the permeability of the porous medium, resulting in evident clogging. The most effective preparation procedure which minimizes the presence of residual particles is dissolution in warm water (60 °C) followed by centrifugation (procedure T60C). The multi-step tests (i.e. injection of guar gum at constant concentration with a step increase of flow velocity), performed at three polymer concentrations (1.5, 3 and 4 g/l) provided information on the rheological properties of guar gum solutions when flowing through a porous medium at variable discharge rates, which mimic the injection in radial geometry. An experimental protocol was defined for the rheological characterization of the fluids in porous media, and empirical relationships were derived for the quantification of rheological properties and clogging with variable injection rate. These relationships will be implemented in the second companion paper (Part II) in a radial transport model for the simulation of large-scale injection of MZVI-guar gum slurries.

  13. Enterocutaneous Fistula: Different Surgical Intervention Techniques for Closure along with Comparative Evaluation of Aluminum Paint, Karaya Gum (Hollister) and Gum Acacia for Peristomal Skin Care

    PubMed Central

    Namrata; Ahmad, Shabi

    2015-01-01

    Introduction Gastrointestinal fistulas are serious complications and are associated with high morbidity and mortality rates. In majority of the patients, fistulas are treatable. However, the treatment is very complex and often multiple therapies are required. These highly beneficial treatment options which could shorten fistula closure time also result in considerable hospital cost savings. Aim This study was planned to study aetiology, clinical presentation, morbidity and mortality of enterocutaneous fistula and to evaluate the different surgical intervention techniques for closure of enterocutaneous fistula along with a comparative evaluation of different techniques for management of peristomal skin with special emphasis on aluminum paint, Karaya gum (Hollister) and Gum Acacia. Materials and Methods This prospective observational study was conducted in the Department of Surgery, M.L.N. Medical College, Allahabad and its associated hospital (S.R.N. Hospital, Allahabad) for a period of five years. Results Majority of enterocutaneous fistula were of small bowel and medium output fistulas (500-1000 ml/24hours). Most of the patients were treated with conservative treatment as compared to surgical intervention. Large bowel fistula has maximum spontaneous closure rate compare to small bowel and duodenum. Number of orifice whether single or multiple does not appear to play statistically significant role in spontaneous closure of fistula. Serum Albumin is a significantly important predictor of spontaneous fistula closure and mortality. Surgical management appeared to be the treatment of choice in distal bowel fistula. The application of karaya gum (Hollister kit), Gum Acacia and Aluminum Paint gave similar outcome. Conclusion Postoperative fistulas are the most common aetiology of enterocutaneous fistula and various factors do play role in management. Peristomal skin care done with Karaya Gum, Gum Acacia and Aluminum Paint has almost equal efficiency in management of skin

  14. Metabolism of acyl-lipids in Chlamydomonas reinhardtii.

    PubMed

    Li-Beisson, Yonghua; Beisson, Fred; Riekhof, Wayne

    2015-05-01

    Microalgae are emerging platforms for production of a suite of compounds targeting several markets, including food, nutraceuticals, green chemicals, and biofuels. Many of these products, such as biodiesel or polyunsaturated fatty acids (PUFAs), derive from lipid metabolism. A general picture of lipid metabolism in microalgae has been deduced from well characterized pathways of fungi and land plants, but recent advances in molecular and genetic analyses of microalgae have uncovered unique features, pointing out the necessity to study lipid metabolism in microalgae themselves. In the past 10 years, in addition to its traditional role as a model for photosynthetic and flagellar motility processes, Chlamydomonas reinhardtii has emerged as a model organism to study lipid metabolism in green microalgae. Here, after summarizing data on total fatty acid composition, distribution of acyl-lipid classes, and major acyl-lipid molecular species found in C. reinhardtii, we review the current knowledge on the known or putative steps for fatty acid synthesis, glycerolipid desaturation and assembly, membrane lipid turnover, and oil remobilization. A list of characterized or putative enzymes for the major steps of acyl-lipid metabolism in C. reinhardtii is included, and subcellular localizations and phenotypes of associated mutants are discussed. Biogenesis and composition of Chlamydomonas lipid droplets and the potential importance of lipolytic processes in increasing cellular oil content are also highlighted.

  15. Phylogenetic and experimental characterization of an acyl-ACP thioesterase family reveals significant diversity in enzymatic specificity and activity

    PubMed Central

    2011-01-01

    Background Acyl-acyl carrier protein thioesterases (acyl-ACP TEs) catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids. Results To explore acyl-ACP TE diversity and to identify novel acyl ACP-TEs, 31 acyl-ACP TEs from wide-ranging phylogenetic sources were characterized to ascertain their in vivo activities and substrate specificities. These acyl-ACP TEs were chosen by two different approaches: 1) 24 TEs were selected from public databases on the basis of phylogenetic analysis and fatty acid profile knowledge of their source organisms; and 2) seven TEs were molecularly cloned from oil palm (Elaeis guineensis), coconut (Cocos nucifera) and Cuphea viscosissima, organisms that produce medium-chain and short-chain fatty acids in their seeds. The in vivo substrate specificities of the acyl-ACP TEs were determined in E. coli. Based on their specificities, these enzymes were clustered into three classes: 1) Class I acyl-ACP TEs act primarily on 14- and 16-carbon acyl-ACP substrates; 2) Class II acyl-ACP TEs have broad substrate specificities, with major activities toward 8- and 14-carbon acyl-ACP substrates; and 3) Class III acyl-ACP TEs act predominantly on 8-carbon acyl-ACPs. Several novel acyl-ACP TEs act on short-chain and unsaturated acyl-ACP or 3-ketoacyl-ACP substrates, indicating the diversity of enzymatic specificity in this enzyme family. Conclusion These acyl-ACP TEs can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids. PMID:21831316

  16. Effect of gum chewing on the pH of dental plaque.

    PubMed

    Fröhlich, S; Maiwald, H J; Flowerdew, G

    1992-01-01

    Saliva stimulation by gum chewing has been reported to neutralize plaque acidity. We compared the plaque pH response to bread with honey followed by sucrose-or sorbitol-sweetened gum chewing for 20 minutes. Bread and honey was chosen as previous work in our laboratory found this a worst case challenge in terms of the extent and duration of the pH decline. The study design was factorial with: 4 subjects x 2 replicates x 3 treatments. Each subject received each of the 3 treatments: food (bread and honey), food followed by sorbitol chewing gum, and food followed by sucrose chewing gum. Subjects accumulated plaque for 3 days on a partial prosthesis with a glass electrode set in the approximal space in the gap left by a missing first molar. Plaque pH was monitored for 150 min: baseline (0-10), food (11-30), +/- gum chewing (31-50), post-chew monitoring (51-150). ANOVA of mean plaque pH showed no difference between treatments at baseline. Significantly higher pH levels (p < 0.01) were shown with both gums compared to no gum during the chew and post-chew phases. Plaque pH data were also converted to absolute acid values (cH). Food alone produced 1703 mumol/min.; food followed by sorbitol chewing gum produced 53 mumol/min.; and food followed by sucrose gum produced 156 mumol/min. While the post-chew pH curves were not identical for sucrose vs. sorbitol chewing gums, both neutralized plaque acidity, probably due to the induced salivary action.

  17. Assessment of ferula Gummosa gum as a binding agent in tablet formulations.

    PubMed

    Enauyatifard, Reza; Azadbakht, Mohammad; Fadakar, Yousef

    2012-01-01

    Ferula gummosa Boiss. (Apiaceae) is one of the natural plants of Iran. The whole plant, but especially the root, contains the gum resin "galbanum". A study of the comparative effects of galbanum gum and two standard binding agents--polyvinylpyrolidone and acacia--on characteristics of acetaminophen and calcium carbonate compacts was made. The Ferula gummosa gum was extracted and its swelling index was determined. Acetaminophen and calcium carbonate granules were prepared using the wet granulation method and were evaluated for their micromeritics and flow properties, while the compacts were evaluated for mechanical properties using the hardness, tensile strength and friability. The drug release from acetaminophen compacts were assessed using dissolution studies. The dry powder of Ferula gummosa gum resin (galbanum) yielded 14% w/w of gum using distilled water as extraction solvent. The swelling index indicates that galbanum gum swelled to about 190% of initial volume in distilled water. Thus galbanum gum has the ability to hydrate and swells in cold water. The bulk and tapped densities and the interspace porosity (void porosity) percent of the granules prepared with different binders showed significant difference. The hardness and tensile strength of acetaminophen and calcium carbonate compacts containing various binders was of the rank order PVP > acacia > galbanum gum (p < 0.05) and the friability percent was of the reverse order (p < 0.05). The ranking for the dissolution rate of tablets containing the different binders was PVP> galbanum gum > acacia. The results of mechanical properties of acetaminophen and calcium carbonate compacts indicate that galbanum gum could be useful to produce tablets with desired mechanical characteristics for specific purposes, and could be used as an alternative substitute binder in pharmaceutical industries.

  18. Plant Microsomal Phospholipid Acyl Hydrolases Have Selectivities for Uncommon Fatty Acids.

    PubMed Central

    Stahl, U.; Banas, A.; Stymne, S.

    1995-01-01

    Developing endosperms and embryos accumulating triacylglycerols rich in caproyl (decanoyl) groups (i.e. developing embryos of Cuphea procumbens and Ulmus glabra) had microsomal acyl hydrolases with high selectivities toward phosphatidylcholine with this acyl group. Similarly, membranes from Euphorbia lagascae and Ricinus communis endosperms, which accumulate triacylglycerols with vernoleate (12-epoxy-octadeca-9-enoate) and ricinoleate (12-hydroxy-octadeca-9-enoate), respectively, had acyl hydrolases that selectively removed their respective oxygenated acyl group from the phospholipids. The activities toward phospholipid substrates with epoxy, hydroxy, and medium-chain acyl groups varied greatly between microsomal preparations from different plant species. Epoxidated and hydroxylated acyl groups in sn-1 and sn-2 positions of phosphatidylcholine and in sn-1-lysophosphatidylcholine were hydrolyzed to a similar extent, whereas the hydrolysis of caproyl groups was highly dependent on the positional localization. PMID:12228415

  19. Direct nonchromatographic assay for 1-acyl-sn-glycerol-3-phosphate acyltransferase

    SciTech Connect

    Rajasekharan, R.; Ray, T.K.; Cronan, J.E. Jr.

    1988-09-01

    1-Acyl-sn-glycerol-3-phosphate acyltransferase (also called lysophosphatidic acid acyltransferase) which catalyzes the acylation of 1-acyl-sn-glycerol-3-phosphate to phosphatidic acid is generally assayed by the use of a radioactive substrate followed by a time-consuming chromatographic separation of substrate and product. We report a direct and highly sensitive nonchromatographic assay for this enzyme based on the ability of Escherichia coli alkaline phosphatase to dephosphorylate 1-acyl-sn-glycerol-3-phosphate but not phosphatidic acid. This selective hydrolysis coupled with the use of /sup 32/P-labeled 1-acyl-sn-glycerol-3-phosphate as substrate permits measurement of the product, /sup 32/P-labeled phosphatidic acid by solvent extraction or precipitation. We also report a series of enzymatic reactions for the efficient conversion of /sup 32/Pi to /sup 32/P-labeled 1-acyl-sn-glycerol-3-phosphate.

  20. Characterization of Lipid A Variants by Energy-Resolved Mass Spectrometry: Impact of Acyl Chains

    NASA Astrophysics Data System (ADS)

    Crittenden, Christopher M.; Akin, Lucas D.; Morrison, Lindsay J.; Trent, M. Stephen; Brodbelt, Jennifer S.

    2016-12-01

    Lipid A molecules consist of a diglucosamine sugar core with a number of appended acyl chains that vary in their length and connectivity. Because of the challenging nature of characterizing these molecules and differentiating between isomeric species, an energy-resolved MS/MS strategy was undertaken to track the fragmentation trends and map genealogies of product ions originating from consecutive cleavages of acyl chains. Generalizations were developed based on the number and locations of the primary and secondary acyl chains as well as variations in preferential cleavages arising from the location of the phosphate groups. Secondary acyl chain cleavage occurs most readily for lipid A species at the 3' position, followed by primary acyl chain fragmentation at both the 3' and 3 positions. In the instances of bisphosphorylated lipid A variants, phosphate loss occurs readily in conjunction with the most favorable primary and secondary acyl chain cleavages.

  1. New structural features of Acacia tortuosa gum exudate.

    PubMed

    Martínez, Maritza; Beltrán, Olga; Rincón, Fernando; León de Pinto, Gladys; Igartuburu, José Manuel

    2015-09-01

    Acacia tortuosa produces a clear gum, very soluble in water. Previous reports showed that it was constituted by four fractions, one of them an arabinogalactan-protein complex. The elucidation of the A. tortuosa gum structure by the combination of classical chemical methods, size exclusion chromatography and NMR spectroscopy, was the objective of this investigation. The data obtained show that the heteropolysaccharide is an arabinogalactan type II, highly ramified, with lateral chains at C-2 as well as at C-6 of the galactose 3-O residues; mono-O-substituted galactoses were not detected. There are residues of mannose, the arabinose, pyranose predominantly, is terminal and 2-O-linked. The abundance of the 4-O-methyl-α-d-glucuronic acid was not previously reported. The proteic fraction is probably represented by an arabinogalactan-protein complex that binds poorly with β-glucosyl Yariv reagent, and two glycoproteins. The NMR spectra suggest that the carbohydrate links to hydroxyproline through the galactose (galactosylation).

  2. Structural characterization of mesquite (Prosopis velutina) gum and its fractions.

    PubMed

    López-Franco, Yolanda L; de la Barca, Ana M Calderón; Valdez, Miguel A; Peter, Martin G; Rinaudo, Marguerite; Chambat, Gérard; Goycoolea, Francisco M

    2008-08-11

    Structural and physicochemical characteristics of mesquite gum (from Prosopis velutina) were investigated using FT-IR spectroscopic, mass spectrometric and chromatographic methods. Four fractions (F-I, F-IIa, F-IIb and F-III) were isolated by hydrophobic interaction chromatography. The samples were characterized and analyzed for their monosaccharide and oligomers composition by high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). L-Arabinose (L-Ara) and D-galactose (D-Gal) were found as the main carbohydrate constituent residues in the polysaccharides from mesquite gum and their ratio (L-Ara/D-Gal) varied within the range 2.54 to 3.06 among the various fractions. Small amounts of D-glucose (D-Glc), D-mannose (D-Man) and D-xylose (D-Xyl) were also detected, particularly in Fractions IIa, IIb and III. Infrared spectroscopy identified polysaccharides and protein in all the samples. Data from mass spectrometry (MALDI-TOF MS) was consistent with the idea that the structure corresponding to the periphereal chains of Fraction I is predominantly a chain of pentoses attached to uronic acid.

  3. Gum and deposit formation from jet turbine and diesel fuels

    SciTech Connect

    Mayo, F.R.; Lan, B.Y.

    1983-09-01

    The objective of this work is to determine the chemistry of deposit formation in hot parts of jet turbine and diesel engines and, thus, to predict and prevent deposit formation. Previous work in the field has been extensive, but a real understanding of deposit formation has been elusive. Work at SRI started on the basis that deposit formation from fuels must take place stepwise and is associated with autoxidation and the hydroperoxide produced. More recent work showed that in the absence of dissolved oxygen, higher temperatures are required for deposit formation. A recent report indicated that gum and deposit formation proceed mainly through oxidation products of the parent hydrocarbon, coupling of these products to dimeric, trimeric and higher condensation products (partly or wholly by radicals from hydroperoxides) and precipitation of insoluble products. The authors know of no information on how these first precipitates are converted to the ultimate, very insoluble, carbonaceous materials that cause engine problems. The present paper describes measurements of rates of oxidation and soluble gum formation in both pure hydrocarbons and mixed hydrocarbon fuels. Some patterns appear that can be largely explained on the basis of what is known about co-oxidations of hydrocarbon mixtures.

  4. Gum containing calcium fluoride reinforces enamel subsurface lesions in situ.

    PubMed

    Kitasako, Y; Sadr, A; Hamba, H; Ikeda, M; Tagami, J

    2012-04-01

    The aim of this study was to assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and a low concentration of fluoride (F) on the hardness of enamel subsurface lesions, utilizing a double-blind, randomized, and controlled in situ model. Fifteen individuals wore removable lingual appliances with 3 bovine-enamel insets containing subsurface demineralized lesions. Three times a day for 14 days, they chewed one of the 3 chewing gums (placebo, POs-Ca, POs-Ca+F). After the treatment period, cross-sectional mineral content, nanoindentation hardness, and fluoride ion mapping by time-of-flight secondary ion mass spectrometry (TOF-SIMS) were evaluated. Although there were no statistical differences in overall mineral content and hardness recovery rates between POs-Ca and POs-Ca+F subsurface lesions (p > 0.05), nanoindentation at 1-μm distance increments from the surface showed statistical differences in hardness recovery rate between POs-Ca and POs-Ca+F in the superficial 20-μm region (p < 0.05). Fluoride mapping revealed distribution of the ion up to 20 μm from the surface in the POs-Ca+F group. Nanoindentation and TOF-SIMS results highlighted the benefits of bioavailability of fluoride ion on reinforcement of the superficial zone of subsurface lesions in situ (NCT01377493).

  5. ZrCl4-mediated regio- and chemoselective Friedel-Crafts acylation of indole.

    PubMed

    Guchhait, Sankar K; Kashyap, Maneesh; Kamble, Harshad

    2011-06-03

    An efficient method for regio- and chemoselective Friedel-Crafts acylation of indole using acyl chlorides in the presence of ZrCl(4) has been discovered. It minimizes/eliminates common competing reactions that occur due to high and multiatom-nucleophilic character of indole. In this method, a wide range of aroyl, heteroaroyl alkenoyl, and alkanoyl chlorides undergo smooth acylation with various indoles without NH protection and afford 3-acylindoles in good to high yields.

  6. Acute ethanol treatment induces a bimodal response of phospholipid acylation rates in rat red blood cells

    SciTech Connect

    Verine, A.; Valette, A.; Richard, D.; Boyer, J. )

    1991-01-01

    A single intraperitoneal injection of ethanol in rats elicited a bimodal response of acylation rates in phosphatidylcholine and phosphatidylethanolamine of intact red blood cells. Within an initial period, ethanol inhibited acylation rates. The inhibition then reversed, leading to increased values which persisted as long as ethanol was present in plasma. Acylation rates were not correlated to ethanol concentrations in plasma. The authors suggest that red cells first desensitize to, then overcompensate for the inhibitory effect of ethanol on acylation reactions. These adaptive changes may be one of the events mediating membrane tolerance to ethanol.

  7. A novel plasmid for detection of N-acyl homoserine lactones.

    PubMed

    Ling, Elizabeth A; Ellison, Matthew L; Pesci, Everett C

    2009-07-01

    Many bacteria utilize acyl-homoserine lactones as cell to cell signals that can regulate the expression of numerous genes. Structural differences in acyl-homoserine lactones produced by different bacteria, such as acyl side chain length and the presence or absence of an oxy group, make many of the commonly used detection bioassays impractical for broad range detection. Here we present a simple, broad range acyl-homoserine lactone detection bioassay that can be used to detect a wide range of these chemical signals. A plasmid (pEAL01) was constructed and transformed into Pseudomonas aeruginosa strain QSC105 to allow for detection of a broad range of acyl-homoserine lactones through induction of a lasB'-lacZ transcriptional fusion. Monitoring beta-galactosidase activity from this bioassay showed that P. aeruginosa strain QSC105 (pEAL01) could detect the presence of eight acyl-homoserine lactones tested at physiological concentrations. This novel strain could also detect acyl-homoserine lactones from the extracts of four different bacteria that produce different acyl-homoserine lactones signals. These data indicate that strain QSC105 (pEAL01) can be used to detect a wide variety of acyl-homoserine lactones by a simple beta-galactosidase assay and this bioassay could be a useful and inexpensive tool to quickly identify the presence of these signal molecules.

  8. Rheology of dispersions of xanthan gum, locust bean gum and mixed biopolymer gel with silicon dioxide nanoparticles.

    PubMed

    Kennedy, Jordan R M; Kent, Katherine E; Brown, Jennifer R

    2015-03-01

    Mixed xanthan gum (XG) and locust bean gum (LBG) biopolymers form thermally reversible gels of interest in tissue engineering and drug delivery. 1% solutions of XG, LBG and 1:1 ratio XG/LBG mixed gels (LX) containing silicon dioxide (SiO2) nanoparticles were rheologically characterized with respect to nanoparticle concentration and temperature. 10% nanoparticles in XG created larger domains of associated polymer, resulting in enhanced viscosity and viscoelastic moduli. In LBG with 10% particles, transient viscosity and a gel-sol transition occurred due to particle bridging and aggregation. In the LX gel, 10% SiO2 particles caused an increase in elasticity. When ramping temperature from 25°C to 85°C, the complex modulus for all solutions containing 10% SiO2 was relatively constant, indicating that nanoparticles counteracted the effect of temperature on the material properties. Understanding the influence of nanoparticle loading on material properties is necessary for biopolymer material development where property prediction and control are critical.

  9. Effect of xanthan gum and guar gum on in situ gelling ophthalmic drug delivery system based on poloxamer-407.

    PubMed

    Bhowmik, Manas; Kumari, Puja; Sarkar, Gunjan; Bain, Mrinal Kanti; Bhowmick, Biplab; Mollick, Md Masud Rahaman; Mondal, Dibyendu; Maity, Dipanwita; Rana, Dipak; Bhattacharjee, Debashis; Chattopadhyay, Dipankar

    2013-11-01

    The aim of this investigation was to develop a novel in situ gelling formulation based on poloxamer-407 (PM) for the sustained release of an ophthalmic drug. In an attempt to reduce the concentration of PM without compromising the in situ gelling capability and also to increase the drug release time, xanthan gum (XG) and guar gum (GG) were added into PM to develop different formulations. At concentrations of 18% and above, the PM was able to undergo sol-gel transition below body temperature. It was found that XG and GG at a weight ratio of 3:7 were able to convert PM solution into gel below body temperature at PM concentrations below 18%. Both the in vitro and in vivo studies indicated that the PM with an XG-GG combination had a better ability to retain the drug than PM itself. The results indicated that the developed in situ gelling formulations containing PM with XG-GG may be a better alternative than a conventional eye drop.

  10. Native and structurally modified gum arabic: exploring the effect of the gum's microstructure in obtaining electroactive nanoparticles.

    PubMed

    Cornelsen, Patricia A; Quintanilha, Ronaldo C; Vidotti, Marcio; Gorin, Philip A J; Simas-Tosin, Fernanda F; Riegel-Vidotti, Izabel C

    2015-03-30

    Electroactive nanoparticles combining gum arabic (GA) and polyaniline (PANI) were prepared by chemical synthesis. The gum consists of highly branched anionic polysaccharides with some protein content. GA was structurally modified by Smith controlled degradation, in order to reduce its degree of branching (GAD), aiming the elucidation of the relationship between the structure and the properties of complex polysaccharides. The modification was studied by SEC, GC-MS, (13)C NMR and colorimetric methods. GAD has lower molecular mass, lower degree of branching and lower uronic acid content. Besides it is enriched in galactose and protein when compared with GA. The obtained composites (GA-PANI and GAD-PANI) were thoroughly characterized. Although the use of both polysaccharides (GA and GAD) produced highly stable electroactive nanoparticles, the best combination of properties was achieved for GA-PANI. The sample GAD was not able to prevent the occurrence of crosslinking between PANI chains, possibly due to its lower microstructural complexity which diminishes the occurrence of hydrogen bonds between the polymers.

  11. The contrasting physiological and subjective effects of chewing gum on social stress.

    PubMed

    Gray, Gemma; Miles, Christopher; Wilson, Nigel; Jenks, Rebecca; Cox, Martin; Johnson, Andrew J

    2012-04-01

    Uncertainty exists with respect to the extent to which chewing gum may attenuate stress-induced rises in cortisol secretion (Johnson, Jenks, Miles, Albert, & Cox, 2011; Scholey et al., 2009; Smith, 2010). The present study used the Trier Social Stress Task (TSST: Kirschbaum, Pirke, & Hellhammer, 1993), a task known to elevate cortisol secretion (Kudielka, Schommer, Hellhammer, & Kirschbaum, 2004), in order to examine the moderating physiological and subjective effects of chewing gum on social stress. Forty participants completed the TSST either with or without chewing gum. As expected, completion of the TSST elevated both cortisol and subjective stress levels, whilst impairing mood. Although gum moderated the perception of stress, cortisol concentrations were higher following the chewing of gum. The findings are consistent with Smith (2010) who argued that elevations in cortisol following the chewing of gum reflect heightened arousal. The findings suggest that chewing gum only benefits subjective measures of stress. The mechanism remains unclear; however, this may reflect increased cerebral blood flow, cognitive distraction, and/or effects secondary to task facilitation.

  12. Detrimental effects of gum chewing on vigilance in children with attention deficit hyperactivity disorder.

    PubMed

    Tucha, Lara; Simpson, William; Evans, Lynsay; Birrel, Laura; Sontag, Thomas A; Lange, Klaus W; Tucha, Oliver

    2010-12-01

    Impairments of attention are cardinal features of attention deficit hyperactivity disorder (ADHD) and can seriously affect the daily life of children with ADHD. Despite effective treatment strategies, there is a need of further treatment options that can be added to available and well established treatments. Further treatment options are needed since available treatments are often time consuming, expensive and limited regarding their external validity. Recent research demonstrated that gum chewing has beneficial effects on cognition including certain aspects of attention. Therefore, gum chewing may benefit children with ADHD in situations requiring particular cognitive efforts. In a crossover study, attentional functioning of 32 children with ADHD and 32 children without the condition was examined. All participants were assessed with chewing gum and without chewing gum. A computerized test was used for the assessment of vigilance and sustained attention. The findings of the present study suggest that gum chewing during task execution has detrimental effects on vigilance of both healthy children and children with ADHD. Sustained attention was not affected by gum chewing. Chewing gum, therefore, appears not to improve attentional performance in children with ADHD.

  13. Chewing gum: cognitive performance, mood, well-being, and associated physiology.

    PubMed

    Allen, Andrew P; Smith, Andrew P

    2015-01-01

    Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies) examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on well-being and performance, as well as postwork mood and cognitive performance. In Study 4, performance and well-being were reported throughout the workday and at the end of the day, and heart rate and cortisol were measured. Under experimental conditions, gum was associated with higher alertness regardless of whether performance tasks were completed and altered sustained attention. Rate of chewing and subjective force of chewing did not alter mood but had some limited effects on attention. Chewing gum during the workday was associated with higher productivity and fewer cognitive problems, raised cortisol levels in the morning, and did not affect heart rate. The results emphasise that chewing gum can attenuate reductions in alertness, suggesting that chewing gum enhances worker performance.

  14. Effects of chewing gum on short-term appetite regulation in moderately restrained eaters.

    PubMed

    Hetherington, Marion M; Regan, Martin F

    2011-10-01

    Orosensory stimulation is an important contributing factor to the development of satiation. Providing orosensory stimulation with few calories may satisfy appetite and help to suppress cravings for high energy snacks. This may be a useful strategy for those motivated to lose or maintain weight. The present study tested the hypothesis that chewing sweetened gum will reduce subjective appetite and subsequent snack intake in moderately restrained eaters. Within-subjects, repeated measures study, sixty healthy participants (53 women; body mass index, in kg/m(2): 26.2±4.5) came to the laboratory 4 times for a standard lunch. Immediately after this meal, participants rated hunger, appetite and cravings for sweet and salty snacks every hour until they returned to the laboratory 3 h later for snack. On two occasions during this 3 h period participants chewed gum for at least 15 min at hourly intervals (45 min) and on two occasions no gum was chewed. On two occasions salty snacks were offered and on two occasions sweet snacks were provided. A small but significant reduction in snack intake was observed, chewing gum reduced weight of snack consumed by 10% compared to no gum (p<0.05). Overall, chewing gum for at least 45 min significantly suppressed rated hunger, appetite and cravings for snacks and promoted fullness (p<0.05). This study demonstrated some benefit of chewing gum which could be of utility to those seeking an aid to appetite control.

  15. Improved welan gum production by Alcaligenes sp. ATCC31555 from pretreated cane molasses.

    PubMed

    Ai, Hongxia; Liu, Min; Yu, Pingru; Zhang, Shaozhi; Suo, Yukai; Luo, Ping; Li, Shuang; Wang, Jufang

    2015-09-20

    Welan gum production by Alcaligenes sp. ATCC31555 from cane molasses was studied in batch fermentation to reduce production costs and enhance gum production. The pretreatment of cane molasses, agitation speed and the addition of supplements were investigated to optimize the process. Sulfuric acid hydrolysis was found to be the optimal pretreatment, resulting in a maximum gum concentration of 33.5 g/L, which is 50.0% higher than those obtained from the molasses' mother liquor. Agitation at 600 rpm at 30°C and addition of 10% n-dodecane following fermentation for 36 h increased the maximum gum production up to 41.0 ± 1.41 g/L, which is 49.1% higher than the greatest welan gum concentration in the literature so far. The welan gum product showed an acceptable molecular weight, similar rheological properties and better thermal stability to that obtained from glucose. These results indicate that cane molasses may be a suitable and inexpensive substrate for cost-effective industrial-scale welan gum production.

  16. Thiol derivatization of Xanthan gum and its evaluation as a mucoadhesive polymer.

    PubMed

    Bhatia, Meenakshi; Ahuja, Munish; Mehta, Heena

    2015-10-20

    Thiol-derivatization of xanthan gum polysaccharide was carried out by esterification with mercaptopropionic acid and thioglycolic acid. Thiol-derivatization was confirmed by Fourier-transformed infra-red spectroscopy. Xanthan-mercaptopropionic acid conjugate and xanthan-thioglycolic acid conjugate were found to possess 432.68mM and 465.02mM of thiol groups as determined by Ellman's method respectively. Comparative evaluation of mucoadhesive property of metronidazole loaded buccal pellets of xanthan and thiolated xanthan gum using chicken buccal pouch membrane revealed higher ex vivo bioadhesion time of thiolated xanthan gum as compared to xanthan gum. Improved mucoadhesive property of thiolated xanthan gum over the xanthan gum can be attributed to the formation of disulfide bond between mucus and thiolated xanthan gum. In vitro release study conducted using phosphate buffer (pH 6.8) revealed a sustained release profile of metronidazole from thiolated xanthan pellets as compared to xanthan pellets. In conclusion, thiolation of xanthan improves its mucoadhesive property and sustained the release of metronidazole over a prolonged period.

  17. Chemical and Functional Properties of Chia Seed (Salvia hispanica L.) Gum

    PubMed Central

    Segura-Campos, Maira Rubi; Ciau-Solís, Norma; Rosado-Rubio, Gabriel; Chel-Guerrero, Luis; Betancur-Ancona, David

    2014-01-01

    Chia (Salvia hispanica L.) constitutes a potential alternative raw material and ingredient in food industry applications due to its dietary fiber content. Gum can be extracted from its dietary fiber fractions for use as an additive to control viscosity, stability, texture, and consistency in food systems. The gum extracted from chia seeds was characterized to determine their quality and potential as functional food additives. The extracted chia gum contained 26.2% fat and a portion was submitted to fat extraction, producing two fractions: gum with fat (FCG) and gum partly defatted (PDCG). Proximal composition and physicochemical characterization showed these fractions to be different (P < 0.05). The PDCG had higher protein, ash, and carbohydrates content than the FCG, in addition to higher water-holding (110.5 g water/g fiber) and water-binding capacities (0.84 g water/g fiber). The FCG had greater oil-holding capacity (25.7 g oil/g fiber) and water absorption capacity (44 g water/g fiber). In dispersion trials, the gums exhibited a non-Newtonian fluid behavior, specifically shear thinning or pseudoplastic type. PDCG had more viscosity than FCG. Chia seed is an excellent natural source of gum with good physicochemical and functional qualities, and is very promising for use in food industry. PMID:26904622

  18. Chemical and Functional Properties of Chia Seed (Salvia hispanica L.) Gum.

    PubMed

    Segura-Campos, Maira Rubi; Ciau-Solís, Norma; Rosado-Rubio, Gabriel; Chel-Guerrero, Luis; Betancur-Ancona, David

    2014-01-01

    Chia (Salvia hispanica L.) constitutes a potential alternative raw material and ingredient in food industry applications due to its dietary fiber content. Gum can be extracted from its dietary fiber fractions for use as an additive to control viscosity, stability, texture, and consistency in food systems. The gum extracted from chia seeds was characterized to determine their quality and potential as functional food additives. The extracted chia gum contained 26.2% fat and a portion was submitted to fat extraction, producing two fractions: gum with fat (FCG) and gum partly defatted (PDCG). Proximal composition and physicochemical characterization showed these fractions to be different (P < 0.05). The PDCG had higher protein, ash, and carbohydrates content than the FCG, in addition to higher water-holding (110.5 g water/g fiber) and water-binding capacities (0.84 g water/g fiber). The FCG had greater oil-holding capacity (25.7 g oil/g fiber) and water absorption capacity (44 g water/g fiber). In dispersion trials, the gums exhibited a non-Newtonian fluid behavior, specifically shear thinning or pseudoplastic type. PDCG had more viscosity than FCG. Chia seed is an excellent natural source of gum with good physicochemical and functional qualities, and is very promising for use in food industry.

  19. [Sugar of substitute stevioside in chewing gum: comparative double blind controllable study].

    PubMed

    Rumiantsev, V A; Beliaev, V V; Zubtsov, V A; Esaian, L K; Namestnikova, I V

    2011-01-01

    In double blind controllable study on 126 volunteers - students of medical academy - influence on рН the mixed saliva of 5 kinds of chewing gums with the different contents of substitute of sugar as xylitol and sorbitol, and also the chewing sweets R.O.C.S., two kinds of chewing gums containing a basis with substitute of sugar stevioside (1.25 and 2.5%) and placebo (a basis without additives) were investigated. Products chewed within 10 minutes. In one of groups surveyed such chewing was preceded with rinsing a mouth by a test solution of saccharose. рН determined within 30 minutes. At chewing gums with substitute of sugar displacement рН the mixed saliva in the alkaline side was revealed a different degree. Thus gums with stevioside did not concede and even surpassed in this action of chewing gums with other substitutes of sugar. In comparison with placebo chewing gums and sweets restored acid-alkaline balance of oral cavities faster. Hence, use of stevioside in structure of chewing gum allows at preservation of its positive actions in oral cavity essentially to reduce concentration substitute of sugar and, hence, its collateral action by an organism.

  20. Effects of prolonged gum chewing on pain and fatigue in human jaw muscles.

    PubMed

    Farella, M; Bakke, M; Michelotti, A; Martina, R

    2001-04-01

    Gum chewing has been accepted as an adjunct to oral hygiene, as salivary stimulant and vehicle for various agents, as well as for jaw muscle training. The aim of this study was to investigate the effects of prolonged gum chewing on pain, fatigue and pressure tenderness of the masticatory muscles. Fifteen women without temporomandibular disorders (TMD) were requested to perform one of the following chewing tasks in three separate sessions: chewing a very hard gum, chewing a soft gum, and empty-chewing with no bolus. Unilateral chewing of gum or empty chewing was performed for 40 min at a constant rate of 80 cycles/min. In each session, perceived muscle pain and masticatory fatigue were rated on visual analog scales (VAS) before, throughout, and after the chewing task. Pressure pain thresholds (PPTs) of masseter and anterior temporalis muscles were assessed before and immediately after the chewing tasks, and again after 24 h. The VAS scores for pain and fatigue significantly increased only during the hard gum chewing, and after 10 min of recovery VAS scores had decreased again, almost to their baseline values. No significant changes were found for PPTs either after hard or soft gum chewing. The findings indicate that the jaw muscles recover quickly from prolonged chewing activity in subjects without TMD.

  1. Rheological characterization and drug release studies of gum exudates of Terminalia catappa Linn.

    PubMed

    Kumar, Sadhis V; Sasmal, Dinakar; Pal, Subodh C

    2008-01-01

    The present study was undertaken to evaluate the gum exudates of Terminalia catappa Linn. (TC gum) as a release retarding excipient in oral controlled drug delivery system. The rheological properties of TC gum were studied and different formulation techniques were used to evaluate the comparative drug release characteristics. The viscosity was found to be dependent on concentration and pH. Temperature up to 60 degrees C did not show significant effect on viscosity. The rheological kinetics evaluated by power law, revealed the shear thinning behavior of the TC gum dispersion in water. Matrix tablets of TC gum were prepared with the model drug dextromethorphan hydrobromide (DH) by direct compression, wet granulation and solid dispersion techniques. The dissolution profiles of the matrix tablets were compared with the pure drug containing capsules using the USP Basket apparatus with 500 ml phosphate buffer of pH 6.8 as a dissolution medium. The drug release from the compressed tablets containing TC gum was comparatively sustained than pure drug containing capsules. Even though all the formulation techniques showed reduction of dissolution rate, aqueous wet granulation showed the maximum sustained release of more than 8 h. The release kinetics estimated by the power law revealed that the drug release mechanism involved in the dextromethorphan matrix is anomalous transport as indicated by the release exponent n values. Thus the study confirmed that the TC gum might be used in the controlled drug delivery system as a release-retarding polymer.

  2. Rheological Behavior of Xanthan Gum Solution Related to Shear Thinning Fluid Delivery for Subsurface Remediation

    SciTech Connect

    Zhong, Lirong; Oostrom, Martinus; Truex, Michael J.; Vermeul, Vincent R.; Szecsody, James E.

    2013-01-15

    Xanthan gum, a biopolymer, forms shear thinning fluids which can be used as delivery media to improve the distribution of remedial amendments injected into heterogeneous subsurface environments. The rheological behavior of the shear thinning solution needs to be known to develop an appropriate design for field injection. In this study, the rheological properties of xanthan gum solutions were obtained under various chemical and environmental conditions relevant to delivery of remedial amendments to groundwater. Higher xanthan concentration raised the absolute solution viscosity and increased the degree of shear thinning. Addition of remedial amendments (e.g., phosphate, sodium lactate, ethyl lactate) caused the dynamic viscosity of xanthan gum to decrease, but the solutions maintained shear-thinning properties. Use of simple salt (e.g. Na+, Ca2+) to increase the solution ionic strength also decreased the dynamic viscosity of xanthan and the degree of shear thinning, although the effect is a function of xanthan gum concentration and diminished as the xanthan gum concentration was increased. At high xanthan concentration, addition of salt to the solution increased dynamic viscosity. In the absence of sediments, xanthan gum solutions maintain their viscosity properties for months. However, xanthan gum solutions were shown to lose dynamic viscosity over a period of days to weeks when contacted with saturated site sediment. Loss of viscosity is attributed to physical and biodegradation processes.

  3. In Vivo Release Kinetics and Antibacterial Activity of Novel Polyphenols-Enriched Chewing Gums.

    PubMed

    Ferrazzano, Gianmaria Fabrizio; Cantile, Tiziana; Coda, Marco; Alcidi, Brunella; Sangianantoni, Giancarla; Ingenito, Aniello; Di Stasio, Michele; Volpe, Maria Grazia

    2016-08-02

    Chewing gums may be particularly effective means for delivering and maintaining bioactive molecules, included in the gum formulation, able to have an anti-cariogenic effect. The purposes of this study were: to develop novel chewing gums containing quercetin (Qt); to evaluate their release using in vivo trial; finally, to test their in vivo antibacterial effect against oral Streptococcus mutans strains. A preliminary study was performed to produce new gums, enriched with the polyphenol quercetin. Then, a first in vivo experimental study was assessed to test the percentages of Qt released in the saliva of young volunteers. Moreover, a second clinical trial was performed to analyze the antibacterial capability of these enriched chewing gums against S. mutans strains after 14 days of daily consumption. The release analysis showed that a more effective release of Qt occurs in the first minutes of chewing, and it does not change saliva pH values. Moreover, Qt included in gums demonstrates an effective antibacterial activity, showing a reduction of the concentration of S. mutans strains in saliva samples, especially after 7 days. Qt included in experimental chewing gums could be efficiently released into the oral cavity and could promote an effective anti-caries concentration in volunteer's saliva, without changing salivary pH values.

  4. Photosensitivity of heterojunctions formed by deposition of gum on a layered III VI semiconductor

    NASA Astrophysics Data System (ADS)

    Drapak, S. I.; Kovalyuk, Z. D.

    2007-09-01

    The list of materials showing promise for the production of photosensitive structures is extended to include an organic material of biological origin known as gum. The current-voltage characteristics of hetero-junctions formed by a gum layer and a layered semiconductor (InSe, GaSe) are studied. An attempt is made to relate some spectral features of the relative quantum efficiency of the structures (for example, nonzero photosensitivity beyond the fundamental absorption edge of the semiconductor material) to the deformation interaction between the condensed gum layer and the layered III VI semiconductor surface.

  5. Acylated flavonol glycosides from the flower of Elaeagnus angustifolia L.

    PubMed

    Bendaikha, Sarah; Gadaut, Méredith; Harakat, Dominique; Magid, Alabdul

    2014-07-01

    Seven acylated flavonol glycosides named elaeagnosides A-G, in addition to seven known flavonoids were isolated from the flowers of Elaeagnus angustifolia. Their structures were elucidated by different spectroscopic methods including 1D, 2D NMR experiments and HR-ESI-MS analysis. In order to identify natural antioxidant and tyrosinase inhibitor agents, the abilities of these flavonoids to scavenge the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and to inhibit tyrosinase activity were evaluated. Results revealed that two of these compounds had significant anti-oxidant effect and one compound showed weak tyrosinase-inhibitory activity compared with kojic acid, quercetin, or ascorbic acid, which were used as positive control.

  6. An outflow linked to a YSO in Gum 31?

    NASA Astrophysics Data System (ADS)

    Vazzano, M. M.; Cappa, C. E.; Bosch, G.; Vásquez, J.

    2016-08-01

    We analyze the distribution of the molecular gas associated with 10349-5824, a young stellar object located on the edge of the H ii region Gum31, with the aim of investigating the existence of bipolar outflows. We use CO(2-1) line observations obtained with the APEX telescope, H line observations on the K band taken with Flamingos 2 in Gemini South and additional data from at 4.5, 8 and 24 m. J103648.97-584010.7 (1), classified as class II, coincides with extended emission in 4.5 m, suggesting the presence of bipolar flows, and with H emission at 2.12 m. Three extended sources detected in H at 0.5 and 1.5 of 1 could also suggest the presence of shocked gas. Additional evidence of bipolar outflows comes from CO(2-1) spectra.

  7. Nonionic gelation agents prepared from hydroxypropyl guar gum.

    PubMed

    Kono, Hiroyuki; Hara, Hideyuki; Hashimoto, Hisaho; Shimizu, Yuuichi

    2015-03-06

    Nonionic gels were prepared from hydroxypropyl guar gum (HPG) with different molar substitution degrees by crosslinking with ethylene glycol diglycidyl ether (EGDE). FTIR and solid-state NMR spectroscopy revealed that the crosslinking degree of HPG gels increased with the amount of EGDE used during the reaction; this result was also confirmed by the water mobility in the swollen gels. Rheological characterization revealed behaviors typical of true gels, and their viscoelastic behaviors strongly depended on the crosslinking degree. The HPG gels absorbed buffers, aqueous saline, and water, and the absorption was not affected by the ionic strength or pH of the solution. In addition, HPG gels with high crosslinking degrees and molar substitution degrees exhibited gelation ability toward protic organic solvents such as methanol, ethanol, and 1-propanol. These HPG gels may find application as gelation agents for many industrial uses.

  8. Impact of the extrusion process on xanthan gum behaviour.

    PubMed

    Sereno, Nuno M; Hill, Sandra E; Mitchell, John R

    2007-07-23

    Processing xanthan gum by extrusion and subsequent drying produces a biopolymer showing particulate, rather than molecular behaviour in aqueous solution. This form of xanthan disperses very readily to give a viscosity that is strongly dependent on salt concentration. On heating above the temperature of the order-disorder transition as determined by calorimetry, there is a viscosity transition that is indicative of the irreversible loss of the particulate structure. It is suggested that the extrusion process melts and aligns xanthan macromolecules. On cooling reordering will occur but in the highly concentrated environment in the extruder ( approximately 45% water w/w), inter-molecular association between neighbouring macromolecules cannot proceed to completion due to kinetic trapping. As a consequence a network structure is created maintained by associations involving ordered regions. A xanthan solution can be prepared from this particulate material by dispersing and subsequent heating far more readily than can be achieved with non-processed xanthan.

  9. Antioxidant Properties of Water-Soluble Gum from Flaxseed Hulls

    PubMed Central

    Bouaziz, Fatma; Koubaa, Mohamed; Barba, Francisco J.; Roohinejad, Shahin; Chaabouni, Semia Ellouz

    2016-01-01

    Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching inhibition assay), respectively. The antioxidant capacity of SFG showed interesting DPPH radical-scavenging capacity (IC50 SFG = 2.5 mg·mL−1), strong ABTS radical scavenging activity (% inhibition ABTS = 75.6% ± 2.6% at 40 mg·mL−1), high reducing power capacity (RPSFG = 5 mg·mL−1), and potent β-carotene bleaching inhibition activity (IC50 SFG = 10 mg·mL−1). All of the obtained results demonstrate the promising potential use of SFG in numerous industrial applications, and a way to valorize flaxseed hulls. PMID:27490574

  10. Antioxidant Properties of Water-Soluble Gum from Flaxseed Hulls.

    PubMed

    Bouaziz, Fatma; Koubaa, Mohamed; Barba, Francisco J; Roohinejad, Shahin; Chaabouni, Semia Ellouz

    2016-08-02

    Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching inhibition assay), respectively. The antioxidant capacity of SFG showed interesting DPPH radical-scavenging capacity (IC50 SFG = 2.5 mg·mL(-1)), strong ABTS radical scavenging activity (% inhibition ABTS = 75.6% ± 2.6% at 40 mg·mL(-1)), high reducing power capacity (RPSFG = 5 mg·mL(-1)), and potent β-carotene bleaching inhibition activity (IC50 SFG = 10 mg·mL(-1)). All of the obtained results demonstrate the promising potential use of SFG in numerous industrial applications, and a way to valorize flaxseed hulls.

  11. Acylation of Antioxidant of Bamboo Leaves with Fatty Acids by Lipase and the Acylated Derivatives’ Efficiency in the Inhibition of Acrylamide Formation in Fried Potato Crisps

    PubMed Central

    Ma, Xiang; Wang, Erpei; Lu, Yuyun; Wang, Yong; Ou, Shiyi; Yan, Rian

    2015-01-01

    This study selectively acylated the primary hydroxyl groups on flavonoids in antioxidant of bamboo leaves (AOB) using lauric acid with Candida antarctica lipase B in tert-amyl-alcohol. The separation and isolation of acylated derivatives were performed using silica gel column chromatography with a mixture of dichloromethane/diethyl ether/methanol as eluents. Both thin layer chromatography and high-performance liquid chromatography analyses confirmed the high efficiency of the isolation process with the purified orientin-6″-laurate, isoorientin-6″-laurate, vitexin-6″-laurate, and isovitexin-6″-laurate that were obtained. The addition of AOB and acylated AOB reduced acrylamide formation in fried potato crisps. Results showed that 0.05% AOB and 0.05% and 0.1% acylated AOB groups significantly (p < 0.05) reduced the content of acrylamide in potato crisps by 30.7%, 44.5%, and 46.9%, respectively. PMID:26098744

  12. Acylation of Antioxidant of Bamboo Leaves with Fatty Acids by Lipase and the Acylated Derivatives' Efficiency in the Inhibition of Acrylamide Formation in Fried Potato Crisps.

    PubMed

    Ma, Xiang; Wang, Erpei; Lu, Yuyun; Wang, Yong; Ou, Shiyi; Yan, Rian

    2015-01-01

    This study selectively acylated the primary hydroxyl groups on flavonoids in antioxidant of bamboo leaves (AOB) using lauric acid with Candida antarctica lipase B in tert-amyl-alcohol. The separation and isolation of acylated derivatives were performed using silica gel column chromatography with a mixture of dichloromethane/diethyl ether/methanol as eluents. Both thin layer chromatography and high-performance liquid chromatography analyses confirmed the high efficiency of the isolation process with the purified orientin-6″-laurate, isoorientin-6″-laurate, vitexin-6″-laurate, and isovitexin-6″-laurate that were obtained. The addition of AOB and acylated AOB reduced acrylamide formation in fried potato crisps. Results showed that 0.05% AOB and 0.05% and 0.1% acylated AOB groups significantly (p < 0.05) reduced the content of acrylamide in potato crisps by 30.7%, 44.5%, and 46.9%, respectively.

  13. Acyl-CoA Synthetase Is Located in the Outer Membrane and Acyl-CoA Thioesterase in the Inner Membrane of Pea Chloroplast Envelopes 1

    PubMed Central

    Andrews, Jaen; Keegstra, Kenneth

    1983-01-01

    Both acyl-CoA synthetase and acyl-CoA thioesterase activities are present in chloroplast envelope membranes. The functions of these enzymes in lipid metabolism remains unresolved, although the synthetase has been proposed to be involved in either plastid galactolipid synthesis or the export of plastid-synthesized fatty acids to the cytoplasm. We have examined the locations of both enzymes within the two envelope membranes of pea (Pisum sativum var Laxton's Progress No. 9) chloroplasts. Inner and outer envelope membranes were purified from unfractionated envelope preparations by linear density sucrose gradient centrifugation. Acyl-CoA synthetase was located in the outer envelope membrane while acyl-CoA thioesterase was located in the inner envelope membrane. Thus, it seems unlikely that the synthetase is directly involved in galactolipid assembly. Instead, its localization supports the hypothesis that it functions in the transport of plastid-synthesized fatty acids to the endoplasmic reticulum. PMID:16663076

  14. Chewing gum in the preoperative fasting period: an analysis of de-identified incidents reported to webAIRS.

    PubMed

    Shanmugam, S; Goulding, G; Gibbs, N M; Taraporewalla, K; Culwick, M

    2016-03-01

    The role of preoperative fasting is well established in current anaesthetic practice with different guidelines for clear fluids and food. However, chewing gum may not be categorised as either food or drink by some patients, and may not always be specified in instructions given to patients about preoperative fasting. The aim of this paper was to review anaesthesia incidents involving gum chewing reported to webAIRS to obtain information on the risks, if any, of gum chewing during the preoperative fasting period. There were nine incidents involving chewing gum reported between late 2009 and early 2015. There were no adverse outcomes from the nine incidents other than postponement of surgery in three cases and cancellation in one. In particular, there were no reports of aspiration or airway obstruction. Nevertheless, there were five cases in which the gum was not detected preoperatively and was found in the patient's mouth either intraoperatively or postoperatively. These cases of undetected gum occurred despite patient and staff compliance with their current preoperative checklists. While the risk of increased gastric secretions related to chewing gum preoperatively are not known, the potential for airway obstruction if the gum is not detected and removed preoperatively is very real. We recommend that patients should be specifically advised to avoid gum chewing once fasting from clear fluids is commenced, and that a specific question regarding the presence of chewing gum should be added to all preoperative checklists.

  15. Matrix Effect on the Spray Drying Nanoencapsulation of Lippia sidoides Essential Oil in Chitosan-Native Gum Blends.

    PubMed

    Paula, Haroldo C B; Oliveira, Erick F; Carneiro, Maria J M; de Paula, Regina C M

    2017-03-01

    Essential oils have many applications in the pharmaceutical, chemical, and food fields, however, their use is limited to the fact that they are very labile, requiring their a priori encapsulation, aiming to preserve their properties.This work reports on the preparation of chitosan-gum nanoparticles loaded with thymol containing Lippia sidoides essential oil, using exudates of Anacardium Occidentale (cashew gum), Sterculia striata (chichá gum), and Anadenanthera macrocarpa trees (angico gum). Nanoparticles were produced by spray drying an emulsion of L. sidoides essential oil and aqueous solution of gums with different chitosan : gum ratios. Samples were characterized by FTIR and UV/VIS spectroscopy, particle size, volume distribution, and zeta potential. The FTIR spectrum showed the main signals of chitosan and the gums. Data obtained revealed that the samples had sizes in the nano range, varying from 17 nm to 800 nm. The zeta potential varied from + 30 mV to - 40 mV. Nanoparticle loading values varied from 6.7 % to 15.6 %, with an average encapsulating efficiency of 62 %, where the samples with high ratios of cashew gum and chichá gum presented high oil loading values. The data revealed that both the chitosan : gum ratio and polysaccharide characteristics play major roles in nanoencapsulation processes.

  16. Stereoelectronic basis for the kinetic resolution of N-heterocycles with chiral acylating reagents.

    PubMed

    Hsieh, Sheng-Ying; Wanner, Benedikt; Wheeler, Philip; Beauchemin, André M; Rovis, Tomislav; Bode, Jeffrey W

    2014-06-10

    The kinetic resolution of N-heterocycles with chiral acylating agents reveals a previously unrecognized stereoelectronic effect in amine acylation. Combined with a new achiral hydroxamate, this effect makes possible the resolution of various N-heterocycles by using easily prepared reagents. A transition-state model to rationalize the stereochemical outcome of this kinetic resolution is also proposed.

  17. ACBP and cholesterol differentially alter fatty acyl CoA utilization by microsomal ACAT.

    PubMed

    Chao, Hsu; Zhou, Minglong; McIntosh, Avery; Schroeder, Friedhelm; Kier, Ann B

    2003-01-01

    Microsomal acyl CoA:cholesterol acyltransferase (ACAT) is stimulated in vitro and/or in intact cells by proteins that bind and transfer both substrates, cholesterol, and fatty acyl CoA. To resolve the role of fatty acyl CoA binding independent of cholesterol binding/transfer, a protein that exclusively binds fatty acyl CoA (acyl CoA binding protein, ACBP) was compared. ACBP contains an endoplasmic reticulum retention motif and significantly colocalized with acyl-CoA cholesteryl acyltransferase 2 (ACAT2) and endoplasmic reticulum markers in L-cell fibroblasts and hepatoma cells, respectively. In the presence of exogenous cholesterol, ACAT was stimulated in the order: ACBP > sterol carrier protein-2 (SCP-2) > liver fatty acid binding protein (L-FABP). Stimulation was in the same order as the relative affinities of the proteins for fatty acyl CoA. In contrast, in the absence of exogenous cholesterol, these proteins inhibited microsomal ACAT, but in the same order: ACBP > SCP-2 > L-FABP. The extracellular protein BSA stimulated microsomal ACAT regardless of the presence or absence of exogenous cholesterol. Thus, ACBP was the most potent intracellular fatty acyl CoA binding protein in differentially modulating the activity of microsomal ACAT to form cholesteryl esters independent of cholesterol binding/transfer ability.

  18. Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride.

    PubMed

    Li, Conghu; Tian, Zhenhua; Liu, Wentao; Li, Guoying

    2015-10-01

    The structural properties of pepsin-solubilized calf skin collagen acylated by lauroyl chloride along with succinic anhydride were investigated in this paper. Compared with native collagen, acylated collagen retained the unique triple helix conformation, as determined by amino acid analysis, circular dichroism and X-ray diffraction. Meanwhile, the thermostability of acylated collagen using thermogravimetric measurements was enhanced as the residual weight increased by 5%. With the temperature increased from 25 to 115 °C, the secondary structure of native and acylated collagens using Fourier transform infrared spectroscopy measurements was destroyed since the intensity of the major amide bands decreased and the positions of the major amide bands shifted to lower wavenumber, respectively. Meanwhile, two-dimensional correlation spectroscopy revealed that the most sensitive bands for acylated and native collagens were amide I and II bands, respectively. Additionally, the corresponding order of the groups between native and acylated collagens was different and the correlation degree for acylated collagen was weaker than that of native collagen, suggesting that temperature played a small influence on the conformation of acylated collagen, which might be concluded that the hydrophobic interaction improved the thermostability of collagen.

  19. Fatty acid acylation of rat brain myelin proteolipid protein in vitro: identification of the lipid donor.

    PubMed

    Bizzozero, O A; Lees, M B

    1986-02-01

    The immediate acyl chain donor for fatty acid esterification of proteolipid protein (PLP) was identified in an in vitro system. Rat brain total membranes, after removal of crude nuclear and mitochondrial fractions, were incubated with radioactive acyl donors, extracted with chloroform/methanol, and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the presence of [3H]palmitic acid, CoA, ATP, and Mg2+, acylation of endogenous PLP occurred at a linear rate for at least 2 h. The radioactivity was associated with the protein via an ester linkage, mainly as palmitic acid. Omission of ATP, CoA, Mg2+, or all three reduced fatty acid incorporation into PLP to 44, 27, 8, and 4%, respectively, of the values in the complete system. Incubation of the membrane fraction with [3H]palmitoyl-CoA in the absence of CoA and ATP led to highly labeled PLP. These data demonstrate that activation of free fatty acid is required for acylation. Phospholipids and glycolipids were not able to acylate the PLP directly. Finally, when isolated myelin was incubated with [3H]palmitoyl-CoA in the absence of cofactors, only PLP was labeled, thus confirming the identity of palmitoyl-CoA as the direct acyl chain donor and suggesting that the acylating activity and the PLP pool available for acylation are both in the myelin.

  20. Ortho C-H Acylation of Aryl Iodides by Palladium/Norbornene Catalysis.

    PubMed

    Dong, Zhe; Wang, Jianchun; Ren, Zhi; Dong, Guangbin

    2015-10-19

    Reported herein is a palladium/norbornene-catalyzed ortho-arene acylation of aryl iodides by a Catellani-type C-H functionalization. This transformation is enabled by isopropyl carbonate anhydrides, which serve as both an acyl cation equivalent and a hydride source.

  1. The Role of Mitochondrial Non-Enzymatic Protein Acylation in Ageing

    PubMed Central

    Hong, Shin Yee; Ng, Li Theng; Ng, Li Fang; Inoue, Takao; Tolwinski, Nicholas S.; Hagen, Thilo; Gruber, Jan

    2016-01-01

    In recent years, various large-scale proteomic studies have demonstrated that mitochondrial proteins are highly acylated, most commonly by addition of acetyl and succinyl groups. These acyl modifications may be enzyme catalysed but can also be driven non-enzymatically. The latter mechanism is promoted in mitochondria due to the nature of the mitochondrial microenvironment, which is alkaline and contains high concentrations of acyl-CoA species. Protein acylation may modify enzyme activity, typically inhibiting it. We posited that organismal ageing might be accompanied by an accumulation of acylated proteins, especially in mitochondria, and that this might compromise mitochondrial function and contribute to ageing. In this study, we used R. norvegicus, C. elegans and D. melanogaster to compare the acylation status of mitochondrial proteins between young and old animals. We observed a specific age-dependent increase in protein succinylation in worms and flies but not in rat. Rats have two substrate-specific mitochondrial deacylases, SIRT3 and SIRT5 while both flies and worms lack these enzymes. We propose that accumulation of mitochondrial protein acylation contributes to age-dependent mitochondrial functional decline and that SIRT3 and SIRT5 enzymes may promote longevity through regulation of mitochondrial protein acylation during ageing. PMID:28033361

  2. Selective acylation of plasma membrane proteins of Mycoplasma agalactiae: the causal agent of agalactia.

    PubMed

    Le Hénaff, M; Guéguen, M M; Fontenelle, C

    2000-01-01

    Revealed by in vivo labeling with (14)C-palmitic acid, about 15 acylated proteins were identified in the plasma membrane of Mycoplasma agalactiae (type strain PG2), including the major component p40. Triton X-114 phase partitioning and Western blotting demonstrated the amphiphilic properties of the acyl proteins and showed that they were also antigenic components. Chemical analyses of fatty acids bound to proteins revealed the following selectivity order within acylation: stearic acid (18:0) > linoleic acid (18:2c) approximately palmitic acid (16:0) > oleic acid (18:1c) > myristic acid (14:0), with 16:0 and 18:1c preferred for the O-acylation and 18:0 for the N-acylation. The ratio [O-ester- + amide-bound acyl chains]/O-ester-linked chains being close to 1.4 as well as the presence of S-glycerylcysteine suggest that acyl proteins in M. agalactiae are true lipoproteins containing N-acyl diacyl glycerylcysteine, probably processed by a mechanism analogous to that described for Gram-negative eubacteria.

  3. Application and Characterization of Gum from Bombax buonopozense Calyxesas an Excipient in Tablet Formulation

    PubMed Central

    Ngwuluka, Ndidi C.; Kyari, Jehu; Taplong, John; Uwaezuoke, Onyinye J.

    2012-01-01

    This study was undertaken to explore gum from Bombax buonopozense calyxes as a binding agent in formulation of immediate release dosage forms using wet granulation method. The granules were characterized to assess the flow and compression properties and when compressed, non-compendial and compendial tests were undertaken to assess the tablet properties for tablets prepared with bombax gum in comparison with those prepared with tragacanth and acacia gums. Granules prepared with bombax exhibited good flow and compressible properties with angle of repose 28.60°, Carr’s compressibility of 21.30% and Hausner’s quotient of 1.27. The tablets were hard, but did not disintegrate after one hour. Furthermore, only 52.5% of paracetamol was released after one hour. The drug release profile followed zero order kinetics. Tablets prepared with bombax gum have the potential to deliver drugs in a controlled manner over a prolonged period at a constant rate. PMID:24300296

  4. The Quantitative Determination of Butylated Hydroxytoluene in Chewing Gum Using GC--MS

    ERIC Educational Resources Information Center

    Witter, A. E.

    2005-01-01

    The experiment to measure concentration of Photophysical Characterization(BHT) and determine percent recovery in chewing gum is described. The results demonstrated that over time, the concentration of BHT in the extract decreased owing to aerial oxidation.

  5. Effect of guar gum on stability and physical properties of orange juice.

    PubMed

    Lv, Ruihuan; Kong, Qing; Mou, Haijin; Fu, Xiaodan

    2017-05-01

    The objective of current study was to determine the stability and physical properties of orange juice which was added with guar gum. The optimal formulation showed good stability and physical properties, in light of better indices on the serum cloudiness (turbidity), sensory analysis, particle size distribution, aroma concentration analysis and rheological properties. By serum cloudiness (turbidity), the viscosity of optimal guar gum used in orange juice was 584mpas; by the other four methods, the optimal formulation was determined: 0.1% guar gum (584mpas) combined with 0.03% carboxymethyl cellulose (CMC). The results indicated that the guar gum can be used to partially replaced CMC and improve the stability and physical properties of orange juice.

  6. Identification of the Gum nebula as the fossil Stroemgren sphere of the Vela X supernova

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.

    1971-01-01

    Evidence is presented for the production of the Gum nebula by the Vela X supernova, as opposed to its ionization by gamma Velorum and zeta Puppis. A model for the excitation of the nebula is proposed.

  7. Cashew-tree (Anacardium occidentale L.) exudate gum: a novel bioligand tool.

    PubMed

    da Silveira Nogueira Lima, Raquel; Rabelo Lima, Jacira; Ribeiro De Salis, Celio; de Azevedo Moreira, Renato

    2002-02-01

    The potential of bioaffinity as a tool for the study of biological-recognition mechanisms is gaining increasing value. The search continues for alternative products that can be obtained from renewable sources, such as the bark exudate gum from the cashew tree (Anacardium occidentale L.), which grows wild in many tropical and subtropical countries. Its potential use as a chromatographic matrix and/or for bioaffinity ligand for proteins (lectins) has been investigated. The crude gum was cross-linked in order to obtain a kind of chromatographic matrix (gel). To evaluate the gum's ability to retain glycoproteins (lectins), affinity chromatography was performed and, in addition, the reological behaviour of the gum was characterized.

  8. ISO/GUM UNCERTAINTIES AND CIAAW (UNCERTAINTY TREATMENT FOR RECOMMENDED ATOMIC WEIGHTS AND ISOTOPIC ABUNDANCES)

    SciTech Connect

    HOLDEN,N.E.

    2007-07-23

    The International Organization for Standardization (ISO) has published a Guide to the expression of Uncertainty in Measurement (GUM). The IUPAC Commission on Isotopic Abundance and Atomic Weight (CIAAW) began attaching uncertainty limits to their recommended values about forty years ago. CIAAW's method for determining and assigning uncertainties has evolved over time. We trace this evolution to their present method and their effort to incorporate the basic ISO/GUM procedures into evaluations of these uncertainties. We discuss some dilemma the CIAAW faces in their present method and whether it is consistent with the application of the ISO/GUM rules. We discuss the attempt to incorporate variations in measured isotope ratios, due to natural fractionation, into the ISO/GUM system. We make some observations about the inconsistent treatment in the incorporation of natural variations into recommended data and uncertainties. A recommendation for expressing atomic weight values using a tabulated range of values for various chemical elements is discussed.

  9. Impact of intracerebroventricular obestatin on plasma acyl ghrelin, des-acyl ghrelin and nesfatin-1 levels, and on gastric emptying in rats.

    PubMed

    Chen, Chih-Yen; Lee, Wei-Jei; Chong, Keong; Lee, Shou-Dong; Liao, You-Di

    2012-07-01

    Obestatin, which is a putative 23-amino-acid peptide, is derived from the C-terminal part of the mammalian preproghrelin gene. Nesfatin-1 mRNA is co-expressed with ghrelin in gastric endocrine X/A-like cells; therefore, nesfatin-1 may also interact with preproghrelin gene products in the stomach. In this study, we investigated the impact of obestatin on the plasma levels of acyl ghrelin, des-acyl ghrelin and nesfatin-1, and on the gastric emptying of a solid nutrient meal 2 h after an intracerebroventricular (ICV) injection in conscious, fasted rats. The rats were implanted with ICV catheters. Plasma levels of acyl ghrelin, des-acyl ghrelin and nesfatin-1, expected to be co-expressed with obestatin, were measured, whereas the human/rat corticotropin-releasing factor (h/rCRF) was applied as an inhibitor of gastric emptying. The ICV administration of obestatin (0.1, 0.3 and 1.0 nmol/rat) did not modify the plasma acyl ghrelin and des-acyl ghrelin levels, the acyl ghrelin/des-acyl ghrelin ratio and nesfatin-1 concentrations. The ICV acute administration of obestatin had no influence on the 2-h rate of gastric emptying of a solid nutrient meal, but the ICV h/rCRF injection delayed it. The weight of food ingested 1 h before ICV injection significantly, but negatively correlated with the gastric emptying of a solid nutrient meal. Our study indicates that the ICV injection of obestatin does not change the 2-h rate of gastric emptying of a solid nutrient meal and the relatively weak interrelationships between ghrelin gene products and nesfatin-1. However, the weight of the ingested food negatively affects the gastric emptying of a solid nutrient meal in conscious, fasted rats.

  10. Acylation of salmon calcitonin modulates in vitro intestinal peptide flux through membrane permeability enhancement.

    PubMed

    Trier, Sofie; Linderoth, Lars; Bjerregaard, Simon; Strauss, Holger M; Rahbek, Ulrik L; Andresen, Thomas L

    2015-10-01

    Acylation of peptide drugs with fatty acid chains has proven beneficial for prolonging systemic circulation, as well as increasing enzymatic stability and interactions with lipid cell membranes. Thus, acylation offers several potential benefits for oral delivery of therapeutic peptides, and we hypothesize that tailoring the acylation may be used to optimize intestinal translocation. This work aims to characterize acylated analogues of the therapeutic peptide salmon calcitonin (sCT), which lowers blood calcium, by systematically increasing acyl chain length at two positions, in order to elucidate its influence on intestinal cell translocation and membrane interaction. We find that acylation drastically increases in vitro intestinal peptide flux and confers a transient permeability enhancing effect on the cell layer. The analogues permeabilize model lipid membranes, indicating that the effect is due to a solubilization of the cell membrane, similar to transcellular oral permeation enhancers. The effect is dependent on pH, with larger effect at lower pH, and is impacted by acylation chain length and position. Compared to the unacylated peptide backbone, N-terminal acylation with a short chain provides 6- or 9-fold increase in peptide translocation at pH 7.4 and 5.5, respectively. Prolonging the chain length appears to hamper translocation, possibly due to self-association or aggregation, although the long chain acylated analogues remain superior to the unacylated peptide. For K(18)-acylation a short chain provides a moderate improvement, whereas medium and long chain analogues are highly efficient, with a 12-fold increase in permeability compared to the unacylated peptide backbone, on par with currently employed oral permeation enhancers. For K(18)-acylation the medium chain acylation appears to be optimal, as elongating the chain causes greater binding to the cell membrane but similar permeability, and we speculate that increasing the chain length further may

  11. Non-enzymatic protein acylation as a carbon stress regulated by sirtuin deacylases

    PubMed Central

    Wagner, Gregory R.; Hirschey, Matthew D.

    2014-01-01

    Cellular proteins are decorated with a wide range of acetyl and other acyl modifications. Many studies have demonstrated regulation of site-specific acetylation by acetyltransferases and deacetylases. Acylation is emerging as a new type of lysine modification, but less is known about its overall regulatory role. Furthermore, the mechanisms of lysine acylation, its overlap with protein acetylation, and how it influences cellular function are major unanswered questions in the field. In this review, we discuss the known roles of acetyltransferases and deacetylases, and the sirtuins as a conserved family of NAD+-dependent protein deacylases that are important for response to cellular stress and homeostasis. We also consider the evidence for an emerging idea of non-enzymatic protein acylation. Finally, we put forward the hypothesis that protein acylation is a form of protein “carbon stress”, that the deacylases evolved to remove as a part of a global protein quality control network. PMID:24725594

  12. Testing nicotine gum for ulcerative colitis patients. Experience with single-patient trials.

    PubMed

    Lashner, B A; Hanauer, S B; Silverstein, M D

    1990-07-01

    Epidemiologic studies have documented an association between nonsmoking and ulcerative colitis and case reports have demonstrated that symptoms improve with smoking and worsen with removal of a nicotine source. A double-blind randomized crossover trial for individual ulcerative colitis patients (single-patient trial, or N of 1 clinical trial) was designed to study the safety, patient acceptance, and the effectiveness of nicotine gum in improving patient symptoms and proctoscopic appearance of involved colon. Seven nonsmoking patients chewed up to 10 squares/day (20 mg) of nicotine gum or placebo gum for two weeks. Therapy was crossed-over every two weeks over the eight-week trial. Effectiveness was judged from comparisons between nicotine-gum and placebo-gum periods of patient self-reported symptoms at the conclusion of each two-week period using visual analog scales and proctoscopic appearance using ordered categorical scales. Three of seven patients, all three of whom were former smokers, demonstrated sufficient improvement without adverse effects to warrant institution of nicotine gum into their drug treatment regimens. Three patients demonstrated an uncertain response, despite tolerating the drug, and have not had nicotine gum added to their regimens. One patient could not tolerate the medication and was withdrawn from the study. No serious side effects were noted. We conclude that a randomized trial for an individual patient is a useful method for evaluating treatment regimens for ulcerative colitis and that nicotine gum may be effective therapy for individual patients with ulcerative colitis who demonstrate an objective response with few adverse effects.

  13. Effect of thermal and freezing treatments on rheological, textural and color properties of basil seed gum.

    PubMed

    Zameni, Akefe; Kashaninejad, Mahdi; Aalami, Mehran; Salehi, Fakhreddin

    2015-09-01

    Hydrocolloids are macromolecular carbohydrates that are added to many foodstuffs to achieve the appropriate rheological and textural properties and to prevent synersis or to increase the viscosity and stability of foodstuffs. In this study the effect of different thermal treatments (25, 50, 75, 100 and 121°C for 20 min) and freezing treatments (-18 and -25 °C for 24 h) on rheological, textural and color change of basil seed gum as a new source of hydrocolloids was investigated. The results demonstrated that basil seed gum solutions had desirable rheological and textural properties. Power law model well described non-newtonian pseudoplastic behavior of basil seed gum in all conditions. When the hydrocolloid samples were heated or frozen, increase in viscosity of basil seed gum solutions was observed. Hardness, adhesiveness and consistency of basil seed gel for control sample were 13.5 g, 16.79, 52.59 g.s, respectively and all increased after thermal treatments. The results revealed that basil seed gum has the excellent ability to stand against heat treatment and the highest hardness, adhesiveness and consistency value of gum gels were observed in sample treated at 121 °C for 20 min. In addition this gum gel has the good ability to stand against freeze-thaw treatment and its textural properties improved after freezing. Therefore, basil seed gum can be employed as a textural and rheological modifier in formulation of foods exposed to thermal and freezing temperatures.

  14. GUM Analysis for SIMS Isotopic Ratios in BEP0 Graphite Qualification Samples, Round 2

    SciTech Connect

    Gerlach, David C.; Heasler, Patrick G.; Reid, Bruce D.

    2009-01-01

    This report describes GUM calculations for TIMS and SIMS isotopic ratio measurements of reactor graphite samples. These isotopic ratios are used to estimate reactor burn-up, and currently consist of various ratios of U, Pu, and Boron impurities in the graphite samples. The GUM calculation is a propagation of error methodology that assigns uncertainties (in the form of standard error and confidence bound) to the final estimates.

  15. Cognitive advantages of chewing gum. Now you see them, now you don't.

    PubMed

    Onyper, Serge V; Carr, Timothy L; Farrar, John S; Floyd, Brittney R

    2011-10-01

    The current series of experiments investigated the effects of the timing of gum chewing on cognitive function, by administering a battery of cognitive tasks to participants who chewed gum either prior to or throughout testing, and comparing their performance to that of controls who did not chew gum. Chewing gum was associated with performance advantages on multiple measures when gum was chewed for 5 min before, but not during, cognitive testing. The benefits, however, persisted only for the first 15-20 min of the testing session, and did not extend to all cognitive domains. To explain this pattern of results, it is proposed that the time-limited nature of performance benefits can be attributed to mastication-induced arousal. Furthermore, the lack of improvement in cognitive function when gum is chewed throughout testing may be because of interference effects due to a sharing of resources by cognitive and masticatory processes. This dual-process mechanism is not only consistent with the outcome of present experiments but can potentially account for a wide range of findings reported in the literature.

  16. Gum-Chewing and Headache: An Underestimated Trigger of Headache Pain in Migraineurs?

    PubMed

    Lippi, Giuseppe; Cervellin, Gianfranco; Mattiuzzi, Camilla

    2015-01-01

    Tension-type headache and migraine are currently considered the second and third most frequent human diseases. Since a variety of conditions that involve the temporomandibular joint and chewing muscles are frequent causes of orofacial pain, the aim of this article was to review current published evidence about the potential relationship between gum-chewing and headache. A systematic electronic search performed on Medline, Scopus and Web of Science using the keywords "headache" or "migraine" and "chewing" allowed to finally identify 1 cross-sectional, 1 observational and 3 randomized studies, along with 3 case reports about the potential association between gum-chewing and headache. Despite the limited evidence, it seems reasonable to suggest that headache attacks may be triggered by gum-chewing in migraineurs and in patients with tension-type headache. Opposite results were obtained in non-migraineurs, since in none of these studies an increased prevalence of headache pain was reported after gum-chewing. Although larger randomized studies will be necessary to definitely establish the relationship between gum-chewing and headache across different populations, it seems cautionary to suggest that subjects with migraine or tension-type headache should avoid or limit gum-chewing in their lifestyle.

  17. Chewing gum may be an effective complementary therapy in patients with mild to moderate depression.

    PubMed

    Erbay, Furkan Muhammed; Aydın, Nazan; Satı-Kırkan, Tülay

    2013-06-01

    Previous studies indicated that chewing gum may relieve stress and depression. There have, however, not been a significant number of studies on clinical usage of chewing gum. In the present study, 30 patients with mild to moderate depression were given either medication combined with chewing gum, or medication only, for 6 weeks. Turkish adaptation of Hamilton Rating Scale for Depression (HAM-D) was used to measure depression levels. Assessments were conducted by the same physician both before, and after treatment. The physician who was responsible for the assessment was not aware of the group allocation. Changes in main HAM-D scores and each item were analyzed by independent samples t test and Chi-Square test, respectively. Those patients who were administrated chewing gum responded better to the treatment than patients who took medication only. The most beneficial effect of chewing gum was observed on the gastrointestinal symptoms, e.g. loss of appetite, and flatulence among others. These results indicate that chewing gum may not be directly effective on depressed mood; however, it may reduce the symptoms originating from depression.

  18. QbD based synthesis and characterization of polyacrylamide grafted corn fibre gum.

    PubMed

    Singh, Akashdeep; Mangla, Bhumika; Sethi, Sheshank; Kamboj, Sunil; Sharma, Radhika; Rana, Vikas

    2017-01-20

    The aim of present investigation was to utilize quality by design approach for the synthesis of polyacrylamide corn fibre gum (PAAm-g-CFG) from corn fibre gum (CFG) by varying concentration of acrylamide and initiator. The spectral analysis (ATR-FTIR, (1)H NMR, DSC, X-ray and Mass spectroscopy) was conducted to assure grafting copolymerization of CFG with acrylamide. The powder flow properties confirm the porous nature of PAAm-g-CFG. The grafted copolymer dispersion showed shear thinning behaviour that follows Herschel Bulkley model. The viscoelastic analysis suggested viscous liquid like nature of PAAm-g-CFG and its viscosity increases with increase in concentration of PAAm-g-CFG. The mucoadhesive strength of synthesized PAAm-g-CFG was found to be higher than moringa oleifera gum, karaya gum, guar gum, xanthan gum, chitosan and gelatin. Further, the results pointed toward enhanced thermal stability of PAAm-g-CFG. Thus, PAAm-g-CFG has a great potential to be used in food and pharmaceutical industry.

  19. Application of guar-xanthan gum mixture as a partial fat replacer in meat emulsions.

    PubMed

    Rather, Sajad A; Masoodi, F A; Akhter, Rehana; Rather, Jahangir A; Gani, Adil; Wani, S M; Malik, A H

    2016-06-01

    The physicochemical, oxidative, texture and microstructure properties were evaluated for low fat meat emulsions containing varying levels of guar/xanthan gum mixture (1:1 ratio) as a fat substitute. Partial replacement of fat with guar/xanthan gum resulted in higher emulsion stability and cooking yield but lower penetration force. Proximate composition revealed that high fat control had significantly higher fat and lower moisture content due to the difference in basic formulation. Colour evaluation revealed that low fat formulations containing gum mixture had significantly lower lightness and higher yellowness values than high fat control formulation. However non-significant difference was observed in redness values between low fat formulations and the high fat control. The pH values of the low fat formulations containing gum mixture were lower than the control formulations (T0 and TC). The MetMb% of the high fat emulsion formulation was higher than low fat formulations. The significant increase of TBARS value, protein carbonyl groups and loss of protein sulphydryl groups in high fat formulation reflect the more oxidative degradation of lipids and muscle proteins during the preparation of meat emulsion than low fat formulations. The SEM showed a porous matrix in the treatments containing gum mixture. Thus, the guar/xanthan gum mixture improved the physicochemical and oxidative quality of low fat meat emulsions than the control formulations.

  20. Prosopis alba exudate gum as excipient for improving fish oil stability in alginate-chitosan beads.

    PubMed

    Vasile, Franco Emanuel; Romero, Ana María; Judis, María Alicia; Mazzobre, María Florencia

    2016-01-01

    The aim of the present work was to employ an exudate gum obtained from a South American wild tree (Prosopis alba), as wall material component to enhance the oxidative stability of fish oil encapsulated in alginate-chitosan beads. For this purpose, beads were vacuum-dried and stored under controlled conditions. Oxidation products, fatty acid profiles and lipid health indices were measured during storage. Alginate-chitosan interactions and the effect of gum were manifested in the FT-IR spectra. The inclusion of the gum in the gelation media allowed decreasing the oxidative damage during storage in comparison to the free oil and alginate-chitosan beads. The gum also improved wall material properties, providing higher oil retention during the drying step and subsequent storage. Fatty acids quality and lipid health indices were widely preserved in beads containing the gum. Present results showed a positive influence of the gum on oil encapsulation and stability, being the main mechanism attributed to a physical barrier effect.

  1. Effect of Gum Chewing on the Recovery From Laparoscopic Colorectal Cancer Surgery

    PubMed Central

    Hwang, Duk Yeon; Kim, Ho Young; Kim, Ji Hoon; Lee, In Gyu; Kim, Jun Ki; Oh, Seung Taek

    2013-01-01

    Purpose We aimed to examine the effect of gum chewing after laparoscopic colorectal cancer surgery. Methods We reviewed the medical records of patients who underwent laparoscopic colorectal cancer surgery in Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine. We divided the patients into 2 groups: group A consisted of 67 patients who did not chew gum; group B consisted of 65 patients who chewed gum. We analyzed the short-term clinical outcomes between the two groups to evaluate the effect of gum chewing. Results The first passage of gas was slightly earlier in group B, but the difference was not significant. However, the length of hospital stay was 6.7 days in group B, which was significantly shorter than that in group A (7.3 days, P = 0.018). Conclusion This study showed that length of postoperative hospital stay was shorter in the gum-chewing group. In future studies, we expect to elucidate the effect of gum chewing on the postoperative recovery more clearly. PMID:24466540

  2. Water adsorption isotherms of carboxymethyl cellulose, guar, locust bean, tragacanth and xanthan gums.

    PubMed

    Torres, María D; Moreira, Ramón; Chenlo, Francisco; Vázquez, María J

    2012-06-20

    Water adsorption isotherms of carboxymethyl cellulose (CMC), guar gum (GG), locust bean gum (LBG), tragacanth gum (TG) and xanthan gum (XG) were determined at different temperatures (20, 35, 50, and 65°C) using a gravimetric method. Several saturated salt solutions were selected to obtain different water activities in the range from 0.09 to 0.91. Water adsorption isotherms of tested hydrocolloids were classified like type II isotherms. In all cases, equilibrium moisture content decreased with increasing temperature at each water activity value. Three-parameter Guggenheim-Anderson-de Boer (GAB) model was employed to fit the experimental data in the water activity range and statistical analysis indicated that this model gave satisfactory results. CMC and GG were the most and the least hygroscopic gums, respectively. Sorption heats decreased with increasing moisture content. Monolayer moisture content evaluated with GAB model was consistent with equilibrium conditions of maximum stability calculated from thermodynamic analysis of net integral entropy. Values of equilibrium relative humidity at 20°C are proposed to storage adequately the tested gums.

  3. Competitive adsorption of toxic heavy metal contaminants by gum kondagogu (Cochlospermum gossypium): a natural hydrocolloid.

    PubMed

    Vinod, V T P; Sashidhar, R B; Sukumar, A A

    2010-02-01

    Gum kondagogu (Cochlospermum gossypium), a naturally occurring tree biopolymer, is exploited as a biosorbent to remove metal ions from aqueous solutions. The removal efficiency of toxic metals by gum kondagogu was determined quantitatively in the order Cd2+ > Cu2+ > Fe2+ > Se2+ > Pb2+ > total Cr > Ni2+ > Zn2+ > Co2+ > As2+ at pH 5.0+/-0.1 and temperature 25+/-2 degrees C by inductively coupled plasma-mass spectrometry (ICP-MS). The biosorption (%) of various metal ions tested was found to be in the range of 97.3-16.7%, at pH 5.0. The morphological and mechanisms of interaction of toxic metal ions with gum kondagogu were assessed by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDXA) and X-ray diffraction (XRD) spectrum. The analysis indicated that biosorption process included morphological changes, precipitation, complexation and ion exchange mechanism for the removal of metal ions by the gum. XRD analysis indicated the amorphous nature of gum kondagogu, which facilitate metal biosorption. The metal ions adsorption leads to its deposition on the gum kondagogu matrix in a crystalline state.

  4. Effects of caffeinated chewing gum on muscle pain during submaximal isometric exercise in individuals with fibromyalgia.

    PubMed

    Umeda, Masataka; Kempka, Laura; Weatherby, Amy; Greenlee, Brennan; Mansion, Kimberly

    2016-04-01

    Physical activity is important to manage symptom of fibromyalgia (FM); however, individuals with FM typically experience augmented muscle pain during exercise. This study examined the effects of caffeinated chewing gum on exercise-induced muscle pain in individuals with FM. This study was conducted with a double-blind, placebo-controlled, cross-over design. Twenty-three patients with FM completed a caffeine condition where they consumed a caffeinated chewing gum that contains 100mg of caffeine, and a placebo condition where they consumed a non-caffeinated chewing gum. They completed isometric handgrip exercise at 25% of their maximal strength for 3 min, and muscle pain rating (MPR) was recorded every 30s during exercise. Clinical pain severity was assessed in each condition using a pain questionnaire. The order of the two conditions was randomly determined. MPR increased during exercise, but caffeinated chewing gum did not attenuate the increase in MPR compared to placebo gum. Clinical pain severity was generally associated with the average MPR and the caffeine effects on MPR, calculated as difference in the average MPR between the two conditions. The results suggest that more symptomatic individuals with FM may experience greater exercise-induced muscle pain, but benefit more from caffeinated chewing gum to reduce exercise-induced muscle pain.

  5. Effect of Detarium microcarpum (Dm) and Mucuna flagellipes (Mf) gums on the quality of white bread.

    PubMed

    Onweluzo, J C; Leelavathi, K; Rao, P H

    1999-01-01

    Incorporation of Detarium Microcarpum (Dm) and Mucuna flagellipes (Mf) water soluble polysaccharides (gums) at 0.0 to 0.5% levels in wheat flour was studied to evaluate their effect on the rheological properties of wheat flour dough and white bread quality. At all levels of incorporation, there were increases (p < or = 0.05) in water absorption of the dough. Doughs containing gums had higher (p < or = 0.05) mixing tolerance index than the control. Set back viscosities decreased by 4.0 RVU and 9.0 RVU with increased levels of Dm and Mf gum incorporation, respectively. Significantly (p < or = 0.05) higher oven spring occurred in all the gum substituted white bread when compared to the control. The 0.5% gum substituted breads had a significantly (p < or = 0.05) higher sensory score for crumb grain, texture but lower (p < 0.05) crumb firmness than the control as determined instrumentally. Textural analysis after 5 days storage revealed that Dm and Mf gums improved moisture retention properties of the bread and reduced crumb firming tendency.

  6. Glucose absorption, hormonal release and hepatic metabolism after guar gum ingestion

    NASA Technical Reports Server (NTRS)

    Simoes Nunes, C.; Malmlof, K.

    1992-01-01

    Six non-anaesthetized Large White pigs (mean body weight 59 +/- 1.7 kg) were fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein and with electromagnetic flow probes around the portal vein and the hepatic artery. The animals were provided a basal none-fibre diet (diet A) alone or together with 6% guar gum (diet B) or 15% purified cellulose (diet C). The diets were given for 1 week and according to a replicated 3 x 3 latin-square design. On the last day of each adaptation period test meals of 800 g were given prior to blood sampling. The sampling was continued for 8 h. Guar gum strongly reduced the glucose absorption as well as the insulin, gastric inhibitory polypeptide (GIP) and insulin-like growth factor-1 (IGF-1) production. However, the reduction in peripheral blood insulin levels caused by guar gum was not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly produced by the gut. The liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut produced IGF-1. Guar gum ingestion also appeared to decrease pancreatic glucagon secretion. Cellulose at the level consumed had very little effect on the parameters considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the latter internal metabolic effects.

  7. Effects of nicotine-containing chewing gum on oral soft and hard tissues: A clinical study.

    PubMed

    Christen, A G; Beiswanger, B B; Mallatt, M E; Tomich, C E; Drook, C A; McDonald, J L; Olson, B L; Stookey, G K

    1985-01-01

    A double-blind clinical trial was conducted to determine whether the use of a chewing gum containing 2.0 mg nicotine (as an adjunct to a stop-smoking program) had any effects upon oral health. A total of 193 adults who smoked cigarettes volunteered with informed consent, were given routine dental prophylaxes, and were examined for the presence of plaque, stained pellicle, gingivitis, calculus, and general oral pathosis. The subjects were then randomly assigned to use either a nicotine-containing or a placebo chewing gum. After 15 weeks the subjects were recalled and re-examined. Smoking cessation was determined through questionnaire and analysis of the carbon monoxide content of alveolar air. At the completion of the study, 79 subjects had used the placebo gum and 78 had used the nicotine gum. Data analysis indicated that the nicotine chewing gum had no significant influence on any of the oral health parameters graded, as compared to the placebo gum. The continuation of smoking, however, was associated with significant increases in gingivitis and calculus rates.

  8. Biological activity of some naturally occurring resins, gums and pigments against in vitro LDL oxidation.

    PubMed

    Andrikopoulos, Nikolaos K; Kaliora, Andriana C; Assimopoulou, Andreana N; Papapeorgiou, Vassilios P

    2003-05-01

    Naturally occurring gums and resins with beneficial pharmaceutical and nutraceutical properties were tested for their possible protective effect against copper-induced LDL oxidation in vitro. Chiosmastic gum (CMG) (Pistacia lentiscus var. Chia resin) was the most effective in protecting human LDL from oxidation. The minimum and maximum doses for the saturation phenomena of inhibition of LDL oxidation were 2.5 mg and 50 mg CMG (75.3% and 99.9%, respectively). The methanol/water extract of CMG was the most effective compared with other solvent combinations. CMG when fractionated in order to determine a structure-activity relationship showed that the total mastic essential oil, collofonium-like residue and acidic fractions of CMG exhibited a high protective activity ranging from 65.0% to 77.8%. The other natural gums and resins (CMG resin 'liquid collection', P. terebinthus var. Chia resin, dammar resin, acacia gum, tragacanth gum, storax gum) also tested as above, showed 27.0%-78.8% of the maximum LDL protection. The other naturally occurring substances, i.e. triterpenes (amyrin, oleanolic acid, ursolic acid, lupeol, 18-a-glycyrrhetinic acid) and hydroxynaphthoquinones (naphthazarin, shikonin and alkannin) showed 53.5%-78.8% and 27.0%-64.1% LDL protective activity, respectively. The combination effects (68.7%-76.2% LDL protection) of ursolic-, oleanolic- and ursodeoxycholic- acids were almost equal to the effect (75.3%) of the CMG extract in comparable doses.

  9. Efficacy of baking soda-containing chewing gum in removing natural tooth stain.

    PubMed

    Mankodi, S M; Conforti, N; Berkowitz, H

    2001-07-01

    A 14-week, double-blind, randomized clinical trial was conducted with 126 healthy volunteers to compare the efficacy of twice-daily use of 3 baking soda-containing chewing gums in removing natural tooth stain when used in conjunction with a program of regular oral hygiene. All 3 chewing gums significantly reduced extrinsic stain (P < .0001) and improved the whitened appearance of teeth (P < .0001) at both the 2-week interim and the final 4-week evaluations. ARM & HAMMER DENTAL CARE The Baking Soda Gum (AHDC) reduced dental stain by 70.8%, compared to reductions of 71.9% and 65.3%, after use of 2 experimental gum formulations. Whitened appearance improved by 1.73 shade tabs using AHDC gum, and up to 2.49 shade tabs with the experimental formulations. These results suggest that the use of baking soda-containing gum after meals, in conjunction with good oral hygiene, can improve both extrinsic dental staining and the whitened appearance of teeth.

  10. Gum arabic/starch/maltodextrin/inulin as wall materials on the microencapsulation of rosemary essential oil.

    PubMed

    Fernandes, Regiane Victória de Barros; Borges, Soraia Vilela; Botrel, Diego Alvarenga

    2014-01-30

    The effects of the partial or total replacement of gum arabic by modified starch, maltodextrin and inulin on the characteristics of rosemary essential oil microencapsulated by spray drying were evaluated in this study. The lowest level of water absorption under conditions of high relative humidity was observed in treatments containing inulin. The wettability property of the powders was improved by the addition of inulin. The total replacement of gum arabic by modified starch or a mixture of modified starch and maltodextrin (1:1, m/m) did not significantly affect the efficiency of encapsulation, although higher Tg values were exhibited by microcapsules prepared using pure gum arabic or gum arabic and inulin. 1,8-cineol, camphor and α-pinene were the main components identified by gas chromatography in the oils extracted from the microcapsules. The particles had smoother surfaces and more folds when gum arabic or inulin was present. Larger particles were observed in the powders prepared with pure gum arabic or modified starch.

  11. 40 CFR 721.7270 - 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl derivs., chloride.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-trimethyl-N-soya acyl derivs., chloride. 721.7270 Section 721.7270 Protection of Environment ENVIRONMENTAL...-soya acyl derivs., chloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl...

  12. 40 CFR 721.7270 - 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl derivs., chloride.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-trimethyl-N-soya acyl derivs., chloride. 721.7270 Section 721.7270 Protection of Environment ENVIRONMENTAL...-soya acyl derivs., chloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl...

  13. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...)-N,N-dimethyl-, N-soya acyl derivs., chlorides. 721.10056 Section 721.10056 Protection of Environment...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses...-dimethyl-, N-soya acyl derivs., chlorides (PMN P-03-47; CAS No. 90194-13-1) is subject to reporting...

  14. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...)-N,N-dimethyl-, N-soya acyl derivs., chlorides. 721.10056 Section 721.10056 Protection of Environment...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses...-dimethyl-, N-soya acyl derivs., chlorides (PMN P-03-47; CAS No. 90194-13-1) is subject to reporting...

  15. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...)-N,N-dimethyl-, N-soya acyl derivs., chlorides. 721.10056 Section 721.10056 Protection of Environment...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses...-dimethyl-, N-soya acyl derivs., chlorides (PMN P-03-47; CAS No. 90194-13-1) is subject to reporting...

  16. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...)-N,N-dimethyl-, N-soya acyl derivs., chlorides. 721.10056 Section 721.10056 Protection of Environment...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses...-dimethyl-, N-soya acyl derivs., chlorides (PMN P-03-47; CAS No. 90194-13-1) is subject to reporting...

  17. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...)-N,N-dimethyl-, N-soya acyl derivs., chlorides. 721.10056 Section 721.10056 Protection of Environment...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses...-dimethyl-, N-soya acyl derivs., chlorides (PMN P-03-47; CAS No. 90194-13-1) is subject to reporting...

  18. Pasting properties of Tamarind (Tamarindus indica) kernel powder in the presence of Xanthan, Carboxymethylcellulose and Locust bean gum in comparison to Rice and Potato flour.

    PubMed

    Kaur, Maninder; Sandhu, Kawaljit Singh; Kaur, Jasmeen

    2013-08-01

    Effects of addition of different levels of gums (xanthan, carboxymethylcellulose and locust bean gum) on the pasting properties of tamarind kernel, potato and rice flour were studied by using Rapid Visco-Analyzer (RVA). Tamarind kernel powder (TKP) varied significantly (P < 0.05) from rice and potato flours with respect to its highest protein, ash and fat contents. The results of RVA analysis indicated that pasting properties of flour/gum mixtures were dependent upon the concentration and type of the gums. Peak, breakdown and final viscosity increased with increase in gum concentration in the flour/gum mixture, but the effect was more pronounced for rice and potato flour than for TKP which showed much lower viscosity responses to all of the gums. Among the three gums studied, the increase in viscosity was significantly higher with addition of locust bean gum followed by xanthan while the lowest was observed with carboxymethylcellulose.

  19. The optimum time to initiate habitual xylitol gum-chewing for obtaining long-term caries prevention.

    PubMed

    Hujoel, P P; Mäkinen, K K; Bennett, C A; Isotupa, K P; Isokangas, P J; Allen, P; Mäkinen, P L

    1999-03-01

    Habitual xylitol gum-chewing may have a long-term preventive effect by reducing the caries risk for several years after the habitual chewing has ended. The goal of this report was (1) to determine if sorbitol and sorbitol/xylitol mixtures provide a long-term benefit, and (2) to determine which teeth benefit most from two-year habitual gum-chewing - those erupting before, during, or after habitual gum-chewing. Children, on average 6 years old, chewed gums sweetened with xylitol, sorbitol, or xylitol/sorbitol mixtures. There was a "no-gum" control group. Five years after the two-year program of habitual gum-chewing ended, 288 children were re-examined. Compared with the no-gum group, sorbitol gums had no significant long-term effect (relative risk [RR], 0.65; 95% confidence interval [c.i.], 0.39 to 1.07; p < 0.18). Xylitol gum and, to a lesser extent, xylitol/sorbitol gum had a long-term preventive effect. During the 5 years after habitual gum-chewing ended, xylitol gums reduced the caries risk 59% (RR, 0.41; 95% c.i., 0.23 to 0.75; p < 0.0034). Xylitol-sorbitol gums reduced the caries risk 44% (RR, 0.56; 95% c.i., 0.36 to 0.89; p < 0.02). The long-term caries risk reduction associated with xylitol strongly depended on when teeth erupted (p < 0.02). Teeth that erupted after 1 year of gum-chewing or after the two-year habitual gum use ended had long-term caries risk reductions of 93% (p < 0.0054) and 88% (p < 0.0004), respectively. Teeth that erupted before the gum-chewing started had no significant long-term prevention (p < 0.30). We concluded that for long-term caries-preventive effects to be maximized, habitual xylitol gum-chewing should be started at least one year before permanent teeth erupt.

  20. A simple method for isolation and construction of markerless cyanobacterial mutants defective in acyl-acyl carrier protein synthetase.

    PubMed

    Kojima, Kouji; Keta, Sumie; Uesaka, Kazuma; Kato, Akihiro; Takatani, Nobuyuki; Ihara, Kunio; Omata, Tatsuo; Aichi, Makiko

    2016-12-01

    Cyanobacterial mutants defective in acyl-acyl carrier protein synthetase (Aas) secrete free fatty acids (FFAs) into the external medium and hence have been used for the studies aimed at photosynthetic production of biofuels. While the wild-type strain of Synechocystis sp. PCC 6803 is highly sensitive to exogenously added linolenic acid, mutants defective in the aas gene are known to be resistant to the externally provided fatty acid. In this study, the wild-type Synechocystis cells were shown to be sensitive to lauric, oleic, and linoleic acids as well, and the resistance to these fatty acids was shown to be enhanced by inactivation of the aas gene. On the basis of these observations, we developed an efficient method to isolate aas-deficient mutants from cultures of Synechocystis cells by counter selection using linoleic acid or linolenic acid as the selective agent. A variety of aas mutations were found in about 70 % of the FFA-resistant mutants thus selected. Various aas mutants were isolated also from Synechococcus sp. PCC 7002, using lauric acid as a selective agent. Selection using FFAs was useful also for construction of markerless aas knockout mutants from Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002. Thus, genetic engineering of FFA-producing cyanobacterial strains would be greatly facilitated by the use of the FFAs for counter selection.