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ACS Combinatorial Science

Shaik Karamthulla, Asim Jana, Lokman H Choudhury
A simple and novel method for the synthesis of 5,6-disubstituted pyrrolo[2,3-d]pyrimidine-2,4-diones has been reported using arylglyoxal-based three-component reactions. Under microwave heating conditions, arylglyoxal, 6-amino uracil, or its derivatives reacts with various thiols in acetic acid medium to provide a series of pyrrolo[2,3-d]pyrimidine-2,4-diones (4) having a thioether and an aryl ring in 5 and 6 positions, respectively. On the other hand reaction of arylglyoxal, amino uracil and malononitrile in place of thiols, provided corresponding 5,6-disubstituted pyrrolo[2,3-d]pyrimidine-2,4-diones (5) with selectively converting one of the -CN to -CONH2 group both in conventional (method A) and microwave heating conditions (method B)...
January 20, 2017: ACS Combinatorial Science
Ying-Ying Chen, Li-Te Chang, Hung-Wei Chen, Chia-Ying Yang, Ling-Wei Hsin
A fast and facile synthesis of a series of 4-nitrophenyl 2-azidoethylcarbamate derivatives as activated urea building blocks was developed. The N-Fmoc-protected 2-aminoethyl mesylates derived from various commercially available N-Fmoc-protected α-amino acids, including those having functionalized side chains with acid-labile protective groups, were directly transformed into 4-nitrophenyl 2-azidoethylcarbamate derivatives in 1 h via a one-pot two-step reaction. These urea building blocks were utilized for the preparation of a series of urea moiety-containing mitoxantrone-amino acid conjugates in 75-92% yields and parallel solution-phase synthesis of a urea compound library consisted of 30 members in 38-70% total yields...
January 18, 2017: ACS Combinatorial Science
Deepti Goyal, Suniba Shuaib, Sukhmani Mann, Bhupesh Goyal
Alzheimer's disease (AD) is a progressive neurodegenerative disease with no clinically accepted treatment to cure or halt its progression. The worldwide effort to develop peptide-based inhibitors of amyloid-β (Aβ) aggregation can be considered an unplanned combinatorial experiment. An understanding of what has been done and achieved may advance our understanding of AD pathology and the discovery of effective therapeutic agents. We review here the history of such peptide-based inhibitors, including those based on the Aβ sequence and those not derived from that sequence, containing both natural and unnatural amino acid building blocks...
January 18, 2017: ACS Combinatorial Science
Petra Králová, Veronika Fülöpová, Michal Malon, Tereza Volná, Igor Popa, Miroslav Soural
Herein we report the polymer-supported synthesis of 3,4-dihydro-2H-1,4-oxazine-3-carboxylic acid derivatives using immobilized Fmoc-Ser(tBu)-OH and Fmoc-Thr(tBu)-OH as the starting materials. After the solid-phase-synthesis of N-alkylated-N-sulfonylated/acylated intermediates, the target dihydro-oxazines were obtained using trifluoroacetic acid (TFA) mediated cleavage from the resin. This approach was also studied to the preparation of dihydro-thiazines from immobilized Fmoc-Cys(Trt)-OH. Inclusion of triethylsilane (TES) in the cleavage cocktail resulted in the stereoselective formation of the corresponding morpholine/thiomorpholine-3-carboxylic acids...
January 13, 2017: ACS Combinatorial Science
Kalpana K Volety, Guido P J Huyberechts
This paper presents a strategy to identify the optimum compositions in metal alloys with certain desired properties in a high-throughput screening environment, using a multi-objective optimization approach. In addition to the identification of the optimum compositions in a primary screening, the strategy also allows pointing to regions in the compositional space where further exploration in a secondary screening could be carried out. The strategy for the primary screening is a combination of two multi-objective optimization approaches namely Pareto optimality and desirability functions...
January 3, 2017: ACS Combinatorial Science
Sung Hyeon Park, Chang Hyuck Choi, Seung Yong Lee, Seong Ihl Woo
Combinatorial optical screening of aprotic electrocatalysts has yet not been achieved primarily due to H+-associated mechanisms of fluorophore modulation. We have overcome this problem by using fluorophore metal-organic complexes. In particular, eosin Y and quinine can be coordinated with various metallic cations (e.g. Li+, Na+, Mg2+, Zn2+, and Al3+) in aprotic solvents, triggering changes in their fluorescent properties. These interactions have been used in a reliable screening method to determine oxygen reduction/evolution reaction activities of 100 Mn-based binary catalysts for the aprotic Li-air battery...
January 3, 2017: ACS Combinatorial Science
Shrabani Panigrahi, Daniela Nunes, Tomás Calmeiro, Kasra Kardarian, Rodrigo Martins, Elvira Fortunato
A ZnO/Cu2O-based combinatorial heterojunction device library was successfully fabricated by a simple spray pyrolysis technique using ITO-coated glass as the substrate. The combinatorial approach was introduced to analyze the impact of the ZnO and Cu2O layer thicknesses on the performance of the solar cells. The thickness of the ZnO layer was varied from ∼50 to 320 nm, and the Cu2O layer was deposited orthogonal to the ZnO thickness gradient. In the case of Cu2O, the thickness varied from ∼200 to 800 nm...
January 3, 2017: ACS Combinatorial Science
Ermete Antolini
Combinatorial chemistry and high-throughput screening represent an innovative and rapid tool to prepare and evaluate a large number of new materials, saving time and expense for research and development. Considering that the activity and selectivity of catalysts depend on complex kinetic phenomena, making their development largely empirical in practice, they are prime candidates for combinatorial discovery and optimization. This review presents an overview of recent results of combinatorial screening of low-temperature fuel cell electrocatalysts for methanol oxidation...
January 3, 2017: ACS Combinatorial Science
Petra Bleckenwegner, Cezarina Cela Mardare, Christoph Cobet, Jan Philipp Kollender, Achim Walter Hassel, Andrei Ionut Mardare
Optical bandgap mapping of Nb-Ti mixed oxides anodically grown on a thin film parent metallic combinatorial library was performed via variable angle spectroscopic ellipsometry (VASE). A wide Nb-Ti compositional spread ranging from Nb-90 at.% Ti to Nb-15 at.% Ti deposited by cosputtering was used for this purpose. The Nb-Ti library was stepwise anodized at potentials up to 10 V SHE, and the anodic oxides optical properties were mapped along the Nb-Ti library with 2 at.% resolution. The surface dissimilarities along the Nb-Ti compositional gradient were minimized by tuning the deposition parameters, thus allowing a description of the mixed Nb-Ti oxides based on a single Tauc-Lorentz oscillator for data fitting...
January 3, 2017: ACS Combinatorial Science
Erin Wachter, Diego Moyá, Edith C Glazer
A chemically reactive Ru(II) "building block", able to undergo condensation reactions with substituted diamines, was utilized to create a small library of luminescent "light switch" dipyrido-[3,2-a:2',3'-c] phenazine (dppz) complexes. The impact of substituent identity, position, and the number of substituents on the light switch effect was investigated. An unbiased, parallel screening approach was used to evaluate the selectivity of the compounds for a variety of different biomolecules, including protein, nucleosides, single stranded DNA, duplex DNA, triplex DNA, and G-quadruplex DNA...
December 28, 2016: ACS Combinatorial Science
Helge Sören Stein, Sally Jiao, Alfred Ludwig
A challenge in combinatorial materials science remains the efficient analysis of X-ray diffraction (XRD) data and its correlation to functional properties. Rapid identification of phase-regions and proper assignment of corresponding crystal structures is necessary to keep pace with the improved methods for synthesizing and characterizing materials libraries. Therefore, a new modular software called htAx (high-throughput analysis of X-ray and functional properties data) is presented that couples human intelligence tasks used for "ground-truth" phase-region identification with subsequent unbiased verification by an algorithm to efficiently analyze which phases are present in a materials library...
December 21, 2016: ACS Combinatorial Science
Tarak K Patra, Venkatesh Meenakshisundaram, Jui-Hsiang Hung, David S Simmons
Machine-learning has the potential to dramatically accelerate high-throughput approaches to materials design, as demonstrated by successes in biomolecular design and hard materials design. However, in the search for new soft materials exhibiting properties and performance beyond those previously achieved, machine learning approaches are frequently limited by two shortcomings. First, because they are intrinsically interpolative, they are better suited to the optimization of properties within the known range of accessible behavior than to the discovery of new materials with extremal behavior...
December 20, 2016: ACS Combinatorial Science
Efraín Hernández-Rivera, Shawn P Coleman, Mark A Tschopp
The objective of this research is to demonstrate how similarity metrics can be used to quantify differences between sets of diffraction patterns. A set of 49 similarity metrics is implemented to analyze and quantify similarities between different Gaussian-based peak responses, as a surrogate for different characteristics in X-ray diffraction (XRD) patterns. A methodological approach was used to identify and demonstrate how sensitive these metrics are to expected peak features. By performing hierarchical clustering analysis, it is shown that most behaviors lead to unrelated metric responses...
December 16, 2016: ACS Combinatorial Science
Santosh K Suram, Yexiang Xue, Junwen Bai, Ronan Le Bras, Brendan Rappazzo, Richard Bernstein, Johan Bjorck, Lan Zhou, R Bruce van Dover, Carla P Gomes, John M Gregoire
Rapid construction of phase diagrams is a central tenet of combinatorial materials science with accelerated materials discovery efforts often hampered by challenges in interpreting combinatorial X-ray diffraction data sets, which we address by developing AgileFD, an artificial intelligence algorithm that enables rapid phase mapping from a combinatorial library of X-ray diffraction patterns. AgileFD models alloying-based peak shifting through a novel expansion of convolutional nonnegative matrix factorization, which not only improves the identification of constituent phases but also maps their concentration and lattice parameter as a function of composition...
January 9, 2017: ACS Combinatorial Science
Zhinian Li, Lei He, Shenliang Wang, Wuzhong Yi, Shihui Zou, Liping Xiao, Jie Fan
The development of efficient catalyst for oxidative coupling of methane (OCM) reaction represents a grand challenge in direct conversion of methane into other useful products. Here, we reported that a newly developed combinatorial approach can be used for ultrafast optimization of La2O3-based multicomponent metal oxide catalysts in OCM reaction. This new approach integrated inkjet printing assisted synthesis (IJP-A) with multidimensional group testing strategy (m-GT) tactfully takes the place of conventionally high-throughput synthesis-and-screen experiment...
January 9, 2017: ACS Combinatorial Science
Marie L Malone, Valerie J Cavett, Brian M Paegel
Combinatorial bead libraries figure prominently in next-generation sequencing and are also important tools for in vitro evolution. The most common methodology for generating such bead libraries, emulsion PCR (emPCR), enzymatically extends bead-immobilized oligonucleotide PCR primers in emulsion droplets containing a single progenitor library member. Primers are almost always immobilized on beads via noncovalent biotin-streptavidin binding. Here, we describe covalent bead functionalization with primers (∼10(6) primers/2...
January 9, 2017: ACS Combinatorial Science
Benjamin Fabre, Jan Pícha, Václav Vaněk, Irena Selicharová, Martina Chrudinová, Michaela Collinsová, Lenka Žáková, Miloš Buděšínský, Jiří Jiráček
We designed a combinatorial library of trifunctional scaffold-derived compounds, which were derivatized with 30 different in-house-made azides. The compounds were proposed to mimic insulin receptor (IR)-binding epitopes in the insulin molecule and bind to and activate this receptor. This work has enabled us to test our synthetic and biological methodology and to prove its robustness and reliability for the solid-phase synthesis and testing of combinatorial libraries of the trifunctional scaffold-derived compounds...
December 12, 2016: ACS Combinatorial Science
Maomin Zhen, Danfeng Zhang, Zeyu Zhang, Yanqing Peng
A magnetically retrievable nanocomposite was prepared by in situ polycondensation and entrapment of iron oxide nanoparticles. This material was found to be efficient in trapping excess electrophilic reagents such as carbonyl compounds, acid chlorides and isothiocyanates. Advantages of the new scavenger include facile preparation, high loading capacity, low cost, satisfactory swelling properties in polar solvents, and convenient magnetic recovery.
December 12, 2016: ACS Combinatorial Science
Ming-Shou Ho, Benjamin E Partridge, Hao-Jan Sun, Dipankar Sahoo, Pawaret Leowanawat, Mihai Peterca, Robert Graf, Hans W Spiess, Xiangbing Zeng, Goran Ungar, Paul A Heiney, Chain-Shu Hsu, Virgil Percec
Synthesis, structural, and retrostructural analysis of a library containing 16 self-assembling perylene (PBI), 1,6,7,12-tetrachloroperylene (Cl4PBI), naphthalene (NBI), and pyromellitic (PMBI) bisimides functionalized with environmentally friendly AB3 chiral racemic semifluorinated minidendrons at their imide groups via m = 0, 1, 2, and 3 methylene units is reported. These semifluorinated compounds melt at lower temperatures than homologous hydrogenated compounds, permitting screening of all their thermotropic phases via structural analysis to discover thermodynamically controlled helical crystallization from propeller-like, cogwheel, and tilted molecules as well as lamellar-like structures...
December 12, 2016: ACS Combinatorial Science
Aizhan Abdildinova, Seung-Ju Yang, Young-Dae Gong
A novel solid-phase synthesis methodology of N-substituted-2-aminothiazolo[4,5-b]pyrazine derivatives was developed. The key step in this synthesis strategy is the tandem reaction of isothiocyanate terminated resin 2 with o-bromo-2-aminopyrazine, affording cyclized 2-aminothiazolo[4,5-b]pyrazine resin 4. To increase the diversity of our library, Suzuki coupling reaction was performed at the position C6. Further functionalization of 2-aminothiazolo[4,5-b]pyrazine core skeleton with various electrophiles such as alkyl halides, acyl chlorides, and sulfonyl chlorides and cleavage from the resin with TFA in DCM generated N-alkyl-, N-acyl-, and N-sulfonyl-2-aminothiazolo[4,5-b]pyrazine derivatives...
December 12, 2016: ACS Combinatorial Science
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