jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Márió Gajdács
Source: Hematológia–Transzfuziológia (article, 2020-06-01)
Field: Chemistry — Organic Chemistry

Szelenoészter-származékok daganatellenes és rezisztenciamódosító hatásának vizsgálata epidemiológiailag releváns daganatsejt-modellrendszerek felhasználásával Absztrakt: Bevezetés: A szerves szelénvegyületekről számos kutatás bizonyítja, hogy képesek modulálni az emlőssejtek intracelluláris redox homeosztázisát, így hatékony és szelektív daganatellenes szerek lehetnek, mivel a daganatos sejtek érzékenyebbek a külső oxidatív stresszhatásokra. Célkitűzés: Újszerű szerkezettel rendelkező szerves szelénvegyületek daganatellenes és MDR-visszafordító hatásának vizsgálata különböző daganatsejtes modellrendszerek felhasználásával in vitro . Módszer: A vegyületek citotoxikus aktivitását MTT módszerrel határoztuk meg, az ABCB1 efflux transzporter gátlását rhodamin 123 akkumulációs vizsgálattal tanulmányoztuk áramlási citometriás módszerrel. A vegyületek apoptózist indukáló hatását Annexin V-FITC módszerrel határoztuk. OSIRIS Molecular Property Explorer és PreADMET 2.0 alkalmazásával becsültük meg a vegyületek fizikai-kémiai és in vivo abszorpciós tulajdonságait. Eredmények: Adott szerkezeti elemekkel (négy vegyület: egy ciklusos szelenoanhidrid és három alkil-keton-szelenoészter) rendelkező szelénvegyületek hatékonynak bizonyultak minden vizsgálatban, míg mások csökkent vagy semmilyen aktivitást nem mutattak; ezek a vegyületek erős citotoxikus hatásúak voltak a nanomoláris tartományban, emellett hatékonyan gátolták az ABCB1 efflux pumpát. A vegyületek lipofilitásának fontos szerepe van az effluxpumpa működésének befolyásolásában. A ciklikus szelenoanhidrid hatékony korai apoptózist indukáló vegyület volt, míg az alkil-keton szelenoészterek nekrotikus folyamatokat indukáltak. Következtetések: Kísérleteink rávilágíttotak a szelén központi szerepére a rákellenes és az MDR-visszafordító hatás szempontjából. A vegyületek pontos molekuláris hatásmechanizmusa még nem ismert: azt feltételezhetjük, hogy a szelénvegyületek aktivitása a szelenoészter csoport hidrolíziséhez köthető. Eredményeink alapján az ígéretes vegyületek további származékainak szintézise és biológiai hatásának vizsgálata indokolt lehet. Chemistry ; Physics ; Efflux ; Molecular biology ; Biology ; Biochemistry Free Radicals and Antioxidants ; Drug Transport and Resistance Mechanisms ; Genomics, phytochemicals, and oxidative stress
Authors: Tian Wu | Li Shi | Susan L. Morris‐Natschke | Sheng Chu Kuo | Kuo Hsiung Lee | Handong Sun
Source: UNC Libraries (article, 2020-10-31)
Field: Materials Science — Biomaterials

Cytotoxic cardiac glycosides and coumarins from Antiaris toxicaria Eight new cardiac glycosides/aglycones (antiaritoxiosides A–G, 1–7, and antiarotoxinin B, 8), two new coumarins (anticarins A–B, 41–42), and two new flavanones (antiarones L–K, 43–44) were isolated from trunk bark of Antiaris toxicaria together with 53 known compounds. The new structures were established by extensive analysis of spectroscopic data. Compound 1 (10-carboxy and 3α-hydroxy) and compounds 3–6 (10-hydroxy) contain unique substituents that are rarely found in cardiac glycosides. The cytotoxic effects of isolated compounds against ten human cancer cell lines, KB, KB-VIN, A549, MCF-7, U-87-MG, PC-3, 1A9, CAKI-1, HCT-9 and S-KMEL-2, were tested using the sulforhodamine B assay. Five compounds (12, 16, 20, 22, and 31) showed significant cytotoxicity against all ten cancer cell lines, with notable potency at the ng/mL level against some cell lines, which merits further development as clinical trial candidates. Glycoside ; Chemistry ; Cytotoxic T cell ; Traditional medicine ; Stereochemistry ; Medicine ; Biochemistry ; In vitro Phytochemistry and Bioactive Compounds ; Phytochemical Studies and Bioactivities
Authors: Lingaswamy Kadari | William Erb | Yury S. Halauko | Олег А. Ивашкевич | Вадим Э. Матулис | Dmitry Lyakhov | Thierry Roisnel | Palakodety Radha Krishna | Florence Mongin
Source: ChemRxiv (preprint, 2020-09-18)
Field: Chemistry — Organic Chemistry

On the N-Arylation of Acetamide Using 2-, 3- and 1’-Substituted Iodoferrocenes Various 2-, 3- and 1’-substituted iodoferrocenes were&lt;br&gt;reacted with acetamide in the presence of copper(I) iodide (1&lt;br&gt;equiv), N,N’-dimethylethylenediamine (1 equiv), tripotassium&lt;br&gt;phosphate (2 equiv) in dioxane at 90 °C for 14 h, and allowed a large range of original 1,2-, 1,3- and 1,1’-disubstituted ferrocenes to be obtained. The results were compared as a function of the substituent and its position on the ring. DFT calculations revealed higher activation barrier for the oxidative addition in the ferrocene series when compared with classical planar aromatics. Structure–property relationships were applied to rationalize the reactivity of the different iodoferrocenes. Acetamide ; Ferrocene ; Substituent ; Chemistry ; Reactivity (psychology) ; Ring (chemistry) ; Medicinal chemistry ; Iodide ; Stereochemistry ; Inorganic chemistry ; Organic chemistry ; Physical chemistry Ferrocene Chemistry and Applications ; Organometallic Complex Synthesis and Catalysis ; Metal complexes synthesis and properties
Authors: Maurizio Del Poeta
Source: UNC Libraries (article, 2020-10-30)
Field: Chemistry — Organic Chemistry

In Vitro Antifungal Activities of a Series of Dication-Substituted Carbazoles, Furans, and Benzimidazoles Aromatic dicationic compounds possess antimicrobial activity against a wide range of eucaryotic pathogens, and in the present study an examination of the structures-functions of a series of compounds against fungi was performed. Sixty-seven dicationic molecules were screened for their inhibitory and fungicidal activities against Candida albicans and Cryptococcus neoformans. The MICs of a large number of compounds were comparable to those of the standard antifungal drugs amphotericin B and fluconazole. Unlike fluconazole, potent inhibitory compounds in this series were found to have excellent fungicidal activities. The MIC of one of the most potent compounds against C. albicans was 0.39 μg/ml, and it was the most potent compound against C. neoformans (MIC, ≤0.09 μg/ml). Selected compounds were also found to be active against Aspergillus fumigatus, Fusarium solani, Candida species other than C. albicans, and fluconazole-resistant strains of C. albicans and C. neoformans. Since some of these compounds have been safely given to animals, these classes of molecules have the potential to be developed as antifungal agents. Dication ; Antifungal ; In vitro ; Chemistry ; Series (stratigraphy) ; Microbiology ; Stereochemistry ; Organic chemistry ; Biology ; Biochemistry ; Molecule Synthesis and biological activity
Authors: Matteo Zanda
Source: Synfacts (article, 2020-07-21)
Field: Chemistry — Organic Chemistry

SYNFORM ISSUE 2020/08 In 2014 the Goldup group Chemistry ; Earth science ; Astrobiology ; Geology Supramolecular Chemistry and Complexes ; Supramolecular Self-Assembly in Materials ; Photoreceptor and optogenetics research
Authors: Korlan Duisenova
Source: e-Publications@Marquette (Marquette University) (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Photophysical Properties and Excited State Dynamics of Porous Organic Materials Charge transfer complexes are charge separated states that are formed at donor - acceptor interfaces and play significant role in charge photogeneration. One of the main criteria for efficient charge transfer is suppression of charge recombination process. Previous experiments show that one of the most effective ways to inhibit recombination is an introduction of bridge molecules between donor and acceptor or increase the number of electron donating and withdrawing groups. These solutions are inspired by photosynthetic reaction centers where charge transfer occurs over long distances. Covalent Organic Frameworks (COFs) are advanced porous crystalline materials that can be constructed of multiple donor and acceptor building blocks. This approach improves efficiency of charge transfer by suppressing dissociation of polaron pairs. In the present work, photophysical and charge dynamics processes of various donor-acceptor systems, namely star-shaped carbazole-π-triazine organic chromophores, BTPA-cased donor-acceptor COFs, and metallophthalocyanine COFs, were investigated using the combination of steady-state spectroscopic techniques and time-resolved femtosecond transient absorption (TA) spectroscopy. The study on star-shaped carbazole-π-triazine organic chromophores showed that formation of charge transfer can be facilitated by positioning a bridging phenyl ring by creation of conjugated system. Nevertheless, the introduction of two phenyl bridge units can distort the coupling leading to weak charge migration from carbazole. Combination of BTPA (5,5',5''-(1,3,5-Benzenetriyl)tris[2-pyridinecarboxaldehyde]) and a series of three different organic precursors: 1,3,5-Tris(4-aminophenyl)benzene (TPB), 4,4',4''-Triaminotriphenylamine (TPA), and 1,3,5-Tris(4-aminophenyl)triazine (TPT) for the synthesis of COF showed that efficient charge transfer and slower recombination process can be achieved by incorporating stronger electron donating group, such as TPA, to enhance excited state dipole moment. Finally, the investigation of charge dynamics in COFs constructed using copper and nickel metallophthalocyanine linked to electron withdrawing 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN) revealed the delocalization of charge between neighboring donor-acceptor units formed within 1.464 – 1.750 ps, which is further transferred between COF layers and dissociates between 0.662 – 3.383 ns. Excited state ; Porosity ; Dynamics (music) ; Porous medium ; Materials science ; Photochemistry ; Chemistry ; Physics ; Atomic physics ; Composite material Luminescence and Fluorescent Materials ; Photochemistry and Electron Transfer Studies ; Polydiacetylene-based materials and applications
Authors: Pablo Simón Marqués
Source: SPIRE - Sciences Po Institutional REpository (preprint, 2020-10-16)
Field: Chemistry — Organic Chemistry

New electron-deficient pi-conjugated systems for potential application in organic photovoltaics. Major contributors to the revival of the organic photovoltaic (OPV) field, non-fullerene acceptors (NFAs) have attracted considerable research interest and efforts in recent years. As a result, power conversion efficiencies now exceed 18%in single junction solar cells. However, these outstanding results have been obtained with complex and expensive structures and processed by spincoating, thus making the up-scaling a true challenge for large surface areas. Hence, in the first chapter a brief overview of the organic photovoltaics and its recent progress isaddressed. Thereafter, the second chapter presents the different series of NFA prepared during this thesis. Two perylene-diimide (PDI) disubstituted regioisomers were newly synthesized and characterized. Then, the impact of the grafting natureand position on the optoelectronic properties and the photovoltaic performances were studied. Thereafter, in collaboration with Heliatek, our efforts were focusedin preparing vacuum-processable non-fullerene acceptors, derived from the indenothiophene (IDT) scaffold. Eventually, the last chapter aims at preparing newbenzothioxanthene (BTXI) derivatives, enhancing its electron-withdrawing behaviour towards a promising family of rylenes for sublimable organic electronics. Conjugated system ; Organic solar cell ; Photovoltaics ; Electron ; Pi ; Materials science ; Nanotechnology ; Chemistry ; Physics ; Engineering ; Electrical engineering ; Photovoltaic system ; Organic chemistry ; Polymer ; Nuclear physics ; Biochemistry Organic Chemistry Cycloaddition Reactions
Authors: Francesco Sciarrabba
Source: The International Islamic University Malaysia Repository (The International Islamic University Malaysia) (article, 2020-04-28)
Field: Chemistry — Organic Chemistry

Nanocompositi a base di seta Sintesi delle nanoparticelle di ZnO utilizzate come dieta per i bachi da seta. Sintesi di nanocompositi a base di seta/zirconia. Base (topology) ; Mathematics Chemical Synthesis and Reactions ; Catalysis for Biomass Conversion ; Nanomaterials for catalytic reactions
Authors: Sepehr Talebian
Source: Research Online (University of Wollongong) (article, 2020-01-01)
Field: Materials Science — Biomaterials

Coaxial hydrogel structures for drug delivery to tumors Biopolymer-based hydrogels have emerged as promising platforms for drug delivery systems (DDSs) due to their inherent biocompatibility, tunable physical properties and controllable degradability. Yet, drug release in majority of these systems is solely contingent on diffusion of drug molecules through the hydrogel, which often leads to burst release of drugs from these systems. As a result, the main aim of this thesis was to develop suitable hydrogel platforms that allow sustained release of anti-cancer drugs, to be ultimately used as implants for local delivery of drugs to tumors. To this end, inspired by the chemistry of mussel adhesive proteins, a new generation of coaxial hydrogel structures were developed that could simultaneously exert both affinity and diffusion control over the release of chemotherapeutic drugs. Specifically, dopamine-modified hydrogel along with chemotherapeutic drugs was used as the main core component to confer affinity-controlled release, while a methacrylated hydrogel was used as the shell composition to provide the controlled diffusion barrier. Initially a well-recognized wet-spinning technique was employed to fabricate coaxial fibers with the given composition, mainly because this fabrication method allows high throughput and continuous production of coaxial structures. Accordingly, it was shown that the fabricated coaxial fibers were robust in both dry and wet conditions, and most importantly they were capable of exerting a controlled release of Doxorubicin (a chemotherapeutic drug) over a span of 3 weeks. Also, in vitro and in vivo evaluations showed that drug loaded coaxial fibers had optimal anticancer activity against pancreatic cancer cells... Drug delivery ; Drug ; Medicine ; Biomedical engineering ; Materials science ; Nanotechnology ; Pharmacology Nanoparticle-Based Drug Delivery ; Hydrogels: synthesis, properties, applications
Authors: Kunal Pal | Debbethi Bera
Source:  (article, 2020-04-09)
Field: Materials Science — Biomaterials

Nanotechnology unbolting new avenues for targeted delivery of cancer therapeutics: A brief overview The particles within the nanoregime are quite smaller (100- 10,000 times) than human cells but are comparable to that of biomolecules like enzymes and receptors. The nanoparticles smaller than 50 nm can easily pervade into most cells, and those particles smaller than 20 nm can easily escape into the circulation through the blood vessels. Nanoparticles are quite conducive to be fabricated appropriately to serve as a device/vehicles of important therapeutic genes or drugs specifically to the cancer cells avoiding any hazardous effects on the normal cells. This review encompasses the recent investigations employing nanocarriers like liposomes, micelles, carbon nanotubes, dendrimers, nanoshells that has been developed with positive results.The cancer therapeutic agents like Doxorubicin, Paclitaxel, Cystatin ,Small interfering RNA(SiRNAs) are encapsulated within these nanocarriers through the processes of entrapping, covalent binding, encapsulation or adsorption. Furthermore these nanoparticles were conjugated with cancer specific targetic ligands like Folic acid, Monoclonal antibody,Luteinising hormone releasing hormone(LHRH)peptide,etc which enable them to successfully deliver the therapeutic agents to the cancerous cells. Henceforth the development of these smart nanodevices will undoubtedly pave the way for coming up with future novel therapeutic strategies for combating the malignant cells circumventing any adverse side effects on the normal cells. Nanocarriers ; Nanotechnology ; Cancer cell ; Nanoparticle ; Drug delivery ; Nanomedicine ; Chemistry ; Cancer ; Materials science ; Medicine Nanoparticle-Based Drug Delivery ; Dendrimers and Hyperbranched Polymers ; RNA Interference and Gene Delivery
Authors: Kuo‐Hsiung Lee
Source: UNC Libraries (article, 2020-11-04)
Field: Chemistry — Organic Chemistry

Discovery and Development of Natural Product-Derived Chemotherapeutic Agents Based on a Medicinal Chemistry Approach ⊥ † Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogs, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolones, dithiophenediones, neo-tanshinlactone, tylophorine, suksdorfin, DCK, and DCP, will be presented with respect to their discovery and preclinical development as potential clinical trial candidates. Research approaches include bioactivity- or mechanism of action-directed isolation and characterization of active compounds, rational drug design-based modification and analog synthesis, as well as structure-activity relationship and mechanism of action studies. Current clinical trials agents discovered by the Natural Products Research Laboratories, University of North Carolina, include bevirimat (dimethyl succinyl betulinic acid), which is now in Phase IIb trials for treating AIDS. Bevirimat is also the first in a new class of HIV drug candidates called “maturation inhibitors”. In addition, an etoposide analog, GL-331, progressed to anticancer Phase II clinical trials, and the curcumin analog JC-9 is in Phase II clinical trials for treating acne and in development for trials against prostate cancer. The discovery and development of these clinical trials candidates will also be discussed. Natural product ; Chemistry ; Natural (archaeology) ; Drug discovery ; Biochemical engineering ; Computational biology ; Product (mathematics) ; Combinatorial chemistry ; Computer science ; Stereochemistry ; Biology ; Engineering ; Biochemistry ; Mathematics Chemical synthesis and alkaloids ; Pharmacological Effects of Natural Compounds ; Microbial Natural Products and Biosynthesis
Authors: Dinesh Prakashrao Kawade | Akshita V. Hadke
Source: International Journal of Pharmaceutical Chemistry and Analysis (article, 2020-12-15)
Field: Chemistry — Organic Chemistry

Synthesis and antimicrobial activities of some novel thieno [2,3-d]- Pyrimidin-4(3H)-One derivatives Pain and inflammation are simultaneous responses in bacterial infections. In current clinical practice, the agents like antimicrobial drug are prescribed concurrently. A POCl3 catalyzed, efficient, one-step and solvent-free synthesis of novel thieno [2, 3-d] pyrimidin-4(3H)-one derivatives from 2-amino-4,5-substitutedthiophene-3-carbonitrile has been developed using various aliphatic acid under conventional heating and microwave irradiation. The formation of compounds was confirmed using elemental analysis and spectroscopic techniques like FTIR, 1H NMR and Mass spectroscopy. All synthesized compounds have been screened for their antimicrobial activity against Escherichia coli (Gram –ve strain), Bacillus subtilis (Gram +ve strain) for antibacterial activity and antifungal activities against Aspergillus niger and Candida albicans. The result showed that synthesized compounds exhibit weak, moderate and good antimicrobial activity. It was observed that the compounds 2a, 2c, 2d, 2e, 2f, 2g, 2j and 2k showed good antimicrobial activity whereas compounds 2b, 2i, 2j showed significant antimicrobial activity compared with standard drug Streptomycin and Amphotericin B respectively. Keyword:POCl3, Thieno[2, 3-d]pyrimidin-4 (3H)-one, Antimicrobial activity, Streptomycin and Amphotericin B Antimicrobial ; Aspergillus niger ; Bacillus subtilis ; Candida albicans ; Chemistry ; Escherichia coli ; Antibacterial activity ; Streptomycin ; Combinatorial chemistry ; Antibiotics ; Bacteria ; Nuclear chemistry ; Microbiology ; Organic chemistry ; Biochemistry ; Biology Synthesis and biological activity ; Synthesis and Reactions of Organic Compounds ; Multicomponent Synthesis of Heterocycles
Authors: Ye Xue
Source: Rowan Digitals Works (Rowan University) (article, 2020-01-01)
Field: Materials Science — Biomaterials

Designing silk protein-based composite materials with tunable heat transfer and magnetic properties Renewable and biocompatible silk protein materials with desired physical properties show promising applications in biomedical field. In this work, a set of protein-based composites with desired thermal and magnetic properties, enhanced by the appropriate distribution of nanofillers in the protein matrix in both 2D-film and 1D-fiber forms was investigated. Results indicate that secondary structures of silk protein materials regenerated by a formic acid-calcium chloride method are different from those of their respective natural silk fibers. Intramolecular beta-sheet structures were found to dominate these silk films, causing these regenerated samples to be water-insoluble but more flexible than traditional silk films with intermolecular beta-sheet crystals. New renewable thermal management materials based on a stable composite system of biocompatible silk fibroin protein materials and AlN /BN were developed. The self-assembly of nanofillers and SF was promoted by water annealing to enhance the interaction between the phases to reduce the phonon scattering. Thermal conductivity of the composites was significantly improved. Silk protein with three types of magnetic nanoparticles were combined and investigated. Results indicate that magnetite (Fe3O4) and barium hexaferrite (BaFe12O19) can inhibit beta-sheet formation due to strong coordination bonding between Fe3+ ions and carboxylate ions and on silk fibroin chains where cobalt particles showed minimal effect. All three types of magnetic composites films maintained high magnetization. This work is significant in that it represents a novel and systematic study on expanding the potential biomedical applications of a set of protein-based composites. SILK ; Composite number ; Materials science ; Composite material ; Heat transfer ; Physics ; Thermodynamics Silk-based biomaterials and applications ; Silkworms and Sericulture Research ; Insect and Arachnid Ecology and Behavior