Thiocyanate (SCN-) is a contaminant requiring remediation in gold mine tailings and wastewaters globally. Seepage of SCN--contaminated waters into aquifers can occur from unlined or structurally compromised mine tailings storage facilities. A wide variety of microorganisms are known to be capable of biodegrading SCN-; however, little is known regarding the potential of native microbes for in situ SCN- biodegradation, a remediation option that is less costly than engineered approaches. Here we experimentally characterize the principal biogeochemical barrier to SCN- biodegradation for an autotrophic microbial consortium enriched from mine tailings, to arrive at an environmentally realistic assessment of in situ SCN- biodegradation potential. Upon amendment with phosphate, the consortium completely degraded up to ∼10 mM SCN- to ammonium and sulfate, with some evidence of nitrification of the ammonium to nitrate. Although similarly enriched in known SCN--degrading strains of thiobacilli, this consortium differed in its source (mine tailings) and metabolism (autotrophy) from those of previous studies. Our results provide a proof of concept that phosphate limitation may be the principal barrier to in situ SCN- biodegradation in mine tailing waters and also yield new insights into the microbial ecology of in situ SCN- bioremediation involving autotrophic sulfur-oxidizing bacteria.
The objective of this study was to determine the effect of chewing commercially available meswak may have on levels of calcium, chloride, phosphate and thiocyanate in stimulated whole saliva. A total of 20 subjects participated in the investigation. They were distributed into two groups. Those in group A (10 individuals) were asked to first chew on a cotton roll (sized #1) followed by the chewing of an equivalent sized 5mm piece of commercially available meswak. Subjects in group B (10 individuals) did the same but, chewed on cotton roll (sized #2) followed by the chewing of an equivalent sized 10mm piece of commercially available meswak. After following a specified chewing protocol, samples of stimulated whole saliva were collected into a graduated tube at the end of every chewing regime. Calcium, chloride, phosphate and thiocyanate analysis were carried out using colour titration and spectrophotometer. Results from this investigation indicated that commercially available meswak chewing sticks apart from containing high amounts of calcium and chloride may possibly release phosphate and thiocyanate into whole saliva. These findings suggest that the commercially available meswak used as chewing sticks may have the potential of releasing substances into saliva that could influence the state of oral health. Further studies have to be carried out to ascertain the therapeutic benefits of chewing commercially available meswak.
An ethanolic solution of caffeine was added to an aqueous solution of metal salts and followed by adding ethanolic solution of adenine and an aqueous solution of potassium thiocyanate to give complexes with general formula [M(CA)2(Ad)X2] where CA is caffeine, Ad is adenine, X is thiocyanate ion and M is Co(II), Ni(II), Cu(II), Zn(II) and Cd(II). The resulting products were characterized using UV-visible and infrared spectroscopies. Elemental analyses were performed using C, H, N analysis and atomic absorption techniques. The magnetic susceptibility and the conductivity were also measured. The results suggested that the complexes have octahedral geometry.
A flexible solid polymer electrolyte (SPE) system based on poly(ε-caprolactone) (PCL), a FDA approved non-toxic and biodegradable material in the effort to lower environmental impact was prepared. Ammonium thiocyanate (NH4SCN) and ethylene carbonate (EC) were incorporated as the source of charge carriers and plasticizing agent, respectively. When 50wt.% of ethylene carbonate (EC) was added to PCL-NH4SCN system, the conductivity increased by two orders from of 3.94×10(-7)Scm(-1) to 3.82×10(-5)Scm(-1). Molecular vibrational analysis via infrared spectroscopy had been carried out to study the interaction between EC, PCL and NH4SCN. The relative percentage of free ions, ion pairs and ion aggregates was calculated quantitatively by deconvoluting the SCN(-) stretching mode (2030-2090cm(-1)). This study provides fundamental insight on how EC influences the free ion dissociation rate and ion mobility. The findings are also in good agreement to conductivity, differential scanning calorimetry and X-ray diffraction results. High dielectric constant value (89.8) of EC had made it an effective ion dissociation agent to dissociate both ion pairs and ion aggregates, thus contributing to higher number density of free ions. The incorporation of EC had made the polymer chains more flexible in expanding amorphous domain. This will facilitate the coupling synergy between ionic motion and polymer segmental motion. Possible new pathway through EC-NH4(+) complex sites for ions to migrate with shorter distance has been anticipated. This implies an easier ion migration route from one complex site to another.
Cyanidation in gold extraction has detrimental impacts on the ecosystem and the population in surrounding areas. The research described in this article aimed to assess the health effects of environmental exposure to cyanide in a community near a gold mining area in Malaysia. A total of 255 members of the exposed community and 117 members of the control community answered questionnaires on their exposure to a gold mine and health outcomes. Urine samples were collected for biomarker assessment (i.e., urinary thiocyanate). The authors found that the mean level of urinary thiocyanate was significantly higher among the exposed community (0.30 ± 0.26 mg/dL) than the control community (0.24 ± 0.23 mg/dL) (p = .0021). The exposed community had a significantly higher prevalence of headaches (prevalence odds ratio [pOR] = 2.6, p = .001), dizziness (pOR = 3.7, p < .001), skin irritation (pOR = 2.1, p = .040), and eye irritation (pOR = 5.1, p = .004). No association occurred between dietary exposure and urinary biomarkers. Smokers living near a gold mine had a higher urinary thiocyanate level (0.56 mg/dL) than smokers in the control community (0.49 mg/dL).
Crucifer vegetables, Brassicaceae and other species of the order Brassicales, e.g., Moringaceae that are commonly consumed as spice and food, have been reported to have potential benefits for the treatment and prevention of several health disorders. Though epidemiologically inconclusive, investigations have shown that consumption of those vegetables may result in reducing and preventing the risks associated with neurodegenerative disease development and may also exert other biological protections in humans. The neuroprotective effects of these vegetables have been ascribed to their secondary metabolites, glucosinolates (GLs), and their related hydrolytic products, isothiocyanates (ITCs) that are largely investigated for their various medicinal effects. Extensive pre-clinical studies have revealed more than a few molecular mechanisms of action elucidating multiple biological effects of GLs hydrolytic products. This review summarizes the most significant and up-to-date in vitro and in vivo neuroprotective actions of sulforaphane (SFN), moringin (MG), phenethyl isothiocyanate (PEITC), 6-(methylsulfinyl) hexyl isothiocyanate (6-MSITC) and erucin (ER) in neurodegenerative diseases.
In this work, a pair of biopolymer materials has been used to prepare high ion-conducting electrolytes for energy storage application (ESA). The chitosan:methylcellulose (CS:MC) blend was selected as a host for the ammonium thiocyanate NH4SCN dopant salt. Three different concentrations of glycerol was successfully incorporated as a plasticizer into the CS-MC-NH4SCN electrolyte system. The structural, electrical, and ion transport properties were investigated. The highest conductivity of 2.29 × 10-4 S cm-1 is recorded for the electrolyte incorporated 42 wt.% of plasticizer. The complexation and interaction of polymer electrolyte components are studied using the FTIR spectra. The deconvolution (DVN) of FTIR peaks as a sensitive method was used to calculate ion transport parameters. The percentage of free ions is found to influence the transport parameters of number density (n), ionic mobility (µ), and diffusion coefficient (D). All electrolytes in this work obey the non-Debye behavior. The highest conductivity electrolyte exhibits the dominancy of ions, where the ionic transference number, tion value of (0.976) is near to infinity with a voltage of breakdown of 2.11 V. The fabricated electrochemical double-layer capacitor (EDLC) achieves the highest specific capacitance, Cs of 98.08 F/g at 10 mV/s by using the cyclic voltammetry (CV) technique.
Vigna sinensis also known as long-podded cowpea or Chinese long bean (Family:Fabaceae) is most widely grown in Southeast Asia. They are a good source of protein, vitamin A, vitamin C, iron, phosphorus, and potassium. The antioxidant potential of crude methanol extract, chloroform, and ethyl acetate soluble fractions of Vigna sinensiswas screened for in- vitro antioxidant activity using total phenolic content, ferric reducing power, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay, ferric thiocyanate (FTC) and thiobarbituric acid (TBA) tests. It was found that ethyl acetate fraction have maximum amount of polyphenolics compounds (2.69 mg/g GAE in concentration 0.5 mg/mL); more effective than methanol and chloroform extract.This fraction also exhibited fairly good antioxidant activity with in both TBA (17.39% mg/g GAE) and FTC (12.65% mg/g GAE) methods.
This study was conducted on selected local herbs such as ulam raja (Cosmos caudatus), kesum (Polygonum minus), selom (Oenanthe javanica), pegaga (Centella asiatica) and curry leaves (Murraya koenigii) to investigate their antioxidative activities. The water extracts of the herbs were analysed for total phenolic content, reducing antioxidant power, ferric thiocyanate (FTC) and the thiobarbituric acid (TBA) test was also accried out. Polygonum minus showed the highest total phenolic content and reducing power among the herbs. Increasing the concentration of the extracts resulted in increased Fe3+ reducing antioxidant power for all the herbs. FTC and TBA tests on the extracts during seven days of storage showed that all the herbs extracts had the ability to reduce oxidation compared to the control (P < 0.05). From the FTC analysis, Murraya koenigii leaves was best in reducing the oxidation rate (67.67%) compared to the other herbs studied. Analysis of TBA showed that Centella asiatica extract had the highest antioxidant effect. However, both TBA and FTC analysis for these two herbs showed no significant difference (P >0.05) from Polygonum minus and butylated hydroxyanisole (BHT) a synthetic antioxidant. Correlation analysis showed positive correlations between amount of total phenolic content and reducing power (r = 0.75) and antioxidative activities (r = 0.58) in linoleic acid emulsion system. This shows that antioxidative activities of these Malaysian herbal plants especially Polygonum minus may be a potential source of natural antioxidants with similar characteristics to the synthetic antioxidant, BHT.
A novel bimetallic double thiocyanate-bridged ruthenium and tungsten metal complex containing bipyridyl and dithiolene co-ligands was synthesized and the behavior of the complex as a dye-sensitizer for a photoelectrochemical (PEG) cell for a direct water splitting reaction was investigated. The ligands and metal complexes were characterized on the basis of elemental analysis as well as uv-Vis, Fourier transform infrared ( Pim) and nuclear magnetic resonance (11I and 13C NMR) spectroscopy. Cyclic voltammetry of the bimetallic complex showed multiple redox couples, in which half potentials E 112 at 0 .625 , 0.05 and 0.61 V were assigned as the formal redox processes of Ru(III)IRu(II) reduction, W(IV)IW(V) and W(V)IW(VI) oxidations, respectively. Photocurrent measurements were performed in homogeneous system and TiO2 was used as the photoanode for photocurrent measurements. Current density generated by the bimetallic complex was higher than that of N3 commercial dye which suggested that the bimetallic complex donated more electrons to the semiconductor.
Vitamin E is known to have potent antioxidant activity and plays an important role in reducing oxidative stress, a pivotal step in atherogenesis. However, several randomised clinical trials using α-tocopherol have failed to demonstrate consistent beneficial effects of antioxidants against atherosclerosis and clinical endpoints. Tocotrienol, a vitamin E compound analogue is shown to have more potent antioxidant activity compared to tocopherol. Finding the optimal anti-oxidative dose is crucial and may effectively be applied for cardioprotection in human. The objective of this study was to determine the optimal dose of tocotrienol rich fraction (TRF) with highest antioxidant activity in vitro using the ferric thiocyanate (FTC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2’, 7’- dichlorofluorescein diacetate (DCFHDA) assays. It was found that TRF exhibited potent antioxidant and free radical scavenging activities with an IC50 of 22.10 + 0.01 µg/ml. In all assays, TRF had optimal antioxidant activity at moderate concentrations (10-100 µg/ml). In conclusion, TRF has potent antioxidant activity, which is optimal at moderate concentrations.
The source and quantity of nutrients available to plants can affect the quality of leafy herbs. A study was conducted to compare quality of Cosmos caudatus in response to rates of organic and mineral-based fertilizers. Organic based fertilizer GOBI (8% N:8% P₂O₅:8% K₂O) and inorganic fertilizer (15% N, 15% P₂O₅, 15% K₂O) were evaluated based on N element rates at 0, 30, 60, 90, 120 kg h⁻¹. Application of organic based fertilizer reduced nitrate, improved vitamin C, antioxidant activity as well as nitrogen and calcium nutrients content. Antioxidant activity and chlorophyll content were significantly higher with increased fertilizer application. Fertilization appeared to enhance vitamin C content, however for the maximum ascorbic acid content, regardless of fertilizer sources, plants did not require high amounts of fertilizer.
An anion exchange monolithic silica capillary column was prepared by surface modification of a hybrid monolithic silica capillary column prepared from a mixture of tetramethoxysilane (TMOS) and methyltrimethoxysilane (MTMS). The surface modification was carried out by on-column copolymerization of N-[3-(dimethylamino)propyl]acrylamide methyl chloride-quaternary salt (DMAPAA-Q) with 3-methacryloxypropyl moieties bonded as an anchor to the silica surface to form a strong anion exchange stationary phase. The columns were examined for their performance in liquid chromatography (LC) and capillary electrochromatography (CEC) separations of common anions. The ions were separated using 50 mM phosphate buffer at pH 6.6. Evaluation by LC produced an average of 30,000 theoretical plates (33 cm column length) for the inorganic anions and nucleotides. Evaluation by CEC, using the same buffer, produced enhanced chromatographic performance of up to ca. 90,000 theoretical plates and a theoretical plate height of ca. 4 mum. Although reduced efficiency was observed for inorganic anions that were retained a long time, the results of this study highlight the potential utility of the DMAPAA-Q stationary phase for anion separations.
Antioxidants play an important role in inhibiting and scavenging radicals, thus providing protection to humans against infections and degenerative diseases. Literature shows that the antioxidant activity is high on herbal and vegetable plants. Realizing the fact, this research was carried out to determine total antioxidant activity and the potential anticancer properties in three types of selected local vegetable shoots such as Diplazium esculentum (paku shoot), Manihot utillissima (tapioca shoot) and Sauropous androgynus (cekur manis). The research was also done to determine the effect of boiling, on total antioxidant activity whereby samples of fresh shoots are compared with samples of boiled shoots. In every case, antioxidant activity is compared to alpha-tocopherol and two methods of extraction used are the organic and the aqueous methods. Besides that, two research methods used were the ferric thiocyanate (FTC) and thiobarbituric acid (TBA) with absorbance of 500nm and 532nm respectively. Oneway ANOVA test at P<0.05 determines significant differences between various samples. In the cytotoxic study, the ethanolic extract and several cell lines i.e. breast cancer (MDA-MB-231 and MCF-7), colon cancer (Caco-2), liver cancer (HepG2) and normal liver (Chang liver) were used. The IC(50)-value was determined by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The antioxidant study found that all the samples in both aqueous and organic extraction were significantly different. The total antioxidant activity values of aqueous extract in descending order are as follows: M. utilissima (fresh) >D. esculentum (fresh) >S.androgynus (fresh) > M.utilissima (boiled) > D. esculentum (boiled) > S.androgynus (boiled). It also was found that S.androgynus shoots ethanolic extract was able to inhibit the viability of the breast cancer cell lines, MDA-MB-231 with the IC50 value of 53.33 micrograms/ml. However, S.androgynus shoots and D. esculentum shoots ethanolic extracts did not inhibit the viability of MDA-MB-231 cell line. While, the tapioca shoot ethanolic extract was able to inhibit the viability of MCF-7 cell line with the IC(50) value of 52.49 micrograms/ml. S.androgynus shoots and D.esculentum shoots ethanolic extracts did not give an IC(50) value against the MCF-7 cell line. S.androgynus, tapioca and D.esculentum shoots ethanolic extracts did not show cytotoxic effect against the Caco-2 and HepG2. There was no IC(50)-value from any sample against Chang Liver cell line. In conclusion, the antioxidant activity of both fresh and boiled samples were higher than alpha-tocopherol, although fresh vegetable shoots were found to be higher in antioxidant activity compared to boiled shoots. This study also suggested that S.androgynus shoots and tapioca shoots have potential as an anticancer agent against certain breast tumours.
The study was conducted to determine thiocyanate (SCN-) and hypothiocyanite (OSCN-) concentrations in resting (RWS) and stimulated whole saliva (SWS) and stimulated parotid saliva (SPS) of 20 healthy young adults aged 21-29 y. Samples of saliva were collected at 12:30, immediately before lunch. Resting saliva was collected by expectoration, and stimulated saliva was collected during the uniform chewing of paraffin wax. Parotid secretion was collected using a modified Carlsson-Crittenden cup (Carlsson et al., Am, J. Physiol., 26, 169-177, 1910). SCN- concentration was determined by the ferric nitrate method (Betts et al., J. Am. Chem. Soc., 75, 5721-5727, 1953) whilst OSCN- was assayed using 2-mercaptoethanol as a reducing agent (Pruitt et al., Caries Res., 16, 315-323, 1982). In RWS, SWS and SPS, the mean SCN- concentrations (in mM) were 1.48 +/- 0.59(S.D.), 0.90 +/- 0.56(S.D.) and 1.24 +/- 0.65(S.D.) whilst the mean OSCN- concentrations (in microM) were 31.21 +/- 13.54(S.D.), 24.90 +/- 12.61 and 30.19 +/- 23.35(S.D.) in the respective salivas. The presence of OSCN- in the secretion collected from the parotid gland supported previous findings by Tenovuo and Pruitt (Tenovuo et al., J. Oral Path, ol. 13, 573-584, 1984), who suggested an endogenous glandular (eukaryotic) source of hydrogen peroxide (H2O2), since parotid saliva from healthy glands is devoid of bacteria and leukocytes.
Thiocyanate (SCN-) forms as a by-product of cyanidation during gold ore processing and can be degraded by a variety of microorganisms utilizing it as an energy, nitrogen, sulphur and/or carbon source. In complex consortia inhabiting bioreactor systems, a range of metabolisms are sustained by SCN- degradation; however, despite the addition or presence of labile carbon sources in most bioreactor designs to date, autotrophic bacteria have been found to dominate key metabolic functions. In this study, we cultured an autotrophic SCN--degrading consortium directly from gold mine tailings. In a batch-mode bioreactor experiment, this consortium degraded 22 mM SCN-, accumulating ammonium (NH4+) and sulphate (SO42-) as the major end products. The consortium consisted of a diverse microbial community comprised of chemolithoautotrophic members, and despite the absence of an added organic carbon substrate, a significant population of heterotrophic bacteria. The role of eukaryotes in bioreactor systems is often poorly understood; however, we found their 18S rRNA genes to be most closely related to sequences from bacterivorous Amoebozoa. Through combined chemical and phylogenetic analyses, we were able to infer roles for key microbial consortium members during SCN- biodegradation. This study provides a basis for understanding the behaviour of a SCN- degrading bioreactor under autotrophic conditions, an anticipated approach to remediating SCN- at contemporary gold mines.
The potential of isothiocyanates to antagonize the carcinogenicity of structurally diverse chemicals has been established in animals. A feasible mechanism of action involves protecting DNA by reducing the availability of the genotoxic metabolites of chemical carcinogens by either inhibiting their generation and/or stimulating their detoxification. In vivo as well as in vitro studies conducted in rat/human primary hepatocytes and precision-cut tissue slices have revealed that isothiocyanates can impair cytochrome P450 activity, including the CYP1 family which is the most active in the bioactivation of carcinogens, by virtue of being mechanism-based inactivators. The aromatic phenethyl isothiocyanate is the most effective of those studied, whereas aliphatic isothiocyanates such as sulforaphane and erucin necessitate high doses in order to manifest such effects that may not always be achievable through the diet. In all systems studied, isothiocyanates are strong inducers of detoxification enzyme systems including quinone reductase, glutathione S-transferase, epoxide hydrolase, and UDP-glucuronosyl transferase. Indeed, in smokers phenethyl isothiocyanate intake increases the urinary excretion of inactive mercapturate metabolites of toxic chemicals present in tobacco. Glucosinolates, the precursors of isothiocyanates, have also the potential to upregulate detoxification enzyme systems, but their contribution to the cancer chemoprevention linked to cruciferous vegetable consumption remains to be evaluated.