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Detalles de la revista
Formato
Revista
eISSN
2603-347X
Publicado por primera vez
15 Dec 2015
Periodo de publicación
1 tiempo por año
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Inglés

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Volumen 6 (2019): Edición 1 (March 2019)

Detalles de la revista
Formato
Revista
eISSN
2603-347X
Publicado por primera vez
15 Dec 2015
Periodo de publicación
1 tiempo por año
Idiomas
Inglés

Buscar

12 Artículos
Acceso abierto

Editorial Note: Where Science Meets Art “145 years since the birth of the painter Trifon Popov”

Publicado en línea: 27 May 2019
Páginas: 6 - 7

Resumen

Acceso abierto

HPLC-DAD profiling and antioxidant activity of the n-butanol extract from aerial parts of Algerian Crithmum maritimum L.

Publicado en línea: 27 May 2019
Páginas: 8 - 16

Resumen

Abstract

In this study, phenolic compounds from Crithmum maritimum L. n-butanol soluble fraction were quantified and identified spectrophotometrically and by using HPLC-DAD technics. They equally investigated for their antioxidant potential utilizing six in vitro assays: DPPH, ABTS•+, O2•−, Bleaching of β-carotene in linoleic acid, CUPRAC and Ferric reducing power. High amounts of total phenolics and flavonoids were recorded: 161.57± 0.479 μg GAeq.mg−1 and 31.56± 0.291 μg Qeq.mg−1 respectively. Nine compounds among them hydroxicinnamic acid and hydroxybenzoic acid derivatives, coumarins and flavonoids were identified. Chlorogenic acid known for their various pharmacological properties was detected as major compound of the extract. Rutin, vanillin, trans-2-hydroxycinnamic acid, ellagic acid, ferrulic acid, 6,7 dihydroxy coumarin, methyl 1,4 benzoquinone and trans-cinnamic acid were also detected. The extract was found to exhibit strong antioxidant capacities in all systems. Based on these results, it is right to conclude the n-butanol extract is promising source of natural antioxidants.

Palabras clave

  • L.
  • HPLC-DAD
  • phenolics
  • flavonoids
  • antioxidant activity
Acceso abierto

Phytochemical Studies Antibacterial and Antioxidant Activities of Aerial Parts of Ferula lutea (Poir.) Maire.

Publicado en línea: 27 May 2019
Páginas: 17 - 25

Resumen

Abstract

The focus of this paper was to assess the phytochemical composition, the antioxidant and antibacterial activities of the crude extracts of the aerial parts of Ferula lutea. Four new compounds were isolated from this genus, and their structures were primarily established by extensive spectroscopic analysis including 1D and 2D spectroscopic techniques. Total phenolics and flavonoids containing in ethyl acetate (AcOEt) and n-butanol (n-BuOH) extracts were quantified [199.1-184.02 mg gallic acid equivalent / g of dry weight], flavonoids [70.24-65.95 mg quercetin / g dry weight]. DDPH scavenging and phosphomolybdenum methods were used to evaluate in vitro antioxidant activity. The obtained results showed a significant antioxidant activity of the two aerial parts. Correlation analysis between the DPPH values and those for TAC indicates the possibility of the two models for evaluating antioxidants power from medicinal plants. Dichloromethane (CH2Cl2), AcOEt and n-BuOH extracts were screened against two gram-negative [Escherichia coli (E.coli) and Pseudo aeruginosa (P.aer)] and two gram-positive [Staphylococcus aureus (S.aur) and Bacillus (Bacil.)] bacteria using disc diffusion method. The results indicate a good inhibition of CH2Cl2 and EtAct extracts on the growth of (Bacil. and E.coli). Furthermore n-but extract showed a significant inhibitory effect only against E.coli.

Palabras clave

  • phenolics
  • flavonoids
  • antioxidant
  • antibacterial
Acceso abierto

A thermodynamic model for solution behavior and solid-liquid equilibrium in Na-K-Mg-Ca-Al(III)-Fe(III)-Cr(III)-Cl-H2O system from low to very high concentration at 25°C

Publicado en línea: 27 May 2019
Páginas: 26 - 36

Resumen

Abstract

In this study we evaluated new mixing (θ and ψ) Pitzer parameters, and developed models for solution behavior and solid liquid equilibria for the following mixed systems: 1) KCl-AlCl3-H2O, 2) KCl-FeCl3-H2O, 3) KCl-CrCl3-H2O, 4) MgCl2-AlCl3-H2O, 5) MgCl2-FeCl3-H2O, 6) MgCl2-CrCl3-H2O, 7) CaCl2-AlCl3-H2O, 8) CaCl2-FeCl3-H2O, and 9) CaCl2-CrCl3-H2O at 25°C. The solubility modeling approach, implemented to the Pitzer specific interaction equations is employed. The values of the binary parameters for the binary sub-systems needed here to parameterize models for mixed systems are taken from our previous studies. Mixing solution parameters are evaluated in this study using activity (when available) and solubility data. Following an approach in our previous modeling studies on M(III) chloride and sulfate systems, in this work we accept that complex Al(III), Cr(III), and Fe(III) aqueous species do not exist in solutions. We test the new models by comparing model predictions with experimental data (activity data for unsaturated solutions and solubility data in ternary systems). The agreement between model predictions and experimental data is very good. Combining present parameterization, with our M(III) models developed previously we fully complete our at 25°C model for the 8th component system Na-K-Mg-Ca-Al(III)-Cr(III)-Fe(III)-Cl-H2O. The resulting model calculates solubilities and solution activities to high solution concentration within experimental uncertainty. Limitations of the model due to data insufficiencies are discussed. The resulting parameterization was developed for the Pitzer formalism based PHREEQC database.

Palabras clave

  • Geochemistry of Aluminum (Al(III))
  • Chromium(Cr(III)) and Iron (Fe(III))
  • Pitzer approach
  • Computer Chemical and Geochemical modeling
  • Solution and solute activity
  • Stable and metastable solid-liquid equilibria
  • Extended brine system model
  • Water-rock interactions
  • Physical Chemistry and Chemical Thermodynamics
Acceso abierto

Interaction of 1,2-alkadienephosphonates with propargyl alcohole

Publicado en línea: 27 May 2019
Páginas: 37 - 41

Resumen

Abstract

The reactivity of 1,2-alkadienephosphonates in nucleophilic addition reactions has been investigated.

Palabras clave

  • 1, 2-Alkadienephosphonates
  • nucleophilic addition
  • β-ketophosphonates
Acceso abierto

Design of Dye-Sensitized Solar triphenodioxazine using TiO2 as a semiconductor

Publicado en línea: 27 May 2019
Páginas: 42 - 49

Resumen

Abstract

The present work deals with the synthesis of multichromophores which strongly absorb the solar spectrum to functionalize the nanoparticle oxide semiconductor used in the hybrid cells. At first, we developed a material that forms a chromophore triphenodioxazine. We obtained some triphenodioxazines with high yields up to 70 percent. On the other hand, we have carried out many tests such as UV-Visible, Cyclic voltammetry for our molecules to check their electronic and optical properties. The results confirmed that these chromophores meet the criteria for use in photovoltaic cells. Finally, we have successfully realized photovoltaic cells with triphenodioxazine. The findings were very interesting since the photovoltaic conversion efficiencies ranged from 4.30% to 6.30%. The new synthesis strategy of these chromophores opens a way for the development of organic materials used for photovoltaics.

Palabras clave

  • photovoltaic conversion
  • hybrid materials
  • chromophore
  • Triphenodioxazine
  • solar cells
Acceso abierto

In-vivo Antidiarrhoeal and anti-ulcerative activities of the Tetraclinis articulata species of the Cupressaceae family

Publicado en línea: 27 May 2019
Páginas: 50 - 53

Resumen

Abstract

Tetraclinis articulata (Thuya of Barbary), endemic to North Africa, is used as a traditional medicine for the treatment of many diseases [1]. We investigated the antidiarrhoel properties of the butanol extract of Tetraclinis articulata (BETA) in male and female Swiss albino mice to support its traditional use. The antidiarrhoeal activity of the plant extract was evaluated in a model of castor oil-induced diarrhoea model in mice and compared to loperamide (a reference inhibitor of diarrhoea). The effect of (BETA) on gastrointestinal motility was determined by the oral administration of charcoal and Castrol oil-induced intestinal fluid accumulation (enteropooling).The (BETA) showed remarkable antidiarrhoeal activity significantly inhibited gastrointestinal motility and castor oil induced enteropolysis (68,18%), more than to the inhibition achieved in loperamide treated mice (60,16%). The second aim of the present study was to evaluate the anti-ulcerative activity of The (BETA), it produced percent protection of control colitis by 77, 40%, while the standard drug (aspirin) produced 81,39% protection. We conclude that Tetraclinis articulata extracts are potential sources of new anti-ulcer agents and antidiarrhoeal drugs.

Palabras clave

  • n-butanol extract
  • antidiarrhoeal activity
  • anti-ulcerative activity
Acceso abierto

Assessment of Antioxidant effect of the essential oil and methanol extract of Centaurea dimorpha Viv. aerial parts from Algeria.

Publicado en línea: 27 May 2019
Páginas: 54 - 62

Resumen

Abstract

The essential oils obtained by hydrodistillation of aerial parts of Centaurea dimorpha Viv. were analyzed by means of gas chromatography-mass spectrometry (GC-MS). The main constituents were Caryophyllene oxide (09.88%), limonene (5.73%), tetradecanoic acid (5.68%), spathulenol (5.44%), methyl hexadecanoate (4.45%), and α-pinene (03.08%). To our best knowledge this is the first study of essential oils from the aerial parts of Centaurea dimorpha growing in Algeria. Moreover the essential oil and methanolic extract were screened for their possible in vitro antioxidant activity by DPPH free radical-scavenging test. The findings showed that the percentage inhibition is 10.67 and 77.01 respectively at a concentration of 1mole/L.

Palabras clave

  • Centaurea dimorpha
  • Essential Oi
  • GC-MS
  • aerial parts
  • Antioxidant activity
Acceso abierto

Comparative Study of the Bacteriological Activity of Zinc Oxide and Copper Oxide Nanoparticles

Publicado en línea: 27 May 2019
Páginas: 63 - 72

Resumen

Abstract

Interest in nanomaterials, especially metal oxides, in the fight against resistant and constantly changing bacterial strains, is more and more expressed. Their very high reactivity, resulting from their large surface area, promoted them to the rank of potential successors of antibiotics.

Our work consisted of the synthesis of zinc oxide (ZnO) and copper oxide (CuO) in the nanoparticle state and the study of their bactericidal effect on various Gram-negative and Gram-positive bacterial strains.

The nanoparticles of metal oxides have been synthesized by sol-gel method. Qualitative analysis and characterization by UV / Visible and infrared spectrophotometry and X-ray diffraction confirmed that the synthetic products are crystalline. The application of the Scherrer equation allows to determine the size of the two metal oxides, namely: 76.94 nm for ZnO and 24.86 nm for CuO.

The bactericidal effect of ZnO and CuO nanoparticles was tested on Gram-positive bacteria (Staphylococcus aureus, Staphylococcus hominis, Staphylococcus haemolyticus, Enterococcus facials) and Gram-negative bacteria (Escherichia coli, Schigella, Klepsiella pneumoniae and Pseudomonas aeruginosa). The results indicate that the tested metal oxides nanoparticles have an effect that varies depending on bacterial species. Indeed, Gram-positive bacteria show greater sensitivity to ZnO nanoparticles whereas Gram-negative bacteria are more sensitive to CuO nanoparticles.

Palabras clave

  • Nanoparticles
  • ZnO
  • CuO
  • sol-gel method
  • bactericidal effect
Acceso abierto

Anticoagulant Activity of Some Ficus carica Varieties Extracts Grown in Algeria

Publicado en línea: 27 May 2019
Páginas: 73 - 78

Resumen

Abstract

The hemostatic system is a complex balanced system that triggers clot formation to prevent blood loss after trauma. To block abnormal bleeding and maintain intravascular blood in a liquid state, in this study we investigated the possible anticoagulant effect of leaves and fruits extracts from some fig varieties grown in Algeria by determining the quick time (QT). The blood samples of the healthy individuals were used. For in vitro coagulation assays, the clotting times obtained in the presence of polyphenols in different extracts of F.carica samples indicate that they exert a high anticoagulant activity on the exogenous pathway of coagulation. Moreover, the polyphenolic extract of ‘Roudane’ variety presented a substantial increase in coagulation. Based on these preliminary results, it can be suggested that the fig polyphenolic extracts (FPE) of this varieties have anticoagulant activity that could be useful in preventing blood clots.

Palabras clave

  • Anticoagulant
  • polyphenols
  • quick time
  • .L
Acceso abierto

Optimization of the extraction parameters of Aloe Vera polyphenols and study of antioxidant and antifungal activities: application to molds isolated from durum wheat

Publicado en línea: 27 May 2019
Páginas: 79 - 90

Resumen

Abstract

The main objectives of this work are to optimize the extraction parameters, to test the antioxidant activity of Aloe Vera extract and to study the impact of this extract on deteriorating molds of Algerian variety of wheat (CIRTA). The extraction was optimized by central composite design. Determination of the polyphenols, flavonoids, and proanthocyanidins was performed by using colorimetric assays. Identification and quantification of phenolic compounds were performed by RPHPLC-UV method. The antioxidant activity was tested by three methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,20-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and CUPRAC (Cupric reducing antioxidant capacity), the antifungal activity of Aloe Vera extract on isolated strains from durum wheat were tested by dilution in a solid medium method. The optimum of total phenolic got was1,044 x 104 µg GAE/g of dry extract. The extract is rich in polyphenols, flavonoids, and proanthocyanidins. The analysis of phenolic compounds of Aloe Vera by RP-HPLC-UV revealed seven phenolic compounds. Strong antioxidant activity was obtained for Aloe Vera extract. Purification and microscopic study of isolated strains gave the possibility of identifying four strains: Alternaria spp1, Alternaria spp2, Penicillium spp, and Aspergillus spp. the antifungal potential of Aloe Veravaries according to the fungal genera and the concentrations of extract used.

Palabras clave

  • Optimization
  • Polyphenols
  • Antioxidant activity
  • Antifungal activity
  • Mold
  • wheat
Acceso abierto

Experimental setup for light-to-heat NIR conversion measurements of gold nanoparticle solutions

Publicado en línea: 27 May 2019
Páginas: 91 - 99

Resumen

Abstract

In recent years, there is a constantly increasing interest in the application of nanoparticles for cancer diagnosis and cancer therapy. In this respect, the most promising nano-objects at present are the gold nanoparticles. A very convenient and powerful property of these objects is their ability to increase their temperature under electro-magnetic irradiation with certain wavelength. In our research we have directed our efforts toward particular nano-objects specifically sensitive to electromagnetic radiation in the near-infrared region (NIR). In order to study the photothermic properties of the solutions of gold nanoparticles in the NIR we constructed a specific electronic setup consisting of a laser system with interchangeable laser diodes with different wavelength NIR light, a thermally-insulated cuvette-holder compartment with temperature measuring probes and a NIR spectrometer to control the stimulated fluorescence emission of the nanoparticle solutions. The temperature measurement compartment with the thermal-insulated cuvette holder was designed to maintain the solutions’ temperature at a fixed value right before the moment of laser irradiation. To maintain the measurement setup at a fixed temperature before the irradiation we used a thermal stabilized system based on two Peltier cells with electronic temperature control. The temperatures of the ambient air and the temperature of the cuvette walls were continuously measured in order to make corrections about the temperature dissipation during the irradiation.

Palabras clave

  • light-to-heat conversion
  • gold nano-rods
  • gold nano-urchins
  • Peltier cell
  • Near Infrared measurements
12 Artículos
Acceso abierto

Editorial Note: Where Science Meets Art “145 years since the birth of the painter Trifon Popov”

Publicado en línea: 27 May 2019
Páginas: 6 - 7

Resumen

Acceso abierto

HPLC-DAD profiling and antioxidant activity of the n-butanol extract from aerial parts of Algerian Crithmum maritimum L.

Publicado en línea: 27 May 2019
Páginas: 8 - 16

Resumen

Abstract

In this study, phenolic compounds from Crithmum maritimum L. n-butanol soluble fraction were quantified and identified spectrophotometrically and by using HPLC-DAD technics. They equally investigated for their antioxidant potential utilizing six in vitro assays: DPPH, ABTS•+, O2•−, Bleaching of β-carotene in linoleic acid, CUPRAC and Ferric reducing power. High amounts of total phenolics and flavonoids were recorded: 161.57± 0.479 μg GAeq.mg−1 and 31.56± 0.291 μg Qeq.mg−1 respectively. Nine compounds among them hydroxicinnamic acid and hydroxybenzoic acid derivatives, coumarins and flavonoids were identified. Chlorogenic acid known for their various pharmacological properties was detected as major compound of the extract. Rutin, vanillin, trans-2-hydroxycinnamic acid, ellagic acid, ferrulic acid, 6,7 dihydroxy coumarin, methyl 1,4 benzoquinone and trans-cinnamic acid were also detected. The extract was found to exhibit strong antioxidant capacities in all systems. Based on these results, it is right to conclude the n-butanol extract is promising source of natural antioxidants.

Palabras clave

  • L.
  • HPLC-DAD
  • phenolics
  • flavonoids
  • antioxidant activity
Acceso abierto

Phytochemical Studies Antibacterial and Antioxidant Activities of Aerial Parts of Ferula lutea (Poir.) Maire.

Publicado en línea: 27 May 2019
Páginas: 17 - 25

Resumen

Abstract

The focus of this paper was to assess the phytochemical composition, the antioxidant and antibacterial activities of the crude extracts of the aerial parts of Ferula lutea. Four new compounds were isolated from this genus, and their structures were primarily established by extensive spectroscopic analysis including 1D and 2D spectroscopic techniques. Total phenolics and flavonoids containing in ethyl acetate (AcOEt) and n-butanol (n-BuOH) extracts were quantified [199.1-184.02 mg gallic acid equivalent / g of dry weight], flavonoids [70.24-65.95 mg quercetin / g dry weight]. DDPH scavenging and phosphomolybdenum methods were used to evaluate in vitro antioxidant activity. The obtained results showed a significant antioxidant activity of the two aerial parts. Correlation analysis between the DPPH values and those for TAC indicates the possibility of the two models for evaluating antioxidants power from medicinal plants. Dichloromethane (CH2Cl2), AcOEt and n-BuOH extracts were screened against two gram-negative [Escherichia coli (E.coli) and Pseudo aeruginosa (P.aer)] and two gram-positive [Staphylococcus aureus (S.aur) and Bacillus (Bacil.)] bacteria using disc diffusion method. The results indicate a good inhibition of CH2Cl2 and EtAct extracts on the growth of (Bacil. and E.coli). Furthermore n-but extract showed a significant inhibitory effect only against E.coli.

Palabras clave

  • phenolics
  • flavonoids
  • antioxidant
  • antibacterial
Acceso abierto

A thermodynamic model for solution behavior and solid-liquid equilibrium in Na-K-Mg-Ca-Al(III)-Fe(III)-Cr(III)-Cl-H2O system from low to very high concentration at 25°C

Publicado en línea: 27 May 2019
Páginas: 26 - 36

Resumen

Abstract

In this study we evaluated new mixing (θ and ψ) Pitzer parameters, and developed models for solution behavior and solid liquid equilibria for the following mixed systems: 1) KCl-AlCl3-H2O, 2) KCl-FeCl3-H2O, 3) KCl-CrCl3-H2O, 4) MgCl2-AlCl3-H2O, 5) MgCl2-FeCl3-H2O, 6) MgCl2-CrCl3-H2O, 7) CaCl2-AlCl3-H2O, 8) CaCl2-FeCl3-H2O, and 9) CaCl2-CrCl3-H2O at 25°C. The solubility modeling approach, implemented to the Pitzer specific interaction equations is employed. The values of the binary parameters for the binary sub-systems needed here to parameterize models for mixed systems are taken from our previous studies. Mixing solution parameters are evaluated in this study using activity (when available) and solubility data. Following an approach in our previous modeling studies on M(III) chloride and sulfate systems, in this work we accept that complex Al(III), Cr(III), and Fe(III) aqueous species do not exist in solutions. We test the new models by comparing model predictions with experimental data (activity data for unsaturated solutions and solubility data in ternary systems). The agreement between model predictions and experimental data is very good. Combining present parameterization, with our M(III) models developed previously we fully complete our at 25°C model for the 8th component system Na-K-Mg-Ca-Al(III)-Cr(III)-Fe(III)-Cl-H2O. The resulting model calculates solubilities and solution activities to high solution concentration within experimental uncertainty. Limitations of the model due to data insufficiencies are discussed. The resulting parameterization was developed for the Pitzer formalism based PHREEQC database.

Palabras clave

  • Geochemistry of Aluminum (Al(III))
  • Chromium(Cr(III)) and Iron (Fe(III))
  • Pitzer approach
  • Computer Chemical and Geochemical modeling
  • Solution and solute activity
  • Stable and metastable solid-liquid equilibria
  • Extended brine system model
  • Water-rock interactions
  • Physical Chemistry and Chemical Thermodynamics
Acceso abierto

Interaction of 1,2-alkadienephosphonates with propargyl alcohole

Publicado en línea: 27 May 2019
Páginas: 37 - 41

Resumen

Abstract

The reactivity of 1,2-alkadienephosphonates in nucleophilic addition reactions has been investigated.

Palabras clave

  • 1, 2-Alkadienephosphonates
  • nucleophilic addition
  • β-ketophosphonates
Acceso abierto

Design of Dye-Sensitized Solar triphenodioxazine using TiO2 as a semiconductor

Publicado en línea: 27 May 2019
Páginas: 42 - 49

Resumen

Abstract

The present work deals with the synthesis of multichromophores which strongly absorb the solar spectrum to functionalize the nanoparticle oxide semiconductor used in the hybrid cells. At first, we developed a material that forms a chromophore triphenodioxazine. We obtained some triphenodioxazines with high yields up to 70 percent. On the other hand, we have carried out many tests such as UV-Visible, Cyclic voltammetry for our molecules to check their electronic and optical properties. The results confirmed that these chromophores meet the criteria for use in photovoltaic cells. Finally, we have successfully realized photovoltaic cells with triphenodioxazine. The findings were very interesting since the photovoltaic conversion efficiencies ranged from 4.30% to 6.30%. The new synthesis strategy of these chromophores opens a way for the development of organic materials used for photovoltaics.

Palabras clave

  • photovoltaic conversion
  • hybrid materials
  • chromophore
  • Triphenodioxazine
  • solar cells
Acceso abierto

In-vivo Antidiarrhoeal and anti-ulcerative activities of the Tetraclinis articulata species of the Cupressaceae family

Publicado en línea: 27 May 2019
Páginas: 50 - 53

Resumen

Abstract

Tetraclinis articulata (Thuya of Barbary), endemic to North Africa, is used as a traditional medicine for the treatment of many diseases [1]. We investigated the antidiarrhoel properties of the butanol extract of Tetraclinis articulata (BETA) in male and female Swiss albino mice to support its traditional use. The antidiarrhoeal activity of the plant extract was evaluated in a model of castor oil-induced diarrhoea model in mice and compared to loperamide (a reference inhibitor of diarrhoea). The effect of (BETA) on gastrointestinal motility was determined by the oral administration of charcoal and Castrol oil-induced intestinal fluid accumulation (enteropooling).The (BETA) showed remarkable antidiarrhoeal activity significantly inhibited gastrointestinal motility and castor oil induced enteropolysis (68,18%), more than to the inhibition achieved in loperamide treated mice (60,16%). The second aim of the present study was to evaluate the anti-ulcerative activity of The (BETA), it produced percent protection of control colitis by 77, 40%, while the standard drug (aspirin) produced 81,39% protection. We conclude that Tetraclinis articulata extracts are potential sources of new anti-ulcer agents and antidiarrhoeal drugs.

Palabras clave

  • n-butanol extract
  • antidiarrhoeal activity
  • anti-ulcerative activity
Acceso abierto

Assessment of Antioxidant effect of the essential oil and methanol extract of Centaurea dimorpha Viv. aerial parts from Algeria.

Publicado en línea: 27 May 2019
Páginas: 54 - 62

Resumen

Abstract

The essential oils obtained by hydrodistillation of aerial parts of Centaurea dimorpha Viv. were analyzed by means of gas chromatography-mass spectrometry (GC-MS). The main constituents were Caryophyllene oxide (09.88%), limonene (5.73%), tetradecanoic acid (5.68%), spathulenol (5.44%), methyl hexadecanoate (4.45%), and α-pinene (03.08%). To our best knowledge this is the first study of essential oils from the aerial parts of Centaurea dimorpha growing in Algeria. Moreover the essential oil and methanolic extract were screened for their possible in vitro antioxidant activity by DPPH free radical-scavenging test. The findings showed that the percentage inhibition is 10.67 and 77.01 respectively at a concentration of 1mole/L.

Palabras clave

  • Centaurea dimorpha
  • Essential Oi
  • GC-MS
  • aerial parts
  • Antioxidant activity
Acceso abierto

Comparative Study of the Bacteriological Activity of Zinc Oxide and Copper Oxide Nanoparticles

Publicado en línea: 27 May 2019
Páginas: 63 - 72

Resumen

Abstract

Interest in nanomaterials, especially metal oxides, in the fight against resistant and constantly changing bacterial strains, is more and more expressed. Their very high reactivity, resulting from their large surface area, promoted them to the rank of potential successors of antibiotics.

Our work consisted of the synthesis of zinc oxide (ZnO) and copper oxide (CuO) in the nanoparticle state and the study of their bactericidal effect on various Gram-negative and Gram-positive bacterial strains.

The nanoparticles of metal oxides have been synthesized by sol-gel method. Qualitative analysis and characterization by UV / Visible and infrared spectrophotometry and X-ray diffraction confirmed that the synthetic products are crystalline. The application of the Scherrer equation allows to determine the size of the two metal oxides, namely: 76.94 nm for ZnO and 24.86 nm for CuO.

The bactericidal effect of ZnO and CuO nanoparticles was tested on Gram-positive bacteria (Staphylococcus aureus, Staphylococcus hominis, Staphylococcus haemolyticus, Enterococcus facials) and Gram-negative bacteria (Escherichia coli, Schigella, Klepsiella pneumoniae and Pseudomonas aeruginosa). The results indicate that the tested metal oxides nanoparticles have an effect that varies depending on bacterial species. Indeed, Gram-positive bacteria show greater sensitivity to ZnO nanoparticles whereas Gram-negative bacteria are more sensitive to CuO nanoparticles.

Palabras clave

  • Nanoparticles
  • ZnO
  • CuO
  • sol-gel method
  • bactericidal effect
Acceso abierto

Anticoagulant Activity of Some Ficus carica Varieties Extracts Grown in Algeria

Publicado en línea: 27 May 2019
Páginas: 73 - 78

Resumen

Abstract

The hemostatic system is a complex balanced system that triggers clot formation to prevent blood loss after trauma. To block abnormal bleeding and maintain intravascular blood in a liquid state, in this study we investigated the possible anticoagulant effect of leaves and fruits extracts from some fig varieties grown in Algeria by determining the quick time (QT). The blood samples of the healthy individuals were used. For in vitro coagulation assays, the clotting times obtained in the presence of polyphenols in different extracts of F.carica samples indicate that they exert a high anticoagulant activity on the exogenous pathway of coagulation. Moreover, the polyphenolic extract of ‘Roudane’ variety presented a substantial increase in coagulation. Based on these preliminary results, it can be suggested that the fig polyphenolic extracts (FPE) of this varieties have anticoagulant activity that could be useful in preventing blood clots.

Palabras clave

  • Anticoagulant
  • polyphenols
  • quick time
  • .L
Acceso abierto

Optimization of the extraction parameters of Aloe Vera polyphenols and study of antioxidant and antifungal activities: application to molds isolated from durum wheat

Publicado en línea: 27 May 2019
Páginas: 79 - 90

Resumen

Abstract

The main objectives of this work are to optimize the extraction parameters, to test the antioxidant activity of Aloe Vera extract and to study the impact of this extract on deteriorating molds of Algerian variety of wheat (CIRTA). The extraction was optimized by central composite design. Determination of the polyphenols, flavonoids, and proanthocyanidins was performed by using colorimetric assays. Identification and quantification of phenolic compounds were performed by RPHPLC-UV method. The antioxidant activity was tested by three methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,20-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and CUPRAC (Cupric reducing antioxidant capacity), the antifungal activity of Aloe Vera extract on isolated strains from durum wheat were tested by dilution in a solid medium method. The optimum of total phenolic got was1,044 x 104 µg GAE/g of dry extract. The extract is rich in polyphenols, flavonoids, and proanthocyanidins. The analysis of phenolic compounds of Aloe Vera by RP-HPLC-UV revealed seven phenolic compounds. Strong antioxidant activity was obtained for Aloe Vera extract. Purification and microscopic study of isolated strains gave the possibility of identifying four strains: Alternaria spp1, Alternaria spp2, Penicillium spp, and Aspergillus spp. the antifungal potential of Aloe Veravaries according to the fungal genera and the concentrations of extract used.

Palabras clave

  • Optimization
  • Polyphenols
  • Antioxidant activity
  • Antifungal activity
  • Mold
  • wheat
Acceso abierto

Experimental setup for light-to-heat NIR conversion measurements of gold nanoparticle solutions

Publicado en línea: 27 May 2019
Páginas: 91 - 99

Resumen

Abstract

In recent years, there is a constantly increasing interest in the application of nanoparticles for cancer diagnosis and cancer therapy. In this respect, the most promising nano-objects at present are the gold nanoparticles. A very convenient and powerful property of these objects is their ability to increase their temperature under electro-magnetic irradiation with certain wavelength. In our research we have directed our efforts toward particular nano-objects specifically sensitive to electromagnetic radiation in the near-infrared region (NIR). In order to study the photothermic properties of the solutions of gold nanoparticles in the NIR we constructed a specific electronic setup consisting of a laser system with interchangeable laser diodes with different wavelength NIR light, a thermally-insulated cuvette-holder compartment with temperature measuring probes and a NIR spectrometer to control the stimulated fluorescence emission of the nanoparticle solutions. The temperature measurement compartment with the thermal-insulated cuvette holder was designed to maintain the solutions’ temperature at a fixed value right before the moment of laser irradiation. To maintain the measurement setup at a fixed temperature before the irradiation we used a thermal stabilized system based on two Peltier cells with electronic temperature control. The temperatures of the ambient air and the temperature of the cuvette walls were continuously measured in order to make corrections about the temperature dissipation during the irradiation.

Palabras clave

  • light-to-heat conversion
  • gold nano-rods
  • gold nano-urchins
  • Peltier cell
  • Near Infrared measurements

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