jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Diana Marcela Ardila Rodríguez
Source: Universidad Industrial de Santander (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

Tytle: 4‒quinolone as a potential building block of the new tetracyclic system ethyl 4‒oxo‒9,10-diphenyl-8,10- dihydro-4h-pyrazolo[4,3-c]pyrido[3,2,1-ij]quinoline-5-carboxylate: synthesis and characterization Las 4‒quinolonas y las pirido[3,2,1‒ij]quinolonas constituyen una importante familia de agentes antibacterianos ampliamente prescritos en el tratamiento de una gran variedad de infecciones en humanos. También, han sido extensamente estudiados como promisorios agentes antidiabéticos, anticancerígenos y antivirales. Así como, las chalconas y el pirazol, compuestos que poseen un amplio espectro de actividades biológicas que incluyen la antioxidante, antibacteriana, antihelmíntica, antiulcerosa, antiviral, anticancerígena y citotóxica. Estos compuestos son precursores esenciales para la síntesis de nuevos compuestos con propiedades farmacológicas mejoradas. Sin embargo, son escasos los reportes en la literatura científica especializada que describen la fusión de estos importantes núcleos; una de las razones es la ausencia de metodologías apropiadas para acceder a este tipo de compuestos. En el LSO se diseñó y desarrolló una ruta de síntesis propia para intentar acceder a nuevos derivados tetracíclicos de la 4‒ oxo‒9‒aril‒10‒fenil(metil)‒8,10‒dihidro‒4H‒pirazolo[4,3‒c]pirido[3,2,1‒ij]quinolina‒5‒carboxilato de etilo, la cual resultó infructuosa. Sin embargo, en el presente Trabajo de Grado, se describe la síntesis de doce (12) nuevos derivados tricíclicos del tipo (E)‒6‒benciliden‒1,7‒dioxo‒6,7‒dihidro‒1H,5H‒pirido[3,2,1‒ij]quinolin‒2‒carboxilatos de etilo, a partir de la 2,3‒ dihidroquinolin‒4(1H)‒ona como precursor idóneo, vía la síntesis de Gould-Jacobs seguida de una reacción de condensación de Claisen-Schmidt, para los cuales de reportan por primera vez sus propiedades físicas y espectroscópicas. Las estructuras de todas las sustancias sintetizadas fueron elucidadas por espectroscopia de infrarrojo, cromatografía de gases acoplada a espectrometría de masas y resonancia magnética nuclear 1H y 13C, así como el análisis bidimensional de correlación heteronuclear HMBC. Heteronuclear molecule ; Context (archaeology) ; Block (permutation group theory) Synthesis and biological activity ; Cancer therapeutics and mechanisms ; Organic Chemistry Synthesis Methods
Authors: Jaya Kumari
Source: Asian Journal of Pharmaceutical and Clinical Research (article, 2018-12-28)
Field: Chemistry — Organic Chemistry

COUMARIN (ESCULETIN) - AN ANTIRHEUMATOID ARTHRITIC COMPOUND: AN UPDATE Context: Esculetin is a natural polyphenolic compound. It is chemically 6,7-dihydroxycoumarin and one of the ingredients of Cortex fraxini, a Chinese traditional medicine. It is used as a dietary supplement and found as non-toxic. Recently, there are many research works evaluated on esculetin in arthritis with supported molecular mechanisms.Objectives: Esculetin becoming more attractive prodrug for arthritis. Hence, the present minireview will consolidate the targeted site of esculetin in the treatment of arthritis over the past decade.Results: The most important molecular mechanism of esculetin is an antioxidant activities with decreased level of reactive oxygen species/reactive nitrogen species. It also inhibited lipoxygenase 5, lipoxygenase 12, and tyrosinase enzymes. It reduces the inflammation by modulating the key inflammatory enzyme matrix metalloproteinase-1 activity. It also lowers the nitrous oxide and prostaglandin E2 level in synovial fluid. Esculetin derivatives such as 5-methoxy esculetin inhibited the activity of nitrogen-activated protein kinases. The updated data also reveal that esculetin suppresses the leukotriene B4 level in plasma of adjuvant-induced arthritis tested animals.Conclusion: The presented update showed that esculetin may be useful as a tool in regulating the mechanism and physiological functions of the inflammatory mediators and enzyme. Hence, the presented review work may be considered as a scientific proof for the development of an attractive drug candidate for the patient with rheumatoid arthritis. Chemistry ; Arthritis ; Pharmacology ; Antioxidant ; Reactive oxygen species ; Coumarin ; Enzyme ; Polyphenol ; Reactive nitrogen species ; Lipoxygenase ; Nitric oxide ; Tyrosinase ; Biochemistry ; Medicine ; Immunology Synthesis and biological activity ; Natural product bioactivities and synthesis ; Cytokine Signaling Pathways and Interactions
Authors: L. Venkateshwarlu | M. Sarangapani | Upender Rao Eslawath | Rajashekar Vadlakonda
Source: International Research Journal of Pharmacy (article, 2018-10-13)
Field: Chemistry — Organic Chemistry

SYNTHESIS AND PHARMACOLOGICAL EVALUATION OF 6-SUBSTITUTED 2-AMINOBENZOTHIAZOLES Heterocyclic compounds and analogues have attracted strong interest due to their biological and pharmacological properties. Nitrogen containing heterocyclics, Benzothiazoles are an important class of heterocyclic compounds and the nucleus containing compounds involved in research aimed at evaluating new products that possess biological activities such as antibacterial, antifungal, anthelmintic, antidiabetic, and anticancer agents. In the present study various derivatives of 6-substituted 2-aminobenzothiazoles were prepared and evaluated for their antibacterial, antifungal, antioxidant and cytotoxic activity by various standard methods. Among the synthesized compounds, most of the compounds exhibited potent activity when compared with that of the standard drugs. Hence the versatile synthetic applicability and biological activity of these heterocyclic compounds will help the chemist to plan, organize and implement new approaches towards discovery of novel derivatives of Benzothiazoles. Toxicology ; Pharmacology ; Chemistry ; Biology Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and biological activity ; Quinazolinone synthesis and applications
Authors: Serene Tai
Source: D-Scholarship@Pitt (University of Pittsburgh) (article, 2018-09-26)
Field: Chemistry — Organic Chemistry

Synthesis of Small Molecule Antagonists at the Androgen Receptor for Prostate Cancer Treatment and Efforts Toward an Enantioselective Co(II)-Catalyzed Cyclopropanation This thesis describes the synthesis of fluorinated cyclopropane analogues to enhance the metabolic stability of a previously published lead candidate for prostate cancer treatment. A structural unique motif such as the bicyclo[1.1.0]pentane was also incorporated to investigate its potential as cyclopropane bioisostere. Preliminary results from liver microsome and luciferase assays suggested that fluorinations on the cyclopropane carbon atoms have little impact on the metabolic stability. However, fluorination on other labile sites showed enhanced metabolic stability while retaining compound potency. An enantioselective route to improve the original racemic synthesis of these analogues was also investigated. The key step was a Co(II)-salen catalyzed enantioselective cis-cyclopropanation of an olefin with ethyl diazoacetate to provide the cyclopropyl amide in 98% ee over three high-yielding steps. Cyclopropanation ; Enantioselective synthesis ; Cyclopropane ; Bioisostere ; Chemistry ; Stereochemistry ; Catalysis ; Combinatorial chemistry ; Chemical synthesis ; Organic chemistry ; Biochemistry ; Ring (chemistry) ; In vitro Cyclopropane Reaction Mechanisms
Authors: Aude Nyadanu
Source: theses.fr (ABES) (preprint, 2018-10-10)
Field: Chemistry — Organic Chemistry

New multicomponent reactions and constrained rings opening towards heterocycles synthesis Les réactions multicomposants (MCR) constituent une réponse à deux grands défis rencontrés par la chimie pharmaceutique : la découverte de nouvelles molécules bioactives ainsi que leur production à moindre coût dans le respect de l’environnement. En effet, en combinant plusieurs réactifs de façon monotope, les MCR permettent de synthétiser une grande diversité de molécules complexes par des procédés simples et rapides, avec de bons rendements, et en limitant fortement les déchets de réaction. Dans le cadre de cette thèse, nous avons mis au point de nouvelles réactions multicomposants impliquant des isonitriles, composés à la réactivité exceptionnellement riche.Nous nous sommes d’abord intéressés à l’utilisation d’acides forts dans la réaction de Ugi. Les premiers essais ont été réalisés avec des acides sulfiniques, sulfoniques, phosphiniques et phosphoniques, sans succès. Mais grâce à l’introduction de l’acide nitrique comme composant acide dans la réaction de Ugi, nous avons décrit une synthèse monotope de nitramines hautement fonctionnalisées à partir d’un aldéhyde, un isonitrile et un nitrate d’ammonium. Nous avons ainsi développé la première réaction multicomposant conduisant à la formation d’une liaison N-N.Nous avons également proposé une nouvelle variante de la réaction de Passerini impliquant des dérivés thiocarbonylés. Ces derniers étant généralement peu stables, nous avons mis au point une stratégie pour générer un thiocarbénium in situ à partir d’un 3-sulfanyl phthalide, en présence de tétrachlorure de titane. Le couplage de ce thiocarbénium avec un isonitrile et un acide carboxylique a conduit à la synthèse divergente de deux types d’hétérocycles soufrés : les thiophthalides et les 3-amino-4-sulfanyl isocoumarines. Cette étude constitue la première approche formelle de la réaction de Thio-Passerini.Enfin, dans la continuité de notre intérêt pour les dérivés soufrés, nous avons décrit une nouvelle synthèse de thiovinyléthers. Ces composés, synthétiquement équivalents à des dérivés thiocarbonylés, ont été obtenus par l’ouverture palladocatalysée de thiocyclopropanes. Si le recours à des métaux de transition pour l’ouverture de cycles contraints est bien connue pour des dérivés oxygénés ou azotés, il s’agit de la première réaction de ce type pour des dérivés soufrés.Ainsi, trois méthodologies originales ont été développées. Elles donnent accès à différents types de composés fonctionnalisés, potentiellement utiles en pharmacie et en agrochimie. Ces travaux s’appuient fortement sur la réactivité unique des isonitriles et viennent compléter cette chimie particulièrement riche. Chemistry ; Computer science ; Combinatorial chemistry Multicomponent Synthesis of Heterocycles ; Synthesis and Characterization of Heterocyclic Compounds ; Chemical Synthesis and Analysis
Authors: Dario Telese | Marcello Forconi | Carla Boga | Gabriele Micheletti
Source: Archivio istituzionale della ricerca (Alma Mater Studiorum Università di Bologna) (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

SYNTHESIS OF BENZISOXAZOLES AND STUDY ON HEMOPROTEINS-CATALYZED KEMP ELIMINATION Catalysis ; Hemeprotein ; Chemistry ; Biochemistry ; Heme Synthesis and Characterization of Heterocyclic Compounds
Authors: Rahma Aroua
Source: theses.fr (ABES) (preprint, 2018-09-28)
Field: Chemistry — Organic Chemistry

Study of organometallic complexes formed by calixarenes functionalized with N-heterocyclic carbenes Une série de calixarènes portant une unité imidazolium ou deux, en conformation cône ont été synthétisés et caractérisés par différentes méthodes. Ces sels chargés positivement constituaient des précurseurs de carbènes N-hétérocycliques pour la synthèse de complexes de nickel correspondants. Les complexes Ni-NHC-calix[4]arènes obtenus ont été testés dans la catalyse de la réaction de couplage croisé de Suzuki-Miyaura. Des moyennes à bonnes conversions ont été obtenues selon l’espacement du centre métallique de la cavité calixarénique, ainsi que le nombre de centre métallique présents sur la même plateforme. Calixarene ; Organometallic chemistry ; Combinatorial chemistry ; Chemistry ; Organic chemistry ; Catalysis ; Molecule Synthetic Organic Chemistry Methods ; Inorganic and Organometallic Chemistry ; Organometallic Complex Synthesis and Catalysis
Authors: Amit Girdhar | Shikha Raheja | Deepti Pandita | Vandana Kharb | Viney Lather
Source: Asian Journal of Pharmacy and Pharmacology (article, 2018-08-01)
Field: Chemistry — Organic Chemistry

Synthesis, docking, characterization and anti-inflammatory activity of novel phosphodiesterase-4 inhibitors Phosphodiestrases (PDEs) have great clinical significance as they regulate the signal transduction mediated by second messengers like cAMP and cGMP, which further regulate many biological processes such as metabolism, growth, differentiation, smooth muscle relaxation and secretion Based on substrate specificities, amino acid sequences, tissue distribution and regulatory properties, PDE family is subdivided into 11 different groups from PDE1 to PDE11. Out of these subtypes, Phosphodiesterase-4 (PDE4) is the important target for many drugs owing to its unique structure and tissue distribution. It is widely distributed in many cells and tissues including leukocytes, vascular Docking (animal) ; Phosphodiesterase ; Chemistry ; Pharmacology ; Computational biology ; Biochemistry ; Enzyme ; Medicine ; Biology Synthesis of β-Lactam Compounds ; Phosphodiesterase function and regulation ; Synthesis and biological activity
Authors: Jie‐Hua Shi | Lihua Zhao | Guo-Feng Shen
Source: Journal of Chromatographic Science (article, 2018-04-09)
Field: Chemistry — Spectroscopy

Characterization of Poly(MAA-co-EDMA) Monolithic Column for High Performance Liquid Chromatography: Scanning Electron Microscopy, Thermodynamic Parameters and Linear Solvation Energy Relationship Methodology A poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column was prepared in situ for high performance liquid chromatography and characterized utilizing scanning electron microscopy, thermodynamic parameters and linear solvation energy relationship methodology. The results revealed that there were many microglobules forming the larger cluster in poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolith prepared under the selected preparation conditions, which composed continuously aligned macroporous channels through the monolith skeleton. The poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column had a good permeability, a high mechanical stability. The interaction model for each probe molecule on the poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column was invariable within the studied temperature range due to an excellent linear relationship between lnk and 1/T for each probe molecule. The chromatographic retention for each probe molecule on the poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolithic column was an enthalpy-driven process due to |∆H°| > |T∆S°| and ∆G°<0. The main interaction forces of the poly(Methacrylate-co-Ethyleneglycol dimethacrylate) monolith with probe molecules contain hydrogen bonding interaction, hydrophobic interaction and dipole-dipole interaction. However, the contribution of each interaction was in the order of hydrogen bonding acidity > hydrophobic interactions > dipole-dipole interaction > hydrogen bonding basicity. In addition, the poly(Methacrylate-co-Ethyleneglycol dimethacrylate)monolithic column is suitable for the separation of both nonpolar and polar compounds. Monolith ; Solvation ; Methacrylate ; Monolithic HPLC column ; Chemistry ; Scanning electron microscope ; Hydrogen bond ; Molecule ; Alkylbenzenes ; Chemical engineering ; High-performance liquid chromatography ; Chromatography ; Analytical Chemistry (journal) ; Polymer chemistry ; Materials science ; Polymer ; Organic chemistry ; Polymerization ; Composite material Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications ; Protein purification and stability
Authors: Kuilong Wang
Source: Journal of Drug Delivery and Therapeutics (article, 2018-11-15)
Field: Materials Science — Biomaterials

Mini Review: Nano-Technology based Drug Deliveries Targeted drug delivery with nano-technology has been researched and identified as being efficient across many treatment conditions. This review assesses some of the existing research work and evidence practice in using nano-technology based drug carriers.&#x0D; Keywords: Nano-technology, drug delivery, nanoparticle formulation, nano-technology carriers, drug resistance Drug ; Nano- ; Drug delivery ; Medicine ; Nanotechnology ; Pharmacology ; Engineering ; Materials science Nanoparticle-Based Drug Delivery ; Cancer Research and Treatment ; Advanced Drug Delivery Systems
Authors: Ján Jančík
Source: Brno University of Technology Digital Library (Brno University of Technology) (article, 2018-05-28)
Field: Chemistry — Spectroscopy

Syntéza a charakterizace pokročilých molekul s implementovaným adamantanovým skeletem Diplomová práce pojednává o syntéze a charakterizaci pokročilých molekul s implementovaným adamantanovým skeletem s perespektivním uplatněním v atraktivní oblasti organické elektroniky. Provedena byla příprava čtyř finálních molekul, z toho tří nových, dosud nepopsaných, na bázi para-bis(2-thienyl)fenylenu, u kterých byly porovnány různé syntetické přístupy s ohledem na výtěžky, ekologickou i finanční stránku. Také bylo studováno využití mikrovlnné syntézy pro provedení cross-kaplingových reakcí při přípravě finálních molekul na bázi para-bis(2-thienyl)fenylenu. U všech molekul bylo využito ethyladamantylových nebo methyladamantylových postranních řetězců. Rovnež byly připraveny dvě zcela nové molekuly na bázi 2,2':5',2''-terthiofenu, opět s využitím ethyladamantylových nebo methyladamantylových postranních řetězců. Připraveny byly také nové významné dimerní adamantanové struktury, u kterých se předpokládá aplikovatelnost v oblasti chemie polymerů v podobě propojovacích mostů. Dále byla provedena série experimentů pro přípravu modifikovaných tetrasubstituovaných adamatanů a také optimalizace syntetické cesty pro přípravu spiroadamantanových derivátů. Chemistry ; Stereochemistry Analytical Chemistry and Chromatography ; Chemical Thermodynamics and Molecular Structure ; Free Radicals and Antioxidants
Authors: 達男 都合
Source: Kyushu University Institutional Repository (QIR) (Kyushu University) (article, 2018-03-20)
Field: Materials Science — Materials Chemistry

Research on Rational Synthesis and Luminescence Properties of Oligo-Nuclear Complexes Using Linear Multidentate Ligands A linear multidentate type ligand (H2L) was prepared two types of oligo-nuclear complexes, di-nuclear complexes (M2(HL)2) and octa-nuclear complexes (M8L6) with divalent 3d transition ions (M = Mn, Zn, and Co).These compounds were synthesized selectively by adjusting pH.Di-nuclear complex was obtained in acidic condition.Octanuclear complex was obtained in basic condition.The structure of M2(HL)2 was consist of two metal ions, two half-deprotonated ligands (HL -), two nitrate anions, and two coordination solvents.The structure of M8L6 was composed of eight metal ions and six full-deprotonated ligands (L 2-).All compounds were characterized by FT-IR spectrum, UV-vis spectrum, elemental analysis, and single X-ray diffraction.M2(HL)2 was transformed to M8L6 by adding the base in solution state.Moreover, irreversible conversion of M2(HL)2 to M8L6 in response to the base addition in solution state was confirmed with UV-vis spectra. Denticity ; Luminescence ; Rational design ; Chemistry ; Nanotechnology ; Materials science ; Optoelectronics ; Organic chemistry ; Metal Lanthanide and Transition Metal Complexes ; Magnetism in coordination complexes ; Organometallic Compounds Synthesis and Characterization
Authors: Valeriu Scutelnic
Source: Infoscience (Ecole Polytechnique Fédérale de Lausanne) (article, 2018-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

Cryogenic infrared spectroscopy as a probe of structure and dynamics of biomolecules The pivotal theory of molecular biology states that the structure of biomolecules is directly related to their function in living systems. In this way, the structural investigation of biological molecules allows understanding and intervening in the fundamental biological processes. Furthermore, the structural characterization of isolated biomolecules in the gas phase offers the advantage of determining their intrinsic structural properties free from environment perturbations. A particularly sensitive gas-phase technique to the finest structural details of biomolecules is cryogenic infrared spectroscopy. The scope of this thesis is to determine the gas-phase structure of a range of biologically relevant molecules in the gas phase. In the first part of this thesis we study the clustering of the amino acid serine into a protonated octamer. As a â magic numberâ cluster it exhibits an unusually high abundance in the gas phase and an outstanding homochiral preference. We report the structure of the protonated serine octamer determined by a combination of experimental and computational techniques: gas-phase infrared spectroscopy of the helium-tagged protonated serine octamer cluster and ab initio molecular dynamics simulations. The found structure is surprisingly asymmetric and explains the homochiral preference of the cluster. In the second part, we introduce an isotopic labeling method for analyzing the conformational heterogeneity of glycans. Infrared-infrared double resonance spectroscopy performed on a helium-tagged protonated monosaccharide provides vibrational fingerprints of individual conformers and, together with quantum mechanical computations, is used to interpret the results from isotopic labeling. In the last part, cryogenic infrared spectroscopy gives insight into the migration of the electronic excitation between two aromatic chromophores of a model peptide. This is possible because the absorption bands in the highly-resolved infrared spectra of the excited states are sensitive to the localization of the electronic energy in each chromophore. Biomolecule ; Infrared ; Spectroscopy ; Infrared spectroscopy ; Dynamics (music) ; Nanotechnology ; Chemistry ; Chemical physics ; Materials science ; Physics ; Optics thermodynamics and calorimetric analyses ; Molecular Spectroscopy and Structure
Authors: Fabiane Valentini Francisqueti‐Ferron
Source: LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) (article, 2018-03-02)
Field: Chemistry — Analytical Chemistry

Inter-relação do Gama- orizanol e ativação dos receptores Adipo- R1 e Adipo- R2: possível efeito na melhora da função renal associada à obesidade Submitted by Fabiane Valentini Francisqueti null (fabiane_vf@yahoo.com.br) on 2018-03-12T18:48:54Z&#13;\nNo. of bitstreams: 1&#13;\ntese.pdf: 3023187 bytes, checksum: 5015cad600d37fc8cdfe179bf8b4abc8 (MD5) Psychology Dye analysis and toxicity ; Free Radicals and Antioxidants ; Antioxidant Activity and Oxidative Stress
Authors: Matteo Zanda
Source: Synthesis (article, 2018-12-13)
Field: Chemistry — Organic Chemistry

SYNFORM ISSUE 2019/1 First of all, Happy New Year! At the beginning of every year there is a "trend" going on in magazines, newspapers and the online marketing community: asking a number of experts about the upcoming trends in the New Year and beyond. As these articles are very popular, we thought we could apply the same concept to our beloved field of chemistry and ask our Editors for their opinion on the hottest trends or topics in organic synthesis. Answers from a few of us can be found in the first article of this year. Chemistry ; Earth science ; Geology Catalytic C–H Functionalization Methods ; Catalytic Cross-Coupling Reactions ; Asymmetric Hydrogenation and Catalysis
Authors: Matteo Zanda
Source: Synfacts (article, 2018-12-14)
Field: Chemistry — Organic Chemistry

SYNFORM ISSUE 2019/01 First of all, Happy New Year! At the beginning of every year there is a "trend" going on in magazines, newspapers and the online marketing community: asking a number of experts about the upcoming trends in the New Year and beyond. As these articles are very popular, we thought we could apply the same concept to our beloved field of chemistry and ask our Editors for their opinion on the hottest trends or topics in organic synthesis. Answers from a few of us can be found in the first article of this year. Chemistry ; Earth science ; Astrobiology ; Geology Catalytic Cross-Coupling Reactions ; Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis