Reduction Of Ferric Ions Research Articles

PHYTOCHEMICAL EVALUATION AND IN VITRO ANTIOXIDANT STATUS OF CLERODENDRUM VOLUBILE (AN INDIGENOUS MEDICINAL PLANT)

ABSTRACTClerodenrum volubile is an important locally used medicinal plant. It is one of the essential herbs nature has provided for mankind to be consumed as spices, vegetable and also used in the treatment of diseases. Qualitative phytoconstituent screening of the plant revealed the presence of steroids, flavonoids, tannins, saponins, and phenolic compound while chalcones, alkaloid and anthraquinone were absent. Quantitative phytochemical evaluation showed values of 8.29±1.26mg/g rutin equivalent for flavonoids, 3.53±0.05mg/g gallic acid equivalent for phenol, 3.97±0.03mg/g tannic acid equivalent for tannins and 13.67±1.27% for saponin per dry weight. As it is imperative to extend research work on therapeutic effects of the arsenal of plants nature has given to us in Africa so as to obtain a cure for various diseases attacking human’s health, antioxidant properties of the plant was evaluated. Antioxidant models used include iron chelating, DPPH radical, superoxide ion, hydrogen peroxide, ABTS radical, hydroxyl radical scavenging activities and ferric ion reducing properties. The obtained IC50 values against DPPH radical were 141.342 and 120.349µg/mL for Clerodendrum volubile and trolox respectively. The chelating effect of the plant extract at 50% inhibition was close to that of ascorbic acid (standard) with 134.34 and 131.19µg/mL concentration respectively. Overall, the aqueous extract of the plant showed antioxidant potential which was close to the effects exerted by known standard antioxidants (ascorbic acid, trolox and EDTA). The plant could hence provide natural antioxidants which are needed to combat numerous free radical-mediated diseases and complications such as aging, cancer, atherosclerosis, which are linked with oxidative stress.

Effects of different levels of sanguinarine on antioxidant indices, immunological responses, ileal microbial counts and jejunal morphology of laying hens fed diets with different levels of crude protein.

This study was carried out to assess the effects of different levels of sanguinarine on antioxidant indices, immunological responses, serum biochemical parameters, ileal microbial counts and jejunal morphology of laying hens fed on diets with different levels of crude protein (CP). A total of 180 laying hens were subjected into nine dietary treatments with four cages of five birds each. Experimental treatments consisted of three levels of CP (85.0, 92.5 and 100% of Hy-Line W36 manual recommendation) and three levels of sanguinarine (0.00, 3.75 and 7.50mg/kg) as a 3×3 factorial arrangement of laying hens which fed during a 70-day feeding trial. The invitro study showed that sanguinarine exhibited sevenfold and threefold decreased antioxidant activities to inhibit 2-2-diphenyl-1-picric hydrazyl free radical as well as ferric ion reducing rather than butylated hydroxyl toluene. Although using the decremental levels of CP caused the increase in heterophil-to-lymphocyte ratio (p<0.01), dietary administration of sanguinarine could suppress the serum cholesterol and malondialdehyde concentrations as well as heterophil-to-lymphocyte ratio (p<0.05). Additionally, decreasing CP content resulted in the decreased percentage of albumin (p<0.05); however, it had no negative effects on humoral immunity. Nonetheless, feeding of at least 3.75mg/kg sanguinarine led to the remarkable increases in serum gamma globulin concentration (p<0.01) and secondary (p<0.05) antibody titres against sheep red blood cells. Moreover, a decline in dietary CP content led to higher villi height and crypt depth (p<0.05; p<0.001) and consequently decreased villi height-to-crypt depth ratio (p<0.001) than the optimum level (100% CP). In spite of the effects of sanguinarine on the suppression of Escherichia coli and Salmonella counts (p<0.05), it markedly enhanced villi height-to-crypt depth ratio as well as lamina propria lymphatic follicles extent, simultaneously (p<0.001). Therefore, in spite of the detrimental effects of feeding low-CP diets on lymphocytes and serum albumin percentages, and villi height-to-crypt depth ratio, the administration of incremental levels of sanguinarine could improve cellular and humoral immunity, decrease ileal microbial counts and in turn improve the intestinal health indices in laying hens.

Reactivity of nano-size zinc powder in the aqueous solution of [FeIII(edta)(H2O)

ABSTRACTNitrogen mono-oxide and sulfur dioxide can be removed by simultaneous absorption into aqueous mixed solutions of sulfite and [FeII(edta)]H2O)]2−, ferrous ion coordinated to an anion of ethylene-diaminetetraacetic acid (EDTA or edta). In the industrial system with coexisting oxygen in the gas phase, [FeII(edta)](H2O)]2− complex is oxidized to [FeIII(edta)](H2O)]− by molecular oxygen. Because the ferric complex has no capability for reaction with NO, the suppression of this undesired oxidation process is a very important technological problem to be overcome. In our preceding work, we discussed the reduction kinetics of ferric ion by metal powder on the basis of the kinetic data regarding the ferric ion reduction in aqueous solutions of [FeIII(edta)](H2O)]− containing aluminum, tin or zinc powders. Zinc powder of normal size was recognized as an effective reducing agent. In the present work, augmentation of reducing capability of zinc powder was examined more. The rate of reduction of nano-size zinc powder was found to be about 11 times higher than that of normal-size zinc one.

TH-CD-BRA-08: Novel Iron-Based Radiation Reporting Systems as 4D Dosimeters for MR-Guided Radiation Therapy

Purpose: To compare novel radiation reporting systems utilizing ferric ion (Fe3+) reduction versus ferrous ion (Fe2+) oxidation in gelatin matrixes for 3D and 4D (3D+time) MR-guided radiation therapy dosimetry. Methods: Dosimeters were irradiated using an integrated 1.5T MRI and 7MV linear accelerator (MR-Linac). Dosimeters were read-out with both a spectrophotometer and the MRI component of the MR-Linac immediately after irradiation. Changes in optical density (OD) were measured using a spectrophotometer; changes in MR signal intensity due to the paramagnetic differences in the iron ions were measured using the MR-Linac in real-time during irradiation (balanced-FFE sequences) and immediately after irradiation (T1-weighted and inversion recovery sequences). Results: Irradiation of Fe3+ reduction dosimeters resulted in a stable red color with an absorbance peak at 512 nm. The change in OD relative to dose exhibited a linear response up to 100 Gy (R2=1.00). T1-weighted-MR signal intensity (SI) changed minimally after irradiation with increases of 8.0% for 17 Gy and 9.7% after escalation to 35 Gy compared to the un-irradiated region. Irradiation of Fe2+ oxidation dosimeters resulted in a stable purple color with absorbance peaks at 440 and 585 nm. The changes in OD, T1-weighted-MR SI, and R1 relative to dose exhibited a linear response up to at least 8 Gy (R2=1.00, 0.98, and 0.99) with OD saturation above 40 Gy. The T1-weighted-MR SI increased 50.3% for 17 Gy compared to the un-irradiated region. The change in SI was observed in both 2D+time and 4D (3D+time) acquisitions post-irradiation and in real-time during irradiation with a linear increase with respect to dose (R2>0.93). Conclusion: The Fe2+ oxidation-based system was superior as 4D dosimeters for MR-guided radiation therapy due to its higher sensitivity in both optical and MR signal readout and feasibility for real-time 4D dose readout. The Fe3+ reduction system is recommended for high dose applications. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. LH-102SPS.

Antioxidant activity of polyphenolic myricetin in vitro cell- free and cell-based systems.

Myricetin (Myc) is one of the most important flavonoids in diet due to its abundance in foods with the highest antioxidant activity. The antioxidant activity of Myc was studied in cell-free and cell-based systems to evaluate the ROS protection efficiency of Myc. The studies were based on the assessment of reducing power of Myc according to ferric ion reduction and intracellular ROS level measurement by assaying the cellular fluorescence intensity using dichlorodihydrofluorescein (DCF) probe as an indicator for ROS in cells. Moreover, the antitoxic capability of Myc was assessed using MTT method. Data indicated that intracellular ROS are highly toxic and applying low concentration of Myc not only inhibited cellular ROS production but also was accompanying with the protection of cells against the highly toxic and the lethal effects of peroxide compounds. Because of strong correlation between cellular ROS and their cell toxic properties, the higher antioxidant potency of Myc in cell medium resulted in effectively blocking intracellular ROS and protecting cell death. This property is achieved by the help of high polar solubility and cell membrane permeability of Myc.

Purification and Recovery of RuBisCO Protein from Alfalfa Green Juice: Antioxidative Properties of Generated Protein Hydrolysate

RuBisCO is the main soluble protein of alfalfa juice. Despite its attractive applications in a wide range of food products this protein remains largely underutilized. Accordingly, the present study was undertaken to investigate the feasibility and efficiency of using ammonium hydroxide (NH4OH) and precipitation at pH 3 for purification and recovery of RuBisCO from industrial Alfalfa green juice. The performance of the proposed RuBisCO recovery method was evaluated through qualitative and quantitative analysis. The results obtained by the proposed method were compared to those achieved for industrial brown juice. The findings from gel electrophoresis (SDS-PAGE), mass spectrometry, and reverse phase high-performance liquid chromatography (RP-HPLC) revealed that RuBisCO was obtained at a high purity of about 90 %. RuBisCO was hydrolyzed using pepsin and the resulting hydrolysate was assayed for antioxidative activity using various antioxidant assays, including the inhibition of linoleic acid oxidation, reduction of ferric ion, and stabilization of ABTS*+ radicals. Overall, the results showed that RuBisCO could be considered as a promising alternative source for the production of novel industrial peptides for application in the pharmaceutical, nutraceutical and functional food industries.

Antidiabetic and Antioxidant Activity of Scoparia dulcis Linn.

The hypoglycaemic activity of methanol extract of Scoparia dulcis was performed on both in vitro and in vivo models along with determination of total extractable polyphenol. Methanol extract of Scoparia dulcis contains 4.9% and water extract contains 3.2% of total extractable polyphenol. The antioxidant activity showed very promising result in both the tested methods that is 2,2-diphenyl-1-picrylhydrazyl and ferric ion reducing capacity. The antioxidant activity is directly correlated to the antidiabetic potential of drug. The two enzymes (amylase and glycosidase) found in intestine are responsible for the increasing postprandial glucose in body. In vitro model was performed on these enzymes and the results showed that methanol extract of Scoparia dulcis was effective to check the postprandial glucose level. The in vivo hypoglycaemic activity of methanol extract of Scoparia dulcis was performed on streptozotocin-induced diabetes mellitus showed significant inhibition of blood glucose level as compared to control and similar to that of standard glibenclamide. The overall data potentiates the traditional value of Scoparia dulcis as an antidiabetic drug.

Comparative study on the antioxidant activity of methanolic and aqueous extracts from the fruiting bodies of an edible mushroom Pleurotus djamor.

In vitro antioxidant activities, total phenolic, and flavonoid contents of Pleurotus djamor extracts were analyzed based on radical scavenging activities of methanol and aqueous extracts using 1,1-diphenyl-2-picryl-hydrazyl (DPPH), N,N-dimethyl-p-phenylenediamine (DMPD), total Fe3+ reducing power, CUPRAC, phosphomolybdenum, metal chelating activity, and lipid peroxidation inhibition assays. Both extract types showed efficient radical scavenging activities against DPPH and DMPD radicals, ferric (Fe3+) and cupric (Cu2+) ion reducing powers, metal chelating activities, and lipid peroxidation inhibition. Total phenolic contents of methanol and aqueous extracts were 2.79 and 5.95 mg of GAE/g, respectively. Flavonoid contents of methanol and aqueous extracts were 6.35 and 5.75 mg of CAE/g, respectively. Consumption of the mushroom P. djamor can be beneficial due to antioxidant properties.

Distinct Antioxidant Activity of a Common Antidepressant Drug Imipramine

Background: Free radicals are known to cause severe damage to most of the biomolecules in the human system and are responsible for various illnesses including neurodegenerative, cardiovascular and autoimmune disorders. Antioxidants can reduce effects of free radicals and are given to patients suffering from such diseases. There are certain natural antioxidants like flavonoids which possess free radical scavenging activities. The flavonoid quercetin is one such compound among naturally occurring antioxidants. The present study has been designed to determine the antioxidant activity in the synthetic antidepressant drug imipramine which is structurally similar to quercetin. Method: Specific standard procedures like ferric ion reducing capacity by FRAP assay, phosphomolybdenum assay and cupric ion reducing (CUPRAC) assay were carried out keeping ascorbic acid as the known standard. Results: Ferric ion reducing property of imipramine by FRAP assay revealed that reducing power of imipramine augmented with increasing amounts of the drug. In the phosphomolybdenum assay antioxidant capacity of imipramine increased in a dose dependent manner. In both these studies imipramine showed greater antioxidant action than ascorbic acid. In CUPRAC assay as the amount of imipramine was increased there was a definite elevation in antioxidant activity; however, it was comparatively less active than ascorbic acid. Conclusion: The highly potent antioxidant property in the antidepressant synthetic compound imipramine may be recognized by physicians involved in treatment of psychosis since patients receiving this drug regularly will certainly be in an advantageous position. The parent structure of imipramine can be modified further to potentiate antioxidant property of the drug.

In vitro evaluation of antioxidant and cytotoxic activities of lignin fractions extracted from Acacia nilotica

Lignin is one of the most important phytomacromolecule with diverse therapeutic properties such as anticancer, antimicrobial, anti-inflammatory and immune-stimulatory. The present study was carried out to evaluate the in vitro antioxidant, free radical scavenging and anti-proliferative/cytotoxic activities of eleven different lignin fractions, extracted from the wood of Acacia nilotica by pressurized solvent extraction (PSE) and successive solvent extraction (SSE) methods. Results indicate that the PSE fractions have high polyphenolic content and reducing power. However, the antioxidant efficiency examined by DPPH and ABTS radical scavenging assay was higher in SSE fractions. All lignin fractions revealed a significant ability to scavenge nitric oxide, hydroxyl and superoxide radicals. The extracted lignin fractions display high ferric ion reducing capacity and also possess excellent antioxidant potential in the hydrophobic (linoleic acid) system. Fractions extracted by polar solvent has the highest iron (Fe2+) chelating activity as compared to other factions, indicating their effect on the redox cycling of iron. Four lignin fractions depicted higher cytotoxic potential (IC50: 2–15μg/mL) towards breast cancer cell line (MCF-7) but were ineffective (IC50: ≥100μg/mL) against normal primary human hepatic stellate cells (HHSteCs). These findings suggest that the lignin extracts of A. nilotica wood has a remarkable potential to prevent disease caused by the overproduction of radicals and also seem to be a promising candidate as natural antioxidant and anti-cancer agents.

Fe2SiS4 nanoparticle—A new heterogeneous Fenton reagent

The heterogeneous Fenton system has become the hotspot in the decontamination field due to the effective Fenton activity with a wide pH range compared with the homogeneous Fenton system. The unstable chemical properties of pyrite leaded to the flourishing investigation of the candidates for the heterogeneous Fenton catalysts. In this article, Fe2SiS4 nanoparticles with better thermodynamic stability were prepared, and its potential as Fenton reagent was investigated. It was found that the polar surface consisted by the unsaturated iron atoms in the Fe2SiS4 crystalline configuration resulting in the realization of Fenton reaction. Meanwhile, sunlight irradiation could promote the reduction of ferric ions and further enhance the Fenton effect.

In vitro and #945;-glucosidase inhibition and antioxidant activities of partially purified Antidesma bunius fruit and Gynura nepalensis leaf extracts

Diabetes mellitus is a metabolic disorder characterized by increased blood glucose levels. Current treatments involve the use of sulfonylureas, α-glucosidase inhibitors, and other synthetic drugs. The study demonstrated the α-glucosidase inhibition and antioxidant properties of partially purified ethanolic extracts of Antidesma bunius fruits and Gynura nepalensis leaves, as possible herbal drug candidates. After ethanol extraction, the extracts were fractionated using normal phase liquid column chromatography, with elution solvents ethyl acetate, methanol and water. Fractionation resulted in five fractions for A. bunius (A1, A2, A3, A4 and A5) and seven fractions for G. nepalensis (G1, G2, G3, G4, G5, G6 and G7). Fraction G1 showed the highest α-glucosidase inhibition activity (90.61±8.05%) and possibly acted via a mixed mode of inhibition. For the antioxidant activities, Fraction A1 exhibited highest radical scavenging activity via DPPH assay (97.39±2.48%), Fraction G7 exhibited highest iron (II)-chelating activity (95.85±1.46%) and Fraction G6 exhibited highest ferric-ion reducing activity via FRAP assay (272.60 μg/mL FeSO4 equivalents). Phytochemical screening revealed that flavonoids and tannins were common among all fractions. The results demonstrated the potential of these plants as antidiabetic herbal treatments; however, further studies and to isolate the active component(s), structure elucidation and toxicity assays need be done first.

Essential oil mediated synthesis of silver nanocrystals for environmental, anti-microbial and antioxidant applications

Our quest for a green, non-toxic and environmentally benign synthetic design for the fabrication of metal nanoparticles has led to the use of essential oil present in plant parts as the bioreductant. In this report, silver particles at nanoscale have been synthesized using essential oil present in the leaves of Coleus aromaticus at physiological pH and at 373K. UV–vis spectra of the colloid display strong plasmon bands centred around 396–411nm, characteristic of silver nanoparticles. Comparative studies of the FTIR spectra of essential oil and silver nanoparticles reveal the involvement of terpenes and their phenolic derivatives in reduction and subsequent stabilization. TEM micrographs and XRD pattern show the formation of 26 and 28nm sized face centred cubic structured crystalline nanospheroids with intermittent formation of nanorods. The phytosynthesized silver nanoparticles are found to be effective in degrading hazardous organic pollutants including methyl orange, methylene blue, eosin yellowish and para nitro phenol within a span of a few minutes. Dose dependant antibacterial activity of the biogenic nanosilver against pathogenic Gramme-negative Escherichia coli (ATCC 25922) and Gramme-positive Staphylococcus aureus (ATCC 25923) has been portrayed through agar-well dispersion method. The antioxidant activity including antiradical activity and reducing power have been depicted through superoxide radical scavenging activity, hydroxyl radical scavenging activity, hydrogen peroxide scavenging activity, nitric oxide scavenging activity, DPPH assay and reducing power activity involving the reduction of ferric ion.

Biological activity of egg-yolk protein by-product hydrolysates obtained with the use of non-commercial plant protease

Enzymatic hydrolysis leads to improved functional and biological properties of protein by-products, which can be further used as nutraceuticals and protein ingredients for food applications. the present study evaluated AcE-inhibitory, antioxidant and immunostimulating activities in hydrolysates of egg-yolk protein by-product (YP), generated during industrial process of delipidation of yolk. the protein substrate was hydrolyzed using non-commercial protease from Asian pumpkin (Cucurbita ficifolia). the reaction was conducted in 0.1 M t ris-Hcl buffer (pH 8.0) at temperature of 37°c for 4 hours using different enzyme doses (100-1000 U/mg of substrate). the protein degradation was monitored by the determination of the degree of hydrolysis (DH), release of free amino groups (FAG) and by rP-HPLc. In the obtained hydrolysates we also evaluated biological activities. It was shown that the highest DH of substrate (46.6%) was obtained after 4h of reaction at the highest amount of enzyme. this hydrolysate exhibited antioxidant activity, including ferric ion reducing (FrAP) (56.41 μg Fe 2+ /mg), ferric ion chelating (695.76 μg Fe 2+ /mg) and DPPH free radical scavenging (0.89 μmol trolox eq /mg) as well as AcE-inhibitory (Ic 50 =837.75 μg/mL) activities. the research showed improved biological properties of enzymatically modified YP by-product.

Biogenic synthesis of silver nanoparticles using a pod extract of Cola nitida: Antibacterial and antioxidant activities and application as a paint additive

This work reports the biogenic synthesis of silver nanoparticles (AgNPs) using the pod extract of Cola nitida, the evaluation of their antibacterial and antioxidant activities, and their application as an antimicrobial additive in paint. The AgNPs were characterized with UV–Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The AgNP solution was dark brown with a maximum absorbance occurring at 431.5nm. The FTIR spectrum showed strong peaks at 3336.85, 2073.48, and 1639.49cm−1, indicating that proteins acted as the capping and stabilization agents in the synthesis of the AgNPs. The AgNPs were spherical, with sizes ranging from 12 to 80nm. Energy dispersive X-ray (EDX) analysis showed that silver was the prominent metal present, while the selected area electron diffraction pattern conformed to the face-centred cubic phase and crystalline nature of AgNPs. At various concentrations between 50 and 150μg/ml, the AgNPs showed strong inhibition of the growth of multidrug resistant strains of Klebsiella granulomatis, Pseudomonas aeruginosa, and Escherichia coli. In addition, at 5μg/ml, the AgNPs completely inhibited the growth of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger, A. flavus and A. fumigatus in a paint-AgNP admixture. The AgNPs exhibited a potent antioxidant activity with an IC50 of 43.98μg/ml against 2,2-diphenyl-1-picrylhydrazyl and a ferric ion reduction of 13.62–49.96% at concentrations of 20–100μg/ml. This study has demonstrated the biogenic synthesis of AgNPs that have potent antimicrobial and antioxidant activities and potential biomedical and industrial applications. To the best of our knowledge, this work is the first to use the pod extract of C. nitida for the green synthesis of nanoparticles.

Use of Nanoscale Zero-Valent Iron (NZVI) Particles for Chemical Denitrification under Different Operating Conditions

The nitrate pollution of waters and groundwaters is an important environmental and health concern. An interesting method to remove the oxidized forms of nitrogen from waters and wastewaters is chemical denitrification by means of metallic iron (Fe0). Particularly advantageous is the use of nanoscopic zero-valent iron particles due to the elevated surface area, which allows reaching extremely high reaction rates. In the present paper, the efficiency of nitrate reduction by means of nanoscopic Fe0 has been investigated under several operating conditions. The iron nanoparticles were synthesized by the chemical reduction of ferric ions with sodium borohydride. The effects of Fe0 dosage, initial N–NO3− concentration and pH on chemical denitrification were identified. In particular, the results of the tests carried out showed that it is possible to reach an almost complete nitrate reduction in treating solutions with a nitrate nitrogen concentration higher than 50 mg/L. Moreover, the process performance was satisfactory also under uncontrolled pH. By means of the trends detected during the experiments, the kinetic-type reaction was identified. Furthermore, a relation between the kinetic constant and the process parameters was defined.

On the ability to electrogenerate hydrogen peroxide and to regenerate ferrous ions of three selected carbon-based cathodes for electro-Fenton processes

This paper compares three different carbon-based materials as cathodes in electro-Fenton processes. In particular, we investigated a graphite, a carbon felt (CF) and a reticulated vitreous carbon (RVC) electrode with a focus on both electrogeneration of hydrogen peroxide and reduction of ferric ions. The influence of the operative parameters such as current intensity, pH, temperature and feeding gas was studied by conducting galvanostatic electrolyses in a two-compartment reactor separated by a cationic membrane. The dissolved oxygen concentration was optimized and monitored.The results obtained showed that all the cathodes presented good ability to electrogenerate hydrogen peroxide. Unlike graphite, the tridimensional electrodes exhibited superior performances in air flow and the possibility to adopt higher currents. Interestingly, their behavior differed significantly in the electroregeneration of ferrous ions. In this case, RVC and CF presented efficiencies and reduction rates higher than graphite and resulted almost unaffected by the operative conditions.

Chemometrics Classification of Argentine Clover and Eucalyptus Honeys According to Palynological, Physicochemical, and Sensory Properties

Palynological, physicochemical, and sensory methods were applied to ascertain the most discriminant variables for honey characterization. Fifteen physicochemical parameters, six indicators of antioxidant capacity and eight sensory attributes were considered. Clover and eucalyptus honeys were differentiated when the linear discriminant analysis was applied. Electrical conductivity, sugars, ferric ion reducing, and Trolox equivalent antioxidant capacity were the most discriminant variables. Odor and color intensities were the sensory attributes scoring the major differences between honeys. The canonical correlations technique pointed out that differences were related primarily to the content of pollen from Trifolium, Medicago sativa, and Lotus. These standards of quality provide a differentiating tool to classify unifloral honeys.

SU‐E‐T‐516: Investigation of a Novel Radiochromic Radiation Reporting System Utilizing the Reduction of Ferric Ion

PurposeTo introduce and characterize a new “reverse‐Fricke” radiation reporting system utilizing the reduction of ferric ions (Fe3+) to ferrous ions (Fe2+).MethodsTwo formulations of the radiochromic reporting system, referred to as A and B, were prepared for investigation. Formulation‐A consisted of 14 mM 1,10‐phenanthroline, 42 mM ethanol, and 57 mM ammonium ferric oxalate in water. Formulation‐B consisted of 27 mM 1,10‐phenanthroline, 42 mM ethanol, and 28 mM ammonium ferric oxalate in water. Solutions were prepared immediately prior to irradiation with a Cobalt‐60 unit with radiation doses of 0, 1, 5, 10, 15, 20, and 25 Gy. The change in optical density over the visible range of 450–650 nm was measured using a spectrophotometer immediately after irradiation. The effective atomic numbers of the formulations were calculated using Mayneord's formula.ResultsIonizing radiation energy absorbed in the solutions causes the reduction of ferric ions (Fe3+) into ferrous ions (Fe2+), which then forms a 1:3 red colored complex with 1,10‐phenanthroline ([(C1 2H8N2)3Fe]2+) that can be measured spectrophotometrically. The absorbance spectra of the resulting complex displayed a peak maximum at 512 nm with a greater change in absorbance for Formulation‐B after receiving comparable radiation doses. The change in absorbance relative to dose exhibited a linear response up to 25 Gy for both Formulation‐A (R2 = 0.98) and Formulation‐B (R2 = 0.97). The novel formulations were also nearly water equivalent (Zeff = 7.42) with effective atomic numbers of 7.65 and 7.52 and mass densities within 0.2% of water.ConclusionBoth formulations displayed visible Fe2+ complex formation with 1,10‐phenanthroline after irradiation using a Cobalt‐60 source. The higher sensitivity measured for Formulation‐B is attributed to the increase in 1,10‐phenanthroline concentration and the increase in the 1,10‐phenanthroline to ammonium ferric oxalate ratio. Further investigation of this radiation reporting system in a 3D matrix material is encouraged.NSF GRFP Grant Award #LH‐102SPS

Comparative Chemical Composition and Antioxidant Properties of the Essential Oils of three Sideritis libanotica Subspecies

The phytochemical composition of the essential oils of three Sideritis libanotica subspecies, namely S. libanotica ssp. libanotica, S. libanotica ssp. linearis and S. libanotica ssp. michroclamys, all collected in Lebanon, was analyzed by GC and GC-MS. The diterpene sideridiol was recognized as the main constituent of both S. libanotica ssp. libanotica (50.8%) and S. libanotica ssp. michroclamys (18.4%) oils, while hexadecanoic acid (10.5%) prevailed in S. libanotica ssp. linearis. The antioxidant activity of the oils was studied in two cell free systems by DPPH radical scavenging and ferric ion reduction (FRAP) assays; only S. libanotica ssp. linearis showed a moderate activity when assayed by the FRAP test (0.6 ± 0.01 mmol TE/mL).