scholarly journals Conversion of l-Leucine to Isovaleric Acid by Propionibacterium freudenreichii TL 34 and ITGP23

2002 ◽  
Vol 68 (2) ◽  
pp. 608-615 ◽  
Author(s):  
Anne Thierry ◽  
Marie-Bernadette Maillard ◽  
Mireille Yvon
Keyword(s):  
High Performance ◽  
Isovaleric Acid ◽  
Resting Cells ◽  
Propionibacterium Freudenreichii ◽  
Swiss Cheese ◽  
Experimental Conditions ◽  
Cell Extracts ◽  
Leucine Catabolism ◽  
Branched Chain ◽  
Main Components

ABSTRACT Several branched-chain volatile compounds are involved in the flavor of Swiss cheese. These compounds are probably produced by enzymatic conversion of branched-chain amino acids, but the flora and the pathways involved remain hypothetical. Our aim was to determine the ability of Propionibacterium freudenreichii, which is one of the main components of the secondary flora of Swiss cheese, to produce flavor compounds during leucine catabolism. Cell extracts and resting cells of two strains were incubated in the presence of l-leucine, α-ketoglutaric acid, and cofactors, and the metabolites produced were determined by high-performance liquid chromatography and gas chromatography. The first step of leucine catabolism was a transamination that produced α-ketoisocaproic acid, which was enzymatically converted to isovaleric acid. Both reactions were faster at pH 8.0 than at acidic pHs. Cell extracts catalyzed only the transamination step under our experimental conditions. Small amounts of 3-methylbutanol were also produced by resting cells, but neither 3-methylbutanal norα-hydroxyisocaproic acid was detected. l-Isoleucine and l-valine were also converted to the corresponding acids and alcohols. Isovaleric acid was produced by both strains during growth in a complex medium, even under conditions simulating Swiss cheese conditions (2.1% NaCl, pH 5.4, 24�C). Our results show that P. frendenreichii could play a significant role in the formation of isovaleric acid during ripening.

scholarly journals Isovaleric acid is mainly produced by Propionibacterium freudenreichii in Swiss cheese

2004 ◽  
Vol 14 (9) ◽  
pp. 801-807 ◽  
Author(s):  
Anne Thierry ◽  
Romain Richoux ◽  
Jean-René Kerjean
Keyword(s):  
Isovaleric Acid ◽  
Propionibacterium Freudenreichii ◽  
Swiss Cheese

In vivo Production of Soluble Inorganic Pyrophosphatases in Two Strains of Vibrio cholerae

1970 ◽  
Vol 24 (1) ◽  
pp. 38-41
Author(s):  
Taslima Taher Lina ◽  
Mohammad Ilias
Keyword(s):  
Vibrio Cholerae ◽  
Specific Activity ◽  
Experimental Conditions ◽  
Environmental Strain ◽  
Cell Extracts ◽  
Atcc Strain ◽  
The Family ◽  
Effects Of Ph ◽  
Vibrio Cholerae O1

The in vivo production of soluble inorganic pyrophosphatases (PPases) was investigated in two strains, namely, Vibrio cholerae EM 004 (environmental strain) and Vibrio cholerae O1 757 (ATCC strain). V. cholerae is known to contain both family I and family II PPase coding sequences. The production of family I and family II PPases were determined by measuring the enzyme activity in cell extracts. The effects of pH, temperature, salinity of the growth medium on the production of soluble PPases were studied. In case of family I PPase, V. cholerae EM 004 gave the highest specific activity at pH 9.0, with 2% NaCl + 0.011% NaF and at 37°C. The strain V. cholerae O1 757 gave the highest specific activity at pH 9.0, with media containing 0% NaCl and at 37°C. On the other hand, under all the conditions family II PPase did not give any significant specific activity, suggesting that the family II PPase was not produced in vivo in either strains of V. cholerae under different experimental conditions. Keywords: Vibrio cholerae, Pyrophosphatases (PPases), Specific activityDOI: http://dx.doi.org/10.3329/bjm.v24i1.1235 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 38-41

Micro-Thermal Field-Flow Fractionation

2002 ◽  
Vol 67 (11) ◽  
pp. 1596-1608 ◽  
Author(s):  
Josef Janča
Keyword(s):  
High Performance ◽  
Thermal Field ◽  
Temperature Drop ◽  
Point Of View ◽  
Constant Field ◽  
Field Flow Fractionation ◽  
Operational Mode ◽  
Experimental Conditions ◽  
Standard Size ◽  
Flow Fractionation

The effect of miniaturization of the separation channel on the performance of thermal field-flow fractionation (TFFF) is substantiated theoretically. The experiments carried out under carefully chosen experimental conditions proved the high performance of the separation of polymers within an extended range of molar masses from relatively low up to ultrahigh-molar-mass (UHMM) samples. The new micro-TFFF allows to achieve high resolution when applying constant field force operation, it makes easy the programming of the temperature drop which is an advantageous operational mode from the point of view of the time of analysis, and it extends considerably the range of perfectly controlled temperature of the cold wall due to a substantial decrease in the heat energy flux compared with standard size channels.

scholarly journals Comparative Study of Anti-Gouty Arthritis Effects of Sam-Myo-Whan according to Extraction Solvents

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 278
Author(s):  
Yun Mi Lee ◽  
Eunjung Son ◽  
Dong-Seon Kim
Keyword(s):  
Uric Acid ◽  
Serum Uric Acid ◽  
Proinflammatory Cytokines ◽  
High Performance ◽  
Weight Bearing ◽  
Gouty Arthritis ◽  
Extraction Solvents ◽  
Main Components ◽  
Factor Α ◽  
Necrosis Factor

Sam-Myo-Whan (SMW) has been used in Korean and Chinese traditional medicine to help treat gout, by reducing swelling and inflammation and relieving pain. This study compared the effects of SMW extracted by using different solvents, water (SMWW) and 30% EtOH (SMWE), in the treatment of gouty arthritis. To this end, we analyzed the main components of SMWW and SMWE, using high-performance liquid chromatography (HPLC). Anti-hyperuricemic activity was evaluated by measuring serum uric acid levels in hyperuricemic rats. The effects of SMWW and SMWE on swelling, pain, and inflammation in gouty arthritis were investigated by measuring affected limb swelling and weight-bearing, as well as by enzyme-linked immunosorbent assays, to assess the levels of proinflammatory cytokines and myeloperoxidase (MPO). In potassium oxonate (PO)-induced hyperuricemic rats, SMWW and SMWE both significantly decreased serum uric acid to similar levels. In monosodium urate (MSU)-induced gouty arthritis mice, SMWE more efficiently decreased paw swelling and attenuated joint pain compare to SMWW. Moreover, SMWE and SMWW suppressed the level of inflammation by downregulating proinflammatory cytokines (interleukin-1β, tumor necrosis factor-α, and interleukin-6) and MPO activity. HPLC analysis further revealed that berberine represented one of the major active ingredients demonstrating the greatest change in concentration between SMWW and SMWE. Our data demonstrate that SMWE retains a more effective therapeutic concentration compared to SMWW, in a mouse model of gouty arthritis.

scholarly journals How Relevant Is It to Use Mineral Proxies to Mimic the Atmospheric Reactivity of Natural Dust Samples? A Reactivity Study Using SO2 as Probe Molecule

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 282
Author(s):  
Darya Urupina ◽  
Manolis N. Romanias ◽  
Frederic Thevenet
Keyword(s):  
High Performance ◽  
Real Life ◽  
Complex Mixtures ◽  
Experimental Conditions ◽  
The Real ◽  
Atmospheric Processes ◽  
Real Effects ◽  
Mineral Aerosols ◽  
Life Impact ◽  
Reactivity Study

The experimental investigation of heterogeneous atmospheric processes involving mineral aerosols is extensively performed in the literature using proxy materials. In this work we questioned the validity of using proxies such as Fe2O3, FeOOH, Al2O3, MgO, CaO, TiO2, MnO2, SiO2, and CaCO3 to represent the behavior of complex mixtures of minerals, such as natural desert and volcanic dusts. Five volcanic dusts and three desert dusts were compared to a number of metal oxides, commonly used in the literature to mimic the behavior of desert dusts in the ability to form sulfites and sulfates on the surface exposed to SO2 gas. First, all samples were aged at room temperature, atmospheric pressure, under controlled experimental conditions of 175 ppm SO2 for 1 h under 30% of relative humidity. Second, they were extracted with 1% formalin and analyzed by High-Performance Liquid Chromatography (HPLC) to quantify and compare the amount of sulfites and sulfates formed on their surfaces. It was evidenced that under the experimental conditions of this study neither one selected pure oxide nor a mixture of oxides can adequately typify the behavior of complex mixtures of natural minerals. Therefore, to evaluate the real-life impact of natural dust on atmospheric processes it is of vital importance to work directly with the natural samples, both to observe the real effects of desert and volcanic dusts and to evaluate the relevancy of proposed proxies.

Determination of the Isoflavone Genistein in Soybeans by High-Performance Liquid Chromatography Following Cloud Point Extraction

2012 ◽  
Vol 95 (3) ◽  
pp. 845-849 ◽  
Author(s):  
Mohammad Mirzaei ◽  
Atieh Karimi Naeini ◽  
Mansoureh Behzadi
Keyword(s):  
Cloud Point ◽  
High Performance ◽  
Cloud Point Extraction ◽  
Uv Detector ◽  
Experimental Conditions ◽  
Solid Ratio ◽  
Assisted Extraction ◽  
Ultrasonic Assisted ◽  
Replicate Measurements

Abstract A simple and sensitive method has been developed for preconcentration and determination of genistein in soybeans. This method is based on cloud point extraction (CPE) of genistein from soybeans using ethylene glycol monoalkyl ether (Genapol X-080) as a nonionic surfactant. The concentration of extracted genistein was determined by HPLC with a UV detector. Optimum experimental conditions were established. With 5% Genapol X-080 (v/v), a liquid/solid ratio of 25:1 mL/g, and ultrasonic-assisted extraction at 40°C for 45 min, the extraction percentage of genistein reached its highest value. The preconcentration factor for genistein was about 16.5. The RSD for seven replicate measurements and the LOD were ±4.45% and 15.0 ng/mL, respectively. CPE is simple, inexpensive, and suitable for extraction of genistein from soybean. It uses environmentally friendly surfactants and offers a convenient alternative to more conventional extraction systems.

scholarly journals Effects of diadenosine polyphosphates and seminal fluid vesicles on rabbit sperm cells

Reproduction ◽  
2003 ◽  
pp. 827-835 ◽  
Author(s):  
A Minelli ◽  
L Liguori ◽  
I Bellezza ◽  
T Renieri ◽  
C Castellini
Keyword(s):  
High Performance ◽  
Acrosome Reaction ◽  
Seminal Fluid ◽  
Membrane Vesicles ◽  
Fluorescein Isothiocyanate ◽  
Plasma Electron ◽  
Sperm Cells ◽  
Experimental Conditions ◽  
Diadenosine Polyphosphates ◽  
Rabbit Spermatozoa

Membrane vesicles were isolated from rabbit seminal plasma. Electron microscopy analyses showed the presence of numerous small, round vesicles with a diameter of about 70 nm. Determination of enzyme activities was carried out by high performance liquid chromatography and showed that the vesicles can degrade the diadenosine polyphosphates (ApnA), Ap3A and Ap4A and ATP and ADP, but not AMP. Studies of the degradation of diadenosine compounds by the vesicles present in seminal fluid showed an increasing production of AMP as the by-product and a time-dependent generation of dephosphorylated products consistent with the presence of ecto-ATP diphosphophosphatase (ecto-apyrase). In the presence of rabbit spermatozoa, AMP did not accumulate because 5'nucleotidase and adenosine deaminase, present at the surface of sperm cells, transformed AMP into adenosine and inosine. The effects of seminal fluid vesicles and diadenosine compounds on the acquisition of fertilizing capacity by rabbit spermatozoa were evaluated by Pisum sativum agglutinin fluorescein isothiocyanate conjugated staining. The results obtained with uncapacitated spermatozoa showed that the capacitating effector BSA could be substituted efficiently by the addition of diadenosine compounds and vesicles previously incubated for 2 h to the capacitative medium. Under these experimental conditions, the spontaneous acrosome reaction rate was not increased. Capacitated rabbit spermatozoa did not undergo acrosome reaction when l-alpha-lysophosphatidylcholine was substituted by diadenosine compounds previously incubated with vesicles. In conclusion, this study has shown that rabbit seminal fluid vesicles can degrade diadenosine compounds to AMP and that the addition of the vesicles and diadenosine compounds to uncapacitated rabbit spermatozoa favours the acquisition of the fertilizing capacity.

Chlorophylls Contents in Echinocactus grusonii Extract

2014 ◽  
Vol 931-932 ◽  
pp. 1507-1511
Author(s):  
Nipha Chaicharoenaudomrung ◽  
Anant Oonsivilai ◽  
Ratchadaporn Oonsivilai
Keyword(s):  
High Performance ◽  
Reversed Phase ◽  
Lower Content ◽  
Chlorophyll Contents ◽  
Crude Extracts ◽  
Phytochemical Profile ◽  
Main Components ◽  
Near Future ◽  
Profile Study ◽  
Barrel Cactus

Currently, Golden Barrel cactus extract is formulated in dietary supplements, on account of its powerful weight loss profit and antioxidant activity. Golden Barrel cactus grusonii (Echinocactus grusonii), a Thai cultivar Golden Barrel cactus which is known as the golden barrel Golden Barrel cactus was therefore investigated for total chlorophylls with the aim of developing as a dietary supplement in future. The chlorophyll contents of 3 and 6 years Echinocactus grusonii extracts were evaluated by High Performance Liquid Chromatography with a Grace-Vydac 201TP54 reversed-phase polymeric C18 column. The results showed that chlorophyll a and chlorophyll b are the main components of Echinocactus grusonii crude extracts also at higher level at age 3 years. It was found that the main chlorophylls contents are chlorophyll a and chlorophyll b at 2.94±0.55μg/ml and 1.63±0.14 μg/ml for 3 years Echinocactus grusonii. In addition, the amount of chlorophyll a and chlorophyll b show lower content at 1.11±0.25μg/ml and 0.67±0.01μg/ml for 6 years Echinocactus grusonii. In conclusion, Echinocactus grusonii age 3 years crude extracts showed total chlorophylls contents higher than at age 6 years. The phytochemical profile study of Echinocactus grusonii age 3 years and 6 years crude extracts are planned in the near future.

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