bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Oxygenated 11‐Keto‐β‐boswellic Acid Analogues and Their Anti‐Inflammatory Potential
Authors: Majeed Muhammed , Nagabhushanam Kalyanam , Bani Sarang , Choudhury Ambar K. 
Published: April 2018

AbstractNovel 9‐α‐hydroxy‐11‐keto‐β‐boswellic acid analogues constituted with versatile functionality at ring A have been synthesized for the first time from 3‐O‐acetyl‐11‐keto β‐boswellic acid (AKBBA) and described herein. The anti‐malarial potential of endoperoxide benzyl ester was evaluated against the malarial parasite and exhibited reasonable anti‐malarial activity (2 μM). Anti‐inflammatory potential of all new analogues was examined against proinflammatory cytokine, Tumor Necrosis Factor‐alpha (TNF‐α) and one of them was found to possess similar activity as that of AKBBA.
Synthesis of 2,3‐Dihydro Flavone Coumarins as a Class of Potent Antifungal and Anti‐inflammatory Agents
Authors: Shaikh Farzanabi , Shastri Samundeeswari , Chougala Bahubali M. , Holiyachi Megharaja , Shastri Lokesh A. , Joshi Shrinivas D. , Sunagar. Vinay A. 
Published: April 2018

AbstractAn efficient, mild and environmentally benign method has been developed for the synthesis of 2,3‐dihydroflavonecoumarins. The reaction of 2‐hydroxyacetophenones 2 with 4‐formylcoumarin 3 using anhydrous potassium carbonate as a mild base. All the synthesized compounds were evaluated for their antifungal activity against Candida albicans, Aspergillus flavus and Aspergillus niger fungal strains by broth dilution method. The tested compounds have exhibited promising in vitro potency with low MIC values rangs from 0.4 to 3.12 μg/mL. The in vitro anti‐inflammatory potency of synthesized compounds by gelatin zymography is comparable to tetracycline and is found to be excellent against Matrix metalloproteinase (MMP‐2). Molecular docking study was performed for all the synthesized compounds with binding site of Cytochrome P450 14 alpha‐sterol demethylase (CYP51) from Mycobacterium tuberculosis in complex with fluconazole PDB (1EA1) and results obtained are quite promising.
The Effect of N‐Doping in Activated Carbon‐Supported Au‐Sr Catalysts for Acetylene Hydrochlorination to Vinyl Chloride
Authors: Li Guangbi , Li Wei , Zhang Jinli , Zhang Wu , Zhou Huan , Si Chuan‐Ling 
Published: April 2018

AbstractWe used N‐doped activated carbon (NAC) as support to prepare a novel Au−Sr catalyst and evaluated the effect of N‐dopants on the performance of Au−Sr catalyst in acetylene hydrochlorination. A promoting effect was observed when N atoms were incorporated into AC framework, and the prepared SrAu/NAC catalyst demonstrated optimal activity compared with the undoped Au/AC and SrAu/AC catalysts. The SrAu/NAC also showed an excellent stability during the 500 h test, with acetylene conversion and vinyl chloride selectivity both exceeding 99.9%. A detailed characterization was investigated through XPS, TPD, TPR, TGA, PXRD, TEM, AAS, and BET to reveal the physicochemical properties of the related catalysts. It is demonstrated that the NAC can function as an effective support to enhance activity and life of Au‐based catalysts with unique electronic property, and the presence of doped nitrogen species as anchor sites is beneficial to increasing the electron density of active Au(III) center through electron transfer from doped N atoms to the active Au(III) species, and stabilizing active Au(III) ions and retarding its reduction within catalyst preparation and use process. Moreover, the combination of N‐dopants and strontium additive may promote a synergistic effect to make active Au species disperse better and significantly enhance the adsorption of HCl, remarkably suppress the reduction of active cationic Au(III), and effectively inhibit carbon deposition in the catalytic reaction.
Aminoquinoline‐Salicylaldimine Dyads as Highly Selective Turn‐On Fluorescent Sensors for Zinc (II) Ions
Authors: Vongnam Kunnigar , Aree Thammarat , Sukwattanasinitt Mongkol , Rashatasakhon Paitoon 
Published: April 2018

AbstractFour new derivatives of 8‐aminoquinolines are successfully synthesized by extension of the
‐conjugated system on the quinoline ring and incorporation of either the salicylaldimine or its reduced amino form. These compounds show selective fluorescence enhancement by Zn2+ ion, attributing to the chelation‐enhanced fluorescence (CHEF) effects, in which the deprotonation of the amido –NH and phenolic ‐OH causes the internal charge transfer (ICT) process. The fluorescent signals of these compounds are shifted from the range of 391–562 nm to 535–590 nm upon addition of Zn2+. The sensing mechanism is investigated by 1H NMR titration, mass spectrometry, and single crystal X‐ray diffraction analysis which suggests a 1:1 binding stoichiometry between the sensor and Zn2+. The detection limits of 0.024 to 0.431 μM and the association constants ranging between 7.0 × 103 and 1.2 × 104 M−1 can be estimated for these four sensors. One of these compounds is fabricated on wax‐patterned filter paper and used as a probe for Zn2+ in aqueous solution with a naked‐eye detection limit at 10 μM.
Palladium Supported on Mesoporous Silica/Graphene Nanohybrid as a Highly Eﬃcient and Reusable Heterogeneous Catalyst for C−H Functionalization
Authors: Dabiri Minoo , Alavioon Seyed Iman , Movahed Siyavash Kazemi 
Published: April 2018

AbstractMesoporous silica/graphene (KIT‐6/G) with pendent 3‐mercaptopropyl groups has been prepared by condensation of surface silanols and (3‐mercaptopropyl)trimethoxysilane (MPTMS). Treatment of the mercaptopropylated with Pd(CH3CN)2Cl2 gave a heterogeneous Pd‐catalyst (Pd@KIT‐6/G‐SH). The catalytic activity of the catalyst was investigated in two types of C−H functionalized for the synthesis of 2‐cyanoacetanilide and 2‐arylpyridine 1‐oxide derivatives via C−H activation. Additionally, for the study of the effect of thiol ligand, the Pd@KIT‐6/G was prepared from the treatment of Pd(CH3CN)2Cl2 with KIT‐6/G. The catalyst has been successfully recovered and reused without loss of activity over seven cycles of reactions.
Plant‐Protein‐Modified TiO2 (SPI@TiO2) for Photodegradation of Dyes
Authors: Wang Yan , She Houde , Ma Qiong , Lian Juhong , Zhong Junbo , Li Jianzhang , Tong Jinhui , He Yufeng , Wang Rongmin , Wang Qizhao 
Published: April 2018

AbstractTiO2 photocatalysts modified by soy protein isolate (SPI@TiO2) were successfully prepared via hydrothermal method and characterized by diffuse reflectance UV‐vis spectroscopy, photoluminescence (PL), brunauere emmette teller (BET), scanning electron microscope (SEM), fourier transforming infrared spectrum (FT‐IR), and electrochemical measurements. The photocatalytic activity of the as‐prepared samples was evaluated by testing photocatalytic degradation Rhodamine‐B (RhB). 0.02SPI@TiO2 showed the highest photocatalytic activity. The improved photocatalytic activity of SPI@TiO2 composites could be attributed to the existence of SPI, which can reduce the recombination rate of electron–hole and enhance the adsorption of dyes.
Molecular Insights into Benzimidazole‐Linked Polymer Interactions with Carbon Dioxide and Nitrogen
Authors: Aparicio Santiago , Yavuz Cafer T. , Atilhan Mert 
Published: April 2018

AbstractInvestigation of the binding affinity gases on porous adsorbents are important for establishing understanding of effective carbon dioxide adsorption and design target specific sorbents for capturing hazardous gases for environmental protection and fuel upgrading. A density functional theory (DFT) study that highlights the impact of benzimidazole‐linked polymer structure design has been conducted to explain the molecular and electronic structure, investigate the interaction sites and elucidate the experimental results on carbon dioxide and nitrogen sorption on these porous structures. DFT calculations were used to infer the strength of the polymer – gas interaction modes as well as to quantify short‐range interactions between the polymer – gas via topological characteristics analysis of intermolecular forces. Obtained results shed light on the carbon dioxide and nitrogen affinity as well as the selectivity during the adsorption process, and yet conclusions were attained on the characteristics of the adsorption type and mechanism in this study.
An Efficient Protocol for the Synthesis of Primary Amides via Rh‐Catalyzed Rearrangement of Aldoximes
Authors: Xu Fen , Song Yuan‐Yuan , Li Yan‐Jie , Li Er‐Long , Wang Xin‐Ran , Li Wen‐Yue , Liu Chun‐Sen 
Published: April 2018

AbstractA system consisting of catalytic amounts of [Rh(CH2=CH2)Cl]2/PPh2Cy, and PhCl as the solvent efficiently catalyzes selective rearrangement of aldoximes to furnish various primary amides in moderate to good yields. Replacing the [Rh(CH2=CH2)Cl]2 with Rh(NBD)2OTf enables the superior transformation to afford the amides with up to 99% yields. Attractive synthetic features associated with this methodology include absence of co‐catalysts, broad functional group tolerance, good to excellent yields, low metal loadings, and operational convenience.
Synthesis and Characterization of Aminoquinonato Bridged Re(I)‐Based Amide Functionalized Dinuclear Metallastirrups and Tetranuclear Lemniscate Metallacycles
Authors: Govindarajan Ramadoss , Divya Dhanaraj , Nagarajaprakash Ramamurthy , Manimaran Bala. 
Published: April 2018

AbstractHerein, we describe a multicomponent self‐assembly approach that has the prospect of furnishing functionalized di‐ and tetranuclear metallacyclic architectures with a very less level of constitutional control using semi‐rigid ligands. The methodology relies on the coordination preference of the metal and the directionality of the ligands. Self‐assembly of Re2(CO)10, aminoquinone ligands (H2L=2,5‐bis(n‐butylamino)‐1,4‐benzoquinone (bbbq), 2,5‐bis(n‐octylamino)‐1,4‐benzoquinone (bobq) and 2,5‐bis(phenethylamino)‐1,4‐benzoquinone (bpbq)) and ditopic pyridyl ligands (N‐L′‐N=bis(4‐pyridinecarboxamide)‐1,2‐ethane (bpce), N,N′‐(1,2‐phenylene)diisonicotinamide (pdia) and N,N′‐bis(4‐pyridylformamide)‐1,4‐benzene (bpfb)) in equimolar ratio afforded amide functionalized metallacyclophanes of 1–9 (Scheme ). Compounds 1–9 have been characterized by elemental analysis, IR, NMR, UV/Vis absorption and ESI‐mass spectroscopic techniques. Molecular structures of 1, 3 and 7 were ascertained by single‐crystal X‐ray diffraction methods.
Solvent Relaxation Accompanied Ultrafast Excited State Proton Transfer Dynamics Revealed in a Salicylideneaniline Derivative
Authors: Mukherjee Puspal , Das Aritra , Faizi Md. Serajul Haque , Sen Pratik 
Published: April 2018

AbstractIn this study, we have investigated the excited state intramolecular proton transfer (ESIPT) and subsequent dielectric relaxation of a newly synthesized Schiff base molecule in cyclohexane, methanol and SDS micelle through femtosecond fluorescence up‐conversion and broadband transient absorption spectroscopy. We found that the molecule showed ultrafast proton transfer with a timescale about 0.2 ps followed by solvent relaxation of the keto tautomer in methanol and SDS medium. In non‐polar cyclohexane, the solvation part was completely absent as expected. Computational study suggested the existence of a transition state in the proton transfer surface. Quantification of the system was done with two step model assigning the first rate constant to the relaxation of the excited state enol form and the second to the barrier crossing from the enol to the keto form.
Insights into the Mechanism of Bile Salt Aggregates Forming in a PEGylated Amphiphilic Polymer/Bile Salt Mixed Micelle
Authors: Tan Qinggang , Bie Min , Wang Zihao , Chu Yanyan , Tao Susu , Xu Xiaoyan , Liu Yingbin 
Published: April 2018

AbstractTailoring the structure of core‐shell interface of amphiphilic copolymer micelles provides a potential to mediate the drug release from micelles. Here, bile salts were used to alter the molecular geometry of core‐shell structured amphiphilic copolymer micelles. With the different sodium deoxycholate (NaDC) addtions in the methoxy polyethylene glycol‐poly(D,L‐lactic acid) (MPEG‐PDLLA) solutions, the NaDC molecule could form different deoxycholic acid (DCA) dimers in the core and shell of micelles. A face‐to‐face DCA dimer structure could form and insert into the core of micelles when a small NaDC addition. This dimer could accelerate the drug release. At a high NaDC addition, a new back‐to‐back DCA dimer could form in the PEG shell region that would reduce the rate of drug release. The results obtained provide fundamental insights into the role of bile salts in adjusting the drug release of amphiphilic copolymer micelles and demonstrate the future potential for controlled drug‐delivery applications.
Synthesis of SnS and ZnS Hollow Microarchitectures Decorated with Nanostructures and Their Photocatalytic Behavior for Dye Degradation
Authors: Pomar Cesar D. , Souza Aryane T. , Sombrio Guilherme , Souza Flavio L. , Bonvent Jean J. , Souza Jose A. 
Published: April 2018

AbstractSnS and ZnS hollow microarchitectures decorated with nanostructures were synthesized by catalysis free thermal evaporation technique using metal microwires and sulfur powder as starting materials. For SnS, we observed a microtube formation comprised of a thin metallic Sn layer in the inner surface, SnS orthorhombic structure thick layer with SnS nanostructures on the top. For ZnS, we found out the formation of hollow sphere with a thin metallic layer in the inner part, a thick cubic phase layer of ZnS, and on this second phase, nanostructures of ZnS hexagonal crystal phase grew up homogeneously. The surface tension, intrinsic to liquids, induces the formation of a microsphere in ZnS sample in order to minimize the surface area. ZnS and SnS hollow semiconducting microstructures have exhibited efficient activity to degrade the methylene blue under simulated sunlight irradiation. The results reveal that ZnS microstructures have higher photoactivity to organic degradation when compare to SnS in the same time interval. The observed results demonstrate the potential of thermal evaporation process without any catalyst material as a simple, fast and efficient route to obtain hollow hierarchically micro/nano architectures of SnS and ZnS with enhanced photocatalytic activity.
Cu‐Catalyzed Aerobic Oxidation of Alcohols with a Multi‐Functional NMI‐TEMPO
Authors: Wang Lianyue , Bie Zhixing , Shang Sensen , Li Guosong , Niu Jingyang , Gao Shuang 
Published: April 2018

AbstractA novel and easily accessible N‐methylimidazole derived TEMPO as multi‐functional molecule combining with commercially available copper(I) iodide and 4,4′‐Di‐tert‐butyl‐2,2′‐dipyridyl afford a catalyst system that shows efficient activity for the oxidation of a broad scope of alcohols under air balloon at room temperature. The corresponding aldehydes and ketones were obtained in good to excellent yields. The procedure is readily amenable to scale up. The present catalytic system shows a high chemoselective oxidation of primary alcohols over secondary alcohols. Cu(II) active species generated in situ from Cu(I) is responsible for the oxidation of alcohols.
An Aqueous Ca‐ion Full Cell Comprising BaHCF Cathode and MCMB Anode
Authors: Adil Md. , Dutta Prasit Kumar , Mitra Sagar 
Published: April 2018

AbstractThe capability of high‐rate cycling and environmental benignity at less expensive defines the ingress of upcoming energy storage system. The urge of such system comes into the picture because today, the state‐of‐the‐art lithium technology is ineffectual to improve its rapid‐charging ability beyond a certain limit, in commercial scale. Here, we introduce reversible electrochemistry of Ca‐ion full cell in conjunction with inexpensive aqueous electrolyte, 1M aq. Ca(ClO4)2. In the full cell, carbon cloth, barium hexacyanoferrate (BaHCF) and meso‐carbon microbeads (MCMB) have been explored as the current collector, cathode and anode material, respectively. The full cell provides 40 mAh g‐1 capacity at 5C rate till 100 cycles. We believe, the investigation of this simple full cell at the early stage of Ca‐ion battery will pave a fast transition in the forthcoming energy storage systems.
A Facile Synthetic Route to Biologically Relevant Substituted 1,4‐Naphthoquinonyl‐2‐oxoindolinylpyrimidines Under Metal‐Free Organocatalytic Conditions
Authors: Brahmachari Goutam , Nayek Nayana 
Published: April 2018

AbstractA simple, straightforward, and highly efficient three‐component one‐pot synthesis of a series of substituted 5‐(3‐(3‐hydroxy‐1,4‐naphthoquinon‐2‐yl)‐2‐oxoindolin‐3‐yl)pyrimidine‐2,4,6(1H,3H,5H)‐triones as biologically relevant molecular hybrids has been accomplished based on a tandem reaction of substituted istains, 2‐hydroxy‐1,4‐napthoquinone and barbituric acid in the presence of sulfamic acid as a low‐cost and eco‐friendly organocatalyst in aqueous ethanol under reflux. High atom‐economy, good yields, metal‐free synthesis, eco‐friendliness, and operational simplicity are some of the important features of this protocol.
Sulfamic Acid‐Catalyzed One‐Pot Synthesis of a New Series of Biologically Relevant Indole‐Uracil Molecular Hybrids in Water at Room Temperature
Authors: Brahmachari Goutam , Begam Sanchari , Nurjamal Khondekar 
Published: April 2018

AbstractA simple, straightforward, and highly efficient three‐component one‐pot synthesis of a new series of biologically‐interesting diverse and functionalized 5‐((1H‐indol‐3‐yl)(aryl)methyl)‐6‐aminopyrimidine‐2,4(1H,3H)‐dione derivatives has been elaborated based on molecular hybridization approach. The target molecules have been rationalizedviatandem reaction of 6‐aminouracils, substituted aromatic aldehydes and indoles in the presence of sulfamic acid as a low‐cost and eco‐friendly organocatalyst in water at room temperature. High atom‐economy, energy‐efficiency, use of water as reaction medium, good to excellent yields, metal‐free synthesis, eco‐friendliness, and operational simplicity are some of the important features of this newly developed protocol.
A Simple Approach for Prediction of the Condensed Phase Heat of Formation of Imidazolium‐Based Ionic Liquids or Salts
Authors: Keshavarz Mohammad Hossein , Nazari Behzad , Jafari Mohammad , Bakhtiari Reza 
Published: April 2018

AbstractSolid or liquid (condensed state) phase enthalpy of formation of a desired new substance at room temperature is a measure of its energy content. It is an important factor for its designing, characteristics and thermochemical stability. A novel method is introduced for reliable prediction of the condensed phase heat of formation of imidazolium based ionic liquids or salts at 298.15 K. It is based on the number of hydrogen and fluorine atoms in cation and anion, respectively, as well as two correcting functions. The reported condensed phase heat of formation of 31 different imidazolium based ionic liquids or salts are used to derive new model. For 9 imidazolium based ionic liquids or salts where the outputs of complex quantum mechanical methods were available, reliability of the new model has been compared with their results. Root Mean Squared Error (RMSE) of the new model and quantum mechanical models are 25.02 and 31.80 kJ/mol, respectively, which confirm higher reliability of the new simple method.
Synthesis of 4′‐Substituted Purine 2′‐Deoxynucleosides and Their Activity against Human Immunodeficiency Virus Type 1 and Hepatitis B Virus
Authors: Kohgo Satoru , Imoto Shuhei , Tokuda Ryoh , Takamatsu Yuki , Higashi‐Kuwata Nobuyo , Aoki Manabu , Amano Masayuki , Kansui Hisao , Onitsuka Kengo , Maeda Kenji , Mitsuya Hiroaki 
Published: April 2018

Abstract2,6‐Diaminopurine and guanine 2′‐deoxynucleosides substituted with a fluoromethyl, methyl, vinyl, ethyl, or azido group at the C‐4’ position of the sugar moiety 1–10 were synthesized and their activity against HIV and HBV were determined. 4′‐Fluoromethyl and 4′‐methyl derivatives 1 and 2, respectively, were synthesized by glycosidation of the 4′‐substituted sugars 11 and 12, respectively, using 2,6‐diaminopurine, followed by deoxygenation of the 2′‐hydroxyl group. 4′‐Vinyl analog 3 was synthesized from 4′‐hydroxymethylnucleoside 19, and 4′‐ethyl derivative 4 was obtained by hydrogenation of 3. 4′‐Azide analog 5 was synthesized by SNAr reaction of guanine derivative 23 with ammonia. Nucleosides 1–5 were converted to the corresponding guanine derivatives 6–10 using adenosine deaminase. Some of these compounds exhibited substantial to potent anti‐HIV and HBV activity with generally favorable cytotoxicity profiles.
Nitrogen‐Rich Salts based on 1,1’‐Dihydroxy‐5,5’‐Azobistetrazole: aNew Family of Energetic Materials with Promising Properties
Authors: Zhang Zhi‐Bin , Zhang Jian‐Guo , Gozin Michael 
Published: April 2018

AbstractA series of nitrogen‐rich energetic heterocyclic 1,1’‐dihydroxy‐5,5’‐azobistetrazole (AZO) salts are synthesized with ethylenediammonium (1), hydrazinium (2), semicarbazidium (3), guanidinium (4), 1‐amino‐1,2,3‐triazolium (5), 4‐amino‐1,2,4‐triazolium (6) and 5‐amino‐tetrazolium (7). The salts have characterized through elemental analysis, Fourier Transform infrared spectroscopy (FT‐IR) spectroscopy, 1H NMR, 13C NMR and mass spectrometry. The crystal structures determined by single crystal X‐ray diffraction. The thermal decomposition behaviors investigated by using the DSC and TG‐DTG technologies. The enthalpies of formation are calculated through the combustion heat data measured through the oxygen bomb calorimetry. All the salts have acceptable thermal stability with the highest decomposition temperature of 301.8 °C, excellent high positive formation enthalpies ranging from 350.5 kJ mol−1 to 1500.3 kJ mol−1, and good insensitivity to outer stimuli compared to the traditional RDX. The promising detonation parameters of the salts yield detonation velocities (D) and pressures (P) are ranging from 7327 m s−1 to 8931 m s−1, and from 21.7 GPa to 32.7 GPa. Considering the advantage, it is possible to prepare these nitrogen‐rich energetic salts as promising energetic materials. It's hoped that the present author's research contributed to the expansion and application of the chemistry of 1,1’‐dihydroxy‐5,5’‐azobistetrazole.
Can Manganese(III)‐Iodosylarene Act as an Oxidant Alongside High‐Valent Manganese(V)‐Oxo Complexes?
Authors: Kang Yiran , Wang Fang , Reinhard Fabián G. Cantú , Xia Chungu , de Visser Sam P. , Wang Yong 
Published: April 2018

AbstractMetalloenzymes often utilize a high‐valent metal‐oxo species in their catalytic cycle that is formed through a combination of reduction/proton transfer steps from O2. In biomimetic chemistry, by contrast, the use of molecular oxygen is challenging and instead addition of iodosylarenes as terminal oxidants generates these high‐valent metal‐oxo intermediates. There has been controversy in the literature for many years, whether the iodosylarene (or one of its side‐products in a reaction with a metal center) can act as an active oxidant. Herein, we present a comprehensive theoretical study on the thioanisole oxidation by a range of possible oxidants originating from a reaction mixture of a Mn(III) complex with iodosylbenzene. We show here that actually there are multiple isomeric iodosylarene complexes in solution and a number of those react with substrates with rate‐determining barriers at par with high‐valent metal‐oxo species. In particular, the [MnIII(PhIO)], [MnV(O)(PhIO)] and [MnIV(O)‐I(Ph)‐O•] complexes are identified as competitive oxidants and as such care should be taken with interpreting experimental rate constants.
Organocatalytic Three‐Component, One‐Pot Reaction of Highly Substituted Tetrahydropyrano[2, 3‐c]pyrazoles
Authors: Wu Chia‐Yu , Chen Kwunmin 
Published: April 2018

AbstractWe have developed an efficient synthetic method for the production of substituted tetrahydropyrano[2, 3‐c]pyrazoles using (E)‐2‐nitro‐1,3‐enynes, 1‐aryl‐3‐substituted pyrazolones and methyl vinyl ketone. The sequential, one‐pot reaction proceeded smoothly to give the desired products in high to excellent yields and stereoselectivities in the presence of a quinine‐derived squaramide organocatalyst.