scholarly journals Recovery of pure C-phycoerythrin from a limestone drought tolerant cyanobacterium Nostoc sp. and evaluation of its biological activity

2020 ◽  
pp. 115-128
Author(s):  
Bahareh Nowruzi ◽  
Hossein Fahimi ◽  
Adriana Sturion Lorenzi
Keyword(s):  
Biological Activity ◽  
Antifungal Agents ◽  
Extreme Environments ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Biotechnological Applications ◽  
Drought Tolerant ◽  
Drought Conditions ◽  
Antibacterial And Antifungal ◽  
First Time

Se realizó la caracterización de ficoeritrina de la cepa A5 de Nostoc sp., seguida de investigación de su actividad biológica para aplicaciones biotecnológicas. Para la extracción de ficoeritrina, el uso de tampón acetato (pH 5.1) produjo 65.04 µg mL-1, y se identificó como C-ficoeritrina. Los resultados de su actividad antioxidante sugirieron su acción como un potente eliminador de radicales libres. Además, la C-ficoeritrina de Nostoc mostró una capacidad notable como agente antibacteriano y antifúngico, con estabilidad significativa de hasta 10 días. La glucosa (4 mg mL-1) fue un buen conservante para la C-ficoeritrina a 25 y 4 ºC. Se obtuvo por primera vez una C-ficoeritrina estable de Nostoc sp. en condiciones de sequía en piedra caliza, lo que demuestra la necesidad de estudiar microorganismos de ambientes extremos. The phycoerythrin characterization from Nostoc sp. strain A5 was done, followed by investigation of its biological activity for biotechnological applications. For phycoerythrin extraction, the use of acetate buffer (pH 5.1) resulted in 65.04 µg mL-1, and C-phycoerythrin was identified. Results of its antioxidant activity suggested action as a potent free radical scavenger. In addition, Nostoc's C-phycoerythrin showed noteworthy ability for antibacterial and antifungal agents with significant stability up to 10 days. Glucose (4 mg mL-1) was a good preservative for C-phycoerythrin at 25 and 4 ºC. A stable C-phycoerythrin from Nostoc sp. was obtained for the first time from limestone drought conditions, showing the need of studying microorganisms from extreme environments.

scholarly journals Hydroxyl radical induced structural changes of collagen

2007 ◽  
Vol 21 (2) ◽  
pp. 91-103 ◽  
Author(s):  
Helan Xiao ◽  
Guoping Cai ◽  
Mingyao Liu
Keyword(s):  
Free Radical ◽  
Hydroxyl Radicals ◽  
Structural Changes ◽  
Type I Collagen ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Type I ◽  
Dependent Manner ◽  
First Time

Extracellular matrix (ECM) plays an important role in cell differentiation, growth, migration and apoptosis. Collagen is the most abundant protein familyin vivo, but its function has still not been clearly defined yet. Reactive oxygen species (ROS) have a central role in oxidative cell stress. Electron spin resonance (ESR) spectroscopy indicates that type I collagen could uniquely scavenge hydroxyl radicals in dose- and time-dependent manner; whereas BSA and gelatin (a denatured collagen) have no such an effect. However, the mechanism by which type I collagen scavenges hydroxyl radicals is different from that of GSH, a well-known free radical scavenger. Using a new method, two-dimensional FTIR correlation analysis, for the first time, we show that the order of functional group changes of type I collagen in this process is amide I earlier than amide II than amide III than –CH– thanν(C=O). The results indicates that the structure of the main chain of collagen changed first, followed by more residue groupν(C=O) exposed to hydroxyl radicals. The reaction with the carbonyl group in collagen causes the hydroxyl free radicals to be scavenged. Therefore, ECM can effectively scavenge ROS under normal physiological conditions. When the proteins of ECM were denatured in the same way as gelatin, they lost their function as a free radical scavenger. All of these results provide new insight into therapy or prevention of oxidative stress, apoptosis and ageing.

scholarly journals Screening for Genes Coding for Putative Antitumor Compounds, Antimicrobial and Enzymatic Activities from Haloalkalitolerant and Haloalkaliphilic Bacteria Strains of Algerian Sahara Soils

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Okba Selama ◽  
Gregory C. A. Amos ◽  
Zahia Djenane ◽  
Chiara Borsetto ◽  
Rabah Forar Laidi ◽  
...  
Keyword(s):  
Extreme Environments ◽  
Extreme Environment ◽  
Antibacterial And Antifungal Activities ◽  
Algerian Sahara ◽  
Antitumor Compounds ◽  
Haloalkaliphilic Bacteria ◽  
Novel Bacteria ◽  
Antibacterial And Antifungal ◽  
First Time ◽  
Bacterial Groups

Extreme environments may often contain unusual bacterial groups whose physiology is distinct from those of normal environments. To satisfy the need for new bioactive pharmaceuticals compounds and enzymes, we report here the isolation of novel bacteria from an extreme environment. Thirteen selected haloalkalitolerant and haloalkaliphilic bacteria were isolated from Algerian Sahara Desert soils. These isolates were screened for the presence of genes coding for putative antitumor compounds using PCR based methods. Enzymatic, antibacterial, and antifungal activities were determined by using cultural dependant methods. Several of these isolates are typical of desert and alkaline saline soils, but, in addition, we report for the first time the presence of a potential new member of the genusNocardiawith particular activity against the yeastSaccharomyces cerevisiae. In addition to their haloalkali character, the presence of genes coding for putative antitumor compounds, combined with the antimicrobial activity against a broad range of indicator strains and their enzymatic potential, makes them suitable for biotechnology applications.

scholarly journals Novel Synthesis and Characterization of Thiosemicarbazone Compounds Containing 4-Acyl-2-pyrazolin-5-ones

2009 ◽  
Vol 6 (3) ◽  
pp. 747-752 ◽  
Author(s):  
Arjun K. Rana ◽  
Nayan R. Parekh ◽  
Harish R. Dabhi ◽  
Sunil S. Nadkarni
Keyword(s):  
Free Radical Scavenger ◽  
Synthesis And Characterization ◽  
Radical Scavenger ◽  
Antibacterial And Antifungal Activity ◽  
X Ray ◽  
H Nmr ◽  
Novel Synthesis ◽  
Antibacterial And Antifungal ◽  
C Nmr

A novel synthesis of 4-acylthiosemicarbazone-3-methyl-1-(4`-methylphenyl)-2-pyrazolin-5-one by condensation of 4-acyl-3-methyl-1-(4`-methylphenyl)-2-pyrazolin-5-one with thiosemicarbazide is carried out. The compounds were characterized on the basis of elemental analysis, IR,1H NMR, Mass, DSC and13C NMR spectral data. The structures were investigated for their antibacterial and antifungal activity. They are very essential to study on cerebral infarction (Free radical scavenger). A single crystal X-ray study of this thiosemicarbazones and their metal complexes is in progress.

Melatonin reduces high levels of lipid peroxidation induced by potassium iodate in porcine thyroid

2019 ◽  
pp. 1-7 ◽  
Author(s):  
Paulina Iwan ◽  
Jan Stepniak ◽  
Malgorzata Karbownik-Lewinska
Keyword(s):  
Lipid Peroxidation ◽  
Oxidative Damage ◽  
Membrane Lipids ◽  
Chemical Properties ◽  
Iodine Concentration ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Protective Effects ◽  
Potassium Iodate ◽  
Hormone Synthesis

Abstract. Iodine is essential for thyroid hormone synthesis. Under normal iodine supply, calculated physiological iodine concentration in the thyroid is approx. 9 mM. Either potassium iodide (KI) or potassium iodate (KIO3) are used in iodine prophylaxis. KI is confirmed as absolutely safe. KIO3 possesses chemical properties suggesting its potential toxicity. Melatonin (N-acetyl-5-methoxytryptamine) is an effective antioxidant and free radical scavenger. Study aims: to evaluate potential protective effects of melatonin against oxidative damage to membrane lipids (lipid peroxidation, LPO) induced by KI or KIO3 in porcine thyroid. Homogenates of twenty four (24) thyroids were incubated in presence of either KI or KIO3 without/with melatonin (5 mM). As melatonin was not effective against KI-induced LPO, in the next step only KIO3 was used. Homogenates were incubated in presence of KIO3 (200; 100; 50; 25; 20; 15; 10; 7.5; 5.0; 2.5; 1.25 mM) without/with melatonin or 17ß-estradiol. Five experiments were performed with different concentrations of melatonin (5.0; 2.5; 1.25; 1.0; 0.625 mM) and one with 17ß-estradiol (1.0 mM). Malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) concentration (LPO index) was measured spectrophotometrically. KIO3 increased LPO with the strongest damaging effect (MDA + 4-HDA level: ≈1.28 nmol/mg protein, p < 0.05) revealed at concentrations of around 15 mM, thus corresponding to physiological iodine concentrations in the thyroid. Melatonin reduced LPO (MDA + 4-HDA levels: from ≈0.97 to ≈0,76 and from ≈0,64 to ≈0,49 nmol/mg protein, p < 0.05) induced by KIO3 at concentrations of 10 mM or 7.5 mM. Conclusion: Melatonin can reduce very strong oxidative damage to membrane lipids caused by KIO3 used in doses resulting in physiological iodine concentrations in the thyroid.

OPTIMASI KONDISI EKSTRAKSI SENYAWA AKTIF ANTIOKSIDAN DARI BIJI ANGGUR

2019 ◽  
Vol 3 (2) ◽  
pp. 35
Author(s):  
Kartini Kartini ◽  
Azminah Azminah
Keyword(s):  
Free Radical ◽  
Optimum Condition ◽  
Active Compound ◽  
Grape Seed ◽  
Free Radical Scavenger ◽  
Water Bath ◽  
Radical Scavenger ◽  
Optimum Conditions ◽  
Ethanolic Solution ◽  
Reduced Pressure

In order to prepare standardized extract, optimization of extraction conditions of grape seed has been done. These conditions are type of menstrum (50, 70 and 96% of ethanolic solution), length of extraction (1, 2 and 4 hours) also method of evaporation (reduced pressure and opened air). Activity on free radical scavenger used as parameters to determine optimum conditions. Based on EC50 (concentration which scavenge 50% amount of free radical) can be concluded that optimum condition for extracting antioxidant active compound from grape seed are 70% ethanolic solution as menstrum, length of extraction 1 hour and evaporation on opened air use water bath.

The Pattern of Acetylation Defines the Priming Activity of Chitosan Tetramers

2019 ◽  
Author(s):  
Sven Basa ◽  
Malathi Nampally ◽  
Talita Honorato ◽  
Subha Narayan Das ◽  
Appa Rao Podile ◽  
...  
Keyword(s):  
Biological Activity ◽  
Degree Of Polymerization ◽  
Chitosan Oligosaccharides ◽  
Degree Of Acetylation ◽  
Bona Fide ◽  
First Time ◽  
Priming Activity

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of <i>β</i>-1,4-linked glucosamine (deacetylated/D) and <i>N</i>-acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially-acetylated chitosan oligosaccharides from a chitosan polymer (DA=35%, DP<sub>w</sub>=905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities. The mixtures were separated into fractions DP4–DP12, which were tested for elicitor and priming activities in rice cells. We confirmed that both activities were influenced by DP, <a>but also observed apparent DA-dependent priming activity, with the ADDD+DADD fraction proving remarkably effective</a>. We then compared all four mono-acetylated tetramers prepared using different chitin deacetylases and observed significant differences in priming activity. This demonstrates for the first time that PA influences the biological activity of chitosans, which can now be recognized as <i>bona fide</i> information-carrying molecules

The Pattern of Acetylation Defines the Priming Activity of Chitosan Tetramers

2019 ◽  
Author(s):  
Sven Basa ◽  
Malathi Nampally ◽  
Talita Honorato ◽  
Subha Narayan Das ◽  
Appa Rao Podile ◽  
...  
Keyword(s):  
Biological Activity ◽  
Degree Of Polymerization ◽  
Chitosan Oligosaccharides ◽  
Degree Of Acetylation ◽  
Bona Fide ◽  
First Time ◽  
Priming Activity

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of <i>β</i>-1,4-linked glucosamine (deacetylated/D) and <i>N</i>-acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially-acetylated chitosan oligosaccharides from a chitosan polymer (DA=35%, DP<sub>w</sub>=905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities. The mixtures were separated into fractions DP4–DP12, which were tested for elicitor and priming activities in rice cells. We confirmed that both activities were influenced by DP, <a>but also observed apparent DA-dependent priming activity, with the ADDD+DADD fraction proving remarkably effective</a>. We then compared all four mono-acetylated tetramers prepared using different chitin deacetylases and observed significant differences in priming activity. This demonstrates for the first time that PA influences the biological activity of chitosans, which can now be recognized as <i>bona fide</i> information-carrying molecules

Strategies for Oral Delivery of Metal-Saturated Lactoferrin

2019 ◽  
Vol 20 (11) ◽  
pp. 1046-1051 ◽  
Author(s):  
Przemysław Gajda-Morszewski ◽  
Klaudyna Śpiewak-Wojtyła ◽  
Maria Oszajca ◽  
Małgorzata Brindell
Keyword(s):  
Biological Activity ◽  
Oral Delivery ◽  
Therapeutic Potential ◽  
Structure And Function ◽  
The Difference ◽  
And Function ◽  
First Time

Lactoferrin was isolated and purified for the first time over 50-years ago. Since then, extensive studies on the structure and function of this protein have been performed and the research is still being continued. In this mini-review we focus on presenting recent scientific efforts towards the elucidation of the role and therapeutic potential of lactoferrin saturated with iron(III) or manganese(III) ions. The difference in biological activity of metal-saturated lactoferrin vs. the unmetalated one is emphasized. The strategies for oral delivery of lactoferrin, are also reviewed, with particular attention to the metalated protein.

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