Antioxidant and α-glucosidase inhibitory activities of eight neglected fruit extracts and UHPLC-MS/MS profile of the active extracts

The 70% ethanolic extracts from eight neglected fruits; Muntingia calabura, Leucaena leucocephala, Spondias dulcis, Syzygium jambos, Mangifera caesia, Ardisia elliptica, Cynometra cauliflora and Ficus auriculata were evaluated for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, α-glucosidase inhibitory activities as well as total phenolic content. The results of this study revealed that M. caesia fruit extract demonstrated the most potent radical scavenging activity. Among the fruits examined for α-glucosidase inhibitory activity, M. calabura and F. auriculata exhibited strong activity with no significant difference. The Pearson correlation indicated that the activities of M. caesia and F. auriculata contributed by phenolic compounds. A total of 65 metabolites were tentatively identified by using ultra-high-performance liquid chromatography tandem mass spectrometry (UHLPC-MS/MS). These findings suggested that the possible application of M. caesia and F. auriculata as a functional food with antioxidant and α-glucosidase inhibitory properties.     

Competitiveness analysis of automotive industry in Turkey using Bayesian networks

The purpose of this study is to analyze the relations between the factors that enable national competitive advantage and the establishment of competitive superiority in automotive industry through a comprehensive analytical model. Bayesian networks (BN) are used to investigate the associations of different factors in the automotive industry which lead to competitive advantage. The results of the study focus on building a road map for the automotive sector policy makers in their way to improve the competitiveness through scenario analysis. Using the probabilistic dependency structure of the Bayesian network all of the variables in the model can be estimated. Thus, with the proposed model the automotive industry can be analyzed as a whole system and not only in terms of single variables. Findings of the model indicate that technological developments in automotive industry can alter the nature of competition in this industry.     

Molecular Characterization of α- and β-Thalassaemia among Malay Patients

Both α- and β-thalassaemia syndromes are public health problems in the multi-ethnic population of Malaysia. To molecularly characterise the α- and β-thalassaemia deletions and mutations among Malays from Penang, Gap-PCR and multiplexed amplification refractory mutation systems were used to study 13 α-thalassaemia determinants and 20 β-thalassaemia mutations in 28 and 40 unrelated Malays, respectively. Four α-thalassaemia deletions and mutations were demonstrated. −−^SEA deletion and α^CSα accounted for more than 70% of the α-thalassaemia alleles. Out of the 20 β-thalassaemia alleles studied, nine different β-thalassaemia mutations were identified of which β^E accounted for more than 40%. We concluded that the highest prevalence of (α- and β-thalassaemia alleles in the Malays from Penang are −−^SEA deletion and β^E mutation, respectively.     

Physicochemical properties of liquid natural rubber bearing fluoro groups for hydrophobic surfaces

The modification of liquid natural rubber (LNR) has attracted interests among chemists as it brings improvements to several of its properties and widens its application to various fields. LNR can be modified into fluorinated LNR (F-LNR) which is of interest to industries due to its remarkable properties, including low surface energies, high thermal stabilities, together with its significant hydrophobic characters. In this work, a new route to prepare fluorinated rubber was presented. Hydroxylated LNR (OH-LNR) was initially synthesized in good yield via oxidation in the presence of tungsten complex catalyst and acetic acid with hydrogen peroxide as an oxidant. The optimum hydroxyl content of 57.0% was obtained within 6 h reaction time at 90 °C. In the second step, the esterification of OH-LNR using pentadecafluorooctanoyl chloride (PDFOC) under mild conditions was conducted, leading to LNR bearing fluoro groups in the side chain of LNR (F-LNR). ATR-FTIR spectroscopy was used to elucidate the structure and determine any changes in the functional groups that may have been induced during the reaction. ¹H NMR spectroscopy was employed to reveal that a high fluorine content of 48.6% was obtained using 3:1 molar ratio of OH-LNR:PDFOC for 8 h at 50 °C. The microstructure of F-LNR was further analyzed using ¹⁹F NMR and ¹³C NMR spectroscopies, and the results confirmed the presence of fluorine in LNR. Thermogravimetric analyses also indicated that the modification improved thermal stability of the LNR. Contact angle measurements were also conducted to verify the hydrophobicity of the fluorinated rubber and the results obtained showed that F-LNR exhibited higher hydrophobicity than LNR.     

Synthesis and application of phenylcarbamodithioate compound for steel protection

Phenyldithiocarbamate compound has been synthesized and studied as corrosion inhibitor for steel. Dithiocarbamate (DTC) compounds with linear alkyl groups are good inhibitors, but their stability is quite low in acidic solutions. It should be noted that long-term stability is important for practical applications, in order to avoid excess use of chemicals. So, we have synthesized phenyl substituted DTC which offers strong inhibition efficiency and extra stability. This new inhibitor is chemically adsorbed on steel through its DTC group, while the aromatic ring provides extra stability and long-term efficiency. For the assessment of corrosion kinetics, we have utilized potentiodynamic and ac impedance studies; also solution assay analysis was realized with atomic absorption spectroscopy. It was revealed that inhibitor exhibits remarkably high efficiency, even under elevated temperature conditions. At 55 °C temperature conditions, i_corr value decreased from 5050 to 154 μA cm^?2, with the addition of 500 ppm inhibitor. The long-term stability of inhibitor was also tested and 85.93% efficiency was obtained after three days of exposure period for 500 ppm concentration.     

Microbial fuel cell-based sensor for Enterobacter sp. KBH6958 activity monitoring during hydrogen production: the effects of pH and glucose concentration

Journal of Applied Electrochemistry - A microbial fuel cell (MFC) is an electricity-generating device utilising electrochemically active microorganisms as biocatalysts. Using MFC as a biosensor to...     

Molecularly imprinted poly(acrylonitrile‐co‐acrylic acid) matrix with sclareol

There are presented results regarding a new set of molecularly imprinted polymers (MIPs) based on acrylonitrile:acrylic acid (AN:AA) copolymer matrix. As template, it was used sclareol, an important anticancer bioactive compound, never used before for molecular imprinting. An emerging and insufficient studied MIP preparation method, namely the phase inversion, was used to prepare 0.8 mm spherical sclareol MIPs (S‐MIPs). Three AN:AA copolymers, having the initial monomer ratios 90:10, 80:20, and 70:30, were synthesized by radical copolymerization in emulsion, without emulsifier. After that, each copolymer was dissolved in the presence of the template (sclareol) in dimethylformamide. The imprinting and the morphology of these new materials were analyzed by rheology, elemental analysis, infrared spectroscopy, size exclusion chromatography, thermogravimetric analysis, differential scanning calorimetry, batch rebinding tests, and Scatchard analysis. The conclusion was that the AN:AA‐80:20 matrix proved to be the optimized solution between high rigidity (given by the AN segments) and high affinity for the template (given by AA segments), the average imprinting factor for this system being 2.67. POLYM. ENG. SCI., 54:1484–1494, 2014. © 2013 Society of Plastics Engineers     

In vitro antioxidant and in vivo xanthine oxidase inhibitory activities of Pandanus amaryllifolius in potassium oxonate‐induced hyperuricemic rats

Xanthine oxidase (XO) plays an important role in the regulation of uric acid and prevents it from being overproduced as in hyperuricemia disease. The combined effects of antioxidant and xanthine oxidase inhibitor would become a promising approach for hyperuricemia treatment. In this research, the antioxidant and xanthine oxidase inhibitory activities of Pandanus amaryllifolius leaf were evaluated. The leaf water extract (PA‐W) showed highest total phenols, and petroleum ether extract (PA‐PE) showed highest total flavonoids contents. The antioxidant activity of DPPH, metal chelating and hydrogen peroxide was highest in PA‐W extract. The treatment of PA‐W extract at 1000 mg kg^?1 body weight in potassium oxonate‐induced hyperuricemic rats showed significant (P < 0.001) decrease in serum uric acid level by 85% and XO activity by 64%, respectively, as compared to the hyperuricemic rats. In conclusion, the P. amaryllifolius possess the dual effect of antioxidant and XO inhibition as potential therapeutic agents in the hyperuricemia treatment.     

Phthalate Sample Preparation Methods and Analysis in Food and Food Packaging: a Review

A review on phthalate esters or phthalic acid esters (PAEs), chemicals of concern since a few decades ago that are widely used as plasticizers in food processing and packaging, is presented taking into account the background of such compounds, the metabolism, human exposure to PAEs, the sources and occurrence in food as well as the toxicological aspects and human health effects. In addition, 45 novel research articles that were published between 2002 and 2017 were identified and their results were tabulated showing the PAEs analysed, food matrix of PAEs, methods of sample preparation/extraction, methods of instrumental analysis and quantitation, percentage recovery and limit of detection (LOD) of the instrument for ease of comparison and referencing. In general, it was found that in the last 15 years, the number of PAEs analysed has increased from the commonly analysed 8 PAEs, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-octyl phthalate (DNOP) and di-(2-ethylhexyl) phthalate (DEHP) to as many as 23 PAEs. The methods of sample preparation have also progressed from the simple liquid-liquid extraction using organic solvents to solid-phase microextraction techniques to the more recent head-space or direct immersion solid-phase microextraction methods. Whereas for the analysis of PAEs, gas chromatography and liquid chromatography are still the preferred methods with improved LOD of analysis ranging from approximately 10 ppm for fatty foods to 1–60 ppt for water, juices and cooking oil samples.