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Ionic Liquid-Assisted Farming: The Electrophilic Fluorination Benchmark.
25 pKa units. Further, the corresponding titration curves are in fair agreement, although the shift of the Hill coefficient from a value of 1 was not always reproduced in simulations. The phase space overlap in Cartesian space between trajectories generated in constant pH and standard MD simulations is fair and suggests that our constant pH MD approach reasonably well preserves the dynamics of the system, allowing dynamic protonation MD simulations without introducing structural artifacts.A simple protocol for the synthesis of triarylmethane derivatives with three different (hetero)aryl groups by decarbonylation of 3,3-diaryl benzofuranones, which can easily be prepared via arylation of benzofuranones, was developed. The reaction proceeds on heating in dimethylformamide (DMF) in the presence of CH3ONa and water to generate the products in good to excellent yields. This reaction can be easily scaled up to give a triarylmethane in a gram scale. Further chemical manipulation of the products enabled useful transformations of the phenol ring, including reduction, arylation, cyclization, etc.The data collected along a metadynamics simulation can be used to recover information about the underlying unbiased system by means of a reweighting procedure. Here, we analyze the behavior of several reweighting techniques in terms of the quality of the reconstruction of the underlying unbiased free energy landscape in the early stages of the simulation and propose a simple reweighting scheme that we relate to the other techniques. We then show that the free energy landscape reconstructed from reweighted data can be more accurate than the negative bias potential depending on the reweighting technique, the stage of the simulation, and the adoption of well-tempered or standard metadynamics. While none of the tested reweighting techniques from the literature provides the most accurate results in all the analyzed situations, the one proposed here, in addition to helping simplifying the reweighting procedure, converges quickly and precisely to the underlying free energy surface in all the considered cases, thus allowing for an efficient use of limited simulation data.Drug-loaded micelles with long circulation time in blood and stimuli-responsiveness under the tumor micro-environment can significantly enhance therapeutic efficacy. In this report, human hair keratin was extracted with a reduction method and then conjugated with zwitterionic poly(2-methacryloxyethyl phosphatidylcholine, MPC) via thiol chain transfer polymerization (thiol CTP). Subsequently, keratin-polyMPC conjugates (KPC) were prepared into micelles and loaded with doxorubicin (DOX) by self-assembly. These micelles exhibited pH, glutathione (GSH), and enzyme triple-responsiveness as well as charge reversibility under the tumor micro-environment. In addition, these micelles showed high toxicity against A549 cells while low toxicity to normal cells. In vivo anticancer efficacy results revealed that these micelles showed better therapeutic efficiency than free DOX. Furthermore, these carriers exhibited prolonged circulation time, good stability, and no hemolysis in blood. Based on the results, these drug delivery systems of micelles were proper candidates as drug carriers.Biofouling, the accumulation of organisms on surfaces, can lead to several undesirable phenomena, including hospital-acquired infections, blockage of water purification systems, and food contamination. The solution to the problem should be nontoxic and environmentally friendly, so that it could be applied on different surfaces and could come into contact with food, water, or human tissues. Peptides can provide such a solution, since they are biocompatible and biodegradable materials that can resist biofouling, either by preventing the attachment of organisms to the surface (antifouling) or by killing the bacteria (antimicrobial activity). This paper presents an amphiphilic peptide with antifouling, antimicrobial, and adhesive properties. The peptide adheres to titanium surfaces and inhibits the adhesion of both Gram-negative and Gram-positive bacteria to surfaces. In addition, it reduces the growth of bacteria in solution. This peptide has both antifouling and antimicrobial properties, which could be useful in health care systems, food packaging, and other systems that suffer from biocontamination.Here, we investigate the association and dissociation mechanisms of a typical intrinsically disordered region (IDR), transcriptional activation subdomain of tumor suppressor protein p53 (TAD-p53), with murine double-minute clone 2 protein (MDM2). Using a combination of cycles of association and dissociation parallel cascade molecular dynamics, multiple standard molecular dynamics (MD), and the Markov state model, we were successful in obtaining the lowest free energy structure of the MDM2/TAD-p53 complex as the structure closest to the crystal structure without prior knowledge of the crystal structure. This method also reproduced the experimentally measured standard binding free energy, and the association and dissociation rate constants, requiring only an accumulated MD simulation cost of 11.675 μs even though that actual dissociation occurs on the order of seconds. We identified few complex intermediates with similar free energies; yet TAD-p53 first binds MDM2 as the second lowest free energy intermediate kinetically with >90% of the flux, adopting a conformation similar to that of one of these few intermediates in its monomeric state. Even though the mechanism of the first step has a conformational-selection-type aspect, the second step shows induced-fit-like features and occurs as concomitant dehydration of the interface, side-chain π-π stacking, and main-chain hydrogen-bond formation to complete binding as an α-helix. In addition, dehydration is a key process for the final relaxation process around the complex interface. These results demonstrate that TAD-p53 kinetically selects its initial binding form and then relaxes to complete the binding.Nonfullerene acceptors (NFAs) have contributed significantly to the progress of organic solar cells (OSCs). However, most NFAs feature a large fused-ring backbone, which usually requires a tedious multiple-step synthesis, and are not applicable to commercial applications. An alternative strategy is to develop nonfused NFAs, which possess synthetic simplicity and facile tunability in optoelectronic properties and solid-state microstructures. In this work, we report two nonfused NFAs, BTCIC and BTCIC-4Cl, based on an A-D-A'-D-A architecture, which possess the same electron-deficient benzothiadiazole central core but different electron-withdrawing terminal groups. The optical properties, energy levels, and molecular crystallinities were finely tuned by changing the terminal groups. Moreover, a decent power conversion efficiency of 9.3 and 10.5% has been achieved by BTCIC and BTCIC-4Cl, respectively, by blending them with an appropriate polymer donor. DNA Repair inhibitor These results demonstrate the potential of A-D-A'-D-A type nonfused NFAs for high-performance OSCs.
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