scholarly journals Halomonas Venusta Mediated Detoxification and Biotransformation of Selenite Into Selenium Nanoparticles Exhibiting Various Biomedical Applications

2020 ◽  
Author(s):  
Diviya Chandrakant Vaigankar ◽  
Santosh Kumar Dubey ◽  
Sajiya Yusuf Mujawar ◽  
Ajeet Kumar Mohanty
Keyword(s):  
Free Radical ◽  
Anthropogenic Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Radical Scavenger ◽  
Rrna Gene ◽  
Bacterial Cells ◽  
Human Pathogens ◽  
X Ray ◽  
Mandovi Estuary

Abstract Marine environment is in constant threat due to anthropogenic activities which are involved in disturbing the aquatic flora and fauna due to accumulation of toxic metals and metalloids. The current study involves the use of microbial remediation strategy for reduction of toxic sodium selenite (Na2SeO3) into less toxic elemental Se (Se0) with concurrent synthesis of Se nanoparticles (SeNPs) possessing several biomedical potential. Selenite reducing bacterial strain isolated from Mandovi estuary of Goa, India was identified as Halomonas venusta based on 16S rRNA gene sequence analysis and designated as strain GUSDM4. It's maximum tolerance level for Na2SeO3 was 100 mM. The 2, 3-diaminonaphthalene based spectroscopic analysis clearly demonstrated 93% reduction of 4 mM Na2SeO3 to Se0 during late stationary growth phase of Halomonas venusta. Biosynthesis of SeNPs commenced within 4 h during log phase which was clearly evident from red colour in the growth medium and a characteristic peak at 265 nm revealed by UV-Vis spectrophotometry. The intracellular synthesis of SeNPs was confirmed by transmission electron microscopy (TEM) of these bacterial cells. Characterization of SeNPs by X-ray crystallography, TEM and energy dispersive X-ray analysis clearly demonstrated spherical SeNPs of 20-80 nm diameter with hexagonal crystal lattice. These SeNPs at 50 µg/mL exhibited 90% free radical scavenging activity and also demonstrated anti-biofilm activity at 20 µg/mL against common human pathogens which was evident by SEM analysis. These SeNPs interestingly revealed excellent dose-dependent and selective anti-proliferative activity against A549 cancer cell line and mosquito larvicidal activity against Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi. Therefore, these studies have demonstrated amazing potential of marine bacterium, Halomonas venusta in bioremediation along with biosynthesis of SeNPs and their applications as free radical scavenger, anti-biofilm, chemo-therapeutic and larvicidal agents which is the first report of its kind.

scholarly journals Bergenin Content and Free Radical Scavenging Activity of Bergenia Extracts

2015 ◽  
Vol 10 (7) ◽  
pp. 1934578X1501000
Author(s):  
Helena Hendrychová ◽  
Jan Martin ◽  
Lenka Tůmová ◽  
Nina Kočevar-Glavač
Keyword(s):  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hplc Method ◽  
Free Radical Scavenging ◽  
Free Radical Scavenging Activity ◽  
Free Radical Scavengers ◽  
Radical Scavenger ◽  
Scavenging Activity ◽  
Different Seasons

Our research was focused on the evaluation of bergenin content and free radical scavenging activity of extracts prepared from three different species of Bergenia - B. crassifolia (L.) Fritsch., B. ciliata (Haw.) Sternb. and B. x ornata Stein. collected during different seasons. Using an HPLC method, the highest total amount of bergenin was revealed in the leaves of B. x ornata and B. crassifolia (4.9 - 5.1 mg.g−1). Free radical scavenging power was determined by two methods - FRAP and NADH. The best free radical scavengers were B. crassifolia (FRAP: 6.7 - 15.9 mg GAE.100g−1; NADH: 20.3 - 50.9%) and B. ornata (FRAP: 13.7 - 15.2 mg GAE.100g−1; NADH: 29.3 - 31.1%). The lowest content of bergenin and the weakest radical scavenger was B. ciliata (bergenin: 3.1 mg.g−1; FRAP: 5.5 - 11.0 mg GAE.100g−1; NADH: 23.2 - 25.6%). The presence of a large percentage of bergenin is responsible for the radical scavenging activity, as shown by the results from the FRAP and NADH assays. Significant, positive correlation was found between bergenin content and radical scavenging activity in both methods.

DPPH Free Radical Scavenger Components from the Fruits of Alpinia rafflesiana Wall. ex. Bak. (Zingiberaceae)

2004 ◽  
Vol 59 (11-12) ◽  
pp. 811-815 ◽  
Author(s):  
Habsah Mohamad ◽  
Faridah Abas ◽  
Dharma Permana ◽  
Nordin H. Lajis ◽  
Abdul Manaf Ali ◽  
...  
Keyword(s):  
Free Radical ◽  
Methanol Extract ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Scavenging Activity ◽  
Colorimetric Analysis ◽  
Natural Sources

The methanol extract of the dried ripe fruits of Alpinia rafflesiana was investigated for its DPPH free radical scavenger constituents. 2′,3′,4′,6′-Tetrahydroxychalcone (7), which has never been isolated from natural sources was found to be most active as a DPPH free radical scavenger with the IC50 value of 55 μᴍ. Other known compounds isolated from this species include 5,6-dehydrokawain (1), flavokawin B (2), 1,7-diphenyl-5-hydroxy-6-hepten-3-one (3), (-)-pinocembrin (4), cardamonin (5) and (-)-pinostrobin (6). The DPPH free radical scavenger compounds were detected using TLC autographic analysis. The percentage inhibition of DPPH free radical scavenging activity was measured on isolates (5-7) using colorimetric analysis.

scholarly journals Ilex khasiana - The silent holly species of Aquifoliaceae on its pharmacognostical importance as a free radical scavenger and antibacterial agent

2020 ◽  
Vol 11 (2) ◽  
pp. 2438-2444
Author(s):  
Charles Lalnunfela ◽  
Lalremsanga H.T. ◽  
Lalhriatpuii T.C. ◽  
Lalthanpuii P.B. ◽  
Kholhring Lalchhandama
Keyword(s):  
Free Radical ◽  
Medicinal Plant ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Northeast India ◽  
Free Radical Scavenger ◽  
Butylated Hydroxytoluene ◽  
Radical Scavenger ◽  
Endangered Medicinal Plant ◽  
Rare And Endangered

Ilex khasiana is a rare and endangered medicinal plant endemic to northeast India. Remaining largely unexplored,it is purported to have a range of medicinal values and may soon join the medicinal plant hall of fame.Extracts of the leaves were prepared using solvents of increasing polarity, namelypetroleum ether (IKP), chloroform (IKC) and methanol (IKM).The preliminary phytochemical screening indicated the presence of alkaloids, phytosterols, triterpenoids, saponins, reducing sugars, glycosides and carbohydrates. Free radical-scavenging activity was assessed using2,2-diphenyl-1-picrylhydrazyl(DPPH). IKC exhibited the highest activity with an IC50 of 17.22 ± 1.87, followed by IKM with an IC50 of 26.93 ± 5.14 and IKP with an IC50 of 37.16 ± 5.11. Butylated hydroxytoluene (BHT)was used as the standard DPPH scavenger and showed an IC50 of 8.31 ±0.72. IKM and IKC also showed positive antibacterial activity againstGram-negative bacteria such asEscherichia coli, Pseudomonas aeruginosa, andKlebsiella pneumoniae, and a Gram-positive bacteriaBacillus subtilis. IKP did not indicate any inhibition against the selected bacteria. Our findings substantiate the basis for further investigations on the medicinal potentials of the plant.  

Synthesis, antibacterial and free radical scavenging activity of some newer N-((10-nitro-1H-indolo [1, 2-c]quinazolin-12-yl)methylene)benzenamines

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
A. Dixit ◽  
D. Pathak ◽  
G.K. Sharma
Keyword(s):  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Free Radical Scavenging Activity ◽  
Diffusion Method ◽  
Radical Scavenger ◽  
Scavenging Activity ◽  
Dpph Method ◽  
Antibacterial Potential

AbstractPresent research is oriented on the synthesis of some novel 12-(N-arylmethaniminyl)indolo[1,2-c]quinazoline analogs (4b1-4b11) and their characterization by 1H NMR, 13C NMR, FTIR and mass spectrophotometry. Their free radical scavenging activity and antibacterial potential were also evaluated. Many derivatives have shown a marked free radical scavenging capacity in all the concentrations but specifically compounds 4b7, 4b8 and 4b11 have shown good antioxidant potential with an IC50 value of 25.18 μmol/L, 28.09 μmol/L ---amp--- 44.22 μmol/L, respectively (DPPH method) and 39.46 μmol/L, 44.47 μmol/L ---amp--- 35.61 μmol/L, respectively (H2O2 method). The antibacterial evaluation was carried out against B. subtilis and E. coli by agar well diffusion method and it revealed that all the compounds in the series were having marked antibacterial activity but compounds 4b9 and 4b11 have shown best antibacterial potential. Then, it was concluded that the derivatives which were containing substituted anilines (4-Nitro, 4-Fluoro, 4-Bromo ---amp--- 4-Chloro-2-nitro) on the carbon attached on the 12th position of indoloquinazoline moiety were having marked potential as an antibacterial and free radical scavenger.

Anti-inflammatory and Radical Scavenge Effects of Arctium lappa

1996 ◽  
Vol 24 (02) ◽  
pp. 127-137 ◽  
Author(s):  
Chun-Ching Lin ◽  
Jer-Min Lin ◽  
Jeng-Jer Yang ◽  
Shu-Chuan Chuang ◽  
Takashi Ujiie
Keyword(s):  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Radical Scavenger ◽  
Scavenging Activity ◽  
Paw Edema ◽  
Arctium Lappa ◽  
Radical Scavenger Activity ◽  
Scavenger Activity

The effects of Arctium lappa L. (root) on anti-inflammatory and free radical scavenger activity were investigated. Subcutaneous administration of A. lappa crude extract significantly decreased carrageenan-induced rat paw edema. When simultaneously treated with CCl4, it produced pronounced activities against CCl4-induced acute liver damage. The free radical scavenging activity of its crude extract was also examined by means of an electron spin resonance (ESR) spectrometer. The IC50 of A. lappa extract on superoxide and hydroxyl radical scavenger activity was 2.06 mg/m 11.8 mg/m1, respectively. These findings suggest that Arctium lappa possess free radical scavenging activity. The inhibitory effects on carrageenan-induced paw edema and CCl4-induced hepatotoxicity could be due to the scavenging effect of A. lappa.

Usnic Acid as a Potential Free Radical Scavenger and its Inhibitory Activity Toward SARS-CoV-2 Proteins

2021 ◽  
Vol 20 (06) ◽  
pp. 655-666
Author(s):  
Jelena Đorović Jovanović ◽  
Nedeljko Manojlović ◽  
Zoran Marković
Keyword(s):  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Usnic Acid ◽  
Hydrogen Atom Transfer ◽  
Free Radical Scavenging ◽  
Radical Scavenger ◽  
Radical Species ◽  
Free Radical Species ◽  
Antioxidative Action

The antioxidative activity and free radical scavenging potency of usnic acid towards eight selected free radical species are examined. The thermodynamic parameters in the absence of harmful free radicals are used to predict the most favorable mechanism of antioxidative action. The reaction enthalpies are used to define the most probable mechanism of free radical scavenging in the presence of free radical species. The obtained results indicate that the favorable mechanism of antiradical action is dependent both on the polarity of solvents and the nature of free radical species. From the achieved results, it is clear that Sequential Proton Loss Electron Transfer (SPLET) is the most probable for antioxidative action in water and methanol, while competition between SPLET and Hydrogen Atom Transfer (HAT) is presented in benzene. The free radical scavenging of eight free radical species under investigation is possible, and the most believable mechanism of action is SPLET, in all three investigated solvents. Since usnic acid exhibits significant radical scavenging activity that affects the maintenance of redox hemostasis, its inhibitory potency toward COVID-19 targeted proteins molecular docking study is performed. The obtained results indicate that usnic acid has the potential to inhibit the functional proteins of SARS-CoV-2.

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