bluuebunny/crossref_metadata_2025_split huggingface dataset:
n‐Dopants Based on Dimers of Benzimidazoline Radicals: Structures and Mechanism of Redox Reactions
Authors: Zhang Siyuan , Naab Benjamin D. , Jucov Evgheni V. , Parkin Sean , Evans Eric G. B. , Millhauser Glenn L. , Timofeeva Tatiana V. , Risko Chad , Brédas Jean‐Luc , Bao Zhenan , Barlow Stephen , Marder Seth R. 
Published: June 2015

AbstractDimers of 2‐substituted N,N′‐dimethylbenzimidazoline radicals, (2‐Y‐DMBI)2 (Y=cyclohexyl (Cyc), ferrocenyl (Fc), ruthenocenyl (Rc)), have recently been reported as n‐dopants for organic semiconductors. Here their structural and energetic characteristics are reported, along with the mechanisms by which they react with acceptors, A (PCBM, TIPS‐pentacene), in solution. X‐ray data and DFT calculations both indicate a longer CC bond for (2‐Cyc‐DMBI)2 than (2‐Fc‐DMBI)2, yet DFT and ESR data show that the latter dissociates more readily due to stabilization of the radical by Fc. Depending on the energetics of dimer (D2) dissociation and of D2‐to‐A electron transfer, D2 reacts with A to form D+ and A− by either of two mechanisms, differing in whether the first step is endergonic dissociation or endergonic electron transfer. However, the D+/0.5 D2 redox potentials—the effective reducing strengths of the dimers—vary little within the series (ca. −1.9 V vs. FeCp2+/0) (Cp=cyclopentadienyl) due to cancelation of trends in the D+/0 potential and D2 dissociation energy. The implications of these findings for use of these dimers as n‐dopants, and for future dopant design, are discussed.
Chemoenzymatic Syntheses of Sialylated Oligosaccharides Containing C5‐Modified Neuraminic Acids for Dual Inhibition of Hemagglutinins and Neuraminidases
Authors: Birikaki Lémonia , Pradeau Stéphanie , Armand Sylvie , Priem Bernard , Márquez‐Domínguez Luis , Reyes‐Leyva Julio , Santos‐López Gerardo , Samain Eric , Driguez Hugues , Fort Sébastien 
Published: June 2015

AbstractA fast chemoenzymatic synthesis of sialylated oligosaccharides containing C5‐modified neuraminic acids is reported. Analogues of GM3 and GM2 ganglioside saccharidic portions where the acetyl group of NeuNAc has been replaced by a phenylacetyl (PhAc) or a propanoyl (Prop) moiety have been efficiently prepared with metabolically engineered E. coli bacteria. GM3 analogues were either obtained by chemoselective modification of biosynthetic N‐acetyl‐sialyllactoside (GM3NAc) or by direct bacterial synthesis using C5‐modified neuraminic acid precursors. The latter strategy proved to be very versatile as it led to an efficient synthesis of GM2 analogues. These glycomimetics were assessed against hemagglutinins and sialidases. In particular, the GM3NPhAc displayed a binding affinity for Maackia amurensis agglutinin (MAA) similar to that of GM3NAc, while being resistant to hydrolysis by Vibrio cholerae (VC) neuraminidase. A preliminary study with influenza viruses also confirmed a selective inhibition of N1 neuraminidase by GM3NPhAc, suggesting potential developments for the detection of flu viruses and for fighting them.
Chiral Bis(imidazolidine)‐Derived NCN Pincer Rh Complex for Catalytic Asymmetric Mannich Reaction of Malononitrile with N‐Boc Imines
Authors: Arai Takayoshi , Moribatake Takuma , Masu Hyuma 
Published: June 2015

AbstractChiral bis(imidazolidine)‐derived NCN–rhodium complexes ([PhBidine‐RhX2] and [tBu‐PhBidine‐RhX2]) were prepared by a CH insertion method, and the structures were unequivocally determined by X‐ray crystallographic analysis. The [tBu‐PhBidine‐Rh(OAc)2] complex smoothly catalyzed an asymmetric Mannich reaction of malononitrile with N‐Boc imines to give products in up to 94 % ee, which are useful for the synthesis of chiral α‐amino acids.
ChemInform Abstract: Ternary Aurides RE4Mg3Au10 (RE: Y, Nd, Sm, Gd—Dy) and Their Silver Analogues.
Authors: Block Theresa , Johnscher Michael , Linsinger Stefan , Rodewald Ute Ch. , Poettgen Rainer 
Published: June 2015

AbstractThe title compounds are prepared by induction melting of the elements in sealed Nb tubes (rapidly heating to about 1500 K, 1300 K for 30 min, and 900 K for 2 h).
ChemInform Abstract: The Equiatomic Intermetallics REPtCd (RE: La, Ce, Pr, Nd, Eu) and Magnetic Properties of CeAuCd.
Authors: Johnscher Michael , Tappe Frank , Niehaus Oliver , Poettgen Rainer 
Published: June 2015

AbstractThe title compounds are prepared by induction‐melting of the elements in sealed Nb ampules (1323 K for 3 h and 773 K for 4 d) and characterized by powder XRD.
ChemInform Abstract: Structural and Magnetic Properties of RTiNO2 (R: Ce, Pr, Nd) Perovskite Nitride Oxides.
Authors: Porter Spencer H. , Huang Zhenguo , Cheng Zhenxiang , Avdeev Maxim , Chen Zhixin , Dou Shixue , Woodward Patrick M. 
Published: June 2015

AbstractLnTiNO2 (Ln: Ce, Pr, Nd) phases are prepared by solid state ammonolysis of Ln2Ti2O7 precursors by repeated gaseous NH3 treatment during annealing (950 °C, 20 h).
ChemInform Abstract: The Crystal Structure of Sc5Co2In4.
Authors: Tyvanchuk Yuriy , Gulay Nataliya , Bigun Inna , Galadzhun Yaroslav , Kalychak Yaroslav 
Published: June 2015

AbstractThe new title compound is prepared by arc melting of the pure elements (annealing at 870 K for 2 months, yield given in g).
ChemInform Abstract: Quinine‐Derived Thiourea and Squaramide Catalyzed Conjugate Addition of α‐Nitrophosphonates to Enones: Asymmetric Synthesis of Quaternary α‐Aminophosphonates.
Authors: Bera Kalisankar , Namboothiri Irishi N. N. 
Published: June 2015

AbstractQuinine based thioureas and squaramides are investigated as catalysts for the asymmetric addition of nitrophosphonates to enones.
ChemInform Abstract: Organocatalytic Enantioselective Formal C(sp2)—H Alkylation.
Authors: Manna Madhu Sudan , Mukherjee Santanu 
Published: June 2015

AbstractThe alkylative desymmetrization of prochiral 2,2‐disubstituted cyclopentene‐1,3‐diones with nitroalkanes using a quinine‐derived chiral catalyst is described.
ChemInform Abstract: Organocatalytic Asymmetric Synthesis of 1,1‐Diarylethanes by Transfer Hydrogenation.
Authors: Wang Zhaobin , Ai Fujin , Wang Zheng , Zhao Wanxiang , Zhu Guangyu , Lin Zhenyang , Sun Jianwei 
Published: June 2015

AbstractA new organocatalytic transfer hydrogenation strategy for the efficient asymmetric synthesis of 1,1‐diarylethanes is given.
ChemInform Abstract: Hydrogenation of Unactivated Enamines to Tertiary Amines: Rhodium Complexes of Fluorinated Phosphines Give Marked Improvements in Catalytic Activity.
Authors: Tin Sergey , Fanjul Tamara , Clarke Matthew L 
Published: June 2015

AbstractThis method uses low catalyst loadings and is suitable for the hydrogenation of tetrasubstituted enamines.
ChemInform Abstract: Rhodium‐Catalyzed Direct C—H Allylation of N‐Sulfonyl Ketimines with Allyl Carbonates.
Authors: Mei Shu‐Tao , Wang Nan‐Jin , Ouyang Qin , Wei Ye 
Published: June 2015

AbstractAn efficient procedure is elaborated for the direct C—H allylation of imines (I) and different cyclic ketimines.
ChemInform Abstract: Copper(I) Iodide Catalyzed Synthesis of Primary Propargylic Alcohols from Terminal Alkyne.
Authors: Kundu Shrishnu Kumar , Mitra Kanchan , Majee Adinath 
Published: June 2015

AbstractThe title compounds (II) are highly efficient obtained by reaction of a variety of terminal alkynes with paraformaldehyde under mild reaction condition.
ChemInform Abstract: Synthesis of α,α‐Difluoro‐β‐amino Carbonyl‐Containing Sulfonamides and Related Compounds.
Authors: Xie Chen , Wu Lingmin , Zhou Jie , Mei Haibo , Soloshonok Vadim A. , Han Jianlin , Pan Yi 
Published: June 2015

AbstractMannich addition reactions between in situ generated α,α‐difluoroenolates and various N‐sulfonyl imines readily occur with exceptionally high reaction rates at ambient temperature.
ChemInform Abstract: Chiral Phosphine‐Phosphoramidite Ligands for Highly Enantioselective Hydrogenation of N‐Arylimines.
Authors: Li Qing , Hou Chuan‐Jin , Liu Xiao‐Ning , Huang De‐Zhi , Liu Yan‐Jun , Yang Rui‐Feng , Hu Xiang‐Ping 
Published: June 2015

AbstractThe highly enantioselective asymmetric hydrogenation of N‐arylamines using chiral phosphine‐phosphoramidite ligands is demonstrated.
ChemInform Abstract: Palladium‐Catalyzed Oxidative C—C Bond Cleavage of α‐Hydroxyketones: Application to C—H Acylation of Azoarenes and Synthesis of a Liver(X) Receptor Agonist.
Authors: Majhi Biju , Ahammed Sabir , Kundu Debasish , Ranu Brindaban C. 
Published: June 2015

AbstractPalladium‐catalyzed oxidative C—C cleavage of α‐hydroxyketones and 2‐aryl acetophenones in the presence of tert‐butyl hydrogen peroxide generates an acyl moiety, which promotes subsequent regioselective C—H acylation producing a series of ortho‐acyl substituted symmetrical and unsymmetrical azoarenes.
ChemInform Abstract: Dual‐Immobilized Copper Catalyst: Carbon Nitride‐Supported Copper Nanoparticles Catalyzed Oxidation of Propargylic Alcohols.
Authors: Lv Wei , Tian Jing , Deng Nan , Wang Yan , Zhu Xiaoshu , Yao Xiaoquan 
Published: June 2015

AbstractThe corresponding catalyst can be effectively recovered at least for three times without any decrease in the catalytic activity.
ChemInform Abstract: Ir‐Catalyzed Arylation, Alkylation of Quinones with Boronic Acids Through C—C Coupling.
Authors: Wang Dawei , Ge Bingyang , Ju Anqi , Zhou Yucheng , Xu Chongying , Ding Yuqiang 
Published: June 2015

AbstractThe utility of this method is demonstrated in the synthesis of β‐secretase 1 inhibitor (VIIa).
ChemInform Abstract: Direct Enantioselective Conjugate Addition of Carboxylic Acids with Chiral Lithium Amides as Traceless Auxiliaries.
Authors: Lu Ping , Jackson Jeffrey J. , Eickhoff John A. , Zakarian Armen 
Published: June 2015

AbstractA broad spectrum of carboxylic acids can be successfully added to α,β‐unsaturated esters after functionalization with optically active auxiliaries of type CPA‐1 and CPA‐2.
ChemInform Abstract: Generation and Trapping of Ketenes in Flow.
Authors: Henry Cyril , Bolien David , Ibanescu Bogdan , Bloodworth Sally , Harrowven David C. , Zhang Xunli , Craven Andy , Sneddon Helen F. , Whitby Richard J. 
Published: June 2015

AbstractKetenes are generated in situ by thermolysis of ethoxyalkynes under flow conditions and trapped with amines or alcohols to form amides and esters respectively.
ChemInform Abstract: Thioboration of α,β‐Unsaturated Ketones and Aldehydes Toward the Synthesis of β‐Sulfido Carbonyl Compounds.
Authors: Civit Marc G. , Sanz Xavier , Vogels Christopher M. , Webb Jonathan D. , Geier Stephen J. , Decken Andreas , Bo Carles , Westcott Stephen A. , Fernandez Elena 
Published: June 2015

AbstractThe synthesis of β‐thio substituted carbonyl compounds is achieved by uncatalyzed reaction of α,β‐unsaturated carbonyl compounds with thiodioxaborolanes under mild reaction conditions.
ChemInform Abstract: N‐Heterocyclic Carbene‐Catalyzed Enantioselective Annulations: A Dual Activation Strategy for a Formal [4 + 2] Addition for Dihydrocoumarins.
Authors: Lee Anna , Scheidt Karl A. 
Published: June 2015

AbstractThe first general method for a highly efficient asymmetric annulation is presented that furnishes substituted dihydrocoumarins from simple precursors.
ChemInform Abstract: Synthesis of Pyrrolidine Derivatives by a Platinum/Broensted Acid Relay Catalytic Cascade Reaction.
Authors: Galvan Alicia , Calleja Jonas , Fananas Francisco J. , Rodriguez Felix 
Published: June 2015

AbstractVarious N‐Boc protected alkynamine substrates are treated with appropriate simple alkenes or alkynes and silane analogues (XIV) and (XVI).
ChemInform Abstract: P‐Stereogenic PNP Pincer‐Pd Catalyzed Intramolecular Hydroamination of Amino‐1,3‐dienes.
Authors: Yang Zehua , Xia Chao , Liu Delong , Liu Yangang , Sugiya Masashi , Imamoto Tsuneo , Zhang Wanbin 
Published: June 2015

AbstractAllyl‐type chiral pyrrolidine derivatives are efficiently synthesized by asymmetric intramolecular hydroamination of amino‐1,3‐dienes with excellent regioselectivities and up to moderate enantioselectivities.
ChemInform Abstract: Further Exploration of the Heterocyclic Diversity Accessible from the Allylation Chemistry of Indigo.
Authors: Shakoori Alireza , Bremner John B , Abdel‐Hamid Mohammed K , Willis Anthony C. , Haritakun Rachada , Keller Paul A 
Published: June 2015

AbstractDepending only on reaction time diverse indigo‐derived heterocycles are accessible.
ChemInform Abstract: Regioselective Catalytic Asymmetric C‐Alkylation of Isoxazolinones by a Base‐Free Palladacycle‐Catalyzed Direct 1,4‐Addition.
Authors: Hellmuth Tina , Frey Wolfgang , Peters Rene 
Published: June 2015

AbstractThe first examples of enantioselective C‐alkylations of isoxazolinones to give all‐carbon quarternary centers are reported using a planar chiral palladacycle catalyst.
ChemInform Abstract: Direct Arylation of Sydnones with Aryl Chlorides Toward Highly Substituted Pyrazoles.
Authors: Brown Andrew W. , Harrity Joseph P. A. 
Published: June 2015

AbstractThe direct Pd‐catalyzed arylation of C‐4 unsubstituted sydnones by using aryl chlorides and bromides as coupling partners is developed.
ChemInform Abstract: A Novel Prins Cascade Process for the Stereoselective Synthesis of Oxa‐bicycles.
Authors: Subba Reddy B. V. , Venkateswarlu A. , Sridevi B. , Marumudi Kanakaraju , Kunwar A. C. , Gayatri G. 
Published: June 2015

AbstractUnder extremely mild reaction conditions, E‐ and Z‐9‐methyldeca3,8‐dien‐1‐ols (I), (IV) undergo cyclization reactions with various aromatic aldehydes leading to the corresponding oxa‐bicycles with excellent selectivity.
ChemInform Abstract: Unprotected Xylose‐Derived Nitrone in Stereodivergent Synthesis of 4‐Hydroxypiperidine Enantiomers: Weak Lewis Acid Induced Alteration of Stereochemistry in 1,3‐Dipolar Cycloaddition.
Authors: Rowicki Tomasz , Malinowski Maciej , Gryszel Maciej , Czerwinska Karolina , Madura Izabela , Mironiuk‐Puchalska Ewa , Koszytkowska‐Stawinska Mariola , Sas Wojciech 
Published: June 2015

AbstractThe two‐step synthesis of chiral bicyclic products (III) and (IV) involves the conversion of substrate (I) into the corresponding hydroxylamine followed by in situ formation of a chiral nitrone and intramolecular 1,3‐dipolar cycloaddition.
ChemInform Abstract: Synthesis of 4‐Substituted Oxazolo[4,5‐c]quinolines by Direct Reaction at the C‐4 Position of Oxazoles.
Authors: Akula Mahesh , Thigulla Yadagiri , Davis Connor , Jha Mukund , Bhattacharya Anupam 
Published: June 2015

AbstractThe title compounds (III) are obtained by a modified Pictet‐Spengler method without the aid of any prefunctionalization.
ChemInform Abstract: Diastereodivergent Pictet—Spengler Cyclization of Bicyclic N‐Acyliminium Ions: Controlling a Quaternary Stereocenter.
Authors: de Carne‐Carnavalet Benoit , Krieger Jean‐Philippe , Folleas Benoit , Brayer Jean‐Louis , Demoute Jean‐Pierre , Meyer Christophe , Cossy Janine 
Published: June 2015

AbstractThe diastereoselectivity of the Pictet—Spengler cyclization of bicyclic N‐acyliminium ions that contain a 3‐azabicyclo[n.3.0]alkane core and an electron‐rich π‐nucleophilic moiety, such as an indol‐2‐yl, indol‐3‐yl, 1‐methylpyrrol‐2‐yl, or 3,5‐dimethoxyphenyl group, is examined.
ChemInform Abstract: Copper‐Catalyzed Aerobic C—H Trifluoromethylation of Phenanthrolines.
Authors: Zhu Cheng‐Liang , Zhang Yong‐Qiang , Yuan Yong‐An , Xu Hao 
Published: June 2015

AbstractDepending on the substituents of the phenanthroline the trifluoromethylation proceeds regioselectively or provides a mixture of regioisomers [cf.
ChemInform Abstract: Cyclization Cascades via N‐Amidyl Radicals Toward Highly Functionalized Heterocyclic Scaffolds.
Authors: Fuentes Noelia , Kong Wangqing , Fernandez‐Sanchez Luis , Merino Estibaliz , Nevado Cristina 
Published: June 2015

AbstractA variety of N‐(arylsulfonyl)acrylamides are used as substrates for the title reactions.
ChemInform Abstract: Copper(I) Iodide Catalyzed Synthesis of Fused Hexacyclic Pyrazolo[4,5,1‐de]quinolino[4,3,2‐mn]acridin‐14(11H)‐ones under Ligand‐Free Conditions.
Authors: Zhang Wen‐Ting , Chen Dong‐Sheng , Li Chao , Wang Xiang‐Shan 
Published: June 2015

AbstractThe synthesis is based on a one‐pot three component reaction of 2‐halogenated benzaldehydes, 1H‐indazol‐6‐amines and cyclohexane‐1,3‐diones.
ChemInform Abstract: An Efficient Iodine—DMSO Catalyzed Synthesis of Quinoxaline Derivatives.
Authors: Xie Caixia , Zhang Zeyuan , Yang Bingchuan , Song Gaolei , Gao He , Wen Leilin , Ma Chen 
Published: June 2015

AbstractVarious quinoxaline systems are obtained by a one‐pot, two‐step oxidation/cyclization sequence.
ChemInform Abstract: Facile Synthesis of Pyrazolo[1,5‐a]pyridopyrazin‐one via Smiles Rearrangement or Direct Cyclization.
Authors: Xiao Youxin , Zhang Zhicheng , Chen Yinbo , Shao Xusheng , Li Zhong , Xu Xiaoyong 
Published: June 2015

AbstractVarious biaryl lactams are conveniently obtained starting from readily available precursors.
ChemInform Abstract: Organocatalyzed Beckmann Rearrangement of Cyclohexanone Oxime in a Microchemical System.
Authors: Zhang Jisong , Dong Chen , Du Chencan , Luo Guangsheng 
Published: June 2015

Abstractε‐caprolactam (II) is obtained from cyclohexanone oxime (I) using trifluoroacetic acid as catalyst under optimized reaction conditions.
ChemInform Abstract: Three Scandium Compounds with Unsaturated Coordinative Metal Sites — Structures and Catalysis.
Authors: Zhang Liying , Wang Li , Wang PengCheng , Song Tianyou , Li Da , Chen Xiaobo , Fan Yong , Xu Jianing 
Published: June 2015

AbstractThree newly synthesized organo‐scandium compounds are tested as catalysts for the cyanosilylation of aromatic aldehydes.
ChemInform Abstract: Steroidal Alkaloids from Veratrum dahuricum (Turcz.) Loes. f. with Genotoxicity on Brain Cell DNA in Mice.
Authors: Cong Yue , Li Jing , Zhang Qing‐Chun , Guo Jing‐Gong , Li Sha‐Sha 
Published: June 2015

AbstractTwo new steroidal alkaloids (I), (II) are isolated together with four known compounds.
ChemInform Abstract: Aza‐Polycyclic Aromatic Hydrocarbons from Saruma henryi.
Authors: Ma Yangmin , Jia Qiangqiang , Wang Pengfei , Cheng Xiaowei , Kang Yongxiang 
Published: June 2015

AbstractA new azafluoranthene alkaloid, sarumine (I), is isolated along with six known N‐containing derivatives of phenanthrenes from the whole herb of Saruma henryi.
ChemInform Abstract: Gallic Acid: Prospects and Molecular Mechanisms of Its Anticancer Activity
Authors: Subramanian A. P. , John A. A. , Vellayappan M. V. , Balaji A. , Jaganathan S. K. , Supriyanto Eko , Yusof Mustafa 
Published: June 2015

AbstractReview: 95 refs.
ChemInform Abstract: Recent Advances in New Generation Dye Removal Technologies: Novel Search for Approaches to Reprocess Wastewater
Authors: Ahmad Akil , Mohd‐Setapar Siti Hamidah , Chuong Chuo Sing , Khatoon Asma , Wani Waseem A. , Kumar Rajeev , Rafatullah Mohd 
Published: June 2015

AbstractReview: 177 refs.
nido‐Dicarbaborate Induces Potent and Selective Inhibition of Cyclooxygenase‐2
Authors: Neumann Wilma , Xu Shu , Sárosi Menyhárt B. , Scholz Matthias S. , Crews Brenda C. , Ghebreselasie Kebreab , Banerjee Surajit , Marnett Lawrence J. , Hey‐Hawkins Evamarie 
Published: June 2015

AbstractCarbaboranes are increasingly studied as pharmacophores, particularly as replacements for aromatic systems. However, especially ortho‐carbaborane is prone to degradation of the cluster, which hampers biological application. This study demonstrates that deboronation of the cluster may not only lead to a more active analogue, but can also improve the solubility and stability of a carbaborane‐containing inhibitor. Notably, introduction of a nido‐dicarbaborate cluster into the cyclooxygenase (COX) inhibitor indomethacin results in remarkably increased inhibitory potency and selectivity for COX‐2 relative to the respective phenyl analogue. The first crystal structure of a carbaborane‐containing inhibitor bound to COX‐2 further reveals a novel binding mode for the inhibitor that is strikingly different from that of indomethacin. These results indicate that nido‐dicarbaborate is a promising pharmacophore that exhibits properties which are also highly beneficial for its introduction into other inhibitor classes.
Latest Developments in Metalloenzyme Design and Repurposing
Authors: Heinisch Tillmann , Ward Thomas R. 
Published: June 2015

AbstractIn the past decade, artificial metalloenzymes (AMEs) have emerged as attractive alternatives to more traditional homogeneous catalysts and enzymes. This microreview presents a selection of recent achievements in the design of such hybrid catalysts. These include artificial zinc hydrolases and metathesases, the heme‐protein repurposing for C–H, N–H, and S–H insertion reactions, novel light‐driven redox hybrid catalysts, novel scaffold proteins, and metallocofactor anchoring techniques and metalloenzyme models.
Scalable Enantioselective Synthesis of Fmoc‐β2‐Serine and Fmoc‐β2‐Threonine by an Organocatalytic Mannich Reaction
Authors: Meyer Daniel , Marti Roger , Seebach Dieter 
Published: June 2015

AbstractThe diastereoselective Mannich reaction of functionalized aldehydes, using a phenethylamine‐derived iminium precursor, by activation with prolines and prolinol derivatives have been studied. Optimized reaction conditions have been developed, allowing for scale‐up and preparation of γ‐amino alcohol derivatives on multi‐gram scale from β‐hydroxypropanal and ‐butanal, with diastereoselectivites of typically >73:27 and yields of >60 %. After chromatographic diastereoisomer separation, hydrogenolytic debenzylation, enantiomerically pure Fmoc‐β2‐Ser(tBu)‐OH and Fmoc‐β2‐Thr(tBu)‐OH were thus prepared on multi‐gram scale in 6 steps and with overall yields of 24 % and 10 %, respectively, starting from commercially available starting compounds.
Hyperoxia promotes polarization of the immune response in ovalbumin‐induced airway inflammation, leading to a TH17 cell phenotype
Authors: Nagato Akinori C. , Bezerra Frank S. , Talvani André , Aarestrup Beatriz J. , Aarestrup Fernando M. 
Published: June 2015

AbstractPrevious studies have demonstrated that hyperoxia‐induced stress and oxidative damage to the lungs of mice lead to an increase in IL‐6, TNF‐α, and TGF‐β expression. Together, IL‐6 and TGF‐β have been known to direct T cell differentiation toward the TH17 phenotype. In the current study, we tested the hypothesis that hyperoxia promotes the polarization of T cells to the TH17 cell phenotype in response to ovalbumin‐induced acute airway inflammation. Airway inflammation was induced in female BALB/c mice by intraperitoneal sensitization and intranasal introduction of ovalbumin, followed by challenge methacholine. After the methacholine challenge, animals were exposed to hyperoxic conditions in an inhalation chamber for 24 h. The controls were subjected to normoxia or aluminum hydroxide dissolved in phosphate buffered saline. After 24 h of hyperoxia, the number of macrophages and lymphocytes decreased in animals with ovalbumin‐induced airway inflammation, whereas the number of neutrophils increased after ovalbumin‐induced airway inflammation. The results showed that expression of Nrf2, iNOS, T‐bet and IL‐17 increased after 24 of hyperoxia in both alveolar macrophages and in lung epithelial cells, compared with both animals that remained in room air, and animals with ovalbumin‐induced airway inflammation. Hyperoxia alone without the induction of airway inflammation lead to increased levels of TNF‐α and CCL5, whereas hyperoxia after inflammation lead to decreased CCL2 levels. Histological evidence of extravasation of inflammatory cells into the perivascular and peribronchial regions of the lungs was observed after pulmonary inflammation and hyperoxia. Hyperoxia promotes polarization of the immune response toward the TH17 phenotype, resulting in tissue damage associated with oxidative stress, and the migration of neutrophils to the lung and airways. Elucidating the effect of hyperoxia on ovalbumin‐induced acute airway inflammation is relevant to preventing or treating asthmatic patients that require oxygen supplementation to reverse the hypoxemia.