Radical Scavenging Agents Research Articles

In vitro propagation of Ocimum sanctum L., Ocimum canum Sims., and Ocimum tenuiflorum L., and evaluation of antioxidant, MMP-9 down regulation of eugenol and camphor

• Eugenol and camphor could be suitable candidates for preventing diseases caused by oxidative stress and free radicals. • Eugenol and camphor are effective MMP-9 inhibitors under in vitro . • Cytokinins are most suitable for micropropagation. Medicinal plants have long been used as a source of drugs. Ocimum species contain a diverse range of distillate that are abundant in phenolics, as well as a variety of other organic ingredients such as phytoconstituents. The present study was undertaken to standardize the medium for shoot and callus induction using nodal and leaf explants of Ocimum sanctum, Ocimum canum and Ocimum tenuiflorum and to perform RAPD analysis for identification of somaclonal variants. To evaluate the free radical scavenging activity of eugenol and camphor and to test MMP-9 inhibition of eugenol and camphor using gelatin zymography. Zeatin (6.8 µM) was observed to be suitable for the induction of shoots among the cytokinins evaluated in Ocimum sanctum and Ocimum canum . BA (6.6 µM) was shown to be more effective for shoot induction in Ocimum tenuiflorum . Supplemented B5 medium with 2,4-D (6.7µM and 4.5 µM) and B5 medium supplemented with NAA (8.5 µM) were reported to be favorable for callus induction in Ocimum sanctum and Ocimum canum respectively. The polymorphism was discovered in in vitro produced plants of Ocimum sanctum, Ocimum canum , and Ocimum tenuiflorum using the primers OPK4 and OPK10. Antioxidant activity of eugenol and camphor has been evaluated using various in vitro antioxidant assays. This study clearly indicates that eugenol is a potent free radical scavenging agent when compared with camphor. Eugenol and camphor were used to alleviate inflammation caused by lipopolysaccharide-induced overexpression of matrix metalloproteinase-9. Both eugenol and camphor are effective MMP-9 inhibitors in vitro , according to the results of this investigation. RT-PCR analysis clearly indicates the down regulation of over expressed MMP-9.

Melanin-like Nanoparticles as an Alternative to Natural Melanin in Retinal Pigment Epithelium Cells and Their Therapeutic Effects against Age-Related Macular Degeneration.

Melanin is a natural pigment that is widely distributed in many parts of the human body, such as the skin and retinal pigment epithelium (RPE) in eyes. In contrast to skin melanin, which is being constantly synthesized by the epidermal melanocytes, melanin in the RPE does not regenerate. Melanin is known to function as a potential radical scavenger and photoprotective agent. However, the protective effects of melanin against oxidative stress decline with increasing age. This phenomenon has been correlated with the pathogenesis of age-related macular degeneration (AMD). To increase the potential antioxidant and photoprotective characteristics of melanin, we designed a therapeutic strategy for replenishment of melanin using PEGylated synthetic melanin-like nanoparticles (MNPs) in the RPE for the treatment of AMD. We performed experiments using AMD-like cellular and mouse models and demonstrated that MNPs are biocompatible and selectively target reactive oxygen species (ROS) with powerful antioxidant properties. MNPs can traffic and accumulate in the RPE and are exclusively located in cytosol, but not the nucleus and mitochondria of the cells, for at least 3 months after a single-dose intravitreal injection. Our findings demonstrate that MNPs are able to substitute for natural melanin in the RPE and suggest the potential efficacy of MNPs as a natural radical scavenger against oxidative stress in ROS-related diseases, such as AMD.

Free radical scavenging, antibacterial potentials and spectroscopic characterizations of benzoyl thiourea derivatives and their metal complexes

In this work, two series of benzoyl thiourea derivatives (TH01-TH05), (TH06-TH10) and their metal complexes were successfully synthesized in good yields (up to 90%) using efficient two-pot synthesis by reacting isothiocyanate with amines and amino acids. The FTIR, 1HNMR, 13CNMR and MALDI-TOF-MS were used for structural elucidation. The FTIR spectra of first series (TH01-TH05) displayed broad absorption band of -OH group at 3600-2800 cm−1 while for 2nd series (TH06-TH10) the absence of OH confirmed the synthesis. The 1HNMR spectra confirmed the synthesis of 1st series have shown singlet peak at 10 to 11.480 ppm for OH proton and two singlets for NH protons at 11.105 ppm and 10.790 ppm respectively. The 13CNMR confirmed synthesis of 1st series by appearance of peaks at 181.328 ppm for (C=S), 170.308 ppm and 168.680 ppm for two (C=O) and aromatic carbons at 133.56-128.954 ppm. The MALDI-TOF-MS results showed presence of molecular ion peaks at appropriate positions. Antimicrobial activity results showed that TH-01, TH-08 and TH-09 have promising antibacterial potential against K. pneumoniae (12 mm) and P. aeruginosa (16 mm and 14 mm) respectively. The DPPH radical scavenging activity of Co-TH05 showed more potential with IC50 value 11.4±0.2 µg/mL than standard ascorbic acid (IC50 10.8±0.5 µg/mL). Results confirmed that the synthesized thiourea derivatives can be efficiently used as radical scavenger and antimicrobial agents.

Aluminum oxide and ethylene bis(diphenylphosphine)‐incorporated poly(imide) separators for lithium‐ion batteries

AbstractAlthough poly(imide)‐based separators have received great attention as an alternative separator for lithium‐ion batteries, there are serious restrictions because their porous structures enable a great amount of current to leak internally. In this work, we report a one‐step coating process for the structures of poly(imide) (PI)‐based separators that effectively closes their pores. To close the large pores on a PI separator, nanosized aluminum oxide as a coating precursor and the free radical scavenging agent ethylene bis(diphenylphosphine) were co‐incorporated into the PI separator. Screening tests confirmed that ethylene bis(diphenylphosphine) (EPP) can effectively scavenge free radical species via chemical reaction and that incorporating Al2O3–EPP composites closed pores of the PI separators. Regarding electrochemical performance, the cell cycled with a PI separator that incorporated Al2O3–EPP exhibited stable cycling, while the cell cycled with a bare PI separator showed failure. These results indicate that incorporating Al2O3–EPP material effectively increases both safety and electrochemical performance. The Al2O3–EPP composites are incorporated onto the PI separator via dip‐coating process in order to improve electrochemical properties of PI separator. The cell cycled with the Al2O3–EPP incorporated PI separator exhibits stable cycling behavior because Al2O3–EPP composites effectively prevent internal short circuit in the cell.

Synthesis, characterization and antioxidant activity of new β-benzylselenated Schiff bases and their palladium complexes

Three new β-benzylselenated Schiff bases, (S)-L1H, (R)-L2H and (R)-L3H, were synthesized from three chiral β-benzylselenated amines, (S)-2a, (R)-2b and (R)-2c, respectively, on condensation with salicylaldehyde. The corresponding palladium complexes, (S)-1, (R)-2 and (R)-3, were synthesized by reactions of these ligands with Na2[PdCl4]. The ligands and their complexes were characterized by spectroscopic (1H, 13C{1H} NMR and FT-IR), polarimetric and elemental analysis. The crystal structure of (S)-1 was determined by single-crystal X-ray diffraction. The ligands bind palladium(II) as deprotonated ((S)-L1 , (R)-L2 and (R)-L3 ) tridentate (Se,N,O-) chelates resulting in complexes of composition [Pd(L1-3 )Cl]. All these compounds have been screened for in vitro DPPH radical scavenging activity using vitamin-C as a reference standard. The DPPH radical scavenging activity was assessed by varying the concentration of each of these compounds. The results of antioxidant activity studies demonstrated that these compounds are good-to-excellent radical scavenging agents. The antioxidant activity was quantitatively expressed as their IC50 values which revealed that the activity of palladium complexes were 50% higher than those of corresponding ligands and very close to that of the standard reference vitamin-C.

Highly Efficient Sulfur and Nitrogen Codoped Graphene Quantum Dots as a Metal-Free Green Photocatalyst for Photocatalysis and Fluorescent Ink Applications.

The demand for modern organic pollutant treatment has prompted the development of environmentally acceptable photocatalytic processes. In this work, we report novel nitrogen and sulfur codoped graphene quantum dot (S,N-GQD) based photocatalysts and fluorescent ink for the first time. For the degradation of organic dyes under visible irradiation, a hydrothermal technique was employed to generate S,N-GQD green nanomaterials. The synthesized samples were examined using XRD, HR-TEM, EDX, FT-IR, PL, and UV–vis spectroscopy. UV-DRS was used to determine the energy band gap of S,N-GQDs, and it was obtained to be around ∼2.54 eV. To explore the catalytic behavior of the produced S,N-GQDs as green nanomaterials, organic dyes (i.e., crystal violet and Alizarin yellow) have been used as a reference dye in this study. Using several radical scavenging agents, the photocatalytic mechanism was examined. This novel photocatalyst offers a promising alternative for the breakdown of organic pollutants. Moreover, these S,N-GQDs can also be used as fluorescent ink for imaging purposes and security reasons.

Mechanistic study on the radical scavenging activity of viniferins

As an important chemical component of grapes, viniferins are essential dimers of natural product resveratrol with good antioxidant activity. In this study, we have examined the antioxidant activity of two viniferin molecules (δ-viniferin and ε-viniferin) with ·OH/·OOH radicals. Density functional theory (DFT) calculations at the M062X/6–311++G(d,p)-SMD//M062X/6–311G(d,p) level of theory in the gas phase, water, and benzene used to examine two crucial radical scavenging pathways: hydrogen atom transfer (HAT) and the radical adduct formation (RAF). Then, the radical scavenging activities of the two molecules are compared kinetically and thermodynamically. The Gibbs free energy of activation (ΔG≠) and rate constant (kTST) are calculated using the conventional transition state theory (TST), and the results reveal that HAT and RAF processes compete in different solvents. Furthermore, molecular electrostatic potential (MEP) and frontier molecular orbital (FMO) of both the compounds are computed to elucidate their antioxidant activity. The results show that the RAF site appears at the >C7C8< double bond position of δ- and ε-viniferins, and the most favorable HAT positions of δ-viniferin and ε-viniferin are 12′-OH and 12-OH, respectively; in addition, ε-viniferin is a more potent radical scavenging agent than δ-viniferin. These findings provide useful insights on the antioxidant activity of viniferins and different radical scavenging mechanisms of antioxidants, which can be beneficial for improving the practical utilization of resveratrol dimer and other analogs.

Novel ternary metal oxide nanoparticles (La2Cu0.8Zn0.2O4) as a potential photocatalyst for visible light photocatalytic degradation of methylene blue and desulfurization of dibenzothiophene

In this work we present the preparation of novel ternary metal oxide nanoparticles, La2Cu0.8Zn0.2O4 (LCZO), using a simple co-precipitation method. The crystalline structure, morphology and composition of the prepared LCZO nanoparticles were characterized by x-ray diffraction, scanning electron microscopy and energy-dispersive x-ray analysis. The diffuse reflectance spectrum investigation showed that LCZO nanoparticles have considerable light absorption in the visible light region. Also, the LCZO nanoparticles possess a band-gap energy of 2.82 eV. To investigate the visible light photocatalytic potential of the prepared LCZO nanoparticles, two photocatalytic reactions were conducted, namely degradation of methylene blue (MB) solution and desulfurization of dibenzothiophene (DBT). In the presence of a 3:1 molar ratio of H2O2/DBT, a high photocatalytic desulfurization rate of DBT (93.7%) was obtained over 0.2 g of LCZO photocatalyst. In addition, the photocatalytic degradation rate of MB solution was 91.4%. The mechanisms of both photocatalytic reactions were studied using different radical scavenging agents, which showed that hydroxyl radicals are responsible for highly efficient desulfurization and degradation reactions. Moreover, reusability experiments reveal that the prepared LCZO photocatalyst has great stability and recyclability for both desulfurization of DBT and degradation of MB after six reaction cycles.

Facile green synthesis, characterization and visible light photocatalytic activity of MgFe2O4@CoCr2O4 magnetic nanocomposite

A new, facile, low-cost, and green sol–gel route for the synthesis of the MgFe2O4@CoCr2O4 magnetic nanocomposite is reported. The photocatalytic performances of the prepared magnetic nanocomposite was investigated for the degradation of organic dye under visible light irradiation. The synthesized magnetic photocatalyst depicted high degradation performance for Reactive Blue 222 dye under the optimized conditions. The nanocomposite dosage, initial dye concentration, dark and visible light, irradiation time, and reusability of photocatalysis had a notable influence on dye degradation performance. Fourier transforms infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM), UV–Vis diffuse reflectance spectroscopy (DRS), and elemental mapping (MAP) analysis were considered to thoroughly characterize the synthesized magnetic nanocomposite. The analysis confirmed that the MgFe2O4@CoCr2O4 had a spinel cubic structure, with a crystallite size of 11 nm, ferromagnetic activity, uniform spherical morphology, narrow bandgap, and spatial distribution of all elements that can be noticed as a merit of this method over other methods developed techniques. The fast and high-efficiency degradation for RB222 dye with 40 mg/L concentration under ambient conditions was 93% in only 10 min. Photodegradation mechanism of RB222 dye was specified in presence of radical scavenger agents and degradation pathway was verified by Gas chromatography–mass spectrometry (GC–MS) analysis. Furthermore, the as synthesized magnetic nanocomposite could be easily separated from the solution by an external magnet, structural integrity and stability of reused photocatalyst attested by FTIR, XRD, SEM, and EDX analysis and their photocatalysis performance was maintained even after four continuous runs in the same optimized condition.

The NO-dependent caspase signaling pathway is a target of deoxynivalenol in growth inhibition in vitro

DON is commonly found in foods and feeds; it presents health risks, especially an increase of growth inhibition in humans, particularly infants and young children. However, there are relatively few research studies devoted to the mechanism of DON-mediated growth retardation. Interestingly, our results showed that DON does not cause any significant production of ROS but results in a persistent and significant release of NO with iNOS increasing activity, mitochondrial ultrastructural changes and decreasing ΔΨm. Moreover, the significant decreases in GH production and secretion induced by DON were dose-dependent, accompanied by an increase of caspase 3, 8 and 9, IL-11, IL-lβ and GHRH. NO scavenging agent (haemoglobin) and free radical scavenging agent (N-acetylcysteine) partially reversed mitochondrial damage, and Z-VAD-FMK increased the levels of GH and decreased the levels of caspase 3, 8 and 9, while haemoglobin decreased the levels of caspase 3, 8 and 9, indicating that NO is the primary target of DON-mediated inhibition. Present research study firstly demonstrated that NO is a key mediator of DON-induced growth inhibition and plays critical roles in the interference of GH transcription and synthesis. The current research is conducive to future research on the molecular mechanisms of DON-induced growth inhibition in humans, especially children.

Secoiridoid dimers and their biogenetic precursors from the fruits of Cornus officinalis with potential therapeutic effects on type 2 diabetes

Cornusdiridoid A-F (1–6), six unusual cornuside-morroniside secoiridoid dimers, and their possible new biogenetic precursor, 3″,5″-dehydroxycornuside (7), together with four known secoiridoids (8–11), were obtained from the fruits of Cornus officinalis. Their structures were elucidated on the basis of various spectroscopic and chemical methods. A plausible biosynthetic pathway of compounds 1–11 was proposed. The α-glucosidase inhibitory, antioxidant and anti-inflammatory activities of these isolates were evaluated. Some of them emerged out as potent antidiabetic, anti-inflammatory and free radical scavenging agents. Molecular docking was also carried out for antidiabetic target α-glucosidase to investigate the possible binding modes of the most potent α-glucosidase inhibitor, vincosamide (9). These results revealed that the secoiridoids from C. officinalis fruits may be served as new potential antidiabetic agents to prevent and treat type 2 diabetes.

New Unnatural Gallotannins: A Way toward Green Antioxidants, Antimicrobials and Antibiofilm Agents.

Nature has been a source of inspiration for the development of new pharmaceutically active agents. A series of new unnatural gallotannins (GTs), derived from d-lyxose, d-ribose, l-rhamnose, d-mannose, and d-fructose have been designed and synthesized in order to study the protective and antimicrobial effects of synthetic polyphenols that are structurally related to plant-derived products. The structures of the new compounds were confirmed by various spectroscopic methods. Apart from spectral analysis, the antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging and iron reducing power (FRAP) assays. Antibacterial activity of compounds was tested in vitro against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212 (reference and control strains), three methicillin-resistant isolates of S. aureus, and three isolates of vancomycin-resistant E. faecalis. For screening of antimycobacterial effect, a virulent isolate of Mycobacterium tuberculosis and two non-tuberculous mycobacteria were used. Furthermore, antibiofilm activity of structurally different GTs against S. aureus, and their ability to inhibit sortase A, were inspected. Experimental data revealed that the studied GTs are excellent antioxidants and radical-scavenging agents. The compounds exhibited only a moderate antibacterial effect against Gram-positive pathogens S. aureus and E. faecalis and were practically inactive against mycobacteria. However, they were efficient inhibitors and disruptors of S. aureus biofilms in sub-MIC concentrations, and interacted with the quorum-sensing system in Chromobacterium violaceum. Overall, these findings suggest that synthetic GTs could be considered as promising candidates for pharmacological, biomedical, consumer products, and for food industry applications.

Trimesitylborane-embedded radical scavenging separator for lithium-ion batteries

Here, we propose a new strategy that employs a functional separator composed of radical scavenging agents for removal of radical species in the cell. In detail, a radical scavenger, trimesitylborane (TRMSB), is embedded on the surface of nano-sized tungsten oxide (WO3) by a simple one-step process and the resulting nanoparticles are coated onto conventional separators by a dip-coating process. Our screening test performed by chemical reaction of TRMSB with a radical indicator (2,2-diphenyl-1-picrylhydrazyl, DPPH) confirms that TRMSB effectively scavenges radical species via a chemical reaction, implying that the use of a WO3-TRMSB–functionalized separator would be effective for decreasing radical concentrations during electrochemical processes. In our electrochemical tests, the cell cycled with a WO3-TRMSB–functionalized separator exhibit showed both improved cycling retention compared to a cell cycled with a bare separator and improved physical and mechanical properties.

Abstract 928: Glypican-3 targeted thorium-227 alpha therapy reduces tumor burden in an orthotopic xenograft model of hepatocellular carcinoma

Abstract The purpose of this study is to develop a thorium-227 (227Th) antibody radioimmunoconjugate targeting glypican-3 (GPC3) and to test its therapeutic efficacy in a hepatocellular carcinoma (HCC) orthotopic xenograft model. GPC3 targeting antibody (αGPC3) was conjugated to bifunctional chelator p-SCN-Bn-H4octapa (octapa), and αGPC3-octapa binding affinity for GPC3 was evaluated by flow cytometry. 227Th radiolabeling of this conjugate was optimized, and in vitro stability of 227Th-αGPC3-octapa was evaluated in PBS with and without free radical scavenging agent over 14 days. For in vivo evaluation, an orthotopic xenograft model was generated by hepatic subcapsular injection of human HCC HepG2 cells. In vivo biodistribution was assessed in blood, tumor and organs at 1, 7 and 21 days after tail vein injection of 227Th-αGPC3-octapa (500 KBq/kg). To test therapeutic efficacy, tumor-bearing animals were injected with 227Th-αGPC3-octapa (250 kBq/kg or 500 kBq/kg) and compared to an irrelevant control antibody, 227Th-αBHV1-octapa (500 kBq/kg), and to a no-treatment control. Tumor burden was assessed with serial serum alpha-fetoprotein (AFP) measurements, a marker of tumor burden validated in this model. Toxicity to 227Th-αGPC3-octapa was measured by serum comprehensive metabolic panel obtained 21 days after injection. GPC3 binding affinity was highest after conjugation of αGPC3 with 10 equivalents of octapa. The protein recovery from the conjugation process was &amp;gt;85%, and mass spectral analysis indicated an average of 3.3 octapa moieties per molecule of αGPC3-octapa. After two weeks, &amp;gt;98% of αGPC3-octapa and αBHV1-octapa had 227Th bound in the presence of scavenging agent. αGPC3-octapa maintained high affinity for GPC3 as measured by flow cytometry, indicating the octapa conjugation reaction did not alter immunoreactivity of αGPC3. In vivo, 227Th-αGPC3-octapa accumulated in the tumor over time and cleared from normal tissues with a %ID/g of &amp;lt;5% by 21 days after injection. Significant antitumor activity was observed after treatment with 227Th-αGPC3-octapa (500 kBq/kg) with mean AFP level of 10,696 ± 19,754ng/mL compared to 308,175 ± 362,372ng/mL and 145,154 ± 166,780ng/mL in the 227Th-αBHV1-octapa and no-treatment control group, respectively. Reductions in serum AFP was observed in all but one tumor-bearing mouse after 500kBq/kg 227Th-αGPC3-octapa therapy. Organ-specific toxicity was not observed after treatment with 227Th-αGPC3-octapa (500 KBq/kg) compared to no-treatment control. In conclusion, we report the development of a GPC3 targeted thorium conjugate and demonstrate its in vivo therapeutic efficacy in a murine orthotopic xenograft model of hepatocellular carcinoma. Citation Format: Kevin P. Labadie, Donald K. Hamlin, Aimee Kenoyer, Sara K. Daniel, Alan F. Utria, Andrew D. Ludwig, Heidi L. Kenerson, Delphine L. Chen, Johnnie Orozco, Raymond S. Yeung, Lily Li, Chris Orvig, Yawen Li, D Scott Wilbur, James O. Park. Glypican-3 targeted thorium-227 alpha therapy reduces tumor burden in an orthotopic xenograft model of hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 928.

Determination of New IR and UV/VIS Spectroscopic Parameters of the C84-D2:22 Isomer for Its Quantitative Assessment, Identification and Possible Applications

The stable isomers of the higher fullerenes C76-D2 and C84-D2:22, as well as fullerenes C60 and C70 were isolated from carbon soot by the new and improved extraction and chromatographic methods and processes. Characterizations of the C84-D2:22 isomer in this study were performed by infrared and electronic absorption spectroscopy. All of the experimentally observed IR and UV/VIS bands were in excellent agreement with the semi-empirical, DFT and TB potential theoretical calculations for this molecule. The molar extinction coefficients and the integrated molar extinction coefficients of the observed larger number of completely separated infrared absorption maxima and shoulders of fullerene C84-D2:22, as well as of its main convoluted maxima, in different and new relevant entire integration ranges, including neighboring, and all surrounding absorption shoulders were determined and their relative intensities compared. In addition, the molar absorptivity of the electronic absorption bands of this carbon cluster was found. The new IR and UV/VIS spectroscopic parameters that are significant for the quantitative determination, identification and numerous possible applications of C84-D2:22 are obtained and their changes compared to C76-D2 observed. Isolated and characterized C84-D2:22, as well as other fullerenes from this research can be used in electronic, optical, chemical and biomedical devices, superconductors, semiconductors, batteries, catalysts, polymers, sensors, solar cells, nanophotonic lenses with better optical transmission, refraction and wettability, diagnostic and therapeutic pharmaceutical substances, such as those against diabetes, cancer, neurodegenerative disorders, free radical scavenging, radio nuclear, antibacterial and antiviral agents that can inhibit HIV 1, HSV, COVID-19, influenza, malaria and so forth.

Inhibition of hydrogen–oxygen/air gaseous detonations using CF3I, H2O, and CO2

The ignition of hydrogen-air mixtures can cause intense explosions. To ensure the safe utilization of hydrogen fuel and prevent catastrophic explosion accidents, the inhibiting effect of flame inhibitors must be understood since they have important consequences for hazard analyses. In the present study, the detonability of hydrogen mixtures diluted with CF3I, H2O, CO2, and N2 is investigated using numerical computations. The inhibiting effect of chemically active (CF3I, H2O, and CO2) and chemically inert (N2) diluents on the chemical length and time scales of a ZND detonation structure was studied using a detailed chemical kinetic mechanism for hydrogen oxidation. The inhibition efficiency of a halogenated compound, CF3I, towards quenching of hydrogen-air/oxygen gaseous detonations was also studied. As an additive, CF3I was found to promote detonation at lower concentrations. However, at higher concentrations, CF3I suppresses gaseous detonations by acting as a radical-scavenging agent. In the present study, a given retardant's effectiveness for suppressing a given detonation wave was evaluated for CF3I, H2O, CO2, and N2. The combined suppression effects of CF3I, H2O, and CO2 were also investigated. The efficacy of a composite inhibitor towards the quenching of a detonation wave was also evaluated and compared.

Biomedical Applications of Scutellaria edelbergii Rech. f.: In Vitro and In Vivo Approach.

In the current study, in vitro antimicrobial and antioxidant activities and in vivo anti-inflammatory and analgesic activities of Scutellaria edelbergii Rech. f. (crude extract and subfractions, i.e., n-hexane, ethyl acetate (EtOAc), chloroform, n-butanol (n-BuOH) and aqueous) were explored. Initially, extraction and fractionation of the selected medicinal plant were carried out, followed by phytochemical qualitative tests, which were mostly positive for all the extracts. EtOAc fraction possessed a significant amount of phenolic (79.2 ± 0.30 mg GAE/g) and flavonoid (84.0 ± 0.39 mg QE/g) content. The EtOAc fraction of S. edelbergii exhibited appreciable antibacterial activity against Gram-negative (Escherichia coli and Klebsiella pneumoniae) strains and significant zones of inhibition were observed against Gram-positive bacterial strains (Bacillus subtilis and Staphylococcus aureus). However, it was found inactive against Candida Albicans and Fusarium oxysporum fungal strains. The chloroform fraction was the most effective with an IC50 value of 172 and 74 µg/mL against DPPH (1,1-Diphenyl-2-picryl-hydrazyl) and ABTS assays, in comparison with standard ascorbic acid 59 and 63 µg/mL, respectively. Moreover, the EtOAc fraction displayed significant in vivo anti-inflammatory activity (54%) using carrageenan-induced assay and significant (55%) in vivo analgesic activity using acetic acid-induced writing assay. In addition, nine known compounds, ursolic acid (UA), ovaul (OV), oleanolic acid (OA), β-sitosterol (BS), micromeric acid (MA), taraxasterol acetate (TA), 5,3′,4′-trihydroxy-7-methoxy flavone (FL-1), 5,7,4′-trihydroxy-6,3′-dimiethoxyflavone (FL-2) and 7-methoxy catechin (FL-3), were isolated from methanolic extract of S. edelbergii. These constituents have never been obtained from this source. The structures of all the isolated constituents were elucidated by spectroscopic means. In conclusion, the EtOAc fraction and all other fractions of S. edelbergii, in general, displayed a significant role as antibacterial, free radical scavenger, anti-inflammatory and analgesic agents which may be due to the presence of these constituents and other flavonoids.

Physico-Chemical Properties, Fractionation and Antioxidant Activity of Some Essential Oils Utilized in Mayonnaise Preparation and Storage

Two types of essential oils (thyme and Stachys) were used in this Estimation. The chemical composition, antioxidant activity (by DPPH assay) and the rancimat method were used to assess the stability effect of these essential oils. The tested oils were added to mayonnaise to evaluate its capability for inhibition of secondary oxidation products. By DPPH assay, antioxidant activity showed that thyme essential oil was the best antioxidant agent as radical scavenging agents at 450 and 500 ppm concentrations, even better than BHT at the 200 ppm concentration. As a typical antioxidant, butylated hydroxytoluene was used for comparison. The mayonnaise samples prepared by adding thyme, stachys essential oils and TBHQ (control +) at concentrations of 200,400, 600 and 200 ppm into the sunflower oil free from antioxidant. At the amounts used in this study, thyme and stachys oils were significantly successful in reducing the oxidation of sunflower oil, especially, at 500 ppm which showed more efficient than BHT. Specifically, in the presence of thyme oil, the induction period of sunflower oil was considerably elongated. However, butylated hydroxytoluene (BHT) was more efficient than thyme and Stachys oils at the 200-ppm concentration against oxidation of oils. all concentrations of thyme and stachys essential oils had an antioxidant activity similar to synthetic antioxidant of TBHQ at a concentration of 200 ppm for inhibition of secondary oxidation products in mayonnaise in comparison with the control sample. As a conveniently available source of natural antioxidants, thyme and stachys essential oils can be used for use in fats, oils and food containing fats.

Composition and Radical Scavenging Activity of Essential Oil from Xylopia aethiopica: A New Chemotype Grown in Nigeria

Despite its use in traditional medicines, studies on the radical scavenging activity of the essential oils from Xylopia aethopica from Nigeria have not been widely reported in literature. Thus, in this work, fresh fruits of Xylopia aethopica were air dried, ground and extracted through hydro-distillation using Clevenger-type distillation apparatus. The essential oil was analyzed using Gas Chromatographic/Flame Ionization Detection (GC/FID) Technique and confirmed by gas chromatographic/mass spectrometric (GC/MS) analysis. The radical scavenging activity of the essential oil was evaluated in comparison with butylated hydroxylanisole (BHA) through 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging assay. A total of Forty-five compounds were detected through the GC/FID and GC/MS analyses of the essential oil of Xylopia aethopica. The major constituents of the essential oil were β-pinene (55.15%), α-thujene (9.23%) and α-eudesmol (8.61%) and α-pinene (6.77%). Other notable constituents were 1, 8-cineole (6.13%), ethyl cinnamate (5.83%) and elemol (5.17%). The methanolic solution of the essential oil showed concentration-dependent scavenging activity on 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) radical. The results of the Scavenging effect of the Xylopia aethopica essential oil compared well with the activity of the commercial radical scavenging agent, Butylated hydroxylanisole (BHA) and this suggests possible uses of the essential oil as sources of natural antioxidants. Data were analyzed using R statistical software.

Waste water of various boiled legumes as potential of radical scavenging agents

Peanut, soybean and chickpea important source of macronutrients and considered as important foodstuff in Malaysia. Boiled legumes are usually sold on by hawker on street. The water used for boiling the legumes is commonly thrown away without considering the radical scavenging potential of this so-called waste. Besides, there is lacking of awareness among the public about its nutritional benefits as part of sustainable food production aimed towards food security and nutrition. Furthermore, food antioxidants might play a significant role as physiological and dietary antioxidants which also could be a substitute for synthetic antioxidants and preservatives. Hence, this study aimed to evaluate the radical scavenging activity of the waste water from the three types of boiled legumes. The legumes were boiled in hot water and the waste water were collected. In this study, the waste water is converted into powder by means of freeze-drying technique. Radical scavenging activity was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, while its phenolic and flavonoid contents were determined using Folin-Ciocalteu assay and aluminum chloride colorimetric assay. The waste water of peanut showed the highest percentage of DPPH inhibition at 85.03±6.91%, followed by chickpea and soybean waste water at 79.89±3.69% and 69.10±6.19%, respectively. Furthermore, the waste water of peanut also showed the lowest IC50 value of 0.503±0.05 mg/mL, followed by soybean and chickpea of 0.554 ±0.01 mg/mL and 0.697±0.04 mg/mL. On a side note, peanut waste water extract showed the highest phenolic and flavonoid contents which are 1.877±0.36 mg GAE/g and 0.736±0.01 mg CE/g, respectively, whereas chickpea showed the lowest content of both which are 0.519±0.01 mg GAE/g and 0.227±0.01 mg CE/g, respectively. As conclusion, the waste water of boiled legumes is worth to be further investigated on their radical scavenging activity using other assays and could be potentially developed into functional foods.