Glycerol Extract Research Articles

Flow injection analysis of free glycerol in biodiesel using a copper electrode as an amperometric detector

The main goal of this work was to develop a simple analytical method for quantification of glycerol based on the electrocatalytic oxidation of glycerol on the copper surface adapted in a flow injection system. Under optimal experimental conditions, the peak current response increases linearly with glycerol concentration over the range 60–3200mgkg−1 (equivalent to 3–160mgL−1 in solution). The repeatability of the electrode response in the flow injection analysis (FIA) configuration was evaluated as 5% (n=10), and the detection limit of the method was estimated to be 5mgkg−1 in biodiesel (equivalent to 250μgL−1 in solution) (S/N=3). The sample throughput under optimised conditions was estimated to be 90h−1. Different types of biodiesel samples (B100), as in the types of vegetable oils or animal fats used to produce the fuels, were analysed (seven samples). The only sample pre-treatment used was an extraction of glycerol from the biodiesel sample containing a ratio of 5mL of water to 250mg of biodiesel. The proposed method improves the analytical parameters obtained by other electroanalytical methods for quantification of glycerol in biodiesel samples, and its accuracy was evaluated using a spike-and-recovery assay, where all the biodiesel samples used obtained admissible values according to the Association of Official Analytical Chemists.

Continuous extraction of glycerol acetates from their mixture using supercritical carbon dioxide

Supercritical carbon dioxide was used for partially selective extraction of triacetin from a mixture of triacetin, diacetin, and monoacetin with a molar ratio of 1:2:1. The extraction was carried out in two stages. In the first stage, a central composite design was used to optimize the four variables of pressure, temperature, liquid CO2 flow rate, and extraction time at three levels using a semi-continuous, supercritical carbon dioxide extraction setup. The composition of the extract under the predicted optimum conditions (i.e., 109bar, 56°C, 0.86mLmin−1, and 61min) was about 69% triacetin accompanied by only 30% diacetin and no detectable monoacetin. In the second stage, the effect of the two factors, pressure (100, 109, and 140bar) and liquid CO2 flow rates of 0.86 and 1.5mLmin−1 measured at average laboratory temperature (27°C) and pressure (0.89bar), were studied using a continuous, supercritical carbon dioxide fractionation setup equipped with a glass-bead packed column kept under a thermal gradient of 56–70°C. The experimental design was organized as a 3×2 general factorial design. Under the best conditions (i.e., 140bar and 1.5mLmin−1), the extraction yield of triacetin and diacetin were 41.8 and 3.0%, respectively, without any detectable monoacetin as verified by GC-FID.

Gemmotherapy-complementary treatment in juvenile rheumatoid arthritis

Rheumatoid arthritis is a chronic disease that damagesandeventually destroys the joints of the body. Juvenile rheumatoid arthritis (JRA) is not a single disease, but a group of diseases with symptoms and signs developed in children younger than 16 years. There are three major forms: pauciarticular disease, poliarticular disease, and systemic disease. The aim of treatment is to stop or slow down the progress of inflammation, improving function, and preventing joint damage. The most usefull drugs are: 1) nonsteroidal anti-inflammatorydrugs (NSAIDs) reduce inflammation, swelling, and pain, 2) disease-modifying antirheumatic drugs (DMARDs), in children Methotrexat is the most used drug, it interferes in the immune processes that cause inflammation and JRA. 3) Biologic response modifiers are a newer, specialized type of immunosuppressive drugs, carefully designed to block the actions of natural substances that are part of the immune response, such as tumor necrosis factor. A variety of complementary approaches can be very effective in relieving pain and improving the outcome of the disease. One of these complementary therapy is gemmoterapy, a scientific use of a special glycerin extracts from plant buds. In our study,19 pacients with diagnosed JRA (15 with pauciarticular disease and 4 with poliarticular form) was treated with specific antirheumatic drugs associating gemmotherapy. It has been used three types of bud extracts (Ribes nigrum, Buxus sempervirens, Vitis vinifera) with proved antirheumatic effects, during a period of 3 months. In all the pacients we observed a clinical amelioration, permitting a slight reduction of the dose of the NSAIDs and the DMARDs.

Renewable elastomers based on blends of maleated polypropylene and plasticized starch

AbstractMost recent developments in polymers from renewable resources have focused on thermoplastics, whereas there has been no comparable development of plastics with elastomeric properties. Here we evaluate the possibility of developing renewable elastomers based on starch. Potato starch plasticized with glycerol (called plasticized starch, or PLS) was melt‐blended with small quantities (5 wt % or 15 wt%) of maleated polypropylene (MAPP). The maleic anhydride groups of the polypropylene are expected to react with the hydroxy groups of starch under melt blending conditions. The resulting blends of MAPP and PLS were characterized by mechanical testing, SEM, DMA, and DSC. SEM, solubility and adhesion tests indicate that the blends are two‐phase materials, in which the continuous phase PLS is physically crosslinked by polypropylene domains. The materials showed rubbery properties as judged by a low glass transition temperature (∼−50°C independent of polypropylene content), and a wide rubbery plateau in DMA experiments that extended from room temperature to as high as 170°C. The tensile properties are also characteristic of elastomers. However, slow aging due to starch crystallization, and extraction of glycerol upon water exposure remain two challenges that must be overcome before the materials can be used as practical elastomers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Comparison of Antitumor Effect in Two Viscum album L. Extracts

Viscum album L. is a parasitic plant, widely used in addition to the treatment of cancer. Mistletoe alcoholic extract and glycerine macerate were inoculated in 40 white Swiss male mice, previously inoculated with Ehrlich Ascitic Carcinoma (EAC). Animals were divided in four equal groups; first group received i.p. in the day 1, 4 and 7 - 50 mg d.s./kg b.w. Viscum album 1:1 alcoholic extract. The second group received i.p. in the day 1, 4 and 7 – 20 ml/kg b.w. Viscum album 1 to 100 glycerine extract. The third group received i.p. Doxorubicin chloride 2.5 mg/ kg b.w. in day 6 of experiment, while the last group received a placebo. Other 40 animals were injected with the same plant extracts, placebo and Doxorubicin chloride, without EAC. In EAC group only 8 from 10 animals survived in the end of the study, in the other groups all animals survived to the end. V. album alcoholic extract increased the white blood cells (WBC) as compared to control, due to granulocytes (GRA), but the most important both mistletoe extracts provided increase WBC as compared to Doxorubicin injected group. Mistletoe extracts elevated the platelets total count (PLT) in non EAC inoculated groups. The Viscum album alcoholic extract prevented the development of ascitic fluid, but it was less effective in reduction of EAC cell concentration. In conclusion, Viscum album alcoholic tincture, and glycerine macerate provided an anticancer effect; they stimulate the immune mechanisms and inhibit the tumor cells proliferation.

Determination of free glycerol in biodiesel at a platinum oxide surface using potential cycling technique

A novel, inexpensive and fast method based on the electrooxidation of glycerol on platinum electrodes by the potential cycling technique has been designed for the determination of free glycerol in biodiesel. A wide range of linearity was achieved between 15 and 150 mg L −1 (0.16 and 1.6 mmol L −1), which corresponds to concentrations ranging between 56 and 560 mg kg −1 (glycerol:biodiesel) for an extraction using 2 g biodiesel. A method for the fast extraction of glycerol from biodiesel with water followed by elimination of organic interferents has also been developed, so that the novel determination method can be applied to various biodiesel samples. The excellent repeatability allows determination of glycerol in numerous samples, with no need for recalibration.

Flow injection analysis-based methodology for automatic on-line monitoring and quality control for biodiesel production

An automated on-line approach based on determination of free and bound glycerol was here proposed to monitor biodiesel production. The method was based on liquid–liquid extraction of glycerol from the biodiesel to an aqueous ethanolic phase in which glycerol is oxidized to formaldehyde with meta periodate with subsequent reaction with acetylacetone. The reaction product was photometrically measured at 410 nm. Free and bound glycerol were differentiated by glycerides hydrolysis with potassium ethylate. The experimental set-up consisted of a flow-injection manifold for liquid–liquid extraction without phase separation and iterative change of the flow direction that enabled: (a) filling the flow manifold with a meta periodate–acetylacetone acceptor phase; (b) sampling of small amounts (μl) from the reactor; (c) determination of free glycerol by extraction from biodiesel to the aqueous phase with simultaneous oxidation-reaction with acetylacetone in the acceptor phase; (d) continuous monitoring of the aqueous phase by passage through a photometric detector; (e) filling the flow manifold with a potassium ethylate-meta periodate–acetylacetone new acceptor phase; (d) repetition of steps b-to-d to determine total glycerol after saponification of the bound glycerol by potassium ethylate; and (f) determination of bound glycerol by difference between the second and first analyses. The results showed that the proposed automated on-line method is a suitable option in routine analysis during biodiesel production.

122. Acute effects of oral administration of a glycerol extract of Echinacea purpurea on peritoneal exudate cells in female swiss mice

122. Acute effects of oral administration of a glycerol extract of Echinacea purpurea on peritoneal exudate cells in female swiss mice

The tuberculin skin test: a hundred, not out?

In 1890, at a World Congress of Medicine in Berlin, Robert Koch announced a substance that he claimed would both cure and prevent tuberculosis. Although this substance, a glycerin extract...

English

In this study we tested the antiviral activity of a crude hot glycerine extract of Aloe vera gel which was grown in Bushehr (Southwest of Iran) against HSV-2 replication in Vero cell line. The extract showed antiviral activity against HSV-2 not only before attachment and entry of virus to the Vero cells but also on post attachment stages of virus replication. The IC50 before attachment and entry of virus to the cells is 428 µg/ml and the CC50 value which is the cytotoxicity of the extract for Vero cells is 3238 µg/ml, while the calculated selectivity index (SI) is 7.56. Also, IC50 of extract on post attachment stages of replication is 536 µg/ml and the SI value for inhibition of the post attachment stages of HSV-2 replication is 6.04. Therefore, compounds of Aloe vera from Bushehr could be a good candidate as a natural source for antiviral drug development against HSV-2.

Optimization of culture medium for rifamycin SV production byAmycolatopsis mediterranei MM2 using statistical designs

In this paper, we conducted a statistical optimization of the medium components for the production of rifamycin SV byAmycolatopsis mediterranei MM2. In order to maximize the yield of rifamycin SV, a Plakett-Burman experimental design (PBD) was initially utilized in the screening of the medium components among 11 nutrients. Glycerol and yeast extract were determined to influence significantly the yield of rifamycin SV. Then, a central-composite experimental design (CCD) was utilized in order to optimize the concentrations of the screened components accqired using the PBD and to predict the mutual interactions occurring between the screened components. The predicted optimal glycerol and yeast extract concentrations were determined to be 43.8 and 9.5 g/L, respectively. At this optimum point, the predicted rifamycin SV yield was 490.5 mg/L, whereas the corresponding experimental yield was 480.3±43.8 mg/L.

Characterization of technetium(vII) reduction by cell suspensions of thermophilic bacteria and archaea

Washed cell suspensions of the anaerobic hyperthermophilic archaea Thermococcus pacificus and Thermoproteus uzoniensis and the anaerobic thermophilic gram-positive bacteria Thermoterrabacterium ferrireducens and Tepidibacter thalassicus reduced technetium [(99)Tc(VII)], supplied as soluble pertechnetate with molecular hydrogen as an electron donor, forming highly insoluble Tc(IV)-containing grayish-black precipitate. Apart from molecular hydrogen, T. ferrireducens reduced Tc(VII) with lactate, glycerol, and yeast extract as electron donors, and T. thalassicus reduced it with peptone. Scanning electron microscopy and X-ray microanalysis of cell suspensions of T. ferrireducens showed the presence of Tc-containing particles attached to the surfaces of non-lysed cells. This is the first report on the reduction in Tc(VII) by thermophilic microorganisms of the domain Bacteria and by archaea of the phylum Euryarchaeota.

Extraction of glycerol from biodiesel into a eutectic based ionic liquid

A Lewis basic mixture of quaternary ammonium salts with glycerol has been used to extract excess glycerol from biodiesel formed from the reaction of triglycerides with ethanol in the presence of KOH. The effect of the cation on the partition coefficient of glycerol was determined, together with the time taken for the systems to reach equilibrium. Protocols were also investigated for the separation of glycerol from the quaternary ammonium salt mixtures.

Determination of free glycerol in biodiesel

AbstractWithin the biodiesel production process, glycerol arises as a side product. This free glycerol is included also in biodiesel in small amounts. Several methods are known to determine it. Some of them are based on gas chromatography (GC). In this paper, a new method is introduced that is based on the extraction of free glycerol into water and its subsequent determination in water solution by high‐performance liquid chromatography (HPLC) with refractometric detection. Comparison of the GC and HPLC methods showed that they led to the same results. The new method is reliable and comparatively fast for the determination of free glycerol in biodiesel.

Systemic and forearm triglyceride metabolism: fate of lipoprotein lipase-generated glycerol and free fatty acids.

Little is known about the fate of the lipolytic products produced by the action of lipoprotein lipase (LPL) on circulating triglyceride-rich lipoproteins in humans. We studied eight lean, healthy male subjects after an overnight fast. Subjects received infusions of lipid emulsions containing triolein labeled with (3)H on both the glycerol backbone and the fatty acid portion of the molecule; (14)C glycerol and (14)C oleate were coinfused to quantify the systemic and forearm release of (3)H glycerol and (3)H oleate resulting from LPL action. There was significant forearm uptake of both whole plasma triglyceride (presumed to represent primarily VLDL; extraction fraction 2.6 +/- 0.6%, P < 0.005 vs. zero) and radiolabeled triglyceride derived from the lipid emulsion (a surrogate for chylomicrons; extraction fraction 31 +/- 4%, P < 0.005 vs zero). Systemic clearance and forearm fractional extraction of glycerol was greater than that of oleate (P < 0.001 and P < 0.02, respectively). The systemic and forearm fractional release of LPL-generated glycerol were similar at 51 +/- 4 and 59 +/- 1%, respectively (NS). In contrast, the forearm fractional release of LPL-generated oleate was less than systemic fractional release (14 +/- 2 vs. 36 +/- 4%, P < 0.0001). These results indicate that there is escape, or spillover, of the lipolytic products of LPL action on triglyceride-rich lipoproteins in humans. They further suggest that LPL-mediated fatty acid uptake is an inefficient process, but may be more efficient in muscle than in adipose tissue.

Amyloid-enhancing factor mediates amyloid formation on fibroblasts via a nidus/template mechanism.

To determine the mechanism by which amyloid-enhancing factor (AEF) promotes amyloid deposition, and to test whether AEF seeds deposition of serum amyloid A (SAA) and facilitates conversion to beta-sheet structure. Fibroblasts were cultured with mouse recombinant SAA1.1 and AEF, SAA1.1, or AEF. AEF was prepared as a glycerol extract of spleen from amyloidotic mice. Amyloid was identified by staining with Congo red and examining for green birefringence under polarized light. SAA was localized immunohistochemically. Texas Red-labeled SAA was visualized in living cultures by fluorescence confocal microscopy. AEF was characterized by Western blot analysis using anti-SAA antiserum and N-terminal sequence analysis. Subunits comprising amyloid in fibroblast cultures were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Amyloid was produced in fibroblast cultures by an AEF-dependent mechanism. AEF, added to culture medium as insoluble protein precipitates, adhered to fibroblast monolayers. SAA bound preferentially to the adherent precipitates. Coincident with SAA binding, precipitates developed an affinity for Congo red. Over time, as more SAA was added, networks of Congo red-positive material producing bright green birefringence also developed outward from AEF precipitates. Amyloid built upon AEF in this manner was composed of full-length SAA. No amyloid was produced in cultures treated with either SAA or AEF alone. SAA and SAA peptides processed in the C-terminal region were the most prominent proteins in the glycerol-extracted AEF preparation. AEF binds to fibroblast monolayers and acts as a sink for SAA. SAA that collects on AEF assembles into an amyloid structure. Thus, it is concluded that AEF serves as both a nidus and a template for amyloid formation.

Antibacterial Activity and Alkaloid Content of Berberis thunbergii, Berberis vulgaris and Hydrastis canadensis

Japanese barberry (Berberis thunbergii DC.) is a species non-native to North America but widely found as a garden ornamental. Due to its invasiveness, it has become a pest in certain parts of Maine. A comparison of alkaloid content and antibacterial activity of Japanese barberry with common barberry (Berberis vulgaris L.) has been carried out to determine whether B. thunbergii might serve as a viable substitute for more commonly used berberine-containing medicinal plants such as goldenseal (HHydrastis canadensis L.)Extracts were prepared by exhaustively extracting B. thunbergii, B. vulgaris, and H. canadensis with 70% ethanol (ratio of roots to solvent was 1 : 5). Additional extracts were prepared with both 65% glycerin, and a mixture of 15% alcohol, 40% glycerin and 45% water (ratio of roots to solvent was 1 : 4).The ethanolic extracts were more potent against five bacteria than either the glycerin extracts or the mixed solvent extracts. Notably, the extracts exhibited strongest activity versus bacteria associated with sore throat (Streptococcus pyogenes) and opportunistic skin infection (Staphylococcus aureus), which supports the traditional uses of berberine-containing plants. The total alkaloid content in the dried roots (% w/w) was found to be 3.47 ± 0.39 (1.38 ± 0.14 berberine) for B. thunbergii, 2.22 ± 0.12 (0.43 ± 0.02 berberine) for B. vulgaris, and 9.04 ± 0.21 (6.34 ± 0.14 berberine) for H. canadensis.

Enhancement of the Humoral Immune Response by Echinacea purpurea in Female Swiss Mice

Various preparations of the plant Echinacea purpurea have been investigated for their potential to enhance immune function, primarily through activation of innate immune responses. Few studies have examined the potential for enhancement of humoral immunity. Using female Swiss mice we administered a volumetric dose of a glycerine extract of E. purpurea by oral gavage, to evaluate effects on the IgM specific antibody forming cell (AFC) response. Four days of treatment following immunization with sheep red blood cells (SRBC) produced a significant enhancement over naïve controls at doses of 0.4 and 0.8 mL/kg/day. A few clinical trials and anecdotal reports have suggested that the greatest efficacy for E. purpurea occurs in acute use following onset of illness. A time course study, using the time of SRBC immunization to mimic the onset of illness, examined the effects of 8 and 4 days of E. purpurea treatment at 0.6 mL/kg/day. Only in the 4‐day administration, with dosing beginning 1 hour after SRBC immunization, was there an observed enhancement of the antibody forming cell response. This supports the acute use of E. purpurea as suggested by anecdotal reports, and demonstrates the potential for enhancement of humoral immune responses as well as innate immune responses.

Portier, Richet, and the discovery of anaphylaxis: A centennial

Portier, Richet, and the discovery of anaphylaxis: A centennial

Stabilization of Caffeic Acid Derivatives in Echinacea purpurea L. Glycerin Extract

Recent work has shown that enzymatic degradation and oxidation of cichoric acid and other caffeic derivatives occurs in Echinacea preparations. However, very little is known as to the means of stabilizing these phytopreparations. To stabilize the glycerin extract of Echinacea purpurea, we have evaluated the effects of 3 natural antioxidants (citric acid, malic acid, and hibiscus extract) on the stability of the major caffeic acid derivatives (caftaric acid, caffeic acid, cichoric acid, and 2-O-feruloyl-tartaric acid). Chlorogenic acid, which normally occurs in an ethanol extract of E. purpurea, was not present in the glycerin extract. The caffeic acid derivatives, with the exception of 2-O-feruloyl-tartaric acid, were subject to degradation in the control sample. 2-O-Feruloyl-tartaric acid was stable during the whole testing period. All antioxidant treatments greatly improved the stability of caffeic acid derivatives. Stability was dependent upon the concentration of antioxidant added.