bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cooperative NHC/Photoredox Catalyzed Ring‐Opening of Aryl Cyclopropanes to 1‐Aroyloxylated‐3‐Acylated Alkanes
Authors: Zuo Zhijun , Daniliuc Constantin G. , Studer Armido 
Published: September 2021

AbstractCyclopropanes are an important class of building blocks in organic synthesis. Herein, a ring‐opening/arylcarboxylation/acylation cascade reaction for the 1,3‐difunctionalization of aryl cyclopropanes enabled by cooperative NHC and organophotoredox catalysis is reported. The cascade works on monosubstituted cyclopropanes that are in contrast to the heavily investigated donor–acceptor cyclopropanes more challenging to be difunctionalized. The key step is a radical/radical cross coupling of a benzylic radical generated in the photoredox catalysis cycle with a ketyl radical from the NHC catalysis cycle. The transformation features metal‐free reaction conditions and tolerates a diverse range of functionalities.
Phenoxy Radical‐Induced Formation of Dual‐Layered Protection Film for High‐Rate and Dendrite‐Free Lithium‐Metal Anodes
Authors: Chen Chao , Liang Qianwen , Chen Zhongxin , Zhu Weiya , Wang Zejun , Li Yuan , Wu Xianwen , Xiong Xunhui 
Published: September 2021

AbstractThe uncontrollable dendrite growth of Li metal anode leads to poor cycle stability and safety concerns, hindering its utilization in high energy density batteries. Herein, a phenoxy radical Spiro‐O8 is proposed as an artificial protection film for Li metal anode owing to its excellent film‐forming capability and remarkable ionic conductivity. A spontaneous redox reaction between the Spiro‐O8 and Li metal results in the formation of a uniform and highly ionic conductive organic film in the bottom. Meanwhile, the phenoxy radicals on surface of Spiro‐O8 facilitate the decomposition of Li salt upon exposed to the ether electrolyte and lead the formation of LiF film on the top. Arising from the synergistic effects of inner high ionic conductive film and outer rigid film, stable Li plating/stripping can be realized at a high current density (4000 cycles at 10 mA cm−2) and a high areal capacity of 5 mAh cm−2 for 550 h with an ultrahigh Li utilization rate of 54.6 %. As a proof of concept, this work shows a facile strategy to rationally fabricate dual‐layered interfaces for Li metal anodes.
Gold‐Catalyzed Reaction of Propargyl Esters and Alkynylsilanes: Synthesis of Vinylallene Derivatives through a Twofold 1,2‐Rearrangement
Authors: Bernardo Olaya , González‐Pelayo Silvia , Fernández Israel , López Luis A. 
Published: September 2021

AbstractThe reaction of propargyl esters with alkynylsilanes under gold catalysis provides vinylallene derivatives through consecutive [1,2]‐acyloxy/[1,2]‐silyl rearrangements. Good yields, full atom‐economy, broad substrate scope, easy scale‐up and low catalyst loadings are salient features of this novel transformation. Density Functional Theory (DFT) calculations suggest a reaction mechanism involving initial [1,2]‐acyloxy rearrangement to generate a gold vinylcarbene intermediate which upon regioselective attack of the alkynylsilane affords a vinyl cation which undergoes a type II‐dyotropic rearrangement involving the silyl group and the metal fragment. Preliminary results on the enantioselective version of this transformation are also disclosed.
A Cryptic Plant Terpene Cyclase Producing Unconventional 18‐ and 14‐Membered Macrocyclic C25 and C20 Terpenoids with Immunosuppressive Activity
Authors: Chen Yue‐Gui , Li De‐Sen , Ling Yi , Liu Yan‐Chun , Zuo Zhi‐Li , Gan Li‐She , Luo Shi‐Hong , Hua Juan , Chen Ding‐Yuan , Xu Fan , Li Man , Guo Kai , Liu Yan , Gershenzon Jonathan , Li Sheng‐Hong 
Published: September 2021

AbstractA versatile terpene synthase (LcTPS2) producing unconventional macrocyclic terpenoids was characterized from Leucosceptrum canum. Engineered Escherichia coli and Nicotiana benthamiana expressing LcTPS2 produced six 18‐/14‐membered sesterterpenoids including five new ones and two 14‐membered diterpenoids. These products represent the first macrocyclic sesterterpenoids from plants and the largest sesterterpenoid ring system identified to date. Two variants F516A and F516G producing approximately 3.3‐ and 2.5‐fold, respectively, more sesterterpenoids than the wild‐type enzyme were engineered. Both 18‐ and 14‐membered ring sesterterpenoids displayed significant inhibitory activity on the IL‐2 and IFN‐γ production of T cells probably via inhibition of the MAPK pathway. The findings will contribute to the development of efficient biocatalysts to create bioactive macrocyclic sesterterpenoids, and also herald a new potential in the well‐trodden territory of plant terpenoid biosynthesis.
Enantioselective Palladium‐Catalyzed Hydrophosphinylation of Allenes with Phosphine Oxides: Access to Chiral Allylic Phosphine Oxides
Authors: Yang Zhiping , Wang Jun (Joelle) 
Published: September 2021

AbstractA Pd‐catalyzed hydrophosphinylation of alkyl and aryl‐oxyallenes with phosphine oxides has been developed for the efficient and rapid construction of a family of chiral allylic phosphine oxides with a diverse range of functional groups. This methodology was further applied in the facile construction of chiral 2H‐chromene and later stage functionalization of cholesterol.
Catalytic Asymmetric Alkynylation of 3,4‐Dihydro‐β‐carbolinium Ions Enables Collective Total Syntheses of Indole Alkaloids
Authors: Liang Lixin , Zhou Shiqiang , Zhang Wei , Tong Rongbiao 
Published: September 2021

AbstractChiral tetrahydro‐β‐carboline (THβC) is not only a prevailing structural feature of many natural alkaloids but also a versatile synthetic precursor for a vast array of monoterpenoid indole alkaloids. Asymmetric synthesis of C1‐alkynyl THβCs remains rarely explored and challenging. Herein, we describe the development of two complementary approaches for the catalytic asymmetric alkynylation of 3,4‐dihydro‐β‐carbolinium ions with up to 96 % yield and 99 % ee. The utility of chiral C1‐alkynyl THβCs was demonstrated by the collective total syntheses of seven indole alkaloids: harmicine, eburnamonine, desethyleburnamonine, larutensine, geissoschizol, geissochizine, and akuammicine.
Versatile Polymer Nanocapsules via Redox Competition
Authors: Zhou Jiajing , Xu Ming , Jin Zhicheng , Borum Raina M. , Avakyan Nicole , Cheng Yong , Yim Wonjun , He Tengyu , Zhou Jingcheng , Wu Zhuohong , Mantri Yash , Jokerst Jesse V. 
Published: September 2021

AbstractPolymer nanocapsules have demonstrated significant value in materials science and biomedical technology, but require complicated and time‐consuming synthetic steps. We report here the facile synthesis of monodisperse polymer nanocapsules via a redox‐mediated kinetic strategy from two simple molecules: dopamine and benzene‐1,4‐dithiol (BDT). Specifically, BDT forms core templates and modulates the oxidation kinetics of dopamine into polydopamine (PDA) shells. These uniform nanoparticles can be tuned between ≈70 and 200 nm because the core diameter directly depends on BDT while the shell thickness depends on dopamine. The supramolecular core can then rapidly disassemble in organic solvents to produce PDA nanocapsules. Such nanocapsules exhibit enhanced physicochemical performance (e.g., loading capacity, photothermal transduction, and anti‐oxidation) versus their solid counterparts. Particularly, this method enables a straightforward encapsulation of functional nanoparticles providing opportunities for designing complex nanostructures such as yolk–shell nanoparticles.
Fatigue‐Resistant Interfacial Layer for Safe Lithium Metal Batteries
Authors: Gao Rui‐Min , Yang Hua , Wang Cao‐Yu , Ye Huan , Cao Fei‐Fei , Guo Zai‐Ping 
Published: September 2021

AbstractThe plating/stripping of Li dendrites can fracture the static solid electrolyte interphase (SEI) and cause significant dynamic volume variations in the Li anode, which give rise to poor cyclability and severe safety hazards. Herein, a tough polymer with a slide‐ring structure was designed as a self‐adaptive interfacial layer for Li anodes. The slide‐ring polymer with a dynamically crosslinked network moves freely while maintaining its toughness and fracture resistance, which allows it can to dissipate the tension induced by Li dendrites on the interphase layer. Moreover, the slide‐ring polymer is highly stretchable, elastic, and displays an ultrafast self‐healing ability, which allows even pulverized Li to remain coalesced without disintegrating upon consecutive cycling. The Li anodes demonstrate greatly improved suppression of Li dendrite formation, as evidenced by the high critical current density (6 mA cm−2) and stable cycling for the full cells with high‐areal capacity LiFePO4, high‐voltage NCM, and S cathodes.
Chiral Benzothiophene Synthesis via Enantiospecific Coupling of Benzothiophene S‐Oxides with Boronic Esters
Authors: Sang Ruocheng , Noble Adam , Aggarwal Varinder K. 
Published: September 2021

AbstractBenzothiophenes are valuable heterocycles that are widely used in medicines, agrochemicals, and materials science. Herein, we report a general method for the synthesis of enantioenriched 2,3‐disubstituted benzothiophenes via a transition‐metal‐free C2‐alkylation of benzothiophenes with boronic esters. The reactions utilize benzothiophene S‐oxides in lithiation‐borylations to generate intermediate arylboronate complexes, and subsequent Tf2O‐promoted S−O bond cleavage to trigger a Pummerer‐type 1,2‐metalate shift, which gives the coupled products with complete enantiospecificity. Primary, secondary and tertiary alkyl boronic esters and aryl boronic esters are successfully coupled with a range of C3‐substituted benzothiophenes. Importantly, this transformation does not require the use of C3 directing groups, therefore it overcomes a major limitation of previously developed transition‐metal‐mediated C2 alkylations of benzothiophenes.
Synthesis and preliminary biological evaluation of antibacterial and antifungal 5‐arylidene tetramic acid‐cadmium(II) complexes
Authors: Matiadis Dimitris , Stefanou Valentina , Tsironis Dimitrios , Panagiotopoulou Angeliki , Igglessi‐Markopoulou Olga , Markopoulos John 
Published: September 2021

AbstractThe synthesis and biological evaluation of 5‐arylidene‐N‐acetyl‐tetramic acids cadmium(II) complexes are reported. Eleven novel compounds were prepared, characterized by nuclear magnetic resonance experiments and screened for their antimicrobial activity against five bacterial species (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and methicillin‐resistant Staphylococcus aureus [MRSA]) and two fungi (Candida albicans and Cryptococcus neoformans). The complexes showed similar or enhanced activities against MRSA in comparison to the corresponding ligands and, additionally, promising antifungal activities against C. neoformans. The most active compounds 3c and 3h showed remarkable activities against MRSA (minimum inhibitory activity [MIC] values of 32 and 4 μg/ml, respectively) and C. neoformans (MIC values of 8 and 16 μg/ml, respectively), accompanied by no human cell toxicity and hemolytic activity within the tested concentration range. The results demonstrate that appropriately functionalized tetramic acids attached with lipophilic alkanoyl chain and after complexation with cadmium(II) ions may act as valuable lead compounds for further investigations toward the development of novel antibacterial and/or antifungal agents.
Cyclometalated Platinum(II) Complexes with Donor‐Acceptor‐Containing Bidentate Ligands and Their Application Studies as Organic Resistive Memories
Authors: Poh Wei Church , Au‐Yeung Ho‐Leung , Chan Alan Kwun‐Wa , Hong Eugene Yau‐Hin , Cheng Yat‐Hin , Leung Ming‐Yi , Lai Shiu‐Lun , Low Kam‐Hung , Yam Vivian Wing‐Wah 
Published: September 2021

AbstractA series of heteroleptic cyclometalated platinum(II) complexes, [Pt(C^N)(O^O)], (1–10) with various donors and acceptors has been synthesized and characterized by 1H NMR spectroscopy, elemental analyses, infrared spectroscopy and mass spectrometry. The X‐ray structure of 2 has also been determined. The electrochemical and photophysical properties of the platinum(II) complexes were studied. These experimental results have been supported by computational studies. Furthermore, two of the complexes have been employed as the active material in the fabrication of resistive memory devices, exhibiting stable binary memory performance with low operating voltage, high ON/OFF ratio and long retention time.
Melatonin ameliorates trimethyltin chloride‐induced cardiotoxicity: The role of nuclear xenobiotic metabolism and Keap1‐Nrf2/ARE axis‐mediated pyroptosis
Authors: Cai Jingzeng , Yang Jie , Chen Xiaoming , Zhang Haoran , Zhu Yue , Liu Qi , Zhang Ziwei 
Published: September 2021

AbstractTrimethyltin chloride (TMT) is a stabilizer for polyvinyl chloride plastics that causes serious health hazards in nontarget organisms. Melatonin (MT) exhibits powerful protective effects in cardiac diseases. As a new environmental pollutant, TMT‐induced cardiotoxicity and the protective effects of MT remain unclear. To explore this, the mice were treated with TMT (2.8 mg/kg) and/or MT (10 mg/kg) for 7 days. Firstly, the histopathological and ultrastructural evaluation showed that TMT induced cardiac damage, tumescent rupture and nuclear pyknosis. Moreover, TMT elevated the expressions of pyroptosis genes NLRP3, ASC and Cas1 and inflammation factors IL‐6, IL‐17 and TNFα. Secondly, TMT reduced antioxidant enzymes (GSH, CAT and T‐AOC) via decreasing the expression of genes associated with the Keap1‐Nrf2/ARE pathway to increase oxidative stress. Thirdly, TMT decreased the expression of genes associated with the ARE‐driven drug metabolizing enzymes (DMEs), including Akr7a3, Akr1b8, and Akr1b10. Besides, TMT upregulated the mRNA expression of nuclear Xenobiotic metabolism on cytochrome P450s enzymes via increasing the expression of CAR, PXP, and AHR genes. Furthermore, MT treatment mitigated the aforementioned adverse changes induced by TMT. Overall, these results demonstrated that TMT caused pyroptosis and inflammation to aggravate cardiac damage via inducing excessive oxidative stress, imbalance of DMEs homeostasis, and nuclear Xenobiotic metabolism disorder, which could be alleviated by MT.
Mechanisms and applications of peptide nucleic acids selectively binding to double‐stranded RNA
Authors: Zhan Xuan , Deng Liping , Chen Gang 
Published: September 2021

AbstractRNAs form secondary structures containing double‐stranded base paired regions and single‐stranded regions. Probing, detecting and modulating RNA structures and dynamics requires the development of molecular sensors that can differentiate the sequence and structure of RNAs present in viruses and cells, as well as in extracellular space. In this review, we summarize the recent progress on the development of chemically modified peptide nucleic acids (PNAs) for the selective recognition of double‐stranded RNA (dsRNA) sequences over both single‐stranded RNA (ssRNA) and double‐stranded DNA (dsDNA) sequences. We also briefly discuss the applications of sequence‐specific dsRNA‐binding PNAs in sensing and stabilizing dsRNA structures and inhibiting dsRNA‐protein interactions.
Understanding the role of Br− during the electrooxidation of I− in aqueous media: I2Br−(aq)‐formation without the precipitation of an iodine film
Authors: Park Cheolmin , Chang Jinho 
Published: September 2021

AbstractZn‐polyiodide redox flow battery is considered to be promising energy storage systems. However, the rate of the I3−(aq)/I−(aq) half redox reaction could be limited by a metastable iodine film in aqueous solutions. In this article, we found that the addition of Br− could inhibit the formation of an iodine film (I2‐F) and form soluble I2Br−(aq) during the electrooxidation of I−. I− was electrochemically oxidized to the soluble form I3−(aq). The depletion of I−(aq) and an increase of I3−(aq) would lead to the formation of I2 and form I2‐F. Then, under a steady state, I−(aq) was electrochemically oxidized to I3−(aq) via I2‐F. However, the reaction pathway for the electrooxidation of I− was significantly altered by the addition of Br−. I− was electrochemically oxidized to I3−(aq) and was further oxidized to I2Br−(aq) without the formation of I2‐F. Moreover, we estimated the stability constant of I2Br−(aq) and consequently the fractional diagrams of I2(aq), I3−(aq), and I2Br−(aq) existing in a solution with both I− and Br− during the electrooxidation of I−, providing the necessity of a highly concentrated Br− condition in the vicinity of an electrode to form I2Br−(aq) as the main iodine species through the electrooxidation of I−.
Development of a nondestructive assay method using Raman spectroscopy in the pharmaceutical production process of a freeze‐dried injection with gemcitabine as active pharmaceutical ingredient
Authors: Kim Jaejin , Han Janghee , Woo Young‐Ah 
Published: September 2021

AbstractFreeze‐dried injectable drugs based on gemcitabine are mainly used as anticancer drugs for pancreatic cancer. High‐performance liquid chromatography (HPLC) analysis is mainly used to analyze the active pharmaceutical ingredient (API) content in the pharmaceuticals prepared in this way. While the HPLC method has high accuracy, it has the disadvantage that it cannot measure all of the large numbers of products produced due to the long measurement time. To solve this problem, a Raman spectrometer was installed in the pharmaceutical production process to measure the API content of all products. After installing a Raman spectrometer in the pharmaceutical production process, the verified quantitative model was used to measure API content in real time. A total of 4500 vials from three batches were tested, and the averages of each of the three batches were 100.0%, 100.2%, and 99.7%.
FSC231 alleviates paclitaxel‐induced neuralgia by inhibiting the interactions between PICK1 and GluA2 and activates GSK‐3β and ERK1/2
Authors: Zhang Xi , Wang Jiagao , Ran Ran , Peng Yuchuan , Xiao Yun 
Published: September 2021

AbstractBackgroundFSC231, a PSD‐95/DLG/ZO‐1 (PDZ) domain inhibitor of protein kinase Cα interacting protein 1 (PICK1), has analgesic effects, but the mechanism remains unclear.MethodsThe expression level of PICK1 in dorsal root ganglion (DRG) of rats was changed by vector plasmid, and the effect of PICK1 on paclitaxel (PTL)‐induced neuralgia of rats was observed in collaboration with FSC231 treatment. The possible molecular mechanisms were explored by quantitative real‐time polymerase chain reaction (qRT‐PCR), Western Blot and co‐immunoprecipitation (Co‐IP) techniques.ResultsPTL treatment can significantly reduce mechanical withdrawal threshold (MWT), shorten thermal withdrawal latency (TWL), promote DRG inflammation and release of substance P (SP), stimulate PICK1 expression, decrease α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole‐propionic acid receptor 2 (AMPAR, GluA2) level and increase glycogen synthase kinase‐3β (GSK‐3β) and extracellular regulated protein kinases1/2 (ERK1/2) phosphorylation in rats, while FSC231 treatment can alleviate the above effects induced by PTL. Overexpression of PICK1 can counteract reduced PICK1 level, increased GluA2 level and decreased GSK‐3β and ERK1/2 phosphorylation levels caused by FSC231 treatment. The results of Co‐IP confirmed the interactions between PICK1 and GluA2. Both FSC231 treatment and silent PICK1 improved PTL‐induced MWT reduction, TWL shortening, inflammation, SP release and related gene expression changes, with cumulative effect.ConclusionFSC231 activates GSK‐3β/ERK1/2 by inhibiting the interaction between PICK1 and GluA2 and alleviates PTL‐induced DRG neuralgia in rats.
Mitochondrial Membrane Disrupting Molecules for Selective Killing of Senescent Cells
Authors: Jana Batakrishna , Kim Sangpil , Chae Jae‐Byoung , Chung Hyewon , Kim Chaekyu , Ryu Ja‐Hyoung 
Published: September 2021

AbstractCellular senescence, a stable form of cell cycle arrest, facilitates protection from tumorigenesis and aids in tissue repair as they accumulate in the body at an early age. However, long‐term retention of senescent cells causes inflammation, aging of the tissue, and progression of deadly diseases such as obesity, diabetes, and atherosclerosis. Various attempts have been made to achieve selective elimination of senescent cells from the body, yet little has been explored in designing the mitochondria‐targeted senolytic agent. Many characteristics of senescence are associated with mitochondria. Here we have designed a library of alkyl‐monoquaternary ammonium‐triphenyl phosphine (TPP) and alkyl‐diquaternary ammonium‐TPP of varying alkyl chain lengths, which target the mitochondria; we also studied their senolytic properties. It was observed that the alkyl‐diquaternary ammonium‐TPP with the longest chain length induced apoptosis in senescent cells selectively via an increase of reactive oxygen species (ROS) and mitochondrial membrane disruption. This study demonstrates that mitochondria could be a potential target for designing new small molecules as senolytic agents for the treatment of a variety of dysfunctions associated with pathological aging.
Optical coherence tomography, intravascular ultrasound or angiography guidance for distal left main coronary stenting. The ROCK cohort II study
Authors: Cortese Bernardo , de la Torre Hernandez Jose M. , Lanocha Magdalena , Ielasi Alfonso , Giannini Francesco , Campo Gianluca , D'Ascenzo Fabrizio , Latini Roberto A. , Krestianinov Oleg , Alfonso Fernando , Trani Carlo , Prati Francesco , Linares Jose A. , Sardella Gennaro , Wlodarczak Adrian , Viganò Elena , Camarero Tamara Garcia , Stella Pieter , Sozykin Alexander , Fineschi Massimo , Burzotta Francesco 
Published: September 2021

AbstractObjectivesto test the safety and efficacy of intravascular imaging and specifically optical coherence tomography (OCT) as a diagnostic tool for left main angioplasty and analyze the mid‐term outcome accordingly.BackgroundClinical data and international guidelines recommend the use of intravascular imaging ultrasound (IVUS) to guide left main (LM) angioplasty. Despite early experience using OCT in this setting is encouraging, the evidence supporting its use is still limited.MethodsROCK II is a multicenter, investigator‐driven, retrospective European study to compare the performance of IVUS and OCT versus angiography in patients undergoing distal‐LM stenting. The primary study endpoint was target‐lesion failure (TLF) including cardiac death, target‐vessel myocardial infarction and target‐lesion revascularization. We designed this study hypothesizing the superiority of intravascular imaging over angiographic guidance alone, and the non‐inferiority of OCT versus IVUS.ResultsA total of 730 patients, 377 with intravascular‐imaging guidance (162 OCT, 215 IVUS) and 353 with angiographic guidance, were analyzed. The one‐year rate of TLF was 21.2% with angiography and 12.7% with intravascular‐imaging (p = 0.039), with no difference between OCT and IVUS (p = 0.26). Intravascular‐imaging was predictor of freedom from TLF (HR 0.46; 95% CI 0.23–0.93: p = 0.03). Propensity‐score matching identified three groups of 100 patients each with no significant differences in baseline characteristics. The one‐year rate of TLF was 16% in the angiographic, 7% in the OCT and 6% in the IVUS group, respectively (p = 0.03 for IVUS or OCT vs. angiography). No between‐group significant differences in the rate of individual components of TLF were found.ConclusionsIntravascular imaging was superior to angiography for distal LM stenting, with no difference between OCT and IVUS.