bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation of the New Antiplasmodial Butanolide, Malleastrumolide A, from Malleastrum sp. (Meliaceae) from Madagascar
Authors: Du Yongle , Abedi Alexander K. , Valenciano Ana Lisa , Fernández‐Murga Maria L. , Cassera Maria B. , Rasamison Vincent E. , Applequist Wendy L. , Miller James S. , Kingston David G. I. 
Published: August 2017

An extract of Malleastrum sp. (Meliaceae) collected in Madagascar by the Madagascar International Cooperative Biodiversity Group was found to have antimalarial activity, with an IC50 value between 2.5 and 5 μg ml−1. After purification by liquid‐liquid partition, chromatography on a Diaion open column, C18 SPE and C18 reversed phase HPLC, the new butanolide, malleastrumolide A, was isolated. The structure of malleastrumolide A was determined by mass spectrometry, NMR, and ECD. The double bond position was determined by cross‐metathesis and mass spectrometry. The compound has antiproliferative activity against the A2780 ovarian cancer cell line with an IC50 value of 17.4 μm and antiplasmodial activity against the drug‐resistant Dd2 strain of Plasmodium falciparum with an IC50 value of 2.74 μm.
Differential expression and androgen regulation of microRNAs and metalloprotease 13 in breast cancer cells
Authors: Ahram Mamoun , Mustafa Ebtihal , Zaza Rand , Abu Hammad Shatha , Alhudhud Mariam , Bawadi Randa , Zihlif Malek 
Published: August 2017

AbstractMicroRNA molecules (miRNAs) play important roles in regulating cell behavior. The expression of certain miRNAs has been shown to be regulated by the androgen receptor (AR), which seems to have a critical role in the tumorigenic process of breast cancer. The differential expression of 84 miRNAs was first examined in three breast cancer cell lines: the luminal MCF‐7 and T47D cells and the molecular apocrine MDA‐MB‐453 cells. Analysis of basal expression of miRNAs revealed that each cell line had distinct miRNA expression where let‐7a and ‐7b were markers of MDA‐MB‐453 cells, whereas miR‐205 was a marker for the luminal cell lines. Treating the cells with the AR agonist, CI‐4AS‐1, resulted in unique alterations in the expression of specific miRNA among the three cell lines. Particularly, the expression of miR‐100 and miR‐125 was reduced in MDA‐MB‐453 cells by five and three folds, respectively. This effect was simultaneous with AR‐induced increase in the expression and extracellular release of metalloprotease‐13 (MMP13). Transfection of cells with either miR‐100 or miR‐125b negated the induction of MMP13 release. Additionally, AR activation induced a morphological alteration of MDA‐MB‐453 cells, which was blocked by miR‐125b only. Collectively, these data indicate that AR may control the biological behavior of breast cancer cells and protein expression via miRNAs.
Distinct Promotive Effects of 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene (DBU) on Polymer Supports in Copper‐Catalyzed Hydrogenation of C=O Bonds
Authors: Watari Ryo , Matsumoto Norio , Kuwata Shigeki , Kayaki Yoshihito 
Published: August 2017

AbstractAn amidine base‐containing polymer, polystyrene‐bound 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (PS‐DBU), proved to serve as a prominent catalyst support. The combined use of selected copper salts with PS‐DBU in the catalytic hydrogenation of acetophenone qualifies DBU as beneficial to generate catalytically active species and stabilize them on the polymer. Catalyst preparation and characterization reveal that the active copper species is in a low‐valent state and the nanosized particles possibly grow on the amidine structure. The high immobilization ability of PS‐DBU almost entirely prohibited copper leaching to the product over six cycles of hydrogenation and catalyst recovery. The copper catalyst attached to PS‐DBU specifically promotes the hydrogenation of various ketones and aldehydes under 10 atm of H2 at 90 °C to afford alcoholic products in satisfactory yields.
Substrate Effects in Graphene‐Based Electric Double‐Layer Capacitors: The Pivotal Interplays between Ions and Solvents
Authors: Yang Huachao , Bo Zheng , Yang Jinyuan , Kong Jing , Chen Xia , Yan Jianhua , Cen Kefa 
Published: August 2017

AbstractGraphene has been considered as a promising active material for electric double‐layer capacitors (EDLCs), primarily owing to its extraordinary monolayer properties, whereas the interfacial behaviors are conspicuously impacted by underlying substrates. In this work, substrate effects on the interfacial wettability, EDL structure, and capacitive behavior of graphene‐based EDLCs are delineated with numerical simulation. Unlike previous studies, a partial wetting transparency of topmost graphene is recognized for hydrophilic supports. In particular, a virtually identical capacitance is demonstrated for graphene with various supports, albeit the substantially different EDL structures stemmed from substrate effects. The achieved invariant capacitance is prominently attributed to the counterbalancing correlations between ions and proximal solvents, going beyond traditional views of modulating capacitance preferentially through ion structural evolutions. Specifically, the suppressed permittivity of apparently ordered water dipoles (i. e. detrimental solvent effects) attenuates the beneficial ionic influences (i. e. reinforced population and closer approach) on shielding the external electric fields. The as‐obtained findings demonstrate the paramount importance of the substrate in mediating interfacial behaviors within electrified EDLC systems and highlight that exploiting the pivotal interplay between ions and solvents could be a novel avenue to further manipulate electrochemical performances.
Model Catalytic Studies of Novel Liquid Organic Hydrogen Carriers: Indole, Indoline and Octahydroindole on Pt(111)
Authors: Schwarz Matthias , Bachmann Philipp , Silva Thais Nascimento , Mohr Susanne , Scheuermeyer Marlene , Späth Florian , Bauer Udo , Düll Fabian , Steinhauer Johann , Hohner Chantal , Döpper Tibor , Noei Heshmat , Stierle Andreas , Papp Christian , Steinrück H.‐P. , Wasserscheid Peter , Görling Andreas , Libuda Jörg 
Published: August 2017

AbstractIndole derivatives were recently proposed as potential liquid organic hydrogen carriers (LOHC) for storage of renewable energies. In this work, we have investigated the adsorption, dehydrogenation and degradation mechanisms in the indole/indoline/octahydroindole system on Pt(111). We have combined infrared reflection absorption spectroscopy (IRAS), X‐ray photoelectron spectroscopy (XPS) and DFT calculations. Indole multilayers show a crystallization transition at 200 K, in which the molecules adopt a strongly tilted orientation, before the multilayer desorbs at 220 K. For indoline, a less pronounced restructuring transition occurs at 150 K and multilayer desorption is observed at 200 K. Octahydroindole multilayers desorb already at 185 K, without any indication for restructuring. Adsorbed monolayers of all three compounds are stable up to room temperature and undergo deprotonation at the NH bond above 300 K. For indoline, the reaction is followed by partial dehydrogenation at the 5‐membered ring, leading to the formation of a flat‐lying di‐σ‐indolide in the temperature range from 330–390 K. Noteworthy, the same surface intermediate is formed from indole. In contrast, the reaction of octahydroindole with Pt(111) leads to the formation of a different intermediate, which originates from partial dehydrogenation of the 6‐membered ring. Above 390 K, all three compounds again form the same strongly dehydrogenated and partially decomposed surface species.
An Unprecedented Blue Chromophore Found in Nature using a “Chemistry First” and Molecular Networking Approach: Discovery of Dactylocyanines A–H
Authors: Bonneau Natacha , Chen Guanming , Lachkar David , Boufridi Asmaa , Gallard Jean‐François , Retailleau Pascal , Petek Sylvain , Debitus Cécile , Evanno Laurent , Beniddir Mehdi A. , Poupon Erwan 
Published: August 2017

AbstractGuided by a “chemistry first” approach using molecular networking, eight new bright‐blue colored natural compounds, namely dactylocyanines A–H (3–10), were isolated from the Polynesian marine sponge Dactylospongia metachromia. Starting from ilimaquinone (1), an hemisynthetic phishing probe (2) was prepared for annotating and matching structurally related natural substances in D. metachromia crude extract network. This strategy allowed characterizing for the first time in Nature the blue zwitterionic quinonoid chromophore. The solvatochromic properties of the latter are reported.
Photoinduced Electron Transfer Switching Mechanism of a Naphthalimide Derivative with its Solvatochromic Behaviour: An Experimental and Theoretical Study with In Cell Investigations
Authors: Singharoy Dipti , Chowdhury Sourav , Mati Soumya Sundar , Ghosh Swadesh , Chattopadhyay Krishnananda , Bhattacharya Subhash Chandra 
Published: August 2017

AbstractThe sole existence of a t‐bone‐shaped naphthalimide derivative [2‐(2‐aminoethyl)‐1H‐benzo[de]isoquinoline‐1,3(2H)dione] (NAP), which gives rise to a photoinduced electron transfer (PET) mechanism, has been established using a combination of experimental and theoretical studies. In parallel an in vitro–in cell PET mechanism has also been shown. To understand the photophysics of NAP, solvent studies have been carried out in different solvents. In addition, theoretical calculations have been conducted to explain the spectroscopic properties through optimized structures. A “turn off” PET mechanism has also been observed in the presence of specific metal ions, namely, Cr3+, Fe3+ and Hg2+ among a series of metal ions. Theoretical studies reveal that NAP–Cr3+, NAP–Fe3+ and NAP–Hg2+ have their HOMO energy states lying in between a HOMO–LUMO energy state of the t‐bone‐type NAP molecule. On the contrary, the HOMO state of the other metal ion–NAP conjugate (NAP–Mn+) does not lie in between the HOMO–LUMO energy gap of the t‐bone‐type NAP molecule. Coupled with in vitro studies, in cell investigations reveal an enhancement of fluorescence intensity of NAP upon cytosolic metal sensing. Furthermore, a very high cell viability of NAP treated cells as tested by MTT assay and a fast permeation of the said compound as revealed by flow cytometry suggest NAP to be a potential candidate in metal sensing and bioimaging applications.
Catalytic Intramolecular Cycloaddition Reactions by Using a Discrete Molecular Architecture
Authors: Roy Bijan , Devaraj Anthonisamy , Saha Rupak , Jharimune Suprita , Chi Ki‐Whan , Mukherjee Partha Sarathi 
Published: August 2017

AbstractA discrete tetragonal tube‐shaped complex (MT‐1) has been synthesised by coordination‐driven self‐assembly of a carbazole‐based tetraimidazole donor L and a Pd(II) 90° acceptor, that is, [cis‐(dppf)Pd(OTf)2] (dppf=diphenylphosphinoferrocene, OTf=CF3SO3−). Complex MT‐1 was characterised by multinuclear NMR, ESI‐MS and single‐crystal X‐ray diffraction analysis (SCXRD), which showed its symmetrical tetrafacial tube‐shaped architecture possessing a large cavity described by four aromatic walls. This coordination cage was successfully utilised as a molecular vessel to perform intramolecular cycloaddition reactions of O‐allylated benzylidinebarbituric acid derivatives inside its confined nanospace. The presence of a catalytic amount of MT‐1 promoted [4+2] cycloaddition reactions in a regio‐ and stereoselective manner, yielding the corresponding penta/tetracyclouracil derivatives in good yields under mild reaction conditions. This protocol is interesting compared with the literature reports for the synthesis of similar chromenopyran pyrimidinedione derivatives under high‐temperature reflux conditions or solid‐state melt reactions (SSMRs).
Preparation of Robust Metal‐Free Magnetic Nanoemulsions Encapsulating Low‐Molecular‐Weight Nitroxide Radicals and Hydrophobic Drugs Directed Toward MRI‐Visible Targeted Delivery
Authors: Nagura Kota , Takemoto Yusa , Moronaga Satori , Uchida Yoshiaki , Shimono Satoshi , Shiino Akihiko , Tanigaki Kenji , Amano Tsukuru , Yoshino Fumi , Noda Yohei , Koizumi Satoshi , Komatsu Naoki , Kato Tatsuhisa , Yamauchi Jun , Tamura Rui 
Published: August 2017

AbstractWith a view to developing a theranostic nanomedicine for targeted drug delivery systems visible by magnetic resonance (MR) imaging, robust metal‐free magnetic nanoemulsions (mean particle size less than 20 nm) consisting of a biocompatible surfactant and hydrophobic, low molecular weight 2,2,5‐trimethyl‐5‐(4‐alkoxy)phenylpyrrolidine‐N‐oxyl radicals were prepared in pH 7.4 phosphate‐buffered saline (PBS). The structure of the nanoemulsions was characterized by electron paramagnetic resonance spectroscopy, and dynamic light scattering and small‐angle neutron‐scattering measurements. The nanoemulsions showed high colloidal stability, low cytotoxicity, enough reduction resistance to excess ascorbic acid, and sufficient contrast enhancement in the proton longitudinal relaxation time (T1) weighted MR images in PBS in vitro (and preliminarily in vivo). Furthermore, the hydrophobic anticancer drug paclitaxel could be encapsulated inside the nanoparticles, and the resulting paclitaxel‐loaded nanoemulsions were efficiently incorporated into HeLa cells to suppress cell growth.
Aruncin B: Synthetic Studies, Structural Reassignment and Biological Evaluation
Authors: Ribaucourt Aubert , Towers Christopher , Josa‐Culleré Laia , Willenbrock Frances , Thompson Amber L. , Hodgson David M. 
Published: August 2017

AbstractA ring‐closing alkene metathesis (RCM)/ oxyselenation‐selenoxide elimination sequence was established to the sodium salts E‐ and Z‐25 of the originally proposed structure for the recently isolated cytotoxin aruncin B (1), as well as to the sodium salt Z‐34 of a related ethyl ether regioisomer; however, none of their corresponding free acids could be obtained. Their acid sensitivity, together with detailed analysis of the spectroscopic data indicated that profound structural revision was necessary. This led to reassignment of aruncin B as a Z‐γ‐alkylidenebutenolide Z‐36. Although a related RCM/ oxyselenation‐selenoxide elimination sequence was used to confirm the γ‐alkylidenebutenolide motif, a β‐iodo Morita‐Baylis–Hillman reaction/ Sonogashira cross‐coupling‐5‐exo‐dig lactonisation sequence was subsequently developed, due to its brevity and flexibility for diversification. Aruncin B (36), together with 14 γ‐alkylidenebutenolide analogues, were generated for biological evaluation.
One‐Pot Self‐Assembly of Peptide‐Based Cage‐Type Nanostructures Using Orthogonal Ligations
Authors: Bartolami Eline , Knoops Jérémie , Bessin Yannick , Fossépré Mathieu , Chamieh Joseph , Dumy Pascal , Surin Mathieu , Ulrich Sébastien 
Published: August 2017

AbstractThe designed arrangement of biomolecular entities within monodisperse nanostructures is an important challenge toward functional biomaterials. We report herein a method for the formation of water‐soluble peptide‐based cages using orthogonal ligation reactions—acylhydrazone condensation and thiol–maleimide addition. The results show that using preorganized cyclic peptides and heterobifunctional spacers as building blocks and a set of orthogonal and chemoselective ligation reactions enable cage formation in one pot from six components and through eight reactions. Molecular modelling simulations reveal the structural dynamics of these structures. Finally, we exploited the reactional dynamics of the acylhydrazone by demonstrating the controlled dissociation of the cage through directed component exchange.
Photochemical and Electrochemical Triggered Bis(hydrazone) Switch
Authors: Gordillo Mónica A. , Soto‐Monsalve Mónica , Carmona‐Vargas Christian C. , Gutiérrez Gustavo , D'vries Richard F. , Lehn Jean‐Marie , Chaur Manuel N. 
Published: August 2017

AbstractHerein, we report the synthesis of a double hydrazone capable of undergoing photochemical E/Z isomerization through the imine double bonds. The bis(hydrazone) 1‐E,E can be considered as a “two‐arm” system in which the controlled movement of each arm is obtained by photo‐modulation, making possible the appearance of two isolable metastable isomeric states 1‐E,Z and 1‐Z,Z. Such states are characterized by very specific structural, optical, and electrochemical properties. The latter allows the reversible return from either 1‐E,Z or 1‐Z,Z to the 1‐E,E state. Our results are of great importance in the further development of molecular machines and photochemically controlled reactions by introducing for the first time double hydrazones as tunable photochemical switches.
Multivalency Increases the Binding Strength of RGD Peptidomimetic‐Paclitaxel Conjugates to Integrin αVβ3
Authors: Raposo Moreira Dias André , Pina Arianna , Dal Corso Alberto , Arosio Daniela , Belvisi Laura , Pignataro Luca , Caruso Michele , Gennari Cesare 
Published: August 2017

AbstractThis work reports the synthesis of three multimeric RGD peptidomimetic‐paclitaxel conjugates featuring a number of αVβ3 integrin ligands ranging from 2 to 4. These constructs were assembled by conjugation of the integrin αVβ3 ligand cyclo[DKP‐RGD]‐CH2NH2 with paclitaxel via a 2′‐carbamate with a self‐immolative spacer, the lysosomally cleavable Val‐Ala dipeptide linker, a multimeric scaffold, a triazole linkage, and finally a PEG spacer. Two monomeric conjugates were also synthesized as reference compounds. Remarkably, the new multimeric conjugates showed a binding affinity for the purified integrin αVβ3 receptor that increased with the number of integrin ligands (reaching a minimum IC50 value of 1.2 nm for the trimeric), thus demonstrating that multivalency is an effective strategy to strengthen the ligand–target interactions.
Dinaphthotetrathiafulvalene Bisimides: A New Member of the Family of π‐Extended TTF Stable p‐Type Semiconductors
Authors: Yamashita Masataka , Kawano Koki , Matsumoto Akinobu , Aratani Naoki , Hayashi Hironobu , Suzuki Mitsuharu , Zhang Lei , Briseno Alejandro L. , Yamada Hiroko 
Published: August 2017

AbstractInvited for the cover of this issue is the group of Hiroko Yamada at Nara Institute of Science and Technology. The image depicts the structure of tetrathiafulvalene, an organic semiconductor, upon a background of Japanese pampas grass on the Soni plateau. Read the full text of the article at 10.1002/chem.201702657.
High‐Energy‐Resolution X‐ray Absorption Spectroscopy for Identification of Reactive Surface Species on Supported Single‐Site Iridium Catalysts
Authors: Hoffman Adam S. , Sokaras Dimosthenis , Zhang Shengjie , Debefve Louise M. , Fang Chia‐Yu , Gallo Alessandro , Kroll Thomas , Dixon David A. , Bare Simon R. , Gates Bruce C. 
Published: August 2017

AbstractInvited for the cover of this issue are the groups of David A. Dixon at the University of Alabama, Simon R. Bare at Stanford Synchrotron Radiation Lightsource and Bruce C. Gates at the University of California, Davis. The image depicts a visual representation of the key conclusion of the work. Read the full text of the article at 10.1002/chem.201701459.
Inside Cover: Study of Karstedt's Catalyst for Hydrosilylation of a Wide Variety of Functionalized Alkenes with Triethoxysilane and Trimethoxysilane (Chin. J. Chem. 8/2017)
Authors: Pan Zhenhuan , Liu Minglun , Zheng Chaoyue , Gao Deqing , Huang Wei 
Published: August 2017

The inside cover picture shows the excellent catalytic performance of Karstedt's catalyst for the hydrosilylation of olefins terminated with various functional groups (amino, alkoxyl, carboxylic, hydroxyl, aldehyde, etc.) with the trimethoxysilane and triethoxysilane reagents in terms of the yield and selectivity. More details are discussed in the article by Gao et al. on page 1227–1230.
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Inside Back Cover: Allosteric Modulation of Human Serum Albumin Induced by Peptide Ligand (Chin. J. Chem. 8/2017)
Authors: Hou Jingfei , Peng Jiaxi , Yu Yue , Lin Yuchen , Liu Changliang , Duan Hongyang , Yang Yanlian , Wang Chen 
Published: August 2017

The inside back cover picture shows the allosteric modulation of human serum albumin (HSA) induced by the Peptide SA06 ligand. Peptide SA06 is a reported peptide ligand comprising 20 amino acids, and is known to non‐covalently bind with HSA to extend the lifetime and improve the pharmacokinetic performance of drug molecules. The structural evidence on the allosteric interaction between peptide ligand and HSA, and the structure‐affinity relations of the binding mechanism have been revealed in this work, which can also shed light on optimization of therapeutic properties in the affinity‐controlled delivery systems. More details are discussed in the article by Wang et al. on page 1270–1277.
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Prediction and prognosis of ventricular tachycardia recurrence after catheter ablation with remote magnetic navigation for electrical storm in patients with ischemic cardiomyopathy
Authors: Jin Qi , Jacobsen Peter Karl , Pehrson Steen , Chen Xu 
Published: August 2017

BackgroundVentricular tachycardia (VT) recurrence after catheter ablation for electrical storm is commonly seen in patients with ischemic cardiomyopathy (ICM).HypothesisWe hypothesized that VT recurrence can be predicted and be related to the all‐cause death after VT storm ablation guided by remote magnetic navigation (RMN) in patients with ICM.MethodsA total of 54 ICM patients (87% male; mean age, 65 ± 7.1 years) presenting with VT storm undergoing acute ablation using RMN were enrolled. Acute complete ablation success was defined as noninducibility of any sustained monomorphic VT at the end of the procedure. Early VT recurrence was defined as the occurrence of sustained VT within 1 month after the first ablation.ResultsAfter a mean follow‐up of 17.1 months, 27 patients (50%) had freedom from VT recurrence. Sustained VT recurred in 12 patients (22%) within 1 month following the first ablation. In univariate analysis, VT recurrence was associated with incomplete procedural success (hazard ratio [HR]: 6.25, 95% confidence interval [CI]: 1.20‐32.47, P = 0.029), lack of amiodarone usage before ablation (HR: 4.71, 95% CI: 1.12‐19.7, P = 0.034), and a longer procedural time (HR: 1.023, 95% CI: 1.00‐1.05, P = 0.05). The mortality of patients with early VT recurrence was higher than that of patients without recurrence (P < 0.01).ConclusionsInducibility of any VT at the end of procedure for VT storm guided by RMN is the strongest predictor of VT recurrence. ICM patients who have early recurrences after VT storm ablation are at high risk of all‐cause death.