Martínez-Reina, C. Marlon and Amado-González, C. Eliseo
Revista Cubana de Química. ene-abr2013, Vol. 25 Issue 1, p9-19. 11p. 3 Color Photographs.
POSTAGE stamps, NOBEL Prizes, NOBEL Prize in Chemistry, STAMP collecting, ANALYTICAL chemistry, ORGANIC chemistry awards, NATURAL products, BIOCHEMISTRY, and AWARDS
Nobel Prizes in Chemistry and Philately, Part II, is a review of the stamps issued in different countries to commemorate the Nobel Prizes in analytical chemistry, organic chemistry, natural products and biochemistry. [ABSTRACT FROM AUTHOR]
PHOTONS, PHYSICAL organic chemistry, PHOTOCHEMISTRY, SUPRAMOLECULAR chemistry, and NUCLEAR spin
This Perspective presents a review and survey of the science and philosophy of my research career over the past five decades at Columbia as a physical organic chemist and photochemist. I explore the role of paradigms, structure, and geometric thinking in my own cognitive and intellectual development. The Perspective describes my investigations of high energy content molecules in electronically excited states and the development of electronic spin and supramolecular photochemistry chemistry. Current research dealing with the nuclear spin chemistry of H2 incarcerated in buckyballs is illustrated. In the second part of this Perspective, I recount a personal role of the philosophy and history of science and the scientific communities' use of paradigms in their every day research and intellectual activities. Examples are given of the crucial role of geometry and structure in the rapid development of organic chemistry and physical organic chemistry over the past century. [ABSTRACT FROM AUTHOR]
Examines proposed partial least squares (PLS) multivariate statistical models for predicting concentration of hydrocarbon- and oxygen-containing functional groups for a calibration set of model homopolymers. Plasma-deposited films; Static secondary ion mass spectrometry (SIMS); PLS modeling; Preprocessing; Prediction of surface oxygen and hydrogen concentration.
COMPOSITION of water, POLYMERS, CATALYSTS, INORGANIC chemistry, and POWER resources
The article discusses research on how the light-induced splitting of water into oxygen and hydrogen generates storable polymers and chemical fuels that could be used to address the world's energy demands. Particular attention is also given to the use of inorganic materials as semiconductor catalysts for such splits.
Depressants are critical reagents for the selective separation of minerals in froth flotation. They serve a vital role in preferentially making the gangue minerals hydrophilic and prevent them from reporting to the mineral-rich froth phase. Current practice involves the use of inorganic depressants, which are toxic and non-biodegradable. Environmentally friendly, flexible and affordable flotation depressants are needed due to the depletion of easy-to-process high-grade ores as well as sustainability and environmental concerns. This paper discusses various organic depressants that have been adopted for selective depression of unwanted minerals in chalcopyrite flotation. The origin and chemistry, organic depressant-gangue minerals interaction mechanism, and the use of organic depressants in the most common chalcopyrite-flotation instances, including chalcopyrite separation from galena, molybdenite, sphalerite, pyrite, pyrrhotite, talc, serpentine and carbonaceous materials, are discussed. This review shows that organic depressants can partially or fully replace current inorganic depressants used in suppressing both sulfide and non-sulfide gangue minerals in chalcopyrite flotation. In this review, a well-detailed and well-referenced discussion is provided for the current state of organic depressants in chalcopyrite flotation, as well as a valuable discussion is provided to comparatively evaluate the depression performance of the various reported organic depressants. Finally, suggestions are made regarding future research challenges and directions. The recent advancements, developing features, and research prospects discussed in this article will provide a helpful reference for academics who want to delve deeper into the greening of chalcopyrite flotation process. [ABSTRACT FROM AUTHOR]
Efficient conversion of light from short wavelengths to longer wavelengths using color conversion layers (CCLs) underpins the successful operation of numerous contemporary display and lighting technologies. Inorganic quantum dots, based on CdSe or InP, for example, have received much attention in this context, however, suffer from instability and toxic cadmium or phosphine chemistry. Organic nanoparticles (NPs), though less often studied, are capable of very competitive performance, including outstanding stability and water-processability. Surfactants, which are critical in stabilizing many types of nano-structures, have not yet been used extensively in organic NPs. Here we show the utility of surfactants in the synthesis and processing of organic NPs by thoroughly characterizing the effect of ionic and non-ionic surfactants on the properties of fluorescent organic NPs. Using this information, we identify surfactant processing conditions that result in nearly 100 % conversion of organic fluorophores into sub-micrometer particles, or nano-dots, with outstanding performance as CCLs. Such water dispersions are environmentally benign and efficiently convert light. They can be used for a range of fluorophores covering a full spectral gamut, with excellent color purity, including full-width at half-maximum (FWHM) values as low as 21 nm. Compared to inorganic (InP) reference CCLs, the organic nano-dot based CCLs show superior color conversion efficiency and substantially improved long-term stability. Compared to inorganic nanoparticles, organic nanoparticles aren't as well understood. Here the authors explore the use of surfactants to prepare organic semiconductor nanoparticles with outstanding photophysical properties. [ABSTRACT FROM AUTHOR]
Chemistry - A European Journal; 1/26/2021, Vol. 27 Issue 6, p1865-1869, 5p
SUSTAINABLE chemistry, ORGANIC synthesis, CHEMICAL engineering, CHEMICAL processes, INORGANIC chemistry, AMMONIUM sulfate, and METHACRYLATES
Keywords: green chemistry; industrial chemistry; organic synthesis; synthetic methods EN green chemistry industrial chemistry organic synthesis synthetic methods 1865 1869 5 01/29/21 20210126 NES 210126 B Making industry greener b : Many principles for the economic production of organic bulk chemicals, the syntheses of which have potentially the highest environmental impact, currently overlap with principles of green chemistry. For about 93 % of the 250 million tons organic chemicals produced annually by oxidation, oxygen is used as the oxidant, in most cases in combination with catalysts to achieve appropriate selectivities. I Addressed Principles of Green Chemistry: Prevent Waste, Atom Economy, Reduce Derivatives, Catalysis vs. Getting Greener: Propylene Oxide O SB 2 sb is not always the most efficient oxidant, as shown in the different synthetic routes to valuable propylene oxide (Scheme 4). The chlorohydrin process uses chlorine and produces CaCl SB 2 sb as the by-product and is therefore not that green. This would allow the entry into a circular economy.[18, 19] Certain initiatives involving large chemical producers were recently started to introduce a circular economy based on chemcycling in order to replace the current linear use of feedstocks. Greener alternatives should also be as economic as possible. [Extracted from the article]
During the COVID-19 pandemic, various drug candidates have been developed, molnupiravir (MK-4482 and EIDD-2801), which is a new orally anti-viral agent under development for the treatment of COVID-19, is under study in the final stage of the clinical trial. Molnupiravir enhances the replication of viral RNA mutations in animals and humans. Due to the high demand for the synthesis of this drug, it was essential to develop an efficient and suitable synthetic pathway from raw material. In this study, molecular docking analysis on molnupiravir is examined also, the mechanism of action (MOA) and the recent synthetic pathway is reported. This review will be helpful to different disciplines such as medicinal chemistry, organic chemistry, biochemistry, and pharmacology. [ABSTRACT FROM AUTHOR]
A pharmacophore system has been found as 1,2,3-triazole, a five-membered heterocycle ring with nitrogen heteroatoms. These heterocyclic compounds can be produced using azide-alkyne cycloaddition processes catalyzed by ruthenium or copper. The bioactive compounds demonstrated antitubercular, antibacterial, anti-inflammatory, anticancer, antioxidant, antiviral, and antidiabetic properties. This heterocycle molecule, in particular, with one or more 1,2,3-triazole cores has been found to have the most powerful antifungal effects. The goal of this review is to highlight recent developments in the synthesis and structure-activity relationship (SAR) investigation of this prospective fungicidal chemical. Also there have been explained drugs and mechanism of action of a triazole compound with antifungal activity. This review will be useful in a variety of fields, including medicinal chemistry, organic chemistry, mycology, and pharmacology. [ABSTRACT FROM AUTHOR]
Freshwater lakes are essential hotspots for the removal of excessive anthropogenic nitrogen (N) loads transported from the land to coastal oceans. The biogeochemical processes responsible for N removal, the corresponding transformation rates and overall removal efficiencies differ between lakes, however, it is unclear what the main controlling factors are. Here, we investigated the factors that moderate the rates of N removal under contrasting trophic states in two lakes located in central Switzerland. In the eutrophic Lake Baldegg and the oligotrophic Lake Sarnen, we specifically examined seasonal sediment porewater chemistry, organic matter sedimentation rates, as well as 33-year of historic water column data. We find that the eutrophic Lake Baldegg, which contributed to the removal of 20 ± 6.6 gN m−2 year−1, effectively removed two-thirds of the total areal N load. In stark contrast, the more oligotrophic Lake Sarnen contributed to 3.2 ± 4.2 gN m−2 year−1, and had removed only one-third of the areal N load. The historic dataset of the eutrophic lake revealed a close linkage between annual loads of dissolved N (DN) and removal rates (NRR = 0.63 × DN load) and a significant correlation of the concentration of bottom water nitrate and removal rates. We further show that the seasonal increase in N removal rates of the eutrophic lake correlated significantly with seasonal oxygen fluxes measured across the water–sediment interface (R2 = 0.75). We suggest that increasing oxygen enhances sediment mineralization and stimulates nitrification, indirectly enhancing denitrification activity. [ABSTRACT FROM AUTHOR]
Revista Cubana de Química. may-ago2021, Vol. 33 Issue 2, p345-366. 22p.
PHARMACEUTICAL chemistry, ORGANIC chemistry, CLERGY, CURRICULUM, and PHARMACISTS
The teaching of the Organic Chemistry for the career of Pharmaceutical Sciences of the Universidad de Oriente is sustained in relationships interdisciplinary and interdisciplinary con it bases on its principle rector: relationship structure-property-applications. The present work shows the results obtained of implementation of integrative seminars in the Pharmaceutical Organic Chemistry I and Chemistry Organic Pharmacist II for a bigger contribution in the pharmaceutical professional's formation. The methods were used: historical-logical, system focus, analysissynthesis, inductive-deductive and specialist criterion. Abilities related with the profession are shown, expressed in the analytic programs of each subject, their correspondence with the seminars and the results reached with this class type during the courses 2018-2019 and 2019-2020. The integration of the contents of the Pharmaceutical Organic Chemistry was achieved I and II, as well as with other subjects of the career, being demonstrated the narrow linking between the Organic Chemistry and the pharmaceutical specialty. [ABSTRACT FROM AUTHOR]
Argote Cruz, Julio Jesús, Sánchez Verdecia, Lázaro Antonio, and Escobedo Sierra, Juan Luis
Roca: Revista Científico-Educacional de la Provincia de Granma; ene-mar2021, Vol. 17 Issue 1, p536-551, 16p
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HIGH throughput screening (Drug development), COMBINATORIAL chemistry, ORGANIC chemistry, EXPECTED returns, ANIMAL species, and NEUROTRANSMITTERS
Drug development from natural products precedes human history by thousands of years. Mankind has learned to take the advantages of such discovered principles by nature which they now used to treat human diseases. Since, owing to the close evolutionary history with plants and animals species, many metabolites that they produce, mimics the human biological activities such as the neurotransmitters, enzymes and hormones. Therefore, many metabolites that plants and animals produce are now used by human being to treat the diseases like diabetes, cancer, microbial infections and Alzheimer's disease. The advent of combinatorial chemistry, organic chemistry and high throughput screening (HTS) has developed many lead molecules to treat human diseases. Unfortunately, these renewed techniques did not bring any expected returns in terms of new drug discoveries and therefore many researchers have shifted their research efforts back to the natural products to discover and develop the multidimensional and multibroadspectrum medicines using genomic engineering, combinatorial mucobiosynthesis and modern analytical techniques. In the present review, we have discussed comprehensively the journey of modern medicines with their prospects and promises. [ABSTRACT FROM AUTHOR]