bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Catalytic Enantioselective Synthesis of Indanes by a Cation‐Directed 5‐endo‐Trig Cyclization.
Authors: Johnston Craig P. , Kothari Abhishek , Sergeieva Tetiana , Okovytyy Sergiy I. , Jackson Kelvin E. , Paton Robert S. , Smith Martin D. 
Published: April 2015

AbstractThe indanes are enantioselectively obtained as single diastereoisomers by a kinetically unfavorable 5‐endo‐trig cyclization, a rare mode of reaction.
ChemInform Abstract: Direct C—H Iodination of 1,3‐Azoles Catalyzed by CuBr2.
Authors: Zhao Xia , Ding Fang , Li Jingyu , Lu Kui , Lu Xiaoyu , Wang Bin , Yu Peng 
Published: April 2015

AbstractThe copper‐catalyzed metalation/iodination proceeds under relatively weak basic conditions using a combination of tBuOLi and phenanthroline.
ChemInform Abstract: Thermal [2 + 2]‐Cycloadditions of Diphenylketene with Aryl‐ and Hetaryl‐Substituted Thioketones
Authors: Heimgartner Heinz , Mloston Grzegorz , Urbaniak Katarzyna , Szychowska Anna , Linden Anthony 
Published: April 2015

Abstractas an efficient route to corresponding tetraarylthietan‐2‐ones (III)
ChemInform Abstract: Ammonium‐Salt‐Tagged IMesAuCl Complexes and Their Application in Gold‐Catalyzed Cycloisomerization Reactions in Water.
Authors: Belger Katrin , Krause Norbert 
Published: April 2015

AbstractAmmonium‐tagged IMesAuCl‐complexes (I) are designed and applied as water soluble NHC‐gold catalysts for the cycloisomerization of allenes (II) to dihydrofurans and alkynediols (IV) and (VI) to spirocyclic products (V) and (VII).
ChemInform Abstract: Synthesis of α‐Halobutenolides Using the Nucleophilicity of Magnesium Alkylidene Carbenoids.
Authors: Satoh Tsuyoshi , Kimura Tsutomu , Fukuda Kazuki , Kashiwamura Gaku 
Published: April 2015

AbstractA novel three‐step method for the synthesis of title compound (VI) is developed starting from readily available materials.
ChemInform Abstract: Direct Arylation of Benzo[b]furan and Other Benzo‐Fused Heterocycles.
Authors: Dao‐Huy Toan , Haider Maximilian , Glatz Fabian , Schnuerch Michael , Mihovilovic Marko D. 
Published: April 2015

AbstractThe novel protocol allows the regioselective direct arylation of benzo‐fused heterocycles with arylbromides to produce the corresponding 2‐substituted products in moderate yields.
ChemInform Abstract: [2 +2 + 2] Cycloaddition of Sulfanylbenzene‐Tethered Diynes with Alkynes for the Synthesis of Multi‐Substituted Dibenzothiophene Derivatives.
Authors: Shibata Takanori , Tahara Yu‐ki , Matsubara Riku 
Published: April 2015

AbstractA Rh‐catalyzed [2 + 2 + 2] cycloaddition of sulfanylbenzene‐ and sulfonylbenzene‐tethered 1,6‐diynes with various alkynes is presented.
ChemInform Abstract: Efficient Synthesis of cis‐3‐Substituted Prolines by Bidentate‐Assisted Palladium Catalysis.
Authors: Feng Ruokun , Wang Binjie , Liu Yue , Liu Zhanxiang , Zhang Yuhong 
Published: April 2015

AbstractThe Pd‐catalyzed oxidative coupling of chiral prolinamide (I) having a N‐quinolinyl directing group with aryl iodides is examined to yield C‐3 substituted products (III) in excellent cis‐selectivity.
ChemInform Abstract: Copper‐Catalyzed Three‐Component Tandem Reactions for the Synthesis of β‐Carboalkoxy‐γ‐lactams.
Authors: Li Zhengning , Feng Yunyun , Li Zengchang , Jiang Lan 
Published: April 2015

AbstractThe title compounds are prepared with high trans‐selectivity from aldimines (I) and (IV) and maleates (II) and (VI) in the presence of polymethylhydrosiloxane (PMHS).
ChemInform Abstract: Synthesis of Highly Functionalized Polycyclic Quinoxaline Derivatives Using Visible‐Light Photoredox Catalysis.
Authors: He Zhi , Bae Minwoo , Wu Jie , Jamison Timothy F. 
Published: April 2015

AbstractThe phenyl iodine dicarboxylate substrates (II) and (XI) can be easily prepared from the corresponding acids and PhI(OAc)2 by ligand exchange and used in the photoreaction without further purification.
ChemInform Abstract: Novel Synthesis of 5‐Methyl‐5,10‐dihydroindolo[3,2‐b]indoles by Pd‐Catalyzed C—C and Two‐Fold C—N Coupling Reactions.
Authors: Hung Tran Quang , Hancker Soeren , Villinger Alexander , Lochbrunner Stefan , Dang Tuan Thanh , Friedrich Aleksej , Breitsprecher Wolfgang , Langer Peter 
Published: April 2015

AbstractThe UV‐VIS and fluorescence properties of some products are investigated.
ChemInform Abstract: Acid‐ and Metal‐Free Synthesis of Annulated Pyrroles in a Deep Eutectic Solvent.
Authors: Rokade Sunil M. , Garande Ashok M. , Ahmad Nazim A. A. , Bhate Prakash M. 
Published: April 2015

AbstractAn environmentally friendly, one‐pot synthesis of optically pure annulated pyrroles [cf.
ChemInform Abstract: One‐Pot Synthesis of Triazoles from Organic Halides and Alkynes in Nonionic Nanomicelles at Room Temperature.
Authors: Xie Aming , Xu Xiao , Li Junjian , Wang Boliang , Dong Wei 
Published: April 2015

AbstractA micelle catalytic process for the synthesis of a wide range of triazoles from halides, alkynes, and sodium azide in water as solvent is developed.
ChemInform Abstract: Organocatalytic Domino Michael‐Heterocyclization Reaction of α,β‐Unsaturated Aldehydes and α‐Cyano Ketones: Synthesis of Enantioenriched 4,5,6‐Trisubstituted 3,4‐Dihydropyranones.
Authors: Guevara‐Pulido James O. , Andres Jose M. , Pedrosa Rafael 
Published: April 2015

AbstractThe reaction of α‐cyano ketones with aldehydes (II) in the presence of chiral diphenylsilylprolinol catalyst gives enantioenriched hemiacetals, which are further oxidized to produce dihydropyranones.
ChemInform Abstract: Indium‐Catalyzed Intramolecular Hydroarylation of Aryl Propargyl Ethers.
Authors: Alonso‐Maranon Lorena , Martinez M. Montserrat , Sarandeses Luis A. , Sestelo Jose Perez 
Published: April 2015

AbstractThe presented reaction selectively delivers the 6‐endo product, namely 2H‐chromenes, and succeeds with substrates equipped with terminal or internal alkynes, tolerates various electron‐rich and electron‐deficient substituents on the benzene as well as the alkyne moiety.
ChemInform Abstract: Iron(II,III) Oxide Nanoparticle‐Catalyzed Selective Synthesis of Unknown Dihydropyrano[c]chromenes under Green Conditions.
Authors: Khodabakhshi Saeed , Karami Bahador , Baghernejad Mojtaba 
Published: April 2015

AbstractThe title compounds (IV) are obtained by one‐pot three‐component condensation between 4‐hydroxycoumarin (I), various aryl glyoxals (II), and malononitrile (III), using magnetically recyclable Fe3O4 nanoparticles as catalyst.
ChemInform Abstract: Enantioselective Construction of Functionalized Thiopyrano‐Indole Annulated Heterocycles via a Formal Thio [3 + 3]‐Cyclization.
Authors: Chen Xiang , Qi Zheng‐Hang , Zhang Shao‐Yun , Kong Ling‐Pei , Wang Yong , Wang Xing‐Wang 
Published: April 2015

AbstractA series of chiral thiopyrano‐indoles (III) and (V) is readily obtained by an enantioselective cyclization of indoline‐2‐thiones (I) with dinitriles (II) and (IV).
ChemInform Abstract: Thioacetamide as an Ammonium Source for Multicomponent Synthesis of Pyridines from Aldehydes and Electron‐Deficient Enamines or Alkynes.
Authors: Wan Jie‐Ping , Zhou Youyi , Jiang Kezhi , Ye Hongyan 
Published: April 2015

AbstractThe multicomponent reaction provides a one‐step access to 3,4,5‐trisubstituted pyridines and succeeds using aryl aldehydes, but fails with alkyl aldehydes.
ChemInform Abstract: Metal‐Free‐Mediated Oxidation Aromatization of 1,4‐Dihydropyridines to Pyridines Using Visible Light and Air.
Authors: Wei Xiaojing , Wang Lin , Jia Wenliang , Du Shaofu , Wu Lizhu , Liu Qiang 
Published: April 2015

Abstract12 Pyridine derivatives of type (II) are prepared from the corresponding 1,4‐dihydropyridines by aerobic aromatization photosensitized by the organic dye TBA‐eosin Y.
ChemInform Abstract: Direct Arylation of Substituted Pyridines with Arylboronic Acids Catalyzed by Iron(II) Oxalate.
Authors: Huang Yibo , Guan Dan , Wang Liang 
Published: April 2015

AbstractOptimum reaction conditions are examined for the arylation of substituted pyridines with arylboronic acids in the presence of iron(II) oxalate and potassium peroxodisulfate.
ChemInform Abstract: Catalytic Oxidative Cyclization of 2′‐Arylbenzaldehyde Oxime Ethers under Photoinduced Electron Transfer Conditions.
Authors: Hofstra Julie L. , Grassbaugh Brittany R. , Tran Quan M. , Armada Nicholas R. , de Lijser H. J. Peter 
Published: April 2015

AbstractThe photocyclization of oxime ethers in the presence of 9,10‐dicyanoanthracene as the sensitizer affords phenanthridines without any nitrile byproducts.
ChemInform Abstract: Domino Four‐Component Synthesis of Novel Cycloocta[b]pyridines.
Authors: Maharani Seeni , Kumar Raju Ranjith 
Published: April 2015

AbstractA domino Knoevenagel condensation/Michael addition/nucleophilic addition/cyclization/aromatization sequence allows the synthesis of cyclooctapyridines in a single transformation.
ChemInform Abstract: Palladium‐Mediated Intramolecular Biaryl Coupling Reaction: Convenient Preparation of Furoquinolinone Derivatives.
Authors: Abe Hitoshi , Kamimura Mayu , Komatsu Yoshinori , Horino Yoshikazu 
Published: April 2015

AbstractN‐S substituted furo[2,3‐c]‐ or furo[3,2‐c]quinoline derivatives are obtained by palladium‐mediated intramolecular biaryl coupling of appropriate furoylanilides.
ChemInform Abstract: Dithienoquinazolines — A Convenient Synthesis by the Oxidative Photocyclization of 4,5‐Dithienyl‐Substituted Pyrimidines and Their Photophysical Properties.
Authors: Verbitskiy Egor V. , Slepukhin Pavel A. , Valova Marina S. , Cheprakova Ekaterina M. , Schepochkin Akesandr V. , Rusinov Gennady L. , Charushin Valery N. 
Published: April 2015

AbstractThe oxidative photocyclization of 4,4‐dithienyl substituted pyrimidines provides a convenient access to dithienoquinazolines, including brominated derivatives such as (VI) and (VIII).
ChemInform Abstract: Synthesis of Novel 2‐(Methylthio)benzo[g][1,2,4]triazolo[1,5‐a]quinazolin‐ 5‐(4H)‐one and Its Derivatives.
Authors: Al‐Salahi Rashad A. , Marzouk Mohamed S. , Ghabbour Hazem A. , Kun Fun H. 
Published: April 2015

AbstractCyclocondensation of 3‐hydrazinoyl‐2‐naphthoic acid (I) with N‐cyanoimidodithiocarbonate (II) gives the target triazoloquinazolinone (III), which provides access to a variety of derivatives upon chemical transformations of its lactam or methylthio groups.
ChemInform Abstract: Catalytic Systems Containing p‐Toluenesulfonic Acid Monohydrate Catalyzed the Synthesis of Triazoloquinazolinone and Benzimidazoquinazolinone Derivatives.
Authors: Mousavi Mir Rasul , Maghsoodlou Malek Taher 
Published: April 2015

AbstractA novel, simple, convenient, and efficient synthesis of the title compounds (IV) and (VII) via a metal‐free, one‐pot three component reaction procedure.
ChemInform Abstract: A General Metal‐Assisted Synthesis of α‐Halo Oxime Ethers from Nitronates and Nitro Compounds.
Authors: Sukhorukov Alexey Yu. , Kapatsyna Maria A. , Yi Tammy Lim Ting , Park Hyeong Ryool , Naumovich Yana A. , Zhmurov Petr A. , Khomutova Yulia A. , Ioffe Sema L. , Tartakovsky Vladimir A. 
Published: April 2015

AbstractBis(oxy)enamines (I) and (XII) undergo an unprecedented reaction with cobalt(II) halides to produce a variety of cyclic and acyclic ethers of α‐halo oximes including previously unavailable trimethylsilyl ethers of α‐iodo oximes.
ChemInform Abstract: Copper Catalyzed C—N Bond Formation/C—H Activation: Synthesis of Aryl 4H‐3,1‐Benzoxazin‐4‐ones.
Authors: Munusamy Sathishkumar , Venkatesan Sathesh , Sathiyanarayanan Kulathu Iyer 
Published: April 2015

AbstractA facile protocol using CuI as catalyst and air as oxidant for the domino reaction of 2‐iodobenzoic acids and benzylamines to give the title compounds is presented.
ChemInform Abstract: Transition‐Metal‐Free Synthesis of Imidazobenzothiazines via Domino C—S/C—N Bond Formation.
Authors: Tu Xingzhao , Zhou Lihong , Li Zhijie , Lei Ning , Zeng Qingle 
Published: April 2015

AbstractThe title compounds are obtained from 2‐mercaptobenzimidazoles and 2‐halobenzyl bromides in an facile, environmentally friendly, and cost‐saving cascade process.
ChemInform Abstract: Tridentate Pyrrolylzinc Compounds: Synthesis, Structures, Reactivities and Catalytic Cyclotrimerization Reaction of Isocyanate.
Authors: Guo Zhiqiang , Wei Xuehong , Tong Hongbo , Liu Diansheng 
Published: April 2015

AbstractSix new tridentate pyrrolylzinc compounds are synthesized and employed as initiator for the cyclotrimerization reaction of isocyanates (I).
ChemInform Abstract: Novel Intramolecular Cyclization‐Skeletal Reorganization of 2‐Arylthiazoles under Photoirradiation.
Authors: Arai Noriyoshi , Ohkuma Takeshi , Mizota Moe 
Published: April 2015

AbstractPhotoirradiation of 2‐arylthiazoles (I) bearing an alkene moiety gives unexpectedly furan‐fused thiazepines (II) as the major products along with [2 + 2] adducts (III) and isothiazoles (IV).
ChemInform Abstract: Atom‐Efficient Regioselective 1,2‐Dearomatization of Functionalized Pyridines by an Earth‐Abundant Organolanthanide Catalyst.
Authors: Dudnik Alexander S. , Weidner Victoria L. , Motta Alessandro , Delferro Massimiliano , Marks Tobin J. 
Published: April 2015

AbstractCp*‐complexed lanthanum hydride dimer is used as catalyst in the 1,2‐selective hydroborylation of pyridines, quinoline and isoquinoline.
ChemInform Abstract: Dehydrogenative Silylation of Alcohols Catalyzed by Half‐Sandwich Iron N‐Heterocyclic Carbene Complexes.
Authors: Cardoso Joao M. S. , Lopes Rita , Royo Beatriz 
Published: April 2015

AbstractVarious tetramethylcyclopentadienyl‐functionalized N‐heterocyclic carbene iron complexes are synthesized which are found to be efficient catalysts for the dehydrogenative silylation of alcohols with silanes.
ChemInform Abstract: Addition of Vinylmetallic Reagents to Chiral 2‐Formyltetrahydrofuran.
Authors: Lamariano‐Merketegi Janire , Lorente Adriana , Gil Alejandro , Albericio Fernando , Alvarez Mercedes 
Published: April 2015

AbstractA carboaluminum reaction, a Nozaki—Hiyama—Kishi reaction, and a chelation‐controlled organometallic addition are investigated for the introduction of a side chain to aldehydes (III) and (VI).
ChemInform Abstract: Facile Base‐Mediated Redox Transformation: An Efficient Strategy for the Synthesis of α‐Acyloxyphosphoryl Compounds.
Authors: Zhao Yalei , Chen Tieqiao , Han Daoqing , Zhao Chang‐Qiu , Han Li‐Biao 
Published: April 2015

AbstractThe atom‐efficient one‐pot synthesis succeeds using aromatic aldehydes and aromatic conjugated aldehydes, but fails using the corresponding aliphatic compounds or ketones.
ChemInform Abstract: Synthesis of Halo‐Enol Phostones by Using DMAP‐Catalyzed Halocyclization of Alkynylphosphonic Monoesters.
Authors: Huang Jiale , Wang Haiyang , Peng Ai‐Yun 
Published: April 2015

AbstractThe title reaction proceeds with high regioselectivity affording 6‐exo‐dig cyclization products as mixtures of E/Z‐isomers.
ChemInform Abstract: Structures of Six New Compounds from Ligularia brassicoides.
Authors: Saito Yoshinori , Sasaki Yoko , Ohsaki Ayumi , Okamoto Yasuko , Gong Xun , Kuroda Chiaki , Tori Motoo 
Published: April 2015

AbstractFour new eremophilane type sesquiterpenoids [e.g. (I)], a new bakkane type sesquiterpenoid (II), and a new secoeremophilane type sesquiterpenoid (III) are isolated from Ligularia brassicoides collected in China.
ChemInform Abstract: Chloranerectuslactone V (I), a New Sesquiterpene from Chloranthus erectus Verdc.
Authors: Huong Tran Thu , Thong Nguyen Van , Minh Tran Thi , Tram Le Huyen , Anh Nguyen Tuan , Cuong Ho Duc , Cuong Pham Van , Ca Diep V. 
Published: April 2015

Abstractisolation and structured elucidation
ChemInform Abstract: Penicibilaenes A (Ia) and B (Ib), Sesquiterpenes with a Tricyclo[6.3.1.01,5]dodecane Skeleton from the Marine Isolate of Penicillium bilaiae MA‐267.
Authors: Meng Ling‐Hong , Li Xiao‐Ming , Liu Yang , Wang Bin‐Gui 
Published: April 2015

AbstractThe title compounds show antifungal activities against the plant pathogen C.
ChemInform Abstract: Secondary Metabolites from the Endophytic Fungus Xylaria cubensis
Authors: Fan Nai‐Wen , Chang Hsun‐Shuo , Cheng Ming‐Jen , Hsieh Sung‐Yuan , Liu Ta‐Wei , Yuan Gwo‐Fang , Chen Ih‐Sheng 
Published: April 2015

Abstractisolation and structure determination of three new sesquiterpenoids, 10‐hydroxythujopsene (I), akotriol (II), and xylaritriol (III), one new diterpenoid, cubentriol (IV), one new aliphatic derivative, akoenic acid ((R)‐V), one new alkaloid, akodionine (VI), and one new isocoumarin, akolitserin (VII) along with seven known compounds from the fermentation broth of the endophytic fungus Xylaria cubensis
ChemInform Abstract: Diterpenoids from Aerial Parts of Clerodendranthus spicatus and Their Cytotoxic Activity.
Authors: Guan Shu‐Cai , Fan Guang‐Yan 
Published: April 2015

AbstractThe new diterpenoid, clerospicasin J (I), is isolated along with six known diterpenoids from the aerial parts of Clerodendranthus spicatus.
ChemInform Abstract: Halichonadins M—Q, Sesquiterpenes from an Okinawan Marine Sponge Halichondria sp.
Authors: Kobayashi Jun'ichi , Tanaka Naonobu , Suto Shohei , Asai Miki , Kusama Taishi , Takahashi‐Nakaguchi Azusa , Gonoi Tohru , Fromont Jane 
Published: April 2015

AbstractIsolation and structure elucidation of four new dimeric sesquiterpenes, halichonadins M—P (I)—(IV) and new sesquiterpene, halichonadin Q (V), are described.
ChemInform Abstract: Access to Fluorine‐Containing Asparagine and Glutamine Analogues via Palladium‐Catalyzed Formate Reduction.
Authors: Usuki Yoshinosuke , Wakamatsu Yosuke , Yabu Minoru , Iio Hideo 
Published: April 2015

AbstractThe synthesis of asparagine and glutamine analogues (V) and (VIII) is based on Pd‐catalyzed reduction of enantiopure formates (I) and (VI).
ChemInform Abstract: Stereoselective Construction of 1β‐Azide‐ and 1β‐Cyano‐2‐deoxyribose Derivatives.
Authors: Fujioka Hiromichi , Okamoto Kazuhisa , Minamitsuji Yutaka , Ueyama Yoshifumi , Matsumoto Nao , Murai Kenichi , Moriya Takahiro 
Published: April 2015

AbstractNew methods for the β‐selective introduction of azido and cyano groups at the anomeric position of 2‐deoxyribose derivatives are developed.
ChemInform Abstract: Germacranolides and Their Diversity of Eupatorium heterophyllum Collected in P. R. China.
Authors: Saito Yoshinori , Mukai Tomomi , Iwamoto Yuko , Baba Makiko , Takiguchi Koji , Okamoto Yasuko , Gong Xun , Kawahara Takayuki , Kuroda Chiaki , Tori Motoo 
Published: April 2015

Abstractisolation and structure elucidation of 8 new hydroperoxyheterophyllin A—H (I)‐(V) and one ketoheterophyllin A (VI)
ChemInform Abstract: Cytotoxic Polyacetylenes from a Formosan Marine Sponge Callyspongia sp.
Authors: Chiu Ching‐Wen , Su Huey‐Jen , Lu Mei‐Chin , Wang Wei‐Hsien , Sheu Jyh‐Horng , Su Jui‐Hsin 
Published: April 2015

AbstractTwo new polyacetylenic compounds, callysponynes A (Ia) and B (Ib), are isolated.
ChemInform Abstract: Seimatoric Acid (I) and Colletonoic Acid (II): Two New Compounds from the Endophytic Fungi, Seimatosporium sp. and Colletotrichum sp.
Authors: Hussain Hidayat , et al.  
Published: April 2015

AbstractPreliminary studies indicate that colletonoic acid (II) shows good antibacterial, antifungal, and antialgal activities.
ChemInform Abstract: Guest‐Induced Emergent Properties in Metal‐Organic Frameworks
Authors: Allendorf Mark D. , Foster Michael E. , Leonard Francois , Stavila Vitalie , Feng Patrick L. , Doty F. Patrick , Leong Kirsty , Ma Eric Yue , Johnston Scott R. , Talin A. Alec 
Published: April 2015

AbstractReview: 82 refs.
ChemInform Abstract: Ethynylglycine Synthon, a Useful Precursor for the Synthesis of Biologically Active Compounds: an Update ‐ Part I: Preparations of Ethynylglycine Synthon
Authors: Benfodda Zohra , Benimelis David , Reginato Gianna , Meffre Patrick 
Published: April 2015

AbstractReview: update on the different routes for the synthesis of the ethynylglycine synthon (R)‐2,2‐dimethyl‐3‐(tert‐butoxycarbonyl)‐4‐ethynyloxazolidine, 56 refs.
ChemInform Abstract: A Computational View on the Reactions of Hydrocarbons with Coinage Metal Complexes
Authors: Besora Maria , Braga Ataualpa A. C. , Sameera W. M. C. , Urbano Juan , Fructos Manuel R. , Perez Pedro J. , Maseras Feliu 
Published: April 2015

AbstractReview: 84 refs.
Aryloxyethyl Thiocyanates Are Potent Growth Inhibitors of Trypanosoma cruzi and Toxoplasma gondii
Authors: Chao María N. , Matiuzzi Carolina Exeni , Storey Melissa , Li Catherine , Szajnman Sergio H. , Docampo Roberto , Moreno Silvia N. J. , Rodriguez Juan B. 
Published: April 2015

AbstractAs a part of our project aimed at searching for new safe chemotherapeutic agents against parasitic diseases, several compounds structurally related to the antiparasitic agent WC‐9 (4‐phenoxyphenoxyethyl thiocyanate), which were modified at the terminal phenyl ring, were designed, synthesized, and evaluated as growth inhibitors against Trypanosoma cruzi, the etiological agent of Chagas disease, and Toxoplasma gondii, the parasite responsible of toxoplasmosis. Most of the synthetic analogues exhibited similar antiparasitic activity and were slightly more potent than our lead WC‐9. For example, two trifluoromethylated derivatives exhibited ED50 values of 10.0 and 9.2 μM against intracellular T. cruzi, whereas they showed potent action against tachyzoites of T. gondii (ED50 values of 1.6 and 1.9 μM against T. gondii). In addition, analogues of WC‐9 in which the terminal aryl group is in the meta position with respect to the alkyl chain bearing the thiocyanate group showed potent inhibitory action against both T. cruzi and T. gondii at the very low micromolar range, which suggests that a para‐phenyl substitution pattern is not necessary for biological activity.
Rational Design of Ruthenium Complexes Containing 2,6‐Bis(benzimidazolyl)pyridine Derivatives with Radiosensitization Activity by Enhancing p53 Activation
Authors: Deng Zhiqin , Yu Lianling , Cao Wenqiang , Zheng Wenjie , Chen Tianfeng 
Published: April 2015

AbstractThe rational design of metal‐based complexes is an effective strategy for the discovery of potent sensitizers for use in cancer radiotherapy. In this study, we synthesized three ruthenium complexes containing bis‐benzimidazole derivatives: Ru(bbp)Cl3 (1), [Ru(bbp)2]Cl2 (2 a) (in which bbp=2,6‐bis(benzimidazol‐1‐yl)pyridine), and [Ru(bnbp)2]Cl2 (2 b) (where bnbp=2,6‐bis‐(6‐nitrobenzimidazol‐2‐yl)pyridine). We evaluated their radiosensitization capacities in vitro and mechanisms of action. Complex 2 b was found to be particularly effective in sensitizing human melanoma A375 cells toward radiation, with a sensitivity enhancement ratio of 2.4. Along with this potency, complex 2 b exhibited a high degree of selectivity between human cancer and normal cells. Mechanistic studies revealed that 2 b promotes radiation‐induced accumulation of intracellular reactive oxygen species (ROS) by reacting with cellular glutathione (GSH) and then causing DNA stand breaks. The subsequent DNA damage induces phosphorylation of p53 (p‐p53) and upregulates the expression levels of p21, which inhibits the expression of cyclin‐B, leading to G2M arrest. Moreover, p‐p53 activates caspases‐3 and ‐8, triggers cleavage of poly(ADP‐ribose) polymerase (PARP), finally resulting in apoptosis. Taken together, the results of this study provide a strategy for the design of ruthenium‐based radiosensitizers for use in cancer therapy.