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ACS Combinatorial Science

Hyun-Jeong Ryu, Seung-Ju Yang, Gee-Hyung Lee, Young-Dae Gong
A 2-amido benzo[d]imidazole library has been constructed on solid-phase synthesis. The key step of this solid-phase synthesis involves the preparation of polymer-bound 2-amino benzo[d]imidazole resin through desulfurative cyclization of thiourea resin by using DMC and DIPEA in DCM, and the resin is then functionalized by acylation at the 2-amine position, to afford 2-amido benzo[d]imidazole resin. In the case of 2-amido benzo[d]imidazole resin having p-I, and m-NO2, the resin was further functionalized by Suzuki/Sonogashira-coupling (p-I), and was reduced to primary amine (m-NO2), followed by acylation...
March 20, 2018: ACS Combinatorial Science
Rachel Coleman, Darci J Trader
To attenuate an over-abundance of cellular protein, it has been hypothesized that the 20S core particle (20S CP) of the proteasome can be chemically stimulated to degrade proteins into non-toxic peptides more quickly. Screening for small molecule 20S CP stimulators is typically performed with a reporter peptide composed of four amino acids and a coumarin group that is released upon proteasome-mediated hydrolysis to generate a fluorescent signal. Screening with this small reporter can lead to false negatives because the reporter peptide is rapidly turned-over without stimulation...
March 19, 2018: ACS Combinatorial Science
Woo-Ri Shin, Simranjeet Singh Sekhon, Sung-Keun Rhee, Jung Ho Ko, Ji-Young Ahn, Jiho Min, Yang-Hoon Kim
Aptamer-based paper strip sensor for detecting Vibrio fischeri was developed. Our method was based on the aptamer sandwich assay between whole live cells, V. fischeri and DNA aptamer probes. Following 9 rounds of Cell-SELEX and one of the negative-SELEX, V. fischeri Cell Aptamer (VFCA)-02 and -03 were isolated, with the former showing approximately 10-fold greater avidity (in the sub-nanomolar range) for the target cells when arrayed on a surface. The colorimetric response of a paper sensor based on VFCA-02 was linear in the range of 4 × 101 to 4 × 105 CFU/mL of target cell by using scanning reader...
March 19, 2018: ACS Combinatorial Science
Po-Chia Chen, Pawel Masiewicz, Vladimir Rybin, Dmitri I Svergun, Janosch Hennig
We present a screening protocol utilizing small-angle X-ray scattering (SAXS) to obtain structural information of biomolecular interactions independent of prior knowledge, so as to complement affinity-based screening and provide leads for further exploration. This protocol categorizes ligand titrations by computing pair-wise agreement between curves, and separately estimates affinities by quantifying complex formation as a departure from the linear sum properties of solution SAXS. The protocol is validated by sparse sequence search around the native poly-uridine RNA motifs of the two-RRM domain Sex-lethal protein (Sxl)...
March 19, 2018: ACS Combinatorial Science
Hajo Meyer, Michael Meischein, Alfred Ludwig
A high-throughput method is presented for the efficient assessment of the formation and stability of nanoparticle suspensions in ionic liquids which differ in their cations and anions. As a proof of principle, Ag was sputtered on a cavity array filled with 9 different ionic liquids. Not all nanoparticle ionic liquid combinations form a stable suspension with separated nanoparticles. Directly after synthesis, the formation of non-agglomerated nanoparticle suspensions with sizes from 4 nm to 9 nm is observed by transmission electron microscopy as well as different time dependencies of the suspension stabilities...
March 9, 2018: ACS Combinatorial Science
Xiao Wang, Detlef Rogalla, Alfred Ludwig
The mechanical stress change of VO2 film substrate combinations during their reversible phase transformation makes them promising for applications in micro/nano-actuators. V1-xWxO2 thin film libraries were fabricated by reactive combinatorial co-sputtering to investigate the effects of the addition of W on mechanical and other transformation properties. High-throughput characterization methods were used to systematically determine the composition spread, crystalline structure, surface topography, as well as the temperature-dependent phase transformation properties: i...
March 5, 2018: ACS Combinatorial Science
I Ayelén Ramallo, Victoria Lucía Alonso, Federico Rua, Esteban Serra, Ricardo L E Furlan
A set of chemically engineered extracts enriched in compounds including N-N and N-O fragments in their structures was prepared. Bromodomain binding screening and bioguided fractionation led to the identification of one oxime hit that interacts with TcBDF3 with affinity in the sub-micromolar range and that shows interesting antiparasitic properties against the different life cycle stages of T. cruzi.
February 26, 2018: ACS Combinatorial Science
Min-Kyung Shin, Yu-Jung Hyun, Ji Hoon Lee, Hyun-Suk Lim
Cyclic peptoids are emerging as an attractive class of peptidomimetics. Compared to their linear counterparts, cyclic peptoids should have increased conformational rigidity and preorganized structures, enabling them to bind more tightly to target proteins without major entropy penalty. Because cyclic peptoids lack the amide protons in their backbones like linear peptoids, it is perceived that cyclic peptoids are seemingly cell permeable as much as linear peptoids. However, no systematic investigation for cell permeability of cyclic peptoids has been reported yet...
February 26, 2018: ACS Combinatorial Science
Rudrakshula Madhavachary, Tryfon Zarganes-Tzitzikas, Pravin Patil, Katarzyna Kurpiewska, Justyna Kalinowska-Tłuścik, Alexander Dömling
The synthesis of uracil/thymine containing tetra/tri-substituted imidazoles were demonstrated using Ugi/Passerini-reaction fol-lowed by a post-cyclization reaction sequence. The approach enables the one-pot facile construction of diverse compounds in moderate to excellent yields (47-82%). The 5-fluorouracil and 5-methyluracil moieties afford potentially bioactive molecules with drug-like properties. These scaffolds are being utilized in the screening deck of the European Lead Factory.
February 19, 2018: ACS Combinatorial Science
Catherine Fagundez, Diver Sellanes, Gloria Lourdes Serra
The results from the synthesis of peptides by Fmoc/SPPS on a 2-CTC resin and then lactamization in solution or solid phase for the preparation of cyclopeptides are presented. Both procedures allow the synthesis of the desired compounds in good to very good yield and with high cyclization efficiency for on-resin macrocyclization. In addition, the activities of the corresponding cyclopeptides against the chloroquine-resistant K1 strain of Plasmodium falciparum were evaluated. Cyclo-Cys(Trt)-Gly-Thr(tBu)-Gly-Cys(Trt)-Gly showed potent in vitro and selective activity against this parasite, EC50 = 28 nM...
February 15, 2018: ACS Combinatorial Science
Yahya E Jad, Santosh Kumar Gudimella, Thavendran Govender, Beatriz G de la Torre, Fernando Albericio
The synthesis of pyrroles has received considerable attention because of their biological and pharmaceutical activities. Herein we describe a solid-phase multicomponent reaction that utilizes Lys as a N donor, β-nitrostyrenes, 1,3-dicarbonyl compounds, and FeCl3 as an easily accessible catalyst under microwave irradiation affords the subsequent pyrrole derivatives in high conversions. The strategy combines three of the most powerful tools in modern synthetic chemistry: the solid-phase mode, the microwave activation and a multicomponent reaction...
February 14, 2018: ACS Combinatorial Science
Lissa S Tsutsumi, John M Elmore, Uyen T Dang, Miranda J Wallace, Ravikanthreddy Marreddy, Robin B Lee, Ghee T Tan, J Hurdle, Richard E Lee, Dianqing Sun
Herein we report the antibacterial structure-activity relationships of cyclic hexapeptide wollamide analogs derived from solid-phase library synthesis. Wollamide B, a cyclic hexapeptide natural product, has been previously found to have activity against Mycobacterium bovis. To further evaluate its antimycobacterial/antibacterial potential, 27 peptides including wollamides A/B, and desotamide B, were synthesized and subsequently tested against a panel of clinically significant bacterial pathogens. Biological evaluation revealed that the cyclic scaffold, amide functionality in position I, tryptophan residue in position V, and the original stereochemistry pattern of the core scaffold were key for antituberculosis and/or antibacterial activity...
February 12, 2018: ACS Combinatorial Science
Tz-Yi Wu, Sandip Dhole, Manikandan Selvaraju, Chung-Ming Sun
A novel and efficient method for the one-pot synthesis of 2H-indazole from readily available building blocks is reported. The reaction of 2-nitrobenzylamines with zinc and ammonium formate underwent partial reduction to nitroso benzylamine followed by an intramolecular cyclization to afford 2H-indazole via N-N bond formation. The carboxylic acid moiety of indazole was proceeded to regioselective alkyne insertion under ruthenium catalysis to form pyranone-fused indazoles. The regioselectivity is influenced by the weak co-ordination of indazole ring nitrogen to the metal center...
January 30, 2018: ACS Combinatorial Science
Hui Xing, Bingbing Zhao, Yujie Wang, Xiaoyi Zhang, Yang Ren, Ningning Yan, Tieren Gao, Jindong Li, Lanting Zhang, Hong Wang
100 nm thick Fe-Co-Ni materials chips were prepared and isothermally annealed at 500, 600 and 700oC, respectively. Pixel-by-pixel composition and structural mapping was performed by micro-beam X-ray at synchrotron light source. Diffraction images were recorded at a rate of 1 pattern/s. The XRD patterns were automatically processed, phase-identified and categorized by hierarchical clustering algorithm to construct the composition-phase map. The resulting maps are consistent with corresponding isothermal sections reported in the ASM Alloy Phase Diagram DatabaseTM, verifying the effectiveness of the present approach in phase diagram construction...
January 30, 2018: ACS Combinatorial Science
R Nishanth Rao, Balamurali Mm, Barnali Maiti, Ranjit Thakuria, Kaushik Chanda
An expeditious catalyst free heteroannulation reaction for imidazo[1,2-a]pyridines/pyrimidines /pyrazines was developed in green solvent under microwave irradiation. Using H2O-IPA as the reaction medium, various substituted 2-aminopyridines/pyrazines/pyrimidines underwent annulation reaction with α-bromoketones under microwave irradiation to provide the corresponding imidazo[1,2-a]pyridines/pyrimidines/pyrazines in excellent yields. The synthetic methodology appears to be very simple and superior to the already reported procedures with the high abundance of commercial reagents and great ability in expanding the molecular diversity...
January 26, 2018: ACS Combinatorial Science
Zhi Zou, Diana M Mate, Kristin Rübsam, Felix Jakob, Ulrich Schwaneberg
Sortase-catalyzed ligations have emerged as powerful tools for the site-specific ligation of peptides and proteins in material science and biocatalysis. In this work, a directed sortase evolution strategy (SortEvolve) has been developed as a general high-throughput screening (HTS) platform to improve activity of sortase A (Application 1) and to perform directed laccase evolution through a semi-purification process in 96-well microtiter plate (MTP) (Application 2). A semi-purification process in polypropylene MTP (PP-MTP) is achieved through the anchor peptide LCI which acts as adhesion promoter...
January 24, 2018: ACS Combinatorial Science
Tiberiu Alecu Burinaru, Marioara Avram, Andrei Avram, Cătălin Mărculescu, Bianca Țîncu, Vasilica Țucureanu, Alina Matei, Manuella Militaru
Metastasis is the main cause of death in cancer patients world-wide. During metastasis cancer cells detach from the primary tumor and invade distant tissue. The cells that undergo this process are called circulating tumor cells (CTCs). Studies show that the number of CTCs in the peripheral blood can predict progression-free survival and overall survival, and can be informative concerning the efficacy of treatment. Research is now concentrated on developing devices that can detect CTCs in the blood of cancer patients with improved sensitivity and specificity that can lead to improved clinical evaluation...
January 24, 2018: ACS Combinatorial Science
Peter Maximilian Kadletz, Yahya Motemani, Joy Iannotta, Steffen Salomon, Chinmay Khare, Lukas Grossmann, Hans Jürgen Maier, Alfred Ludwig, Wolfgang W Schmahl
Ti-Ta thin films exhibit properties that are of interest for applications as micro actuators and as biomedical implants. A Ti-Ta thin film materials library was deposited at T = 25 °C by magnetron sputtering employing the combinatorial approach, which led to a compositional range of Ti87Ta13 to Ti14Ta86. Subsequent high-throughput characterization methods permitted a quick and comprehensive study of the crystallographic, microstructural and morphological properties which strongly depend on the chemical composition...
January 22, 2018: ACS Combinatorial Science
Rintaro Iwata Hara, Yuta Mitsuhashi, Keita Saito, Yuske Maeda, Takeshi Wada
Peptides are still difficult to synthesize when they contain sterically hindered amino acids such as α,α-di-substituted amino acids and N-substituted amino acids. In this study, solid-phase syntheses of oligopeptides containing multiple α-aminoisobutyric acid (Aib) residues were performed in high yields by using a non-swellable resin as the solid-support and 3-nitro-1,2,4-triazol-1-yl-tris(pyrrolidin-1-yl)phosphonium hexafluorophosphate (PyNTP) as the condensing reagent.
January 17, 2018: ACS Combinatorial Science
Mladena Glavaš, Matija Gredičak, Ivanka Jeric
Multicomponent reactions represent a highly efficient approach to a broad spectrum of structurally diverse compounds starting from simple and affordable compounds. A focused library of tweezers-like compounds is prepared by employing the multicomponent Passerini reaction comprising enediyne-derived amino aldehydes. The reaction proceeds under mild conditions yielding Passerini products in good to excellent yields. Post-condensation modifications of Passerini products are demonstrated through a simple deprotection/coupling approach comprising amino functionality, furnishing enediyne cores with highly decorated arms...
January 17, 2018: ACS Combinatorial Science
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