Wyniki wyszukiwania dla: natural products
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Light-Induced Transformation of the Aromatic Heptaene Antifungal Antibiotic Candicidin D into Its All-Trans Isomer
PublikacjaIllumination of the aromatic heptaene macrolide antifungal antibiotic candicicin D with UV light results in an isomerization of the molecule. The product formed after irradiation of the candicidin complex with UV light (λ=365nm), namely, iso-candicidin D, was isolated and subjected to 2D NMR studies, consisting of DQF-COSY, ROESY, TOCSY, HSQC, and HMBC experiments. The obtained spectral data unambiguously evidenced that iso-candicidin...
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Monosaccharides as Potential Chiral Probes for the Determination of the Absolute Configuration of Secondary Alcohols
PublikacjaHerein, a new method for the elucidation of the absolute configuration of chiral secondary alcohols is proposed. This method is an alternative for a widely used approach reported by Mosher and Dale and similar methods that are based on the 1H NMR shift (δ) changes of protons that are attached to the substituents of the oxymethine carbon atom. The presented method is not based on tracking the chemical shift changes and utilizes...
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New potent STS inhibitors based on fluorinated 4-(1-phenyl-1H-[1,2,3]triazol-4-yl)-phenyl sulfamates
PublikacjaA series of fluorinated analogs based on the frameworks of 4-(1- phenyl-1H-[1,2,3]triazol-4-yl)-phenyl sulfamates have been synthesized as steroid sulfatase (STS) inhibitors. The design of chemical structures of new potential STS inhibitors was supported by molecular docking techniques to identify potential interactions between inhibitors and amino acid residues located in the STS active site. The STS inhibitory potency was evaluated...
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Synthesis and biological evaluation of thiophosphate tricyclic coumarin derivatives as steroid sulfatase inhibitors
PublikacjaSteroid sulfatase (STS) enzyme inhibition is an important approach to the management of hormone-dependent breast cancer. In this paper, we report convenient methods for the synthesis and biological evaluation of thiophosphate tricyclic coumarin analogs exhibiting STS activity. The described methods are based on the straightforward preparation of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-2-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one,...
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Synthesis and antiproliferative activity of new mycophenolic acid conjugates with adenosine derivatives
PublikacjaNew conjugates of mycophenolic acid (MPA) and adenosine derivatives were synthesized and assessed as potential immunosuppressants on Jurkat cell line and peripheral blood mononuclear cells (PBMC) from healthy donors. As compared to MPA, all compounds were found to be more active against Jurkat cell line. The antiproliferative activities were compared with MPA and adenosine, in both 2′,3′-O-isopropylidene protected and free hydroxyl...
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New conjugates of mycophenolic acid and their antiproliferative activity
PublikacjaThe new conjugates of mycophenolic acid (MPA) were obtained in the reaction of N6-(ω-aminoalkyl)adenosines with MPA in the presence of EDCI as a coupling reagent. New compounds 4a–h were evaluated on leukemia cell line (Jurkat) and PBMC from healthy donors. Length of the linker influenced observed activity. The compound 4b possessing 1,3-diamine spacer exhibited the most promising results and can be considered to further investigations.
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Productivity effects of trade in natural resources—comparison with mechanisms of technological specialisation
PublikacjaThis paper compares two alternative growth paths, assessing the effects on productivity of specialisation in natural resources (NR) and in technologically advanced products. The empirical analysis exploits product-level export data for 109 developing and 51 developed economies over the period 1996–2018. We document two distinct types of specialisation, based on exports either of natural resources or of technological products, and...
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Export diversification and dependence on natural resources
PublikacjaLow export diversification is a risk-augmenting factor for many countries dependent on natural resources. The literature tends to focus on the growth effects of resource dependence (‘resource curse’ debate) while not much is known on how it affects the variety of non-resource exports. To quantify this effect we decompose the relative Theil index using product-level export data from 160 countries over the time period 1996–2018....
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Natural sweeteners: Sources, extraction and current uses in foods and food industries
PublikacjaFood producers have leaned towards alternative natural and synthetic sweeteners in food formulations to satisfy market demands. Even so, several synthetic sweeteners (e.g., aspartame, saccharin, sucralose) are becoming less popular due to health-related concerns, lower nutritional values, and controversies around their safety. Conversely, natural sweeteners confer favourable customer perceptions due to their association to a healthier...
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Bee Products and Essential Oils as Alternative Agents for Treatment of Infections Caused by S. aureus
PublikacjaBacteria of the genus Staphylococcus are important human and veterinary pathogens. A crucial characteristic for this group of bacteria is that they can easily acquire mechanisms of antibiotic resistance for a plethora of antibiotics currently in use for human and animal therapies. Therefore, there is a great need to find novel, non-antibiotic chemotherapeutics with marked antistaphylococcal activity. Promising but still underestimated...
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Polyurethane Glycerolysate as a Modifier of the Properties of Natural Rubber Mixtures and Vulcanizates
PublikacjaChemical recycling of polyurethanes can be realized in several different ways, but the most important methods are glycolysis and glycerolysis. Both methods permit recovery of polyols (when the process is realized with the mass excess of depolymerizing agent) or substitutes of polyols, which contain urethane moieties in the main chains and terminate mainly in hydroxyl groups (when the process is realized with the mass excess of...
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The possibility of use by-products for synthesis of emulsifiers
PublikacjaIn the last years the interest in use of materials originated from natural sources, e.g. vegetables to produce attractive products still grows. According to that, also the synthesis of these products should be adequate to the green chemistry requirements. The typical example observed in recent years focuses on utlization of bioglycerol - the by - product of global biodiesel manufacturing. The still growing production of biodiesel...
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Membrane technologies assisting plant-based and agro-food by-products processing: A comprehensive review
PublikacjaBackground Nowadays, membrane-based technologies (e.g. microfiltration, ultrafiltration, nanofiltration, membrane distillation, and pervaporation) have demonstrated to meet the requirements to be involved in different food and bioproduct processes. Scope and approach Several applications have been developed, including either separation, recovery or concentration of bioactive molecules from agro-food products and by-products,...
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Latest Insights on Novel Deep Eutectic Solvents (DES) for Sustainable Extraction of Phenolic Compounds from Natural Sources
PublikacjaPhenolic compounds have long been of great importance in the pharmaceutical, food, and cosmetic industries. Unfortunately, conventional extraction procedures have a high cost and are time consuming, and the solvents used can represent a safety risk for operators, consumers, and the environment. Deep eutectic solvents (DESs) are green alternatives for extraction processes, given their low or non-toxicity, biodegradability, and reusability....
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Trade differentiation and the characteristics of new imported and exported products - international panel data analysis
PublikacjaDrawing on o large panel of international economies we have shown how the set of imported and exported products evolves in economic growth process. Strong activity at the extensive margin, manifested through the rise in the number of active export and import lines, is typical for early stages of development. Trade diversification tendency, typical for a predominant mass of observations in our panel, is associated with changes in...
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Fabrication and Characterization of Green Polyurethane Foams with Enhanced Vibration Damping Capability
PublikacjaOver the past decades, there has been an intensive development of the technologies and innovations aimed at increasing the quality of life. This development largely concerns the comfort of use of everyday products that, among others, are products of the automotive, construction, or furniture industries. Considering the increase in the comfort of using products such as cars, houses, and flats, one of the comfort features of their...
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A comprehensive review on current and emerging technologies toward the valorization of bio‐based wastes and by products from foods
PublikacjaIndustries in the agro-food sector are the largest generators of waste in the world. Agro-food wastes and by products originate from the natural process of senescence, pretreatment, handling, and manufacturing processes of food and beverage products. Notably, most of the wastes are produced with the transformation of raw materials (such as fruits, vegetables, plants, tubers, cereals, and dairy products) into different processed...
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Extraction pathways and purification strategies towards carminic acid as natural-based food colorant: A comprehensive review
PublikacjaAs a current trend of fabricating healthier products, food manufacturing companies seek for natural-based food colorant aiming to replace the synthetic ones, which apart from meeting sensorial and organoleptic aspects, they can also act as health promoters offering additional added value. Carminic acid is a natural based food colorant typically found in several insect taxa. However, there are current approaches which pursue the...
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Income obtained according to particular rates only by taxpayers conducting non-agricultural business activity in 2016
Dane BadawczeA special form of income taxation addressed to the SME sector is the Lump sum on registered income, which is a simplified form of income tax payment for natural persons conducting business activity.The choice of this form of taxation is optional. In 2016, the tax in this form could be paid by taxpayers who in 2015 obtained income from non-agricultural...
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From polymer waste to potential main industrial products: Actual state of recycling and recovering
Publikacjalastics have become widely used materials in everyday life due to their special properties such as durability, easy processing, light-weight and low-cost of production. However, because of their stable and non-biodegradable nature, postconsumer plastics become an issue to the environment. The growing amounts of waste are generated, as plastic products are commonly used only once before disposal. The alternatives of practical techniques...