The aqueous extract of leaf (LE), fruit (FE) and seed (SE) of Moringa oleifera was assessed to examine the ability to inhibit the oxidative DNA damage, antioxidant and anti-quorum sensing (QS) ...potentials. It was found that these extracts could significantly inhibit the OH-dependent damage of pUC18 plasmid DNA and also inhibit synergistically with trolox, with an activity sequence of LE>FE>SE. HPLC and MS/MS analysis was carried out, which showed the presence of gallic acid, chlorogenic acid, ellagic acid, ferulic acid, kaempferol, quercetin and vanillin. The LE was with comparatively higher total phenolics content (105.04mg gallic acid equivalents (GAE)/g), total flavonoids content (31.28mg quercetin equivalents (QE)/g), and ascorbic acid content (106.95mg/100g) and showed better antioxidant activity (85.77%), anti-radical power (74.3), reducing power (1.1 ascorbic acid equivalents (ASE)/ml), inhibition of lipid peroxidation, protein oxidation, OH-induced deoxyribose degradation, and scavenging power of superoxide anion and nitric oxide radicals than did the FE, SE and standard α-tocopherol. Eventually, LE and FE were found to inhibit violacein production, a QS-regulated behavior in Chromobacterium violaceum 12472.
In order to determine antioxidant activity, the five extracts/fractions of red onion peel were studied for their total content of phenolics (TPC), flavonoids (TFC), antioxidant activity (AOA), free ...radical scavenging activity (FRSA), assayed by DPPH radical in the terms of anti-radical power (ARP) and reducing power (RP), expressed as ascorbic acid equivalents (ASE)/ml. High TPC (384.7±5.0mg GAE/g), TFC (165.2±3.2mg QE/g), AOA (97.4±7.6%), ARP (75.3±4.5) and RP (1.6±0.3 ASE/ml) were found for the ethyl acetate (EA) fraction. EA fraction had markedly higher antioxidant capacity than butylated hydroxytoluene (BHT) in preventive or scavenging capacities against FeCl3-induced lipid peroxidation, protein fragmentation, hydroxyl (site-specific and non-site-specific), superoxide anion and nitric oxide radicals. EA fraction also showed dose dependent antimutagenic activity by following the inhibition of tobacco-induced mutagenicity in Salmonella typhimurium strains (TA102) and hydroxyl radical-induced nicking in plasmid pUC18 DNA. HPLC and MS/MS analysis showed the presence of ferulic, gallic, protocatechuic acids, quercetin and kaempferol. The large amount of polyphenols contained in EA fraction may cause its strong antioxidant and antimutagenic properties. This information shows that EA fraction of red onion peel can be used as natural antioxidant in nutraceutical preparations.
Since last century, peptides have emerged as potential drugs with >90 FDA approvals for various targets with several in the pipeline. Sulphur, in peptides is present either as thiol (-SH) from Cys or ...thioether from Met. In this review, all the peptides approved by FDA since 2000 containing sulphur have been included. Among them ∼50 % contains disulphide bridges. This clearly demonstrates the significance of disulphide bonds in peptide drugs. This can be achieved synthetically by using orthogonal protecting groups (PGs) for –SH. These PGs are compatible with Solid Phase Peptide Synthesis (SPPS), which is still the method of choice for peptide synthesis. The orthogonal PGs used for Cys thiol side chain protecting for disulphide bond formation have been included which are currently in use both by academia and industry from small scale to large scale synthesis. In addition, the details of the FDA approved drugs containing Cys and Met (or both) have also been discussed.
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•50 % of FDA approved peptides containing sulphur.•Total 26 peptide drugs have been approved since 2000 which contains sulphur as disulphide, thioether and thiophene.•Toolkit of cysteine orthogonal protecting groups used in Peptide Synthesis.•ADCs bioconjugation with linker is via thiol which comes from Cys of antibody.
The NIR (near-infrared) persistent phosphor, LiGa
5
O
8
:Cr
3+
(LGO:Cr), is a suitable candidate for bioimaging applications. Understanding the trap characteristics of the LGO:Cr persistent phosphors ...could enhance their properties. LGO:Cr can be prepared by two different methods: solid-state reaction and sol–gel. In this work, thermoluminescence (TL) analysis of LGO:Cr prepared by the two methods has been performed, revealing that the mode of preparation and irradiation energy play a vital role in using this phosphor. TL analysis found that, for in vivo imaging, LGO:Cr prepared using solid-state synthesis and irradiated with UV rays is better than the LGO:Cr prepared using sol–gel. However, LGO:Cr prepared using sol–gel is better for dosimetry than LGO:Cr prepared using solid-state synthesis provided it has stable fading and a linear dose response. Computerized glow curve deconvolution (CGCD) was performed using a temperature-dependent frequency factor equation. The results showed that the TL curve of LGO:Cr can be described using 13 TL peaks. The activation energy of the trap ranges from 0.6 eV to 1.44 eV, the fraction of empty traps that take part in the retrapping process is about 0.001–0.216, the temperature-dependent frequency factor ranges from 36,000 to 39,300 s
−1
°K
−2
, and the capture cross-section varies from
2.157
z
.
10
-
17
t
o
8.789
z
.
10
-
18
, where
z
is the ratio of effective mass to the remaining mass of the electron.
The antioxidant and anti-quorum sensing activities of eight extracts were studied in green pods of
Acacia nilotica. The specific phenolic compositions and their quantifications were performed by HPLC ...and MS/MS, which showed that the HEF (pH 4) was higher in gallic acid, ellagic acid, epicatechin, rutin, and GTs. In order to find antioxidant potential of various extracts, their activities were studied for TPC, AOA, FRSA, RP, inhibition of LPO, FIC activity, HO
and
O
2
-
scavenging activities. Among them HEF (pH 4) has shown potent antioxidant activity. HEF (pH 4) was also found effective in protecting plasmid DNA and HAS protein oxidation induced by HO
. Pre-treatment of HEF (pH 4) at 75 and 150
mg/kg body weight for 6 days caused a significant increase in the levels of CAT and SOD and decrease in the level of MDA content in liver, lungs, kidneys and blood when compared to CCl
4-intoxicated rats. Eventually, the extracts were also screened for anti-QS activity. Of these extracts two showed QS inhibition: HEF (pH 4) and HCE. The results obtained strongly indicate that green pod of
A. nilotica are important source of natural antioxidants.
•Clarify common misconception regarding quasi-equilibrium condition.•Derive a temperature dependent frequency factor.•Derive a new TL equation based on probability theory which incorporate the ...temperature dependent frequency factor.
A new equation has been developed that bridges discrepancies between the theoretical model and the experimental setup. The validity of the quasi-equilibrium equation has been analyzed and it was found that quasi-equilibrium is valid but its use is incorrect. Again, the new equation incorporates the temperature-dependent frequency factor, thereby giving a physically realistic outlook to the new equation. The temperature-dependent frequency factor is given by s=σnHT2 where H=3.25×1021z. Simulations were performed to check the validity of the differential equation and its solution. From the comparison, it was found that the two curves are similar which suggest that the differential eqn and its solution are equal. Again a comparison of the temperature dependent and temperature independent eqn was performed and it was found that the two curve differ a lot.
•Theoretical concept of magnetism in dilute magnetic semiconductors (DMS).•Doping of II-VI class of DMS materials with transition metals.•Doping of III-V class of DMS with rare earth metals.•DMS ...based light emitting diodes (LEDs) and information storage devices.•DMS based high efficiency solar cells.
While there are immense possibilities from integration of electric and magnetic properties of materials in magnetic semiconductors, fine tuning the synthesis processes for the fabrication of magnetic materials that can exhibit magnetism even at high temperatures have been of particular interest and has also been a significant challenge for dilute magnetic semiconductors (DMS) synthesis. A brief overview of the different types of DMS materials available and the mechanism of their operation have been discussed in this review article. Furthermore, some important applications arising out of the novel and exciting properties of the DMS materials have also been discussed.
Pure and doped iron oxide and hydroxide nanoparticles are highly potential materials for biological, environment, energy and other technological applications. On demand of the applications, single ...phase as well as multiple phase of different polymorphs or composites of iron oxides with compatible materials for example, zeolite, SiO
2
, or Au are prepared. The properties of the as-synthesized nanoparticles are predominantly dictated by the local structure and the distribution of the cations. Mössbauer spectroscopy is a perfect and efficient characterization technique to investigate the local structure of the Mössbauer-active element such as Fe, Au, and Sn. In the present review, the local structure transformation on the optimization of the magnetite coexisted with iron hydroxides, spin dynamics of the bare, caped, core–shell and the composites of iron oxide nanoparticles (IONPs), dipole–dipole interactions and the diffusion of IONPs were discussed, based on the findings using Mössbauer spectroscopy.
Graphical abstract