Search results for: metal compounds

Authors: Sehrish Iftikhar, Ahmad Ali Shahid, Kiran Nawaz, Waheed Anwar

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Discovery and development of new compounds require intense studies in chemistry, biochemistry. Numerous experiments under laboratory-, greenhouse- and field conditions can be performed to select suitable candidates and to understand their full potential. Novel fungicides are fundamental to combat plant diseases. Fusarium solani is important plant pathogen. New broad spectrum foliar fungicides against complex II were designed in this study. Complex II, namely succinate dehydrogenase (SDH), or succinate quinone oxidoreductase (SQR) is a multi-subunit enzyme at the crossroads of TCA and ETC at the inner mitochondrial membrane. The need for new and innovative fungicides is driven by resistance management, regulatory hurdles and increasing customer expectations amongst others. Fungicidal activity was assessed for the effect on mycelial growth and spore germination of the fungi using fungicide amended media assay. In mycelial growth assay compounds C10 and C6 were highly active against all the isolates. The compounds C1 and C10 were found most potent in spore germination test. It fully proved that the SDHIs designed in this paper displayed as good inhibitory effects against Fusarium solani.

Keywords: Wilt, Fusarium, SDH, antifungal

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Authors: Neelam Patel

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Farmers in peri-urban areas of developing countries depend on wastewater for Irrigation but with great environmental and health hazards. Since, irrigation with wastewater is growing in the developing countries but its suitability to environment and other health factors should be checked. Metal pollution is a very serious issue these days, various neuro, physical and mental disorders are prevailing due to the metal pollution. Waste water contaminated with heavy metals got accumulated in the soil and then bioaccumulated in the vegetables irrigated with waste water. A 3-year field experiment on cauliflower has been done by using wastewater with two different methods of irrigation i.e. Drip and Flood irrigation and checked the impact on the cauliflower and soil quality. Heavy metals (Cr, Cu, Ni, Zn and Pb) have been studied in wastewater used for the irrigation and their accumulation in the soil and vegetable was studied. The study reveals that the concentration of heavy metals increases by 100 times from initial in soil. After 3 years, the concentration of Copper(41 ppm) Chromium(39.4 ppm) Lead(62.2ppm) Zinc(100.5 ppm) and Nickel(75.7 ppm) in Flood irrigated soil while in Drip irrigated soil , Copper (36.4 ppm) Chromium(36.8 ppm) Lead(53.7 ppm) Zinc(70.3 ppm) and Nickel (53.9 ppm). In vegetable, the wastewater irrigated shows an increase in the concentration of metals with the time and the accumulation of Nickel (6.98ppm), Lead (30.18 ppm) and Zinc (55.83 ppm) in drip irrigated while in flood irrigated, Nickel (30.58 ppm), Lead (73.95ppm) Zinc (93.50 ppm) and Copper (54.58 ppm) in edible part of cauliflower which is above the permissible limits suggested by different international agencies. On other hand, the nutrients content i.e. Nitrogen, Phosphorus and Potassium in soil was increased in concentration with time. The study pointed out that the metal contaminated waste water consisting the nutrients in it but also heavy metals which causes health issues in human. While the increase in concentration of nutrients in the soil indirectly helpful to the farmers economically by restricting the use of fertilizers. But the metal pollution directly affects the health of human being. The different method of irrigation suggested that the drip irrigated vegetable acquired less metal then the flood one and is a better combo with the waste water for the irrigation.

Keywords: drip irrigation, heavy metals, metal contamination, waste water

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Authors: Kamil Dydek, Szymon Demski, Kamil Majchrowicz, Paulina Kozera, Bogna Sztorch, Dariusz Brząkalski, Zuzanna Krawczyk, Robert Przekop, Anna Boczkowska

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Thanks to their excellent properties, i.e. high stiffness and strength in relation to their weight, corrosion resistance, and low thermal expansion, Carbon Fiber Reinforced Polymers (CFRPs) are a group of materials readily used in many industrial sectors, e.g. aviation, automotive, wind energy. Conventional CFRPs also have their disadvantages, namely, relatively low electrical conductivity and brittle cracking. To counteract this, a thermoplastic acrylic resin was proposed, which was further modified by the addition of organosilicon compounds and multi-walled carbon nanotubes (MWCNTs). The addition of the organosilicon compounds was aimed at improving the dispersion of the MWCNTs and obtaining good adhesion between the resin and the carbon fibre, where the MWCNTs were used as a conductive filler. In addition, during the fabrication of laminates using the infusion method, thermoplastic nonwovens doped with MWCNTs were placed between the carbon reinforcement layers to achieve a synergistic effect with an increase in electrical and mechanical properties.

Keywords: CFRP, acrylic resin, organosilicon compounds, mechanical properties, electrical properties

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Authors: S. Holly, R. Schnitzer, P. Haslberger, D. Zügner

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The development of new filler consumables necessitates a high effort regarding samples and experiments to achieve the required mechanical properties and chemistry. In the scope of the development of a metal-cored wire with the target tensile strength of 1150 MPa and acceptable impact toughness, thermodynamic and kinetic calculations via MatCalc were used to reduce the experimental work and the resources required. Micro alloying elements were used to reach the high strength as an alternative approach compared to the conventional solid solution hardening. In order to understand the influence of different micro alloying elements in more detail, the influence of different elements on the precipitation behavior in the weld metal was evaluated. Investigations of the microstructure were made via atom probe and EBSD to understand the effect of micro alloying elements. The calculated results are in accordance with the results obtained by experiments and can be explained by the microstructural investigations. On the example of aluminium, the approach is exemplified and clarifies the efficient way of development.

Keywords: alloy development, high strength steel, MatCalc, metal-cored wire

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Authors: Meena Kumari, Ajitha Sharma, Mohan Babu Amberkar, Hasitha Manohar, Joseph Thomas, K. L. Bairy

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Aim: To evaluate the pattern of occurrence of adverse drug reactions (ADRs) with platinum compounds in cancer chemotherapy at a tertiary care hospital. Methods: It was a retrospective, descriptive case record study done on patients admitted to the medical oncology ward of Kasturba Hospital, Manipal from July to November 2012. Inclusion criteria comprised of patients of both sexes and all ages diagnosed with cancer and were on platinum compounds, who developed at least one adverse drug reaction during or after the treatment period. CDSCO proforma was used for reporting ADRs. Causality was assessed using Naranjo Algorithm. Results: A total of 65 patients was included in the study. Females comprised of 67.69% and rest males. Around 49.23% of the ADRs were seen in the age group of 41-60 years, followed by 20 % in 21-40 years, 18.46% in patients over 60 years and 12.31% in 1-20 years age group. The anticancer agents which caused adverse drug reactions in our study were carboplatin (41.54%), cisplatin (36.92%) and oxaliplatin (21.54%). Most common adverse drug reactions observed were oral candidiasis (21.53%), vomiting (16.92%), anaemia (12.3%), diarrhoea (12.3%) and febrile neutropenia (0.08%). The results of the causality assessment of most of the cases were probable. Conclusion: The adverse effect of chemotherapeutic agents is a matter of concern in the pharmacological management of cancer as it affects the quality of life of patients. This information would be useful in identifying and minimizing preventable adverse drug reactions while generally enhancing the knowledge of the prescribers to deal with these adverse drug reactions more efficiently.

Keywords: adverse drug reactions, platinum compounds, cancer, chemotherapy

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Authors: Edgar Aguilar-Ortíz, Nicolas Lévaray, Mireille Vonlanthen, Eric G. Morales-Espinoza, Ernesto Rivera, Xiao Xia Zhu

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Four new star compounds bearing a porphyrin core and cholic acid units, (TPPh(Zn) tetra-CA, TPPh(2H) tetra-CA, TPPh(Zn) octa-CA and TPPh(2H) octa-CA), have been synthesized using the Click Chemistry approach, which consist on azide-alkyne couplings. These novel functionalized porphyrins were characterized by 1H and 13C NMR spectroscopy and their structure was confirmed by MALDI-TOF. The optical properties of these compounds were studied by absorption and fluorescence spectroscopy. On the other hand, order to evaluate the amphiphilic properties of the cholic acid units combined with the optical response of the porphyrin core, we performed absorption and fluorescence studies in function of the polarity of the environment. It was found that as soon as we increase the polarity of the solvent, the Zn-metallated porphyrins, (TPPh(Zn) tetra-CA and TPPh(Zn) octa-CA), are able to form J aggregates, whereas the free-base porphyrins, TPPh(2H) tetra-CA and TPPh(2H) octa-CA, behaved differently.

Keywords: aggregates, amphiphilic, cholic acid, click-chemistry, porphyrin

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Authors: Rui Chen, Jinfeng Zhang, Chun-Sing Lee

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In the past couple of decades, nanoscale metal-organic frameworks (NMOFs) have been highlighted as promising delivery platforms for biomedical applications, which combine many potent features such as high loading capacity, progressive biodegradability and low cytotoxicity. While NMOF has been extensively used as carriers for drugs of different modalities, so far there is no report on exploiting the advantages of NMOF for combination therapy. Herein, we prepared core-shell nanoparticles, where each nanoparticle contains a single graphitic-phase carbon nitride (g-C3N4) nanosheet encapsulated by a zeolitic-imidazolate frameworks-8 (ZIF-8) shell. The g-C3N4 nanosheets are effective visible-light photosensitizer for photodynamic therapy (PDT). When hosting DOX (doxorubicin), the as-synthesized core-shell nanoparticles could realize combinational photo-chemo therapy and provide dual-color fluorescence imaging. Therefore, we expect NMOFs-based core-shell nanoparticles could provide a new way to achieve much-enhanced cancer therapy.

Keywords: carbon nitride, combination therapy, drug delivery, nanoscale metal-organic frameworks

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Authors: Sameena Malik, Ghosh Prakash, Sandeep Mudliar, Vishal Waindeskar, Atul Vaidya

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In this study, the biodegradability enhancement along with COD color and toxicity removal of pharmaceutical effluent by O₃, O₃/Fe²⁺, O₃/nZVI processes has been evaluated. The nZVI particles were synthesized and characterized by XRD and SEM analysis. Kinetic model was reasonably developed to select the ozone doses to be applied based on the ozonation kinetic and mass transfer coefficient values. Nano catalytic ozonation process (O₃/nZVI) effectively enhanced the biodegradability (BI=BOD₅/COD) of pharmaceutical effluent up to 0.63 from 0.18 of control with a COD, color and toxicity removal of 62.3%, 93%, and 75% respectively compared to O₃, O₃/Fe²⁺ pretreatment processes. From the GC-MS analysis, 8 foremost organic compounds were predominantly detected in the pharmaceutical effluent. The disappearance of the corresponding GC-MS spectral peaks during catalyzed ozonation process indicated the degradation of the effluent. The changes in the FTIR spectra confirms the transformation/destruction of the organic compounds present in the effluent to new compounds. Subsequent aerobic biodegradation of pretreated effluent resulted in biodegradation rate enhancement by 5.31, 2.97, and 1.22 times for O₃, O₃/Fe²⁺ and O₃/nZVI processes respectively.

Keywords: iron nanoparticles, pharmaceutical effluent, ozonation, kinetics, mass transfer

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Authors: Bayan Alqasem, Israa Othman, Mohammad Abu Haija, Fawzi Banat

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The large-scale production of wastewater containing highly toxic pollutants made it necessary to find efficient water treatment technologies. Phenolic compounds, which are known to be persistent and hazardous, are highly presented in wastewater. In this study, different ferrite catalysts CrFe₂O₄, CuFe₂O₄, MgFe₂O₄, MnFe₂O₄, NiFe₂O₄, and ZnFe₂O₄ were employed to study the catalytic degradation of phenol aqueous solutions. The catalysts were prepared via sol-gel and co-precipitation methods. All of the prepared catalysts were characterized using infrared spectroscopy (IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The ferrites catalytic activities were tested towards phenol degradation using high-performance liquid chromatography (HPLC). The photocatalytic properties of the ferrites were also investigated. The experimental results suggested that CuFe₂O₄ is an effective catalyst for the removal of phenol from wastewater. Additionally, different CuFe₂O₄composites were also prepared either by varying the metal ratios or incorporating chemically reduced graphene oxide in the ferrite cluster.

Keywords: phenol degradation, ferrite catalysts, ferrite composites, photocatalysis

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Authors: A. J. Babajanyan, T. A. Abrahamyan, H. A. Minasyan, K. V. Nerkararyan

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Optical radiation emitted from a metal-coated fiber tip apex at liquid-air interface was measured. The intensity of the output radiation was strongly depending on the relative position of the tip to a liquid-air interface and varied with surface fluctuations. This phenomenon permits in-situ real-time investigation of nano-metric vibrations of the liquid surface and provides a basis for development of various origin ultrasensitive vibration detecting sensors. The described method can be used for detection of week seismic vibrations.

Keywords: fiber-tip, liquid-air interface, nano vibration, opto-mechanical sensor

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Authors: K. Hiro, T. Wada

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Thermodynamic properties of liquids under negative pressures are interesting and important in fields of scienceand technology. Here, phase transitions of a thermotropic liquid crystal are investigatedin a range from positive to negative pressures with a metal Berthelot tube using a commercial pressure transducer.Two co-existinglines, namely crystal (Kr) – nematic (N), and isotropic liquid (I) - nematic (N) lines, weredrawn in a pressure - temperature plane. The I-N line was drawn to ca. -5 (MPa).

Keywords: Berthelot method, liquid crystal, negative pressure, phase transitions

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Authors: I. O. Oyatayo, K. T. Oyatayo, B. Mamman

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This study was aimed at the assessment of heavy metal pollution of the water in river Benue along Ibi, Taraba State, Nigeria. Water samples were collected at ten sampling points over a distance of 100 meters each. The following water quality parameters were determined: TDS, copper, zinc, chromium, iron, mercury, nickel, and manganese, and the results were compared with the Nigerian Standard for Drinking Water Quality (NSDWQ) and WHO maximum permitted limits. The water quality analysis was conducted using the atomic absorption spectrophotometer (Model: 01-0960-00) at 510 nm. The mean value concentrations of copper, zinc, chromium, nickel, mercury, and mercury are within the permissible limits, while that of iron is above the limit. The summary of ANOVA single-factor statistics with a specified rejection level at α 0.05 is insignificant. The study concludes that the quality of water from river Benue along Ibi is deteriorating and unfit for human consumption. It was recommended that residents of the study area should be enlightened on the effects of indiscriminate dumping of waste and the proper handling and application of fertilizer and herbicides, as some of these end up in the river via surface runoff.

Keywords: heavy, metal, pollution, river, Ibi

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Authors: T. Scattolin, E. Cavarzerani, F. Visentin, F. Rizzolio

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Organopalladium compounds have recently attracted attention for their high stability even under physiological conditions and, above all, for their remarkable in vitro cytotoxicity towards cisplatin-resistant cell lines. Among the organopalladium derivatives, those bearing at least one N-heterocyclic carbene ligand (NHC) and the Pd(II)-η³-allyl fragment have exhibited IC₅₀ values in the micro and sub-micromolar range towards several cancer cell lines in vitro and in some cases selectivity towards cancerous vs. non-tumorigenic cells. Herein, a selection of allyl and indenyl palladates were synthesized using a solvent-free method consisting of grinding the corresponding palladium precursors with different saturated and unsaturated azolium salts. All compounds have been fully characterized by NMR, XRD and elemental analyses. The intramolecular H, Cl interaction has been elucidated and quantified using the Voronoi Deformation Density scheme. Most of the complexes showed excellent cytotoxicity towards ovarian cancer cell lines, with I₅₀ values comparable to or even lower than cisplatin. Interestingly, the potent anticancer activity was also confirmed in a high-serous ovarian cancer (HGSOC) patient-derived tumoroid, with a clear superiority of this class of compounds over classical platinum-based agents. Finally, preliminary enzyme inhibition studies of the synthesized palladate complexes against the model TrxR show that the compounds have high activity comparable to or even higher than auranofin and classical Au(I) NHC complexes. Based on such promising data, further in vitro and in vivo experiments and in-depth mechanistic studies are ongoing in our laboratories.

Keywords: anticancer activity, palladium complexes, organoids, indenyl and allyl ligands

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Authors: Carine Enow-Ayor Tarkang, Victorine Neh Akenji, Dmitri Rouwet, Jodephine Njdma, Andrew Ako Ako, Franco Tassi, Jules Remy Ngoupayou Ndam

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Groundwater is the major water resource in the whole of Bafia used for drinking, domestic, poultry and agricultural purposes, and being an area of intense agriculture, there is a great necessity to do a quality assessment. Bafia is one of the main food suppliers in the Centre region of Cameroon, and so to meet their demands, the farmers make use of fertilizers and other agrochemicals to increase their yield. Less than 20% of the population in Bafia has access to piped-borne water due to the national shortage, according to the authors best knowledge very limited studies have been carried out in the area to increase awareness of the groundwater resources. The aim of this study was to assess heavy metal contamination levels in ground and surface waters and to evaluate the effects of agricultural inputs on water quality in the Bafia area. 57 water samples (including 31 wells, 20 boreholes, 4 rivers and 2 springs) were analyzed for their physicochemical parameters, while collected samples were filtered, acidified with HNO3 and analyzed by ICP-MS for their heavy metal content (Fe, Ti, Sr, Al, Mn). Results showed that most of the water samples are acidic to slightly neutral and moderately mineralized. Ti concentration was significantly high in the area (mean value 130µg/L), suggesting another Ti source besides the natural input from Titanium oxides. The high amounts of Mn and Al in some cases also pointed to additional input, probably from fertilizers that are used in the farmlands. Most of the water samples were found to be significantly contaminated with heavy metals exceeding the WHO allowable limits (Ti-94.7%, Al-19.3%, Mn-14%, Fe-5.2% and Sr-3.5% above limits), especially around farmlands and topographic low areas. The heavy metal concentration was evaluated using the heavy metal pollution index (HPI), heavy metal evaluation index (HEI) and degree of contamination (Cd), while the Ficklin diagram was used for the water based on changes in metal content and pH. The high mean values of HPI and Cd (741 and 5, respectively), which exceeded the critical limit, indicate that the water samples are highly contaminated, with intense pollution from Ti, Al and Mn. Based on the HPI and Cd, 93% and 35% of the samples, respectively, are unacceptable for drinking purposes. The lowest HPI value point also had the lowest EC (50 µS/cm), indicating lower mineralization and less anthropogenic influence. According to the Ficklin diagram, 89% of the samples fell within the near-neutral low-metal domain, while 9% fell in the near-neutral extreme-metal domain. Two significant factors were extracted from the PCA, explaining 70.6% of the total variance. The first factor revealed intense anthropogenic activity (especially from fertilizers), while the second factor revealed water-rock interactions. Agricultural activities thus have an impact on the heavy metal content of groundwater in the area; hence, much attention should be given to the affected areas in order to protect human health/life and thus sustainably manage this precious resource.

Keywords: Bafia, contamination, degree of contamination, groundwater, heavy metal pollution index

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Authors: Anelise Leal Vieira Cubas, Marina de Medeiros Machado, Marília de Medeiros Machado

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The volatile organic compounds - BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) petroleum derivatives, have high rates of toxicity, which may carry consequences for human health, biota and environment. In this direction, this paper proposes a method of treatment of these compounds by using corona discharge plasma technology. The efficiency of the method was tested by analyzing samples of BTEX after going through a plasma reactor by gas chromatography method. The results show that the optimal residence time of the sample in the reactor was 8 minutes.

Keywords: BTEX, degradation, cold plasma, ecological sciences

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Authors: Julie Connelly, Tanvi Toprani, Xin Xie, Dhinoth Kumar Bangarusamy, Kris C. Gunsalus

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The overuse of antibiotics worldwide has contributed to the development of multi-drug resistant (MDR) pathogenic bacterial strains. There is an increasing urgency to discover antibiotics to combat MDR pathogens. The microbiome of the Arabian Gulf is a largely unexplored and potentially rich source of novel bioactive compounds. Microbes that inhabit the Abu Dhabi coastal regions adapt to extreme environments with high salinity, hot temperatures, large temperature fluctuations, and acute exposure to solar energy. The microbes native to this region may produce unique metabolites with therapeutic potential as antibiotics and antifungals. We have isolated 200 pure bacterial strains from mangrove sediments, cyanobacterial mats, and coral reefs of the Abu Dhabi region. In this project, we aim to screen the marine bacterial strains to identify antibiotics, in particular undocumented compounds that show activity against existing antibiotic-resistant strains. We have acquired the ESKAPE pathogen panel, which consists of six antibiotic-resistant gram-positive and gram-negative bacterial pathogens that collectively cause most clinical infections. Our initial efforts of the primary screen using colony-picking co-culture assay have identified several candidate marine strains producing potential antibiotic compounds. We will next apply different assays, including disk-diffusion and broth turbidity growth assay, to confirm the results. This will be followed by bioactivity-guided purification and characterization of target compounds from the scaled-up volume of candidate strains, including SPE fraction, HPLC fraction, LC-MS, and NMR. For antimicrobial compounds with unknown structures, our final goal is to investigate their mode of action by identifying the molecular target.

Keywords: marine bacteria, natural products, drug discovery, ESKAPE panel

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Authors: Sam Bartlett, Thomas Bacquart, Arul Murugan, Abigail Morris

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Fuel cell electric vehicles provide the potential to decarbonise road transport, create new economic opportunities, diversify national energy supply, and significantly reduce the environmental impacts of road transport. A potential issue, however, is that the catalyst used at the fuel cell cathode is susceptible to degradation by impurities, especially sulphur-containing compounds. A recent European Directive (2014/94/EU) stipulates that, from November 2017, all hydrogen provided to fuel cell vehicles in Europe must comply with the hydrogen purity specifications listed in ISO 14687-2; this includes reactive and toxic chemicals such as ammonia and total sulphur-containing compounds. This requirement poses great analytical challenges due to the instability of some of these compounds in calibration gas standards at relatively low amount fractions and the difficulty associated with undertaking measurements of groups of compounds rather than individual compounds. Without the available reference materials and analytical infrastructure, hydrogen refuelling stations will not be able to demonstrate compliance to the ISO 14687 specifications. The hydrogen purity laboratory at NPL provides world leading, accredited purity measurements to allow hydrogen refuelling stations to evidence compliance to ISO 14687. Utilising state-of-the-art methods that have been developed by NPL’s hydrogen purity laboratory, including a novel method for measuring total sulphur compounds at 4 nmol/mol and a hydrogen impurity enrichment device, we provide the capabilities necessary to achieve these goals. An overview of these capabilities will be given in this paper. As part of the EMPIR Hydrogen co-normative project ‘Metrology for sustainable hydrogen energy applications’, NPL are developing a validated analytical methodology for the measurement of speciated sulphur-containing compounds in hydrogen at low amount fractions pmol/mol to nmol/mol) to allow identification and measurement of individual sulphur-containing impurities in real samples of hydrogen (opposed to a ‘total sulphur’ measurement). This is achieved by producing a suite of stable gravimetrically-prepared primary reference gas standards containing low amount fractions of sulphur-containing compounds (hydrogen sulphide, carbonyl sulphide, carbon disulphide, 2-methyl-2-propanethiol and tetrahydrothiophene have been selected for use in this study) to be used in conjunction with novel dynamic dilution facilities to enable generation of pmol/mol to nmol/mol level gas mixtures (a dynamic method is required as compounds at these levels would be unstable in gas cylinder mixtures). Method development and optimisation are performed using gas chromatographic techniques assisted by cryo-trapping technologies and coupled with sulphur chemiluminescence detection to allow improved qualitative and quantitative analyses of sulphur-containing impurities in hydrogen. The paper will review the state-of-the art gas standard preparation techniques, including the use and testing of dynamic dilution technologies for reactive chemical components in hydrogen. Method development will also be presented highlighting the advances in the measurement of speciated sulphur compounds in hydrogen at low amount fractions.

Keywords: gas chromatography, hydrogen purity, ISO 14687, sulphur chemiluminescence detector

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Authors: Carl-Magnus Everitt, Bo Alfredsson

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Contact mechanics and tribology have been combined with fundamental fatigue and fracture mechanics to form the asperity mechanism which supplies an explanation for the surface-initiated rolling contact fatigue damage, called pitting or spalling. The cracks causing the pits initiates at one surface point and thereafter they slowly grow into the material before chipping of a material piece to form the pit. In the current study, the lubrication aspects on fatigue initiation are simulated by passing a single asperity through a thermal elastohydrodynamic lubricated, TEHL, contact. The physics of the lubricant was described with Reynolds equation and the lubricants pressure-viscosity relation was modeled by Roelands equation, formulated to include temperature dependence. A pressure dependent shear limit was incorporated. To capture the full phenomena of the sliding contact the temperature field was resolved through the incorporation of the energy flow. The heat was mainly generated due to shearing of the lubricant and from dry friction where metal contact occurred. The heat was then transported, and conducted, away by the solids and the lubricant. The fatigue damage caused by the asperities was evaluated through Findley’s fatigue criterion. The results show that asperities, in the size of surface roughness found in applications, may cause surface initiated fatigue damage and crack initiation. The simulations also show that the asperities broke through the lubricant in the inlet, causing metal to metal contact with high friction. When the asperities thereafter moved through the contact, the sliding provided the asperities with lubricant releasing the metal contact. The release of metal contact was possible due to the high viscosity the lubricant obtained from the high pressure. The metal contact in the inlet caused higher friction which increased the risk of fatigue damage. Since the metal contact occurred in the inlet it increased the fatigue risk more for asperities subjected to negative slip than positive slip. Therefore the fatigue evaluations showed that the asperities subjected to negative slip yielded higher fatigue stresses than the asperities subjected to positive slip of equal magnitude. This is one explanation for why pitting is more common in the dedendum than the addendum on pinion gear teeth. The simulations produced further validation for the asperity mechanism by showing that asperities cause surface initiated fatigue and crack initiation.

Keywords: fatigue, rolling, sliding, thermal elastohydrodynamic

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Authors: M. Shirinbayan, J. Fitoussi, N. Abbasnezhad, A. Lucas, A. Tcharkhtchi

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Sheet Molding Compounds (SMCs) with special microstructures are very attractive to use in automobile structures especially when they are accidentally subjected to collision type accidents because of their high energy absorption capacity. These are materials designated as standard SMC, Advanced Sheet Molding Compounds (A-SMC), Low-Density SMC (LD-SMC) and etc. In this study, testing methods have been performed to compare the mechanical responses and damage phenomena of SMC, LD-SMC, and A-SMC under quasi-static and high strain rate tensile tests. The paper also aims at investigating the effect of an initial pre-damage induced by fatigue on the tensile dynamic behavior of A-SMC. In the case of SMCs and A-SMCs, whatever the fibers orientation and applied strain rate are, the first observed phenomenon of damage corresponds to decohesion of the fiber-matrix interface which is followed by coalescence and multiplication of these micro-cracks and their propagations. For LD-SMCs, damage mechanisms depend on the presence of Hollow Glass Microspheres (HGM) and fibers orientation.

Keywords: SMC, Sheet Molding Compound, LD-SMC, Low-Density SMC, A-SMC, Advanced Sheet Molding Compounds, HGM, Hollow Glass Microspheres, damage

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Authors: Howaida I. Abd-Alla, Nagwa M. M. Shalaby

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The fruit rind of Fortunella margarita (Nagami Kumkuat) was investigated for its chemical constituents. Thirteen metabolites were obtained and classified into, a sterol; β-sitosterol (1) and twelve phenolic compounds, three coumarins; xanthotoxin (2), isopimpinellin (3), umbelliferone (4), nine flavonoids of O-glycosides of flavone; apigenin-7-O-β-D-glucopyranoside (5), apigenin-7-O-rhamnoglucoside (rhoifolin) (6), C-glycosides; vitexin (7), vicenin II (8), and the methoxylated; 6-methoxyapigenin-7-methyl ether (9) and tangeretin (10) as well as flavanones class; naringenin (11), liquiritigenin (12), hesperdin (hesperetin-7-rhamnoglucoside) (13). All compounds were identified for the first time in F. margarita except compound (8). The major glycosides 5, 6, and 13 and total crude extract showed potential antiviral activity against live Newcastle disease virus vaccine strains (Komarov and LaSota) and live infectious bursitis viruses vaccine strain D78 replication in VERO cell cultures and on specific pathogen-free embryonated chicken eggs. Antiviral inhibitory concentration fifty (IC50), cytotoxic concentration fifty (CC50), and therapeutic index (TI) were calculated. In addition, the extract and compounds 7 and 13 showed marked antimicrobial activity against different strains of fungi, Gram-positive and negative bacteria, including some foodborne pathogens of animal origin, caused human disease. These results suggested that the extract of F. margarita may be considered potentially useful as a source of natural antiviral and antimicrobial agents. It can be used as an ingredient for functional food and/or pharmaceuticals.

Keywords: antimicrobial, antiviral, Fortunella margarita, Nagami Kumkuat, phenolic secondary metabolites

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Authors: Ozlem Temiz Arpaci, Meryem Tasci, Hakan Goker

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Benzimidazole, a structural isostere of indol and purine nuclei that can interact with biopolymers, can be identified as master key. So that benzimidazole compounds are important fragments in medicinal chemistry because of their wide range of biological activities including antimicrobial activity. We planned to synthesize some benzimidazole compounds for developing new antimicrobial drug candidates. In this study, we put some heterocyclic rings on second position and an amidine group on the fifth position of benzimidazole ring and synthesized them using a multiple step procedure. For the synthesis of the compounds, as the first step, 4-chloro-3-nitrobenzonitrile was reacted with cyclohexylamine in dimethyl formamide. Imidate esters (compound 2) were then prepared with absolute ethanol saturated with dry HCl gas. These imidate esters which were not too stable were converted to compound 3 by passing ammonia gas through ethanol. At the Pd / C catalyst, the nitro group is reduced to the amine group (compound 4). Finally, various aldehyde derivatives were reacted with sodium metabisulfite addition products to give compound 5-20. Melting points were determined on a Buchi B-540 melting point apparatus in open capillary tubes and are uncorrected. Elemental analyses were done a Leco CHNS 932 elemental analyzer. 1H-NMR and 13C-NMR spectra were recorded on a Varian Mercury 400 MHz spectrometer using DMSO-d6. Mass spectra were acquired on a Waters Micromass ZQ using the ESI(+) method. The structures of them were supported by spectral data. The 1H-NMR, 13C NMR and mass spectra and elemental analysis results agree with those of the proposed structures. Antimicrobial activity studies of the synthesized compounds are under the investigation.

Keywords: benzimidazoles, synthesis, structure elucidation, antimicrobial

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Authors: Arunporn Itharat, Kamonmas Srikwan, Srisopa Ruangnoo, Pakakrong Thongdeeying

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Background: The rhizomes of Smilax glabra (SG) has long been used in Traditional Chinese and Thai herbal medicine to treat a variety of infectious diseases and immunological disorders. Objective: To investigate the in vitro anti-allergic activities of crude extracts and pure isolated flavonoid compounds from SG by determination of inhibitory effects on antigen-induced release of β-hexosaminidase from RBL-2H3 cells. Methods: The in vitro inhibitory effects of crude aqueous and organic extracts on beta-hexosaminidase release in RBL-2H3 cells were evaluated as an in vitro indication of possible anti-allergic activity in vivo. Bioassay-guided fractionation of extracts was used to isolate flavonoid compounds from the ethanolic extracts. Results: The 95% and 50% ethanolic extracts of SG showed remarkably high anti-allergic activity, with IC50 values of 5.74 ± 2.44 and 23.54 ± 4.75 μg/ml, much higher activity than that for Ketotifen (IC50 58.90 μM). The water extract had negligible activity (IC50 > 100 μg/ml). The two isolated flavonols, Engeletin and Astilbin, showed weak anti-allergic activity, IC50 values 97.46 ± 2.04 and > 100 μg/ml, respectively. Conclusions: The 95% and 50% ethanolic extracts of SG showed strong anti-allergic activity but two flavonol constituents did not show any significant anti-allergic activity. These findings suggest that a combination of effects of various phytochemicals in crude extracts used in traditional medicine are responsible for the purported anti-allergic activity of SG herbal preparations. The plethora of constituents in crude extracts, as yet unidentified, are likely to be acting synergistically to account for the strong observed anti-allergic in vitro activity.

Keywords: Smilax glabra, anti-allergic activity, RBL-2H3 cells, flavonoid compounds

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Authors: V. Pérez-Herranz, M. Pinel, E. M. Ortega, M. García-Gabaldón

Abstract:

In the present work, Electrochemical Impedance Spectrocopy (EIS) is applied to study the transport of different metal cations through a cation-exchange membrane. This technique enables the identification of the ionic-transport characteristics and to distinguish between different transport mechanisms occurring at different current density ranges. The impedance spectra are dependent on the applied dc current density, on the type of cation and on the concentration. When the applied dc current density increases, the diameter of the impedance spectra loops increases because all the components of membrane system resistance increase. The diameter of the impedance plots decreases in the order of Na(I), Ni(II) and Cr(III) due to the increased interactions between the negatively charged sulfonic groups of the membrane and the cations with greater charge. Nyquist plots are shifted towards lower values of the real impedance, and its diameter decreases with the increase of concentration due to the decrease of the solution resistance.

Keywords: ion-exchange membranes, Electrochemical Impedance Spectrocopy, multivalent metal cations, membrane system

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Authors: Sabeen Alam, Mehboob Alam

Abstract:

The research work entitled “Effect of Bacillus pumilus strains on heavy metal accumulation in lettuce grown on contaminated soil” focused on functional role of Bacillus pumilus strains inoculated with lettuce seed in mitigating heavy metal in chromite mining soil. In this experiment, factor A was three Bacillus pumilus strains (sequence C-2PMW-8, C-1 SSK-8 and C-1 PWK-7) while soil used for this experiment was collected from Prang Ghar mining site and lettuce seeds were grown in three levels of chromite mining soil (2.27, 4.65 and 7.14 %). For mining soil minimum days to germinate noted in lettuce grown on garden soil inoculated with sequence. Maximum germination percentage noted was for C-1 SSK-8 grown on garden soil, maximum lettuce height for sequence C-2 PWM-8, fresh leaf weight for C-1 PWK-7 inoculated lettuce, dry weight of lettuce leaf for lettuce inoculated with C-1 SSK-8 and C-1 PWK-7 strains, number of leaves per plant for lettuce inoculated with C-1 SSK-8, leaf area for C-2 PMW-8 inoculated lettuce, survival percentage for C-1 SSK-8 treated lettuce and chlorophyll content for C-2 PMW-8. Results related to heavy metals accumulation showed that minimum chromium was in lettuce and in soil for all three sequences, cadmium (Cd) in lettuce and in soil for all three sequences, manganese (Mn) in lettuce and in soil for three sequences, lead (Pb) in lettuce and in soil for three sequences. It can be concluded that chromite mining soil significantly reduced the growth and survival of lettuce, but when lettuce was inoculated with Bacillus.pumilus strains, it enhances growth and survival. Similarly, minimum heavy metal accumulation in plant and soil, regardless of type of Bacillus pumilus used, all three sequences has same mitigating effect on heavy metal in both soil and lettuce. All the three Bacillus pumilus strains ensured reduction in heavy metals content (Mn, Cd, Cr) in lettuce, below the maximum permissible limits of WHO 2011.

Keywords: bacillus pumilus, heavy metals, permissible limits, lettuce, chromite mining soil, mitigating effect

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Authors: Pakakrong Thongdeeying, Srisopa Ruangnoo, Arunporn Itharat

Abstract:

The rhizomes of Smilax corbularia Kunth have long been used as common ingredients in anticancer preparations. Thus, the objective of this study is to investigate cytotoxicity of S. corbularia and its ingredients against cholangiocarcinoma cell line (KKU-M156) by SRB assay. Ethanolic and water extracts of S. corbularia rhizomes were obtained using the procedures followed by Thai traditional doctors. Bioassay guided isolation was used to isolate cytotoxic compounds. The results revealed that the ethanolic extract of S. corbularia exhibited activity against KKU-M156 cell line with an IC50 value of 84.53±1.62 µg/ml, but the water extract showed no cytotoxic activity. Three flavonoid compounds [astilbin (1), engeletin (2), and quercetin (3)] were isolated from the ethanolic extract. Compound 3 exhibited the strongest activity against KKU-M156 cell line (IC50 = 8.14 ± 1.15 µg/ml), but 1 and 2 showed no cytotoxic activity (IC50 > 100 µg/ml). In conclusion, quercetin showed the highest efficacy against cholangiocarcinoma. These results support the traditional use of this plant by Thai traditional doctors for cancer treatment.

Keywords: cholangiocarcinoma, cytotoxicity, flavonoid, Smilax corbularia

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Authors: Ramandeep Kaur, Kamaljit Kaur, Preeti Ahluwalia, Poonam A. Sachdev

Abstract:

Bread is an ideal vehicle to impart bioactive compounds to the consumers in a convenient manner. This study evaluated bread enriched with red sweet pepper powder (RSP) at 2, 4, 6, 8, 10% and compared to control bread (without RSP). The bread crumbs were assayed for bioactive, physical, nutritional, textural, color, and sensory properties. Bread supplemented with RSP improved its color, nutritional, and bioactive properties. The low moisture content and increased hardness were observed at higher levels of RSP. Color intensity (expressed as L*, a*, b* values) of bread with 2 and 4% RSP were lower than those of high levels, and the same trend was observed for protein, fibre and ash content of bread. Significant (p < 0.05) increases were recorded for bioactive compounds such as total phenols (0.145 to 235 mg GAE/g), antioxidant activity (56% to 78%) and flavonoids (0.112 to 0.379 mg/g) as the level of powder increased. Bread enriched with 8% RSP showed improved sensory profile as compared to control, whereas a further increase in RSP decreased the sensory and textural properties. Thus, RSP act as a natural colorant and functional food that enhanced the functional and nutritional properties of bread and can be used to customize bread for specific health needs.

Keywords: breads, bioactive compounds, red sweet pepper powder, sensory scores

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Authors: Sushil Kumar Singh, Ashok Kumar, Ankit Ganeshpurkar, Ravi Singh, Devendra Kumar

Abstract:

In spectrum of neurodegenerative diseases, Alzheimer’s disease (AD) is characterized by the presence of amyloid β plaques and neurofibrillary tangles in the brain. It results in cognitive and memory impairment due to loss of cholinergic neurons, which is considered to be one of the contributing factors. Donepezil, an acetylcholinesterase (AChE) inhibitor which also inhibits butyrylcholinesterase (BuChE) and improves the memory and brain’s cognitive functions, is the most successful and prescribed drug to treat the symptoms of AD. The present work is based on designing of the selective BuChE inhibitors using computational techniques. In this work, machine learning models were trained using classification algorithms followed by screening of diverse chemical library of compounds. The various molecular modelling and simulation techniques were used to obtain the virtual hits. The amide derivatives of 4-(phenylsulfonamido) benzoic acid were synthesized and characterized using 1H & 13C NMR, FTIR and mass spectrometry. The enzyme inhibition assays were performed on equine plasma BuChE and electric eel’s AChE by method developed by Ellman et al. Compounds 31, 34, 37, 42, 49, 52 and 54 were found to be active against equine BuChE. N-(2-chlorophenyl)-4-(phenylsulfonamido)benzamide and N-(2-bromophenyl)-4-(phenylsulfonamido)benzamide (compounds 34 and 37) displayed IC50 of 61.32 ± 7.21 and 42.64 ± 2.17 nM against equine plasma BuChE. Ortho-substituted derivatives were more active against BuChE. Further, the ortho-halogen and ortho-alkyl substituted derivatives were found to be most active among all with minimal AChE inhibition. The compounds were selective toward BuChE.

Keywords: Alzheimer disease, butyrylcholinesterase, machine learning, sulfonamides

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Authors: Kuan Lun Pan, Moo Been Chang

Abstract:

Volatile organic compounds (VOCs) are one of major air contaminants, and they can react with nitrogen oxides (NOx) in atmosphere to form ozone (O3) and peroxyacetyl nitrate (PAN) with solar irradiation, leading to environmental hazards. In addition, some VOCs are toxic at low concentration levels and cause adverse effects on human health. How to effectively reduce VOCs emission has become an important issue. Thermal catalysis is regarded as an effective way for VOCs removal because it provides oxidation route to successfully convert VOCs into carbon dioxide (CO2) and water (H2O(g)). Single perovskite-type catalysts are promising for VOC removal, and they are of good potential to replace noble metals due to good activity and high thermal stability. Single perovskites can be generally described as ABO3 or A2BO4, where A-site is often a rare earth element or an alkaline. Typically, the B-site is transition metal cation (Fe, Cu, Ni, Co, or Mn). Catalytic properties of perovskites mainly rely on nature, oxidation states and arrangement of B-site cation. Interestingly, single perovskites could be further synthesized to form double perovskite-type catalysts which can simply be represented by A2B’B”O6. Likewise, A-site stands for an alkaline metal or rare earth element, and the B′ and B′′ are transition metals. Double perovskites possess unique surface properties. In structure, three-dimensional of B-site with ordered arrangement of B’O6 and B”O6 is presented alternately, and they corner-share octahedral along three directions of the crystal lattice, while cations of A-site position between the void of octahedral. It has attracted considerable attention due to specific arrangement of alternating B-site structure. Therefore, double perovskites may have more variations than single perovskites, and this greater variation may promote catalytic performance. It is expected that activity of double perovskites is higher than that of single perovskites toward VOC removal. In this study, double perovskite-type catalyst (La2CoMnO6) is prepared and evaluated for VOC removal. Also, single perovskites including LaCoO3 and LaMnO3 are tested for the comparison purpose. Toluene (C7H8) is one of the important VOCs which are commonly applied in chemical processes. In addition to its wide application, C7H8 has high toxicity at a low concentration. Therefore, C7H8 is selected as the target compound in this study. Experimental results indicate that double perovskite (La2CoMnO6) has better activity if compared with single perovskites. Especially, C7H8 can be completely oxidized to CO2 at 300oC as La2CoMnO6 is applied. Characterization of catalysts indicates that double perovskite has unique surface properties and is of higher amounts of lattice oxygen, leading to higher activity. For durability test, La2CoMnO6 maintains high C7H8 removal efficiency of 100% at 300oC and 30,000 h-1, and it also shows good resistance to CO2 (5%) and H2O(g) (5%) of gas streams tested. For various VOCs including isopropyl alcohol (C3H8O), ethanal (C2H4O), and ethylene (C2H4) tested, as high as 100% efficiency could be achieved with double perovskite-type catalyst operated at 300℃, indicating that double perovskites are promising catalysts for VOCs removal, and possible mechanisms will be elucidated in this paper.

Keywords: volatile organic compounds, Toluene (C7H8), double perovskite-type catalyst, catalysis

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Authors: Juzhong Tan, William Kerr

Abstract:

Conching is one critical procedure in chocolate processing, where special flavors are developed, and smooth mouse feel the texture of the chocolate is developed due to particle size reduction of cocoa mass and other additives. Therefore, determination of the particle size and volatile compounds profile of cocoa bean is important for chocolate manufacturers to ensure the quality of chocolate products. Currently, precise particle size measurement is usually done by laser scattering which is expensive and inaccessible to small/medium size chocolate manufacturers. Also, some other alternatives, such as micrometer and microscopy, can’t provide good measurements and provide little information. Volatile compounds analysis of cocoa during conching, has similar problems due to its high cost and limited accessibility. In this study, a self-made electronic nose system consists of gas sensors (TGS 800 and 2000 series) was inserted to a conching machine and was used to monitoring the volatile compound profile of chocolate during the conching. A model correlated volatile compounds profiles along with factors including the content of cocoa, sugar, and the temperature during the conching to particle size of chocolate particles by genetic programming was established. The model was used to predict the particle size reduction of chocolates with different cocoa mass to sugar ratio (1:2, 1:1, 1.5:1, 2:1) at 8 conching time (15min, 30min, 1h, 1.5h, 2h, 4h, 8h, and 24h). And the predictions were compared to laser scattering measurements of the same chocolate samples. 91.3% of the predictions were within the range of later scatting measurement ± 5% deviation. 99.3% were within the range of later scatting measurement ± 10% deviation.

Keywords: cocoa bean, conching, electronic nose, genetic programming

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Authors: Christina Drosou, Konstantina E. Kyriakopoulou, Andreas Bimpilas, Dimitrios Tsimogiannis, Magdalini C. Krokida

Abstract:

Rationale: Agiorgitiko is one of the most widely-grown and commercially well-established red wine varieties in Greece. Each year viticulture industry produces a large amount of waste consisting of grape skins and seeds (pomace) during a short period. Grapes contain polyphenolic compounds which are partially transferred to wine during winemaking. Therefore, winery wastes could be an alternative cheap source for obtaining such compounds with important antioxidant activity. Specifically, red grape waste contains anthocyanins and flavonols which are characterized by multiple biological activities, including cardioprotective, anti-inflammatory, anti-carcinogenic, antiviral and antibacterial properties attributed mainly to their antioxidant activity. Ultrasound assisted extraction (UAE) is considered an effective way to recover phenolic compounds, since it combines the advantage of mechanical effect with low temperature. Moreover, green solvents can be used in order to recover extracts intended for used in the food and nutraceutical industry. Apart from the extraction, pre-treatment process like drying can play an important role on the preservation of the grape pomace and the enhancement of its antioxidant capacity. Objective: The aim of this study is to recover natural extracts from winery waste with high antioxidant capacity using green solvents so they can be exploited and utilized as enhancers in food or nutraceuticals. Methods: Agiorgitiko grape pomace was dehydrated by air drying (AD) and accelerated solar drying (ASD) in order to explore the effect of the pre-treatment on the recovery of bioactive compounds. UAE was applied in untreated and dried samples using water and water: ethanol (1:1) as solvents. The total antioxidant potential and phenolic content of the extracts was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and Folin-Ciocalteu method, respectively. Finally, the profile of anthocyanins and flavonols was specified using HPLC-DAD analysis. The efficiency of processes was determined in terms of extraction yield, antioxidant activity, phenolic content and the anthocyanins and flavovols profile. Results & Discussion: The experiments indicated that the pre-treatment was essential for the recovery of highly nutritious compounds from the pomace as long as the extracts samples showed higher phenolic content and antioxidant capacity. Water: ethanol (1:1) was considered a more effective solvent on the recovery of phenolic compounds. Moreover, ASD grape pomace extracted with the solvent system exhibited the highest antioxidant activity (IC50=0.36±0.01mg/mL) and phenolic content (TPC=172.68±0.01mgGAE/g dry extract), followed by AD and untreated pomace. The major compounds recovered were malvidin3-O-glucoside and quercetin3-O-glucoside according to the HPLC analysis. Conclusions: Winery waste can be exploited for the recovery of nutritious compounds using green solvents such as water or ethanol. The pretreatment of the pomace can significantly affect the concentration of phenolic compounds, while UAE is considered a highly effective extraction process.

Keywords: agiorgitico grape pomace, antioxidants, phenolic compounds, ultrasound assisted extraction

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