bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Abnormal and Direct para‐Trifluoroacetylation of Branched Alkyl Phenyl Ketones by Magnesium‐Promoted Reductive Aromatic Substitution.
Authors: Maekawa Hirofumi , Ozaki Taro , Zulkeflee Dayana , Murakami Taro , Kihara Shin , Nishiguchi Ikuzo 
Published: May 2012

AbstractA simple two‐step sequence allows the conversion of phenyl ketones into p‐trifluoroacetyl derivatives via cross‐coupling with ester (II) followed by desilylation of the mixed acetals.
ChemInform Abstract: Palladium‐Catalyzed Carbonylative α‐Arylation for Accessing 1,3‐Diketones.
Authors: Goegsig Thomas M. , Taaning Rolf H. , Lindhardt Anders T. , Skrydstrup Troels 
Published: May 2012

AbstractThe reactions are carried out in a two‐chamber reactor with “ex situ” generation of CO from 9‐methyl‐9H‐fluorene‐9‐carbonyl chloride in one chamber.
ChemInform Abstract: Direct Synthesis of α‐Amino Amides from N‐Alkyl Amines by the Copper‐Catalyzed Oxidative Ugi‐Type Reaction.
Authors: Ye Xin , Xie Chunsong , Huang Rui , Liu Jinhua 
Published: May 2012

AbstractTh novel synthesis of the structurally important units of biologically active compounds from methyl amines and isocyanides allows the presence of various functional groups.
ChemInform Abstract: Pd(OAc)2‐Catalyzed Carbonylative Coupling of Aryl Iodide with ortho‐Haloamines in Water.
Authors: Tambade Pawan J. , Patil Yogesh P. , Qureshi Ziyauddin S. , Dhake Kishor P. , Bhanage Bhalchandra M. 
Published: May 2012

AbstractOptimized conditions allow the synthesis of a broad spectrum of o‐haloanilides which are difficult to prepare by conventional methods.
ChemInform Abstract: Regio‐ and Stereoselective Carbobismuthination of Alkynes.
Authors: Nishimoto Yoshihiro , Takeuchi Midori , Yasuda Makoto , Baba Akio 
Published: May 2012

AbstractThe simple reaction of a terminal alkyne, BiBr3, and a ketene silyl acetal affords alkenylbismuth dibromides with high stereo‐ and regioselectivity.
ChemInform Abstract: Palladium‐Catalyzed Regioselective Arylation of Arene C—H Bond Assisted by the Removable 2‐Pyridylsulfinyl Group.
Authors: Zhang Xunbin , Yu Ming , Yao Jinzhong , Zhang Yuhong 
Published: May 2012

AbstractIn most cases, the method allows the preparation of one regioisomeric biaryl derivative.
ChemInform Abstract: Suzuki—Miyaura Cross‐Couplings of Arenediazonium Tetrafluoroborate Salts with Arylboronic Acids Catalyzed by Aluminum Hydroxide Supported Palladium Nanoparticles.
Authors: Li Xing , Yan Xu‐Ying , Chang Hong‐Hong , Wang Li‐Chao , Zhang Yan , Chen Wen‐Wen , Li Yan‐Wei , Wei Wen‐Long 
Published: May 2012

AbstractAn efficient and general protocol for Suzuki—Miyaura cross coupling of arene diazonium salts (I) with arylboronic acids (II) and (IV) using Pd nanoparticles stabilized in aluminum hydroxide is presented.
ChemInform Abstract: Direct Vinylogous Aldol Reaction Triggered by Tetrabutylammonium Fluoride: A Highly Regioselective and Diastereoselective Addition of Cyclic β‐Haloenals to Aromatic Aldehydes.
Authors: Zhang Jingli , Gu Lianghu , Gong Yuefa 
Published: May 2012

AbstractOptimized mild conditions produce the corresponding syn‐adducts predominantly.
ChemInform Abstract: SIAPhos: Phosphorylated Sulfonimidamides and Their Use in Iridium‐Catalyzed Asymmetric Hydrogenations of Sterically Hindered Cyclic Enamides.
Authors: Patureau Frederic W. , Worch Christin , Siegler Maxime A. , Spek Anthony L. , Bolm Carsten , Reek Joost N. H. 
Published: May 2012

AbstractIon exchange of ligands such as (I) with Ir or Rh complexes generates the neutral complexes with P—N—S—N chelates.
ChemInform Abstract: Synthesis, Characterization, and Hypoglycemic Activity of 3‐(Arylsulfonyl)spiroimidazolidine‐2,4‐diones.
Authors: Iqbal Zafar , Akhtar Tashfeen , Hendsbee Arthur D. , Masuda Jason D. , Hameed Shahid 
Published: May 2012

AbstractKey intermediates like (III) are prepared according to Bucherer—Bergs reaction and are subsequently sulfonylated following the classical pathway.
ChemInform Abstract: Catalytic Diastereoselective Reduction of α,β‐Epoxy and α,β‐Aziridinyl Ynones.
Authors: Druais Valerie , Meyer Christophe , Cossy Janine 
Published: May 2012

AbstractIn the presence of (I) or its enantiomer, the corresponding propargylic alcohols can be obtained with high diastereoselectivity.
ChemInform Abstract: Asymmetric Michael Addition Reactions of 3‐Substituted Benzofuran‐2(3H)‐ones to Nitroolefins Catalyzed by a Bifunctional Tertiary‐Amine Thiourea.
Authors: Li Xin , Xue Xiao‐Song , Liu Cong , Wang Bin , Tan Bo‐Xuan , Jin Jia‐Lu , Zhang Yue‐Yan , Dong Nan , Cheng Jin‐Pei 
Published: May 2012

AbstractMichael reaction of a variety of 3‐substituted benzofuranones with β‐nitroolefins proceeds efficiently in the presence of a tertiary amine—thiourea organocatalyst to give benzofuranones bearing an all‐carbon quaternary stereocenter at position 3.
ChemInform Abstract: Rapid Consecutive Three‐Component Coupling‐Fiesselmann Synthesis of Luminescent 2,4‐Disubstituted Thiophenes and Oligothiophenes.
Authors: Teiber Marco , Mueller Thomas J. J. 
Published: May 2012

AbstractThe modified Sonogashira coupling of aroyl chlorides (I) with alkynes (II) followed by Fiesselmann cyclocondensation of resulting alkynones with mercaptoacetate (III) leads to trisubstituted thiophenes (IV).
ChemInform Abstract: Rational and Practical Synthesis of α,α‐Difluoro‐γ‐lactams.
Authors: Li Bin‐Hui , Li Ke‐Lai , Chen Qing‐Yun 
Published: May 2012

AbstractSubstrate (I) reacts with alkenes in the presence of NaHCO3 to produce the addition products (III) which can be cyclized by NaOH.
ChemInform Abstract: Synthesis of Propargylic and Allenic Carbamates via the C—H Amination of Alkynes.
Authors: Grigg R. David , Rigoli Jared W. , Pearce Simon D. , Schomaker Jennifer M. 
Published: May 2012

AbstractPropargylic carbamates are obtained via C—H amination of the starting homopropargylic substrates using a hypervalent iodonium oxidant and a Rh complex as a catalyst.
ChemInform Abstract: Quick and Highly Efficient Copper‐Catalyzed Cycloaddition of Organic Azides with Terminal Alkynes.
Authors: Wang Dong , Zhao Mingming , Liu Xiang , Chen Yongxin , Li Na , Chen Baohua 
Published: May 2012

AbstractA variety of disubstituted triazoles is efficiently obtained by azide—alkyne cycloaddition under solvent‐free conditions by use of [Cu(phen)(PPh3)2]NO3 as catalyst.
ChemInform Abstract: Scope and Regioselectivity of the 1,3‐Dipolar Cycloaddition of Azides with Methyl 2‐Perfluoroalkynoates for an Easy, Metal‐Free Route to Perfluoroalkylated 1,2,3‐Triazoles.
Authors: Wei Jiamei , Chen Jie , Xu Jiechao , Cao Long , Deng Hongmei , Sheng Weihua , Zhang Hui , Cao Weiguo 
Published: May 2012

AbstractThe reaction of the process is controlled by frontier molecular orbitals and steric hindrance in the transition states (24 examples).
ChemInform Abstract: Studies on the Synthesis and Antibacterial Activity of 3,6‐Disubstituted 1,2,4‐Triazolo[3,4‐b]1,3,4‐thiadiazoles.
Authors: Plech Tomasz , Wujec Monika , Kosikowska Urszula , Malm Anna , Kapron Barbara 
Published: May 2012

AbstractHeating of aminotriazoles (I), obtained by conventional procedures, with halophenyl isothiocyanates (II) in the environment of anhydrous dimethylformamide yields the 3,6‐disubstituted triazolothiadiazoles (III).
ChemInform Abstract: Synthesis of 1H,7H,12bH‐Pyrano[3′,4′:5,6]pyrano[3,4‐c][1]benzopyran‐1‐one via Domino Knoevenagel/Hetero‐Diels—Alder Reaction with Theoretical Investigations.
Authors: Khoshkholgh Malihe Javan , Hosseindokht Mohammad Reza , Balalaie Saeed , Bozorgmehr Mohammad Reza , Bijanzadeh Hamid Reza 
Published: May 2012

AbstractThe Cu(I)‐catalyzed cycloaddition of ortho‐propynyloxybenzaldehydes (I) with the pyranone (II) constitutes an efficient synthesis of the title compounds (III).
ChemInform Abstract: Domino Reactions of 2‐Methyl Chromones Containing an Electron Withdrawing Group with Chromone‐Fused Dienes.
Authors: Gong Jian , Xie Fuchun , Ren Wenming , Chen Hong , Hu Youhong 
Published: May 2012

AbstractCascade reaction of methylchromones bearing an electron‐withdrawing group at position 3, e.g. (I), (VI) or (VIII), with chromone‐derived dienes (II) or (IV) provides access to varying types of polycyclic compounds, e.g. (III), (V), (VII) or (IX), depending on the nature of electron‐withdrawing group and of the diene used.
ChemInform Abstract: One‐Pot Synthesis of 3,4‐Disubstituted Coumarins under Catalysis of Mn3O4 Nanoparticles.
Authors: Sun Huayin , Zhang Yonghui , Guo Fengfeng , Yan Yizhe , Wan Changfeng , Zha Zhenggen , Wang Zhiyong 
Published: May 2012

AbstractMn3O4‐catalyzed reaction of hydroxymethylphenols (I) with β‐keto esters (II) and (IV) provides access towards disubstituted coumarins in moderate yields.
ChemInform Abstract: Manganese Perchlorate‐Catalyzed Greener Synthesis of 12‐Aryl‐ or 12‐Alkyl‐8,9,10,12‐tetrahydrobenzo[α]xanthen‐11‐one Derivatives under Ultrasonication.
Authors: Kaur Bhupinder , Parmar Anupama , Kumar Harish 
Published: May 2012

AbstractThe reaction is carried out under environmentally benign conditions.
ChemInform Abstract: Combining Two‐Directional Synthesis and Tandem Reactions. Part 17. Expedient Formation of Functionalized Azabicycles.
Authors: Aggarwal Pooja , Procopiou George , Robbins Diane , Harbottle Gareth , Lewis William , Stockman Robert A. 
Published: May 2012

AbstractThe TiCl4‐mediated reaction of ketones (I) and (IV) with primary amines involves an enamine formation/Michael addition/aza‐Michael addition sequence to give diastereomeric mixtures of azabicycles.
ChemInform Abstract: A Novel and Efficient Synthesis of Pyrido[1,2‐a]‐Fused 1,3‐Diazaheterocyclic Compounds via a One‐Pot Three‐Component Reaction.
Authors: Alizadeh Abdolali , Rezvanian Atieh 
Published: May 2012

AbstractThe simple method allows the preparation of the biologically important heterocyclic systems within a short time.
ChemInform Abstract: Tandem Regio‐ and Stereospecific Cyclization of Ethyl Isonicotinate with Cyanoacetylenic Alcohols to Provide Novel Polycondensed Heterocyclic Systems.
Authors: Trofimov Boris A. , Mal'kina Anastasiya G. , Nosyreva Valentina V. , Shemyakina Olesya A. , Albanov Alexander I. , Afonin Andrei V. , Kazheva Olga N. , Alexandrov Grigorri G. , Dyachenko Oleg A. 
Published: May 2012

AbstractThe reaction produces 1,3‐oxazolidino‐1,2‐dihydropyridine intermediates which undergo Diels—Alder cyclodimerization to give the polycyclic heterocycles (III).
ChemInform Abstract: A Facile Synthesis of 5‐Halopyridine‐4‐carboxylic Acid Esters via a Minisci Reaction.
Authors: Regan Collin F. , Pierre Fabrice , Schwaebe Michael K. , Haddach Mustapha , Jung Michael E. , Ryckman David M. 
Published: May 2012

AbstractA convenient one‐pot procedure is developed for the synthesis of the title compounds, where ester (II) is found to be optimal for the process.
ChemInform Abstract: A Chemoselective Hydroxymethylation: New Route for the Synthesis of 6‐Aroyl‐4‐(4H‐triazol‐3‐yl)thiomorpholin‐3‐ones.
Authors: Krishnaraj Thulasiraman , Muthusubramanian Shanmugam 
Published: May 2012

AbstractReaction of triazolyl‐substituted amides with paraformaldehyde generates hydroxymethyl intermediates which undergo direct cyclization to pharmacologically important thiomorpholinones in fair yields.
ChemInform Abstract: Reactions of 1,3,5‐Triazinylnitroformaldoxime. Part 4. Synthesis of (5‐R‐1,2,4‐Oxadiazol‐3‐yl)‐1,3,5‐triazines.
Authors: Bakharev V. V. , Gidaspov A. A. , Selezneva E. V. , Parfenov V. E. , Ul'yankina I. V. , Nazarova I. S. , Palatova Yu. T. , El'tsov O. S. 
Published: May 2012

AbstractTitle compounds (V) and (VII) are obtained from nitroformaldoximes (I) in a three‐step procedure involving amination and O‐acylation of the oxime followed by acid‐mediated cyclization.
ChemInform Abstract: Gold(I)‐Catalyzed Stereoselective Synthesis of Alkenyl Phosphates by Hydrophosphoryloxylation.
Authors: Nun Pierrick , Egbert Jonathan D. , Oliva‐Madrid Maria‐Jose , Nolan Steven P. 
Published: May 2012

AbstractTitle hydrophosphoryloxylation of alkynes proceeds smoothly in the presence of low amounts of gold catalyst (0.01—1 mol%) to selectively afford the kinetic enol phosphates (III), (V), (VII).
ChemInform Abstract: Asymmetric α‐2‐Tosylethenylation of N,N‐Dialkyl‐L‐amino Acid Esters via the Formation of Non‐Racemic Ammonium Enolates.
Authors: Tayama Eiji , Igarashi Tomohito , Iwamoto Hajime , Hasegawa Eietsu 
Published: May 2012

AbstractTitle tosylethenylation of pyrrolidinyl‐protected L‐amino acid esters (I) and (IV) proceeds with moderate to high enantioselectivity (up to 96% e.e.).
ChemInform Abstract: Bi‐Component Semiconductor Oxide Photoanodes for the Photoelectrocatalytic Oxidation of Organic Solutes and Vapors: A Short Review with Emphasis to TiO2‐WO3 Photoanodes
Authors: Georgieva J. , Valova E. , Armyanov S. , Philippidis N. , Poulios I. , Sotiropoulos S. 
Published: May 2012

AbstractReview: 224 refs.
Development of a chiral stationary phase based on cinchonidine. Comparison with a quinine‐based chiral column
Authors: Keunchkarian Sonia , Grisales Jaiver Osorio , Padró Juan M. , Boeris Susana , Castells Cecilia B. 
Published: May 2012

AbstractA chiral anion‐exchanger stationary phase based on cinchonidine (CD) was developed. Two columns were packed with and without endcapping (EC) treatment (CD‐chiral stationary phase[CD‐CSP(EC)] and [CD‐CSP], respectively) and studied for their ability to separate N‐2,4‐dinitrophenyl α‐amino acids (DNP‐amino acids) enantiomers over a temperature range of 10–40 °C with a hydro‐organic buffer mobile phase. The more hydrophobic, endcapped stationary phase showed significantly larger retentive capacity than the non‐endcapped one. The apparent thermodynamic transfer parameters of the enantiomers from the mobile to both CSPs were estimated from van't Hoff plots within the cited temperature range. Similar studies with two natural quinine‐based columns (QN‐CSP and QN‐CSP(EC)) were previously reported. In this work, a critical comparison in the chiral recognition ability to DNP‐amino acids of these cinchonidine and QN‐based chiral columns was drawn. It has been found that QN‐based CSPs show greater chiral recognition capability towards these derivatives than CD‐CSPs. The influence of the QN methoxy group on the equilibrium constants of the enantioselective interaction between these DNP‐amino acids with these two cinchona CSPs could be assessed. Chirality 24:512–518, 2012. © 2012 Wiley Periodicals, Inc.
Synthesis of atropisomeric 1‐phenylpyrrole‐derived amino alcohols: New chiral ligands
Authors: Faigl Ferenc , Mátravölgyi Béla , Szöllősy Áron , Czugler Mátyás , Tárkányi Gábor , Vékey Károly , Kubinyi Miklós 
Published: May 2012

AbstractAn efficient synthetic method has been developed for the preparation of a new family of atropisomeric amino alcohols with 1‐phenylpyrrole backbone. The synthesis is based on the different reactivities of the two carboxylic groups in optically active 1‐[2‐carboxy‐6‐(trifluoromethyl)phenyl]‐1H‐pyrrole‐2‐carboxylic acid (1). The chemical structures of the key intermediates were confirmed by spectroscopic methods and single crystal X‐ray diffraction measurements. The very first application of a new optically active amino alcohol as catalyst for the enantioselective addition of diethylzinc to benzaldehyde demonstrated the practical usefulness of atropisomeric compounds in which there are six‐atom chains between the two functional groups. Chirality 24:532–542, 2012. © 2012 Wiley Periodicals, Inc.
Stepwise cumulation of RUNX3 methylation mediated by Helicobacter pylori infection contributes to gastric carcinoma progression
Authors: Lu Xiao‐Xiao , Yu Jiang‐Liu , Ying Li‐Sha , Han Jing , Wang Shi , Yu Qi‐Ming , Wang Xin‐Bao , Fang Xian‐Hua , Ling Zhi‐Qiang 
Published: May 2012

AbstractBACKGROUND:Helicobacter pylori has been recognized as a definite carcinogen for gastric cancer (GC); however, the pathogenesis of H. pylori infection remains unclear. Runt‐related transcription factor 3 (RUNX3) is a candidate tumor suppressor gene whose deficiency is causally related to GC. However, in H. pylori infection‐associated GC, the role of RUNX3 has not been studied.METHODS:The authors used real‐time methylation‐specific polymerase chain reaction analysis to determine methylation status of the RUNX3 promoter in a spectrum of gastric lesions, including 220 samples of chronic atrophic gastritis, 196 samples of intestinal metaplasia, 134 samples of gastric adenoma, 102 samples of dysplasia, and 202 samples of GC with paired noncancerous mucosa tissues and corresponding blood specimens. The association of abnormal methylation with precancerous gastric lesions was evaluated along with the association between RUNX3 methylation and H. pylori infection, and the concordance of methylation levels was investigated between serum and tissues.RESULTS:The results indicated that increasing RUNX3 promoter methylation was correlated with distinct stages of GC progression. GC tissues had the highest methylation proportion (75.2%) compared with precancerous gastric lesions, including chronic atrophic gastritis (15.9%), intestinal metaplasia (36.7%), gastric adenoma (41.8%), and dysplasia (54.9%). H. pylori infection, a major risk factor for GC, contributed to the inactivation of RUNX3 in gastric epithelial cells through promoter hypermethylation. The levels of RUNX3 methylation in serum were in significant concordance with the methylation levels observed in GC tissues (P = .887).CONCLUSIONS:The current findings supported RUNX3 methylation as a risk factors for the carcinogenesis of chronic atrophic gastritis with H. pylori infection and indicated that circulating RUNX3 methylation is a valuable biomarker for the detection of early GC. Cancer 2012. © 2012 American Cancer Society.
Real‐Time Spatial Gene Expression Analysis within Current‐Producing Biofilms
Authors: Franks Ashley E. , Glaven Richard H. , Lovley Derek R. 
Published: May 2012

AbstractThe expression of genes involved in central metabolism and extracellular electron transfer was examined in real‐time in current‐producing anode biofilms of Geobacter sulfurreducens. Strains of G. sulfurreducens were generated, in which the expression of the gene for a short half‐life fluorescent protein was placed under control of the promoter of the genes of interest. Anode biofilms were grown in a chamber that permitted direct examination of the cell fluorescence with confocal scanning laser microscopy. Studies on nifD and citrate synthase expression in response to environmental changes demonstrated that the reporter system revealed initiation and termination of gene transcription. Uniform expression throughout the biofilms was noted for the genes for citrate synthase; PilA, the structural protein of the conductive pili; and OmcZ, a c‐type cytochrome essential for optimal current production, which was localized at the anode‐biofilm interface. These results demonstrate that even cells at great distance from the anode, or within expected low‐pH zones, are metabolically active and likely to contribute to current production and that there are factors other than gene expression differences influencing the distribution of OmcZ. This real‐time reporter approach is likely to be a useful tool in optimizing the design of technologies relying on microbe‐electrode interactions.
Second‐order statistics of system with N‐branch microdiversity and L‐branch macrodiversity operating over gamma shadowed Nakagami‐m fading channels
Authors: Sekulović Nikola M. , Stefanović Mihajlo Č. , Milović Daniela M. , Stanojčić Selena Ž. 
Published: May 2012

SUMMARYThe problem concerning short‐term fading and long‐term fading (shadowing) and their deleterious effects on wireless systems performance has been in focus for a long time. In this paper, motivated by the results of propagation measurements in land‐mobile and indoor‐mobile systems, and by the fact that gamma distribution can describe shadowing reliably, Nakagami‐m distribution is used to model the signal envelope and gamma distribution is used to model the average signal power. Receive diversity with maximal‐ratio combining and selection combining is implemented at the microlevel and macrolevel, respectively. The general case is explored, which assumes that microdiversity and macrodiversity are provided through arbitrary number of channels. Because shadowing has larger correlation distance than short‐term fading, correlated macrodiversity channels are studied. This paper investigates the dynamics of the received signal. A novel rapidly converging infinite‐series expression for average level crossing rate and average fade duration are obtained. Numerical results are graphically presented to examine the impact of fading severity, shadowing severity, number of diversity branches at the microlevel, number of base stations and correlation between base stations to the system's performance. Computer simulations are also performed to verify the validity and the accuracy of proposed theoretical analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Chiral (Mercaptophenyl)oxazolines as Auxiliaries for Asymmetric Coordination Chemistry
Authors: Wenzel Marianne , Meggers Eric 
Published: May 2012

Abstract(4S)‐2‐(4‐Isopropyl‐4,5‐dihydrooxazol‐2‐yl)‐4‐nitrobenzenethiol {(S)‐TS} and its tert‐butyl derivative {(S)‐TS′} were developed as chiral auxiliaries for the asymmetric synthesis of polypyridyl ruthenium complexes. In their deprotonated form, these (mercaptophenyl)oxazolines were used as bidentate ligands and allowed the efficient transfer of chirality from the oxazoline moiety to the ruthenium stereocenter. After the induction of the absolute metal‐centered configuration, the auxiliaries were labilized by converting the coordinated thiolate into a thioether ligand upon methylation with Meerwein salt, followed by the thermal replacement with 2,2′‐bipyridine or 1,10‐phenanthroline ligands under retention of configuration to afford octahedral polypyridyl ruthenium complexes with high enantiomeric excesses. These thiol‐based auxiliaries complement our previously developed acid‐labile chiral auxiliaries and thus expand the toolbox for the asymmetric synthesis of chiral ruthenium complexes.
Silver nanoparticle‐induced mutations and oxidative stress in mouse lymphoma cells
Authors: Mei Nan , Zhang Yongbin , Chen Ying , Guo Xiaoqing , Ding Wei , Ali Syed F. , Biris Alexandru S. , Rice Penelope , Moore Martha M. , Chen Tao 
Published: May 2012

AbstractSilver nanoparticles (Ag‐NPs) have increasingly been used for coatings on various textiles and certain implants, for the treatment of wounds and burns, as a water disinfectant, and in air‐freshener sprays. The wide use of Ag‐NPs may have potential human health impacts. In this study, the mutagenicity of 5‐nm Ag‐NPs was evaluated in the mouse lymphoma assay system, and modes of action were assessed using standard alkaline and enzyme‐modified Comet assays and gene expression analysis. Treatments of L5178Y/Tk+/‐ mouse lymphoma cells with 5‐nm uncoated Ag‐NPs resulted in a significant yield of mutants at doses between 3 and 6 μg/mL; the upper range was limited by toxicity. Loss of heterozygosity analysis of the Tk mutants revealed that treatments with uncoated Ag‐NPs induced mainly chromosomal alterations spanning less than 34 megabase pairs on chromosome 11. Although no significant induction of DNA damage in Ag‐NP‐treated mouse lymphoma cells was observed in the standard Comet assay, the Ag‐NP treatments induced a dose‐responsive increase in oxidative DNA damage in the enzyme‐modified Comet assay in which oxidative lesion‐specific endonucleases were added. Gene expression analysis using an oxidative stress and antioxidant defense polymerase chain reaction (PCR) array showed that the expressions of 17 of the 59 genes on the arrays were altered in the cells treated with Ag‐NPs. These genes are involved in production of reactive oxygen species, oxidative stress response, antioxidants, oxygen transporters, and DNA repair. These results suggest that 5 nm Ag‐NPs are mutagenic in mouse lymphoma cells due to induction of oxidative stress by the Ag‐NPs. Environ. Mol. Mutagen. 2012. © 2012Wiley Periodicals, Inc.