bluuebunny/crossref_metadata_2025 huggingface dataset:
Biologically rapid synthesized silver nanoparticles from aqueous Eucalyptus camaldulensis leaf extract: Effects on hyphal growth, hydrolytic enzymes, and biofilm formation in Candida albicans
Authors: Wunnoo Suttiwan , Paosen Supakit , Lethongkam Sakkarin , Sukkurd Rattanavadee , Waen‐ngoen Tassanai , Nuidate Taiyeebah , Phengmak Manthana , Voravuthikunchai Supayang P.
Published: January 2021

Bionanotechnology has increasingly gained attention in biomedical fields as antifungal and antibiofilm agents. In this study, biosynthesized silver nanoparticles (bio‐AgNPs) using aqueous Eucalyptus camaldulensis leaf extract were successfully performed by a one‐step green approach. Spherical‐shaped nanoparticles, approximately 8.65 nm, exhibited noncytotoxicity to erythrocytes, HeLa, and HaCaT cells. The synthesized nanoparticles showed strong fungicidal activity ranging from 0.5 to 1 µg/ml. The nanoparticles affected Candida adhesion and invasion into host cells by reduced germ tube formation and hydrolytic enzyme secretion. Inhibitory effects of bio‐AgNPs on Candida biofilms were evaluated by the prevention of yeast‐to‐hyphal transition. A decrease in cell viability within mature biofilm demonstrated the ability of bio‐AgNPs to penetrate into the extracellular matrix and destroy yeast cell morphology, leading to cell death. Molecular biology study on biofilms confirmed downregulation in the expression of genes ALS3, HWP1, ECE1, EFG1, TEC1, ZAP1, encoding hyphal growth and biofilm development and PLB2, LIP9, SAP4, involved in hydrolytic enzymes. In addition to candida treatment, the bio‐AgNPs could be applied as an antioxidant to protect against oxidative stress‐related human diseases. The findings concluded that bio‐AgNPs could be used as an antifungal agent for candida treatment, as well as be incorporated in medical devices to prevent biofilm formation.
Substrate availability drives mixed culture fermentation of glucose to lactate at steady state
Authors: Hoelzle Robert D. , Puyol Daniel , Virdis Bernardino , Batstone Damien
Published: January 2021

Mixed‐culture fermentation (MCF) enables carbon recycling from complex organic waste streams into valuable feedstock chemicals. Using complex microbial consortia, MCF systems can be tuned to produce a range of biochemicals to meet market demand. However, the metabolic mechanisms and community interactions which drive biochemical production changes under differing conditions are currently poorly understood. These mechanisms are critical to useful MCF production models. Furthermore, predictable product transitions are currently limited to pH‐driven changes between butyrate and ethanol, and chain‐elongation (fed by lactate, acetate, and ethanol) to butyrate, valerate, and hexanoate. Lactate, a high‐value biopolymer feedstock chemical, has been observed in transition states, but sustained production has not been described. In this study, steady state lactate production was achieved by increasing the organic loading rate of a butyrate‐producing system from limiting to nonlimiting conditions at pH 5.5. Crucially, butyrate production resumed upon return to substrate‐limited conditions. 16S ribosomal DNA community profiling combined with metaproteomics demonstrated that the butyrate‐producing lineage Megasphaera redirected carbon flow through the methylglyoxal bypass when substrate was nonlimiting, which altered the community structure and metabolic expression toward lactate production. This metabolic mechanism can be included in future MCF models to describe the changes in product generation in substrate nonlimiting conditions.
Electrochemical Oxidative Arylsulfonylation and 1,2‐Alkyl Shift Sequences of Alkenyl Cyclobutanols for the Synthesis of β‐Sulfonated Cyclopentanones
Authors: Kim Yebin , Kim Dae Young
Published: January 2021

A novel process for the synthesis of β‐sulfonated cyclopentanones via electrochemical oxidative radical arylsulfonylation and 1,2‐alkyl shift sequences of vinyl cyclobutanols was successfully developed. This approach represents a practical method for the preparation of β‐sulfonated cyclopentanones under environmentally benign reaction conditions.
Visible‐Light Photoredox‐Catalyzed α‐Allylation of α‐Bromocarbonyl Compounds Using Allyltrimethylsilane
Authors: Gontala Arjun , Jang Gwang Seok , Woo Sang Kook
Published: January 2021

The development of a greener allylation reagent for α‐allylation of carbonyl compounds is of great necessity. Here we present allyltrimethylsilane as a novel allylation reagent in the photoredox‐catalyzed α‐allylation of carbonyl compounds such as ketones, esters, and amides. The reaction process shows good functional group tolerance and generates a good yield of the product. The reaction mechanism is a radical‐mediated reaction by photo‐induced single electron transfer.
Using the Integrated Genome Viewer to reveal amplicon‐derived polymorphism enriched at the phenylthiocarbamide locus in the teaching lab
Authors: Brenner Eric D. , Scheid Paul E. , DeGrazia Justin , Geltzeiler Alexa R. , Katari Manpreet S.
Published: January 2021

Due to its distinct phenotype and relatively simple inheritance pattern, the phenylthiocarbamide (PTC) loci is frequently utilized in teaching laboratories to demonstrate genetic concepts such as Mendelian inheritance and population genetics. We have developed a next‐generation sequencing and bioinformatics approach to analyze the PTC gene locus to reveal single nucleotide polymorphism (SNP) variation at nucleotide position 785 that predicts tasting ability in humans. Here students purify DNA from their own cheek cells, perform polymerase chain reaction (PCR) amplification of the PTC gene followed by cleaved amplified polymorphic sequence (CAPS) testing. Students perform a second PCR on the PTC loci using high‐fidelity Taq to create bar‐coded amplicons for next‐generation sequencing on the Ion Torrent Personal Genome Machine. Bioinformatic verification reveals polymorphic variation by aligning the entire class PTC PCR fragment sequence to the human gene using Bowtie2 and visualizing the results in the Integrated Genome Viewer. This exercise presents a learning opportunity for students to use next‐generation sequencing to predict their own PTC taste sensitivity phenotype coupled with the standard CAPS method. This approach brings the PTC teaching method into the genomics era.
The nexus of business sustainability and organizational learning: A systematic literature review to identify key learning principles for business transformation
Authors: Hermelingmeier Verena , von Wirth Timo
Published: January 2021

Companies play a central role in the quest for sustainable development. Organizational learning theories have been utilized to explain sustainability‐related change processes in firms. However, implications from studies at the nexus of business sustainability and organizational learning are highly dependent on varying conceptualizations. The objective of this study is to provide clarity on the plurality of conceptual underpinnings in research and to uncover principles that are associated with deeper organizational change processes, that is, business transformation. Building on insights from a systematic literature review, we develop a sustainability learning typology, from which we distill three learning principles for business transformation: (1) the deutero learning mode, (2) the societal learning scope, and (3) the cooperative advantage objective. We formulate needs for future research to further elaborate on the learning principles associated with business transformation and suggest implications for practice.
Quantification of glycated IgG in CHO supernatants: A practical approach
Authors: Lhota Gabriele , Sissolak Bernhard , Striedner Gerald , Sommeregger Wolfgang , Vorauer‐Uhl Karola
Published: January 2021

Post‐translational, nonenzymatic glycation of monoclonal antibodies (mAbs) in the presence of reducing sugars (in bioprocesses) is a widely known phenomenon, which affects protein heterogeneity and potentially has an impact on quality, safety, and efficacy of the end product. Quantification of individual glycation levels is compulsory for each mAb therapeutically applied in humans. We therefore propose an analytical method for monitoring glycation levels of mAb products during the bioprocess. This is a useful tool for process‐design considerations, especially concerning glucose‐feed strategies and temperature as major driving factors of protein glycation. In this study, boronate affinity chromatography (BAC) was optimized for determination of the glycation level of mAbs in supernatants. In fact, the complex matrix found in supernatants is an underlying obstacle to use BAC, but with a simple clean‐up step, we found that the elution profile could be significantly improved so that qualitative and quantitative determination could be reached. Complementary analytical methods confirmed the performance quality, including the correctness and specificity of the results. For quantitative determination of mAb glycation in supernatants, we established a calibration procedure for the retained mAb peak, identified as glycated antibody monomers. For this approach, an available fully characterized mAb standard, Humira®, was successfully applied, and continuous monitoring of mAbs across three repetitive fed‐batch processes was finally performed. With this practical, novel approach, an insight was obtained into glycation levels during bioprocessing, in conjunction with glucose levels and product titer over time, facilitating efficient process development and batch‐consistency monitoring.
Domestic violence during COVID‐19 pandemic: The case for Indian women
Authors: Maji Sucharita , Bansod Saurabh , Singh Tushar
Published: January 2021

Domestic violence is one of the most pernicious gendered ailments of human society. Researchers have confirmed the inevitable consequences of domestic violence (physical, sexual, and emotional) in increased vulnerability to psychopathologies in addition to physical morbidity. Domestic violence cases are vast in India, and the numbers are further aggravated at an alarming rate during the COVID‐19 pandemic. The present study aimed at exploring the cases of domestic violence among Indian women during the COVID‐19 pandemic. Newspapers reporting the incidents of domestic violence during the last 5 years were analysed to explore the issues related to the surge in domestic violence incidents during the COVID‐19 lockdown period. A major increase in domestic violence cases was observed during the COVID‐19 period as compared to the previous years. Also, the cases were higher during the initial phases of the pandemic but gradually decreased as time progressed.The impact of the COVID‐19 pandemic on women was unprecedented and worse than before. Home containment as a measure to protect the health and well‐being of the general public has resulted in increased sufferings for women in terms of both sufferings from diseases and increased domestic violence.
Arthpyrone L, a New Pyridone Alkaloid from a Deep‐Sea Arthrinium sp., Inhibits Proliferation of MG63 Osteosarcoma Cells by Inducing G0/G1 Arrest and Apoptosis
Authors: Zhang Yuying , Li Mengru , Zhang Qianqian , Wang Zhaoyang , Li Xiuxiu , Bao Jie , Zhang Hua
Published: January 2021

Fractionation of the ethanol extract of a marine fungus, Arthrinium sp., afforded a new pyridone alkaloid (arthpyrone L (1)), the structure with absolute configuration of which was established by comprehensive spectroscopic analyses. In vitro cell viability assays revealed that compound 1 showed antiproliferative effects toward human A549 (lung), MG63, U2OS (bone), MCF‐7 and MDA‐MB‐231 (breast) cancer cells. MG63 cell lines were chosen for further biological evaluations and presented apoptosis and cell cycle arrest (G0/G1 phase) upon treatment of 1. Subsequent mechanism studies demonstrated that the growth inhibition of 1 against MG63 cells was via activation of caspase‐modulated apoptotic pathway and inhibition of PI3K/Akt pathway.
Bioactive Phytochemicals and Antioxidant Capacity of Wheatgrass Treated with Salicylic Acid under Organic Soil Cultivation
Authors: Islam Mohammad Zahirul , Park Buem‐Jun , Lee Young‐Tack
Published: January 2021

This study was undertaken to determine the influence of salicylic acid (SA) on the bioactive phytochemicals and antioxidant capacity of wheatgrass extract in the organic growing medium. Wheatgrass was cultivated in SA‐enriched organic growing medium, obtained from acetylsalicylic acid (aspirin) of various concentrations (0 [control], 0.25, 0.50, 1.00, and 2.00 mM) in a plant growth chamber by controlling atmosphere (20/15 °C, day/night), light (14/10 h, light/dark; light intensity 150 μmol m−2 s−1, using quantum dot light‐emitting diodes), and atmospheric moisture (60 %) for 10 d. The 0.25 mM SA‐treatment showed the highest impact on germination rate, wheatgrass length, weight, yield, and chlorophyll content. Levels of bioactive phytochemicals, mainly phenolic compounds, flavonoids, β‐carotene, and vitamin C, were the highest in the 1.00 mM SA‐treated wheatgrass extract. The DPPH radical and nitrite‐scavenging capacities were the highest in the 1.00 mM SA‐treated wheatgrass extract. The 0.50 mM SA‐treated wheatgrass extract showed the highest superoxide dismutase‐like capacity, whereas the 2.00 mM SA‐treated wheatgrass extract showed the highest anthocyanin content and ABTS radical‐scavenging capacity. Therefore, it might be suggested that the appropriate levels of SA‐treatment were between 0.5 and 1.0 mM to enhance the bioactive phytochemicals and antioxidant capacity of wheatgrass.
Phosphonic Analogs of Alanine as Acylpeptide Hydrolase Inhibitors
Authors: Walczak Maciej , Chryplewicz Agnieszka , Olewińska Sandra , Psurski Mateusz , Winiarski Łukasz , Torzyk Karolina , Oleksyszyn Józef , Sieńczyk Marcin
Published: January 2021

Acylpeptide hydrolase is a serine protease, which, together with prolyl oligopeptidase, dipeptidyl peptidase IV and oligopeptidase B, belongs to the prolyl oligopeptidase family. Its primary function is associated with the removal of N‐acetylated amino acid residues from proteins and peptides. Although the N‐acylation occurs in 50–90 % of eukaryotic proteins, the precise functions of this modification remains unclear. Recent findings have indicated that acylpeptide hydrolase participates in various events including oxidized proteins degradation, amyloid β‐peptide cleavage, and response to DNA damage. Considering the protein degradation cycle cross‐talk between acylpeptide hydrolase and proteasome, inhibition of the first enzyme resulted in down‐regulation of the ubiquitin‐proteasome system and induction of cancer cell apoptosis. Acylpeptide hydrolase has been proposed as an interesting target for the development of new potential anticancer agents. Here, we present the synthesis of simple derivatives of (1‐aminoethyl)phosphonic acid diaryl esters, phosphonic analogs of alanine diversified at the N‐terminus and ester rings, as inhibitors of acylpeptide hydrolase and discuss the ability of the title compounds to induce apoptosis of U937 and MV‐4‐11 tumor cell lines.
RNA‐Cleaving DNA Thresholder Controlled by Concentrations of miRNA Cancer Marker
Authors: Gomes de Oliveira Andrey Giovanni , Dubovichenko Mikhail V. , ElDeeb Ahmed A. , Wanjohi Joseph , Zablotskaya Sofia , Kolpashchikov Dmitry M.
Published: January 2021

Oligonucleotide gene therapy (OGT) agents suppress specific mRNAs in cells and thus reduce the expression of targeted genes. The ability to unambiguously distinguish cancer from healthy cells can solve the low selectivity problem of OGT agents. Cancer RNA markers are expressed in both healthy and cancer cells with a higher expression level in cancer cells. We have designed a DNA‐based construct, named DNA thresholder (DTh) that cleaves targeted RNA only at high concentrations of cancer marker RNA and demonstrates low cleavage activity at low marker concentrations. The RNA‐cleaving activity can be adjusted within one order of magnitude of the cancer marker RNA concentration by simply redesigning DTh. Importantly, DTh recognizes cancer marker RNA, while cleaving targeted RNA; this offers a possibility to suppress vital genes exclusively in cancer cells, thus triggering their death. DTh is a prototype of computation‐inspired molecular device for controlling gene expression and cancer treatment.
Sirtuin 1 promotes autophagy and proliferation of endometrial cancer cells by reducing acetylation level of LC3
Authors: Huang Shuai , Li Ye , Sheng Guihua , Meng Qingwei , Hu Qian , Gao Xuexiao , Shang Zhiyuan , Lv Qiubo
Published: January 2021

Endometrial cancer (EC) constitutes a common female genital tract tumor with a rising incidence rate. Sirtuin 1 (SIRT1) is a member of histone deacetylase, which extensively participates in the progression of aging, cell death, and tumorigenesis. This study explored the effect of SIRT1‐mediated LC3 acetylation on autophagy and proliferation of EC cells. SIRT1 expression in EC tissues and adjacent tissues, EC cell lines and normal human epithelial cells was detected. SIRT1 expression was elevated in EC cell lines and tissues. Knockdown of SIRT1 inhibited proliferation, migration, and invasion of EC cells. Then, EC cells were starved in serum‐free medium, and levels of autophagy‐related proteins were detected. Starvation induced autophagy of EC cells. The starvation‐treated EC cells showed an increased SIRT1 expression, a decreased LC3 acetylation level and an increased autophagy level. The proliferation and autophagy of EC cells under different treatments were evaluated. In EC cells transfected with overexpressing SIRT1, LC3 acetylation was inhibited and cell proliferation was promoted. Moreover, overexpressing SIRT1 facilitated growth and autophagy of transplanted tumors in nude mice. In conclusion, SIRT1 promoted autophagy and proliferation of EC cells by reducing acetylation level of LC3.
Development and validation of a prediction model for angiographic perforation during chronic total occlusion percutaneous coronary intervention: OPEN‐CLEAN perforation score
Authors: Hirai Taishi , Grantham James Aaron , Sapontis James , Nicholson William J. , Lombardi William , Karmpaliotis Dimitri , Moses Jeffrey , Nugent Karen , Gosch Kensey L. , Salisbury Adam C. ,   The OPEN CTO Study Group
Published: January 2021

Background

Perforation is the most frequent complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and is associated with adverse events including mortality.

Methods

Among 1,000 consecutive patients enrolled in 12 center prospective CTO PCI study (OPEN CTO), all perforations were reviewed by the angiographic core‐lab. Eighty‐nine patients (8.9%) with angiographic perforation were compared to 911 patients without perforation. We sought to describe the clinical and angiographic predictors of angiographic perforation during CTO PCI and develop a risk prediction model.

Results

Among eight clinically important candidate variables, independent risk factors for perforation included prior CABG (OR 2.0 [95% CI, 1.2–3.3], p < .01), occlusion length (OR 1.2 per 10 mm increase [95% CI, 1.1–1.3], p < .01), ejection fraction (OR 1.2 per 10% decrease [95% CI, 1.1–1.5], p < .01), age (OR 1.3 per 5 year increase [95%CI, 1.1–1.5], p < .01), and heavy calcification (OR 1.7 [95% CI, 1.0–2.7], p = .04). Three other potential candidate variables, glomerular filtration rate, proximal cap ambiguity, and target vessel, were not independently associated with perforation. The model was internally validated using bootstrapping methods. From the full model, a simplified perforation prediction score (OPEN‐CLEAN score: CABG, Length [occlusion], EF < 50%, Age, CalcificatioN) was developed, which discriminated the risk of angiographic perforation well (c‐statistics = 0.75) and demonstrated good calibration.

Conclusion

This simple 5‐variable prediction score may help CTO operators to risk‐stratify patients for angiographic perforation using variables available prior to CTO PCI procedures.
Diagnosis of maternal Hodgkin lymphoma following abnormal findings at noninvasive prenatal screening test (NIPT): Report of two cases
Authors: Castellino Alessia , Elba Simona , Sorasio Roberto , Castellino Claudia , Bonferroni Margherita , Grasso Mariella , Grosso Enrico , Giacchello Rosalba , Signorile Anna Franca , Celeghini Ivana , Mattei Daniele , Mordini Nicola , Foglietta Myriam , Masturzo Bianca , Priotto Roberto , Zonta Andrea , Rapezzi Davide , Massaia Massimo
Published: January 2021

Abnormal NIPT results, contrasting with normal fetus development, could disclose maternal malignancy, and this possibility should always be explained during pretest counseling. In this case, a complete diagnostic assessment is recommended and should be managed by a multidisciplinary team to define the best timing for diagnostic procedures, delivery, and treatment.
COVID‐19 pneumonia in a pediatric sickle cell patient requiring red blood cell exchange
Authors: Walker Shannon C. , Murphy Meghan L. , Hendricks Hope , Dulek Daniel E. , Volanakis Emmanuel J. , Borinstein Scott C.
Published: January 2021

Patients with sickle cell disease are already at high risk for respiratory complications, which SARS‐CoV‐2 can rapidly worsen. The case emphasizes the importance of efficiently maximizing standard therapies in sickle cell patients with COVID‐19.
Floating aortic thrombus with celiac artery embolus presenting with chronic epigastric and right upper quadrant pain: A case report
Authors: Jahanshahi Fatemeh , Kalantar Motamedi Alireza
Published: January 2021

Arterial occlusion may be the cause of chronic pain, and vascular diagnostic procedures should be a part of the workup in patients with unexplained chronic visceral pain.
Influence of the MnO2 Phase on Oxygen Evolution Reaction Performance for Low‐Loading Iridium Electrocatalysts
Authors: Wang Zheyuan , Gao Wenluan , Xu Qingli , Ren Xiaona , Xu Shuang , Zhu Shuaikang , Niu Xiaopo , Li Xiaoxue , Zhao Rong , Han Yunxi , Li Guozhu , Wang Qingfa
Published: January 2021

Developing high‐performance, low‐loading, Ir‐based electrocatalysts for the oxygen evolution reaction (OER) in acidic media is still a great challenge. Herein, we fabricated an iridium manganese catalyst with only 5 % iridium. The influence of the manganese dioxide phase states (α‐, β‐, γ‐ and δ‐MnO2) on the OER performance of IrO2/MnO2 catalysts was investigated. α‐MnO2, as the substrate, can generate smaller iridium particles and more high‐valence‐state iridium to promote OER performance. Therefore, the 5 % IrO2/α‐MnO2 electrocatalyst exhibits excellent electrocatalytic OER performance with a high mass activity of 216.67 A/gIr and 655.33 A/gIr at 1.53 V in acidic and alkaline media, respectively, significantly outperforming commercial IrO2.
Modulating Hydroxyl‐Rich Interfaces on Nickel–Copper Double Hydroxide Nanotyres to Pre‐activate Alkaline Ammonia Oxidation Reactivity
Authors: Yang Anzhou , Wang Jingchun , Su Keying , Lei Wu , Qiu Xiaoyu , Tang Yawen
Published: January 2021

The surface hydroxyl groups of NixCu1−x(OH)2 play a crucial role in governing their conversion efficiency into NixCu1−xOx(OH)2−x during the electro‐chemical pre‐activation process, thus affecting the integral ammonia oxidation reaction (AOR) reactivity. Herein, the rational design of hierarchical porous NiCu double hydroxide nanotyres (NiCu DHTs) was reported for the first time by considering hydroxyl‐rich interfaces to promote pre‐activation efficiency and intrinsic structural superiority (i.e., annulus, porosity) to accelerate AOR kinetics. A systematic investigation of the structure–function relationship was conducted by manipulating a series of NiCu DHs with tunable intercalations and morphologies. Remarkably, the NiCu DHTs exhibit superior AOR activity (onset potential of 1.31 V with 7.52 mA cm−2 at 1.5 V) and high ammonia sensitivity (detection limit of 9 μm), manifesting one of the best non‐noble metal AOR electrocatalysts and electro‐analytical electrodetectors. This work deepens the understanding of the crucial role of surface hydroxyl groups on determining the catalytic performance in alkaline medium.
Self‐Assembled Binaphthyl‐Bridged Amphiphilic AABB Phthalocyanines: Nanostructures for Efficient Antimicrobial Photodynamic Therapy
Authors: Revuelta‐Maza Miguel Ángel , de las Heras Elena , Agut Montserrat , Nonell Santi , Torres Tomás , de la Torre Gema
Published: January 2021

Herein, the photodynamic activity of phthalocyanine (pc)‐assembled nanoparticles against bacterial strains is demonstrated. The photosensitizers (PS) studied in this work are two chiral ZnIIPcs (PS‐1 and PS‐2), with an AABB geometry (where A and B refer to differently substituted isoindole constituents). They contain differently functionalized, chiral binaphthyloxy‐linked A isoindole units, which determine the hydrophobicity of the system, and cationic methyl pyridinium moieties in the other two isoindoles to embody hydrophilicity. Both compounds have the ability to self‐assemble into nanoparticles in aqueous media and have proved efficient in the photo‐inactivation of Staphylococcus aureus and Escherichia coli, selected as models of Gram‐positive and Gram‐negative bacteria. The average size of the nanoparticles was determined by substitution at the binaphthyl core and, in turn, influences the toxicity of the PS. Thus, PS‐1, presenting a nonsubstituted binaphthyl core, forms larger nanoparticles with a larger cationic surface than the octyl‐functionalized PS‐2. Although both PSs present similar structure and photophysical features, the self‐assembled nanostructures of PS‐1 are more effective at killing both types of strain, showing an outstanding photo‐inactivation capacity with the Gram‐negative E. coli.
Cations and Anions of Dibenzo[a,e]pentalene and Reduction of a Dibenzo[a,e]pentalenophane
Authors: Hermann Mathias , Böttcher Tobias , Schorpp Marcel , Richert Sabine , Wassy Daniel , Krossing Ingo , Esser Birgit
Published: January 2021

Dibenzo[a,e]pentalene (DBP) is a non‐alternant conjugated hydrocarbon with antiaromatic character and ambipolar electrochemical behavior. Upon both reduction and oxidation, it becomes aromatic. We herein study the chemical oxidation and reduction of a planar DBP derivative and a bent DBP‐phane. The molecular structures of its planar dication, cation radical and anion radical in the solid state demonstrate the gained aromaticity through bond length equalization, which is supported by nucleus independent chemical shift‐calculations. EPR spectra on the cation radical confirm the spin delocalization over the DBP framework. A similar delocalization was not possible in the reduced bent DBP‐phane, which stabilized itself by proton abstraction from a solvent molecule upon reduction. This is the first report on structures of a DBP cation radical and dication in the solid state and of a reduced bent DBP derivative. Our study provides valuable insight into the charged species of DBP for its application as semiconductor.
The Effect of Auxiliary Nitrogenated Linkers on the Design of New Cadmium‐Based Coordination Polymers as Sensors for the Detection of Explosive Materials
Authors: Aguirre‐Díaz Lina M. , Echeverri Marcelo , Paredes‐Gil Katherine , Snejko Natalia , Gómez‐Lor Berta , Gutiérrez‐Puebla Enrique , Monge M. Ángeles
Published: January 2021

Three new cadmium‐based coordination polymers, denoted [Cd(hfipbb)(4,4’‐bipy)] (CdPF‐1), [Cd(hfipbb)(2,2’‐bipy)] (CdPF‐2), and [Cd(hfipbb)(1,10‐phen)] (CdPF‐3), have been hydrothermally synthesized by using the well‐known V‐shaped organic linker 4,4’‐(hexafluoroisopropylidene)bis(benzoic acid) (H2hfipbb), together with different nitrogenated auxiliary linkers. Considering the d10 configuration of the transition metal selected, the luminescent properties for these CdPF‐n materials were explored, finding that materials CdPF‐2 and CdPF‐3 act as excellent sensors in the detection of explosive nitro aromatic compounds. The photoluminescence properties of CdPF‐2 and CdPF‐3 revealed that significant and sensitive fluorescence quenching was observed toward NP (nitrophenol) for CdPF‐2 and PA (picric acid) for CdPF‐3 in MeOH suspensions.
Proton Switch in the Secondary Coordination Sphere to Control Catalytic Events at the Metal Center: Biomimetic Oxo Transfer Chemistry of Nickel Amidate Complex
Authors: Kim Soohyung , Jeong Ha Young , Kim Seonghan , Kim Hongsik , Lee Sojeong , Cho Jaeheung , Kim Cheal , Lee Dongwhan
Published: January 2021

High‐valent metal‐oxo species are key intermediates for the oxygen atom transfer step in the catalytic cycles of many metalloenzymes. While the redox‐active metal centers of such enzymes are typically supported by anionic amino acid side chains or porphyrin rings, peptide backbones might function as strong electron‐donating ligands to stabilize high oxidation states. To test the feasibility of this idea in synthetic settings, we have prepared a nickel(II) complex of new amido multidentate ligand. The mononuclear nickel complex of this N5 ligand catalyzes epoxidation reactions of a wide range of olefins by using mCPBA as a terminal oxidant. Notably, a remarkably high catalytic efficiency and selectivity were observed for terminal olefin substrates. We found that protonation of the secondary coordination sphere serves as the entry point to the catalytic cycle, in which high‐valent nickel species is subsequently formed to carry out oxo‐transfer reactions. A conceptually parallel process might allow metalloenzymes to control the catalytic cycle in the primary coordination sphere by using proton switch in the secondary coordination sphere.
Real‐Time Analysis of Polyphenol–Protein Interactions by Surface Plasmon Resonance Using Surface‐Bound Polyphenols
Authors: Delannoy López Daniela Mélanie , Tran Dong Tien , Viault Guillaume , Dairi Sofiane , Peixoto Philippe Alexandre , Capello Yoan , Minder Laëtitia , Pouységu Laurent , Génot Elisabeth , Di Primo Carmelo , Deffieux Denis , Quideau Stéphane
Published: January 2021

A selection of bioactive polyphenols of different structural classes, such as the ellagitannins vescalagin and vescalin, the flavanoids catechin, epicatechin, epigallocatechin gallate (EGCG), and procyanidin B2, and the stilbenoids resveratrol and piceatannol, were chemically modified to bear a biotin unit for enabling their immobilization on streptavidin‐coated sensor chips. These sensor chips were used to evaluate in real time by surface plasmon resonance (SPR) the interactions of three different surface‐bound polyphenolic ligands per sensor chip with various protein analytes, including human DNA topoisomerase IIα, flavonoid leucoanthocyanidin dioxygenase, B‐cell lymphoma 2 apoptosis regulator protein, and bovine serum albumin. The types and levels of SPR responses unveiled major differences in the association, or lack thereof, and dissociation between a given protein analyte and different polyphenolic ligands. Thus, this multi‐analysis SPR technique is a valuable methodology to rapidly screen and qualitatively compare various polyphenol–protein interactions.
Computational Insights into Different Mechanisms for Ag‐, Cu‐, and Pd‐Catalyzed Cyclopropanation of Alkenes and Sulfonyl Hydrazones
Authors: Wu Yong , Cao Shanshan , Douair Iskander , Maron Laurent , Bi Xihe
Published: January 2021

The [2+1] cycloaddition reaction of a metal carbene with an alkene can produce important cyclopropane products for synthetic intermediates, materials, and pharmaceutical applications. However, this reaction is often accompanied by side reactions, such as coupling and self‐coupling, so that the yield of the cyclopropanation product of non‐silver transition‐metal carbenes and hindered alkenes is generally lower than 50 %. To solve this problem, the addition of a low concentration of diazo compound (decomposition of sulfonyl hydrazones) to alkenes catalyzed by either CuOAc or PdCl2 was studied, but side reactions could still not be avoided. Interestingly, however, the yield of cyclopropanation products for such hindered alkenes were as high as 99 % with AgOTf as a catalyst. To explain this unexpected phenomenon, reaction pathways have been computed for four different catalysts by using DFT. By combining the results of these calculations with those obtained experimentally, it can be concluded that the efficiency of the silver catalyst is due to the barrierless concerted cycloaddition step and the kinetic inhibition of side reactions by a high concentration of alkene.
C−N Axial Chiral Hypervalent Iodine Reagents: Catalytic Stereoselective α‐Oxytosylation of Ketones
Authors: Alharbi Haifa , Elsherbini Mohamed , Qurban Jihan , Wirth Thomas
Published: January 2021

A simple synthesis of a library of novel C−N axially chiral iodoarenes is achieved in a three‐step synthesis from commercially available aniline derivatives. C−N axial chiral iodine reagents are rarely investigated in the hypervalent iodine arena. The potential of the novel chiral iodoarenes as organocatalysts for stereoselective oxidative transformations is assessed using the well explored, but challenging stereoselective α‐oxytosylation of ketones. All investigated reagents catalyse the stereoselective oxidation of propiophenone to the corresponding chiral α‐oxytosylated products with good stereochemical control. Using the optimised reaction conditions a wide range of products was obtained in generally good to excellent yields and with good enantioselectivities.
Small Figure‐Eight Luminophores: Double‐Twisted Tethered Cyclic Binaphthyls Boost Circularly Polarized Luminescence
Authors: Nojima Yuki , Hasegawa Masashi , Hara Nobuyuki , Imai Yoshitane , Mazaki Yasuhiro
Published: January 2021

Double‐twisted cyclic binaphthyls, in which two naphthalenes are tethered by ‐O(CH2)nO‐ linkage (n=1–3), have been synthesized. X‐ray analyses and DFT calculations revealed a tightly constrained stereogenic figure‐eight geometry. Tethering of two naphthalenes by short linkage forces a small dihedral angle, and the cyclic binaphthyls with short tether (n=1, 2) exhibit remarkable boosting of the glum value (1.0–1.6×10−2) in circularly polarized luminescence (CPL) and unusual glum/gabs ratios (0.93–1.3). These experimental high |glum| values are in accord with the results of excited state TD‐DFT calculations, which show transannular interactions and that consequent extensive delocalization occurs throughout the figure‐eight π‐core. As a result, the present figure‐eight luminophore promote the elongation of the magnetic transition dipole moment that results in significant increases in glum values.
Accessing Lanthanide‐to‐Lanthanide Energy Transfer in a Family of Site‐Resolved [LnIIILnIII′] Heterodimetallic Complexes
Authors: Abad Galán Laura , Aguilà David , Guyot Yannick , Velasco Verónica , Roubeau Olivier , Teat Simon J. , Massi Massimiliano , Aromí Guillem
Published: January 2021

The ligand H3L (6‐[3‐oxo‐3‐(2‐hydroxyphenyl)propionyl]pyridine‐2‐carboxylic acid), which exhibits two different coordination pockets, has been exploited to engender and study energy transfer (ET) in two dinuclear [LnIIILnIII′] analogues of interest, [EuYb] and [NdYb]. Their structural and physical properties have been compared with newly synthesised analogues featuring no possible ET ([EuLu], [NdLu], and [GdYb]) and with the corresponding homometallic [EuEu] and [NdNd] analogues, which have been previously reported. Photophysical data suggest that ET between EuIII and YbIII does not occur to a significant extent, whereas emission from YbIII originates from sensitisation of the ligand. In contrast, energy migration seems to be occurring between the two NdIII centres in [NdNd], as well as in [NdYb], in which YbIII luminescence is thus, in part, sensitised by ET from Nd. This study shows the versatility of this molecular platform to further the investigation of lanthanide‐to‐lanthanide ET phenomena in defined molecular systems.
An Electron‐Accepting aza‐BODIPY‐Based Donor–Acceptor–Donor Architecture for Bright NIR Emission
Authors: Kage Yuto , Kang Seongsoo , Mori Shigeki , Mamada Masashi , Adachi Chihaya , Kim Dongho , Furuta Hiroyuki , Shimizu Soji
Published: January 2021

A bright near‐infrared (NIR) fluorescent molecule was developed based on the donor–acceptor–donor (D–A–D) approach using an aza‐BODIPY analog called pyrrolopyrrole aza‐BODIPY (PPAB) as an electron‐accepting chromophore. Directly introducing electron‐donating triphenylamine (TPA) to develop a D–A–D structure caused redshifts of absorption and emission of PPAB into the NIR region with an enhanced fluorescence brightness of up to 5.2×104 m−1 cm−1, whereas inserting a phenylene linker between the TPA donor and the PPAB acceptor induced solvatochromic behavior in emission. Transient absorption spectra and theoretical calculations revealed the presence of a highly emissive hybridized locally excited and charge‐transfer state in the former case and the contribution of the dark charge‐separated state to the excited state in the latter case. The bright D–A–D PPAB as a novel emitter resulted in a NIR electroluminescence with a high external quantum efficiency of 3.7 % and a low amplified spontaneous emission threshold of ca. 80 μJ cm−2, indicating the high potential for NIR optoelectronic applications.
Photoinduced Palladium‐Catalyzed Dicarbofunctionalization of Terminal Alkynes
Authors: Yang Zhen , Koenigs Rene M.
Published: January 2021

Herein, a conceptually distinct approach was developed that allowed for the dicarbofunctionalization of alkynes at room temperature using simple, bench‐stable alkyl iodides and a second molecule of alkyne as coupling partner. Specifically, the photochemical activation of palladium complexes enabled this strategic dicarbofunctionalization via addition of alkyl radicals from secondary and tertiary alkyl iodides and formation of an intermediate palladium vinyl complex that could undergo subsequent Sonogashira reaction with a second alkyne molecule. This alkylation–alkynylation sequence allowed the one‐step synthesis of 1,3‐enynes including heteroarenes and biologically active compounds with high efficiency without exogenous photosensitizers or oxidants and now opens up pathways towards cascade reactions via photochemical palladium catalysis.
Divergent Carbocatalytic Routes in Oxidative Coupling of Benzofused Heteroaryl Dimers: A Mechanistic Update
Authors: Casadio David S. , Aikonen Santeri , Lenarda Anna , Nieger Martin , Hu Tao , Taubert Stefan , Sundholm Dage , Muuronen Mikko , Wirtanen Tom , Helaja Juho
Published: January 2021

Mildly thermal air or HNO3 oxidized activated carbons catalyse oxidative dehydrogenative couplings of benzo[b]fused heteroaryl 2,2’‐dimers, e.g., 2‐(benzofuran‐2‐yl)‐1H‐indole, to chiral 3,3’‐coupled cyclooctatetraenes or carbazole‐type migrative products under O2 atmosphere. DFT calculations show that the radical cation and the Scholl‐type arenium cation mechanisms lead to different products with 2‐(benzofuran‐2‐yl)‐1H‐indole, being in accord with experimental product distributions.
Chiral derivatives of xanthones and benzophenones: Synthesis, enantioseparation, molecular docking, and tumor cell growth inhibition studies
Authors: Phyo Ye' Zaw , Teixeira Joana , Gonçalves Ricardo , Palmeira Andreia , Tiritan Maria Elizabeth , Bousbaa Hassan , Pinto Madalena M.M. , Fernandes Carla , Kijjoa Anake
Published: January 2021

Liquid chromatography enantioseparation and determination of enantiomeric purity of synthetized xanthone and benzophenone derivatives comprising one or more chiral moieties are reported. High enantioselectivity and resolution were observed in (S,S)‐Whelk‐O1 chiral stationary phase (CSP) for the enantiomeric mixtures of compounds comprising an aromatic ring linked to the stereogenic center(s), with α values ranging from 1.35 to 4.15 and Rs values ranging from 2.22 to 13.87. Among all the tested enantiomeric mixtures, those comprising three chiral moieties positioned in the xanthone scaffold gave the best chromatographic results. Enantiomers comprising an alkyl chain linked to the stereogenic centers were enantioseparated on a Lux® Celullose‐2 CSP. For both CSPs, the elution was performed in polar organic mode. The enantiomeric ratio (e.r.) values were always higher than 99%. Additionally, assessment of chiral recognition mechanisms on (S,S)‐Whelk‐O1 CSP was performed by molecular docking approach, which are in accordance with the chromatographic parameters. The nature and number of chiral moieties in the central aromatic scaffold of either xanthone or benzophenone derivatives are proved to be crucial for enantiorecognition. The evaluation of the growth inhibition of human tumor cell lines revealed that (S,S)‐(+)‐5 was the most potent compound, with values of GI50 of 12.83 ± 2.09 μM for A375‐C5 melanoma, 12.40 ± 1.16 μM for MCF‐7 breast adenocarcinoma, and 13.06 ± 1.29 μM for NCI‐H460 non‐small cell lung cancer. In some cases, the growth inhibitory effects demonstrated to be dependent on the stereochemistry of the compounds.
Using Native Woody Plants for Phytomanagement of Urban Technosols Contaminated by Wood Pole Preservatives
Authors: Heine Philippe , Yavari Sara , Frenette‐Dussault Cédric , Zagury Gérald J. , Brisson Jacques , Labrecque Michel
Published: January 2021

Technosols are a major component of urban areas with little to no value, but many benefits can be gained by the use of native plants for their ecological reclamation. The aim of this study is to examine the capacity of North American native woody species to establish in and remediate a wood preservative‐contaminated technosol. Nine species are planted in mesocosms containing highly contaminated or non‐contaminated synthetic technosols. Remediation potential and plant physiology parameters (survival, photosynthesis and root growth) are monitored during one growing season. Results show an inverse relation between species performance ranking in the non‐contaminated technosol compared to ranking in contaminated soil. Overall, Salix bebbiana and Sambucus canadensis show good potential for phytomanagement of heterogenous contaminated technosols, offering the best compromise between performance in non‐contaminated and contaminated soils. Most species are able to phytoextract copper (Cu), with Rhus typhina, Alnus crispa, and S. bebbiana showing the highest Cu concentrations in stems. The use of multiple native species for technosol reclamation can be beneficial due to the heterogeneous nature of soil contaminants.
Exploiting Folding and Degradation Machineries To Target Undruggable Proteins: What Can a Computational Approach Tell Us?
Authors: Serapian Stefano A. , Triveri Alice , Marchetti Filippo , Castelli Matteo , Colombo Giorgio
Published: January 2021

Advances in genomics and proteomics have unveiled an ever‐growing number of key proteins and provided mechanistic insights into the genesis of pathologies. This wealth of data showed that changes in expression levels of specific proteins, mutations, and post‐translational modifications can result in (often subtle) perturbations of functional protein–protein interaction networks, which ultimately determine disease phenotypes. Although many such validated pathogenic proteins have emerged as ideal drug targets, there are also several that escape traditional pharmacological regulation; these proteins have thus been labeled “undruggable”. The challenges posed by undruggable targets call for new sorts of molecular intervention. One fascinating solution is to perturb a pathogenic protein's expression levels, rather than blocking its activities. In this Concept paper, we shall discuss chemical interventions aimed at recruiting undruggable proteins to the ubiquitin proteasome system, or aimed at disrupting protein‐protein interactions in the chaperone‐mediated cellular folding machinery: both kinds of intervention lead to a decrease in the amount of active pathogenic protein expressed. Specifically, we shall discuss the role of computational strategies in understanding the molecular determinants characterizing the function of synthetic molecules typically designed for either type of intervention. Finally, we shall provide our perspectives and views on the current limitations and possibilities to expand the scope of rational approaches to the design of chemical regulators of protein levels.
Multiscale modeling of a modified Blalock‐Taussig surgery in a patient‐specific tetralogy of Fallot
Authors: Keramati Hamed , van Houts Lex , Chen Ching Kit , van de Vosse Frans , Nakao Masakazu , Kim Sangho , Leo Hwa Liang
Published: January 2021

Tetralogy of Fallot (TOF) is a congenital heart anomaly that causes a drastic reduction in the oxygen level. In this study, we coupled a lumped‐parameter model with a patient‐specific three‐dimensional (3D) model which included a modified Blalock‐Taussig (MBT) shunt. By forming a closed loop, we investigated the effects of certain parameters on the flow rates and the pressures at different locations of the developed network. A local sensitivity analysis on an initial zero‐dimensional (0D) closed‐loop model was conducted. The 0D lumped parameter (LP) model was then refined based on the results of the multiscale 0D‐3D model and the local sensitivity analysis was repeated for the refined 0D model. It was shown that the maximum pressure of the pulmonary bed had the highest sensitivity of 94% to the diameter of MBT shunt. We observed that the existence of the flow in the shunt during the diastole caused an elevated wall shear stress (WSS) in the pulmonary artery. In this work, we calculated the flow velocity and pressure field in a 3D patient‐specific aorta with an MBT shunt, and then we used the results to increase the accuracy of our LP model to simulate numerous 0D simulations in a significantly shorter time, which is potentially applicable for medical decision‐making.
Image‐based computational fluid dynamics for estimating pressure drop and fractional flow reserve across iliac artery stenosis: A comparison with in‐vivo measurements
Authors: Skopalik Simeon , Hall Barrientos Pauline , Matthews James , Radjenovic Aleksandra , Mark Patrick , Roditi Giles , Paul Manosh C.
Published: January 2021

Computational Fluid Dynamics (CFD) and time‐resolved phase‐contrast magnetic resonance imaging (PC‐MRI) are potential non‐invasive methods for the assessment of the severity of arterial stenoses. Fractional flow reserve (FFR) is the current “gold standard” for determining stenosis severity in the coronary arteries but is an invasive method requiring insertion of a pressure wire. CFD derived FFR (vFFR) is an alternative to traditional catheter derived FFR now available commercially for coronary artery assessment, however, it can potentially be applied to a wider range of vulnerable vessels such as the iliac arteries. In this study CFD simulations are used to assess the ability of vFFR in predicting the stenosis severity in a patient with a stenosis of 77% area reduction (>50% diameter reduction) in the right iliac artery. Variations of vFFR, overall pressure drop and flow split between the vessels were observed by using different boundary conditions. Correlations between boundary condition parameters and resulting flow variables are presented. The study concludes that vFFR has good potential to characterise iliac artery stenotic disease.