bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heteroditopic Ligand Accommodating a Fused Phenanthroline and a Schiff Base Cavity as Molecular Spacer in the Study of Electron and Energy Transfer
Authors: Pellegrin Yann , Quaranta Annamaria , Dorlet Pierre , Charlot Marie France , Leibl Winfried , Aukauloo Ally 
Published: April 2005

AbstractThe synthesis and characterisation of the heteroditopic ligand N,N′‐bis(3,5‐di‐tert‐butylsalicylidene)‐5,6‐(1,10‐phenanthroline)diamine (DPSalH2) bearing a phenanthroline and a bis(salicylidene)diimine cavity are reported. This versatile ligand combines two of the most widely used ligands in coordination chemistry. Sequential metallation of the phenanthroline end with RuII and the salophenic cavity with CuII is described. Electrochemical behaviour of the supramolecular complexes [Ru(bpy)2(DPSalH2)]2+ and [Ru(bpy)2(DPSalCu)]2+ are analysed in connection with UV/Vis and EPR spectroscopy. The data for the one‐electron‐reduced species and the singly oxidised species of the binuclear RuII–CuII complex confirmed the formation of metalloradical complexes. Density functional calculations on the free ligand and the copper‐only complex indicate in both cases that the HOMOs and LUMOs are developed on the Schiff base cavity with minor contributions on the bipyridine end. These findings support a bichromophoric character for our ruthenium complexes in the ground state, a necessary condition in the design of supramolecular systems for the study of electron transfer. Photophysical studies indicate fast quenching of the triplet excited state in both complexes, which suggests strong intercomponent excited‐state interactions. Evidence is presented that this quenching is due to intramolecular electron transfer, at least in the case of [Ru(bpy)2(DPSalH2)]2+, for which a charge‐separated state with a remarkable lifetime of about 30 μs was observed.
Molecular Conformation and Packing of Peptide β Hairpins in the Solid State: Structures of Two Synthetic Octapeptides Containing 1‐Aminocycloalkane‐1‐Carboxylic Acid Residues at the i+2 Position of the β Turn
Authors: Harini Veldore Vidya , Aravinda Subrayashastry , Rai Rajkishor , Shamala Narayanaswamy , Balaram Padmanabhan 
Published: April 2005

AbstractPeptide β‐hairpin formation is facilitated by centrally positioned D‐Pro‐Xxx segments. The synthetic peptides Boc‐Leu‐Phe‐Val‐D‐Pro‐Ac6c‐Leu‐Phe‐Val‐OMe (1) and Boc‐Leu‐Phe‐Val‐D‐Pro‐Ac8c‐Leu‐Phe‐Val‐OMe (2) were synthesized in order to explore the role of bulky 1‐aminocycloalkane‐1‐carboxylic acid residues (Acnc, where n is the number of carbon atoms in the ring), at the i+2 position of the nucleating β turn in peptide β hairpins. Peptides 1 and 2 crystallize in the monoclinic space group P21 with two molecules in the asymmetric unit. The crystal structures of 1 and 2 provide conformational parameters for four peptide hairpin molecules. In all cases, the central segments adopts a type II′ β‐turn conformation, and three of the four possible cross‐strand hydrogen bonds are observed. Fraying of the hairpins at the termini is accompanied by the observation of NH⋅⋅⋅π interaction between the Leu(1)NH group and Phe(7) aromatic group. Cross strand stabilizing interactions between the facing residues Phe(2) and Phe(7) are suggested by the observed orientation of aromatic rings. Anomalous far‐UV CD spectra observed in solution suggest that close proximity of the Phe rings is maintained even in isolated molecules. In both peptides 1 and 2, the asymmetric unit consists of approximately orthogonal hairpins, precluding the formation of a planar β‐sheet arrangement in the solid state. Solvent molecules, one dioxane and one water in 1, three water molecules in 2, mediate peptide association. A comparison of molecular conformation and packing motifs in available β‐hairpin structures permits delineation of common features. The crystal structures of β‐hairpin peptides provide a means of visualizing different modes of β‐sheet packing, which may be relevant in developing models for aggregates of polypeptides implicated in disease situations.
Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)4 Complexes with Dynamic Phosphinidene Behavior
Authors: Borst Mark L. G. , van der Riet Niels , Lemmens Renske H. , de Kanter Franciscus J. J. , Schakel Marius , Ehlers Andreas W. , Mills Allison M. , Lutz Martin , Spek Anthony L. , Lammertsma Koop 
Published: April 2005

AbstractThe synthesis of highly strained bicyclic phosphirane and phosphirene iron–tetracarbonyl complexes, that is, complexes with 2‐aza‐1‐phosphabicyclo[n.1.0]alkanes and ‐alkenes (n=3–5), is explored by using intramolecular cycloaddition of an in situ generated electrophilic phosphinidene complex, [R(iPr)NPFe(CO)4], to its CC‐ and CC‐containing R substituent. Saturated bicyclic complexes 7 a–c with n=4–2 are remarkably stable, as illustrated by the X‐ray crystal structure for 7 b (n=3), yet all readily undergo retroaddition to react with phenylacetylene. Shuttling of the phosphinidene iron complex between two equivalent CC groups is demonstrated for a 1‐butene‐substituted 2‐aza‐1‐phosphabicyclo[3.1.0]hexane by selective 1H NMR magnetization transfer from the phosphirane protons to the olefinic protons. Even the more strained unsaturated bicycles 17 a,b (n=4,3) are surprisingly stable as illustrated by the X‐ray crystal structure for 17 a (n=4), but the smaller phosphabicyclo[3.1.0]hex‐5‐ene (17 c, n=2) dimerizes to tricyclic 19 with a unique ten‐membered heterocyclic ring; an X‐ray crystal structure is reported. Like their saturated analogues also the bicyclic phosphirenes readily undergo retroaddition as shown by the reaction of their phosphinidene iron moiety with phenylacetylene.
Rhodium‐Catalyzed Nondecarbonylative Addition Reaction of ClCOCOOC2H5 to Alkynes
Authors: Hua Ruimao , Onozawa Shun‐ya , Tanaka Masato 
Published: April 2005

AbstractAddition of ethoxalyl chloride (ClCOCOOEt) to terminal alkynes at 60 °C in the presence of a rhodium(I)–phosphine complex catalyst chosen from a wide range affords 4‐chloro‐2‐oxo‐3‐alkenoates regio‐ and stereoselectively. Functional groups such as chloro, cyano, alkoxy, siloxy, and hydroxy are tolerated. The oxidative addition of ethoxalyl chloride to [RhCl(CO)(PR3)2] proceeds readily at 60 °C or room temperature and gives [RhCl2(COCOOEt)(CO)(PR3)2] (PR3 = PPh2Me, PPhMe2, PMe3) complexes in high yields. The structure of [RhCl2(COCOOEt)(CO)(PPh2Me)2] was confirmed by X‐ray crystallography. Thermolysis of these ethoxalyl complexes has revealed that those ligated by more electron‐donating phosphines are fairly stable against decarbonylation and reductive elimination. [RhCl2(COCOOEt)(CO)(PPh2Me)2] reacts with 1‐octyne at 60 °C to form ethyl 4‐chloro‐2‐oxo‐3‐decenoate. The catalysis is therefore proposed to proceed by oxidative addition of ethoxalyl chloride, insertion of an alkyne into the ClRh bond of the resulting intermediate, and reductive elimination of alkenyl‐COCOOEt.
Metal‐Induced Chiral Folding of Depsipeptide Dendrimers
Authors: Buschhaus Boris , Hampel Frank , Grimme Stefan , Hirsch Andreas 
Published: April 2005

AbstractThe synthesis and metal complexation of chiral depsipeptide dendrimers 3 and 7 containing an ethylenediaminetetraacetic acid (EDTA) ester‐derived core is reported. The EDTA ester cavity of these dendrimers selectively complexes Zn2+ and Cu2+ ions leading to diastereoselective folding. To elucidate the coordination motif in the resulting “foldamers” of 3‐ZnCl2, 7‐ZnCl2, 3‐CuCl2, and 7‐CuCl2, the coordination behavior of the tetramethyl ester of EDTA (8) has been investigated as a model case. The corresponding complexes 8‐ZnCl2 and 8‐CuCl2 have been structurally characterized by 1H NMR spectroscopy and X‐ray analysis. The complexes involve the inherently chiral octahedral cis‐α coordination motif, in which 8 serves as a tetradentate ligand. In the case of the ZnII complex 8‐ZnCl2, both Δcis‐α(S,S,λ) and Λcis‐α(R,R,λ) stereoisomers were found in the unit cell. For the CuII complex 8‐CuCl2, only one stereoisomer, namely Δcis‐α(S,S,λ) was found in the crystal under investigation. 1H NMR spectroscopy has shown that the same coordination motif is diastereoselectively formed in the chiral Zn2+ dendrimers 3‐ZnCl2 and 7‐ZnCl2. Likewise, the calculated CD spectrum of the Δcis‐α(S,S,λ) stereoisomer of the model complex 8‐CuCl2 shows good agreement with the experimental spectrum of the CuII dendrimers 3‐CuCl2 and 7‐CuCl2, allowing assignment of the absolute configurations of the preferred foldamers as Λcis‐α(R,R,λ) for 3‐CuCl2 and Δcis‐α(S,S,λ) for 7‐CuCl2. This work represents the first example of metal‐complexation‐mediated diastereoselective folding of chiral dendrimers with known absolute configuration.
Atom‐Type Assignment in Molecules and Clusters by Perturbation Theory—A Complement to X‐ray Structure Analysis
Authors: Weigend Florian , Schrodt Claudia 
Published: April 2005

AbstractAn approach to distinguish elements with similar atomic numbers in molecules and clusters is presented and applied to experimentally synthesized and structurally characterized mixed‐metallic compounds. By first treating a homogenized reference system constructed from the original compound and applying first‐order perturbation theory it is possible to find the most stable distribution of the atom types to the atomic sites in a very efficient way. This work is focused on the appropriate choice of homogenized reference systems and on applications treating experimentally synthesized compounds. With these examples is shown that the method is a helpful complement to X‐ray crystal structure analysis.
Synthesis and Investigation of Tin(II) Pyrophosphate Sn2P2O7.
Authors: Chernaya Victoria V. , Mitiaev Alexander S. , Chizhov Pavel S. , Dikarev Evgeny V. , Shpanchenko Roman V. , Antipov Evgeny V. , Korolenko Mikhail V. , Fabritchnyi Pavel B. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
High‐Pressure Synthesis, Crystal Structure Determination, and a Ca Substitution Study of the Metallic Rhodium Oxide NaRh2O4.
Authors: Yamaura Kazunari , Huang Qingzhen , Moldovan Monica , Young David P. , Sato Akira , Baba Yuji , Nagai Takuro , Matsui Yoshio , Takayama‐Muromachi Eiji 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Formation and Magnetic Properties of the Ln‐Based Compounds of Type Ln6Fe13‐xAl1+x (Ln: Pr, Sm, Gd).
Authors: Minh P. T. L. , McCallum R. W. , Lewis L. H. , Dennis K. W. , Kramer M. J. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Benzopyrans. Part 47. Reactions of 3‐(β‐Dimethylaminoacryloyl)‐1‐benzopyran‐4‐one with Some Nitrogen Nucleophiles.
Authors: Ghosh Chandra Kanta , Karak Sumit Kumar , Patra Amarendra 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Stereohomogeneous Cyclopropanecarbaldehydes and Cyclopropyl Ketones by Cycloalkylation of 4‐Hydroxy‐1‐alkenyl Carbamates.
Authors: Kalkofen Rainer , Brandau Sven , Wibbeling Birgit , Hoppe Dieter 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Triazine Derivatives of (1,x)‐Diazacycloalkanes. Part 1. Synthesis and Characterization of a Series of 1‐Methyl‐4‐[2‐aryl‐1‐diazenyl]piperazines and a Series of Ethyl 4‐[2‐Aryl‐1‐diazenyl]‐1‐piperazinecarboxylates.
Authors: Little Vanessa Renee , Vaughan Keith 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 1,4:3,6‐Dianhydro‐D‐mannitol 2,5‐(Hydrogen phosphate) and Its Usage in Palladium‐Catalyzed Hydroxycarbonylation of Styrene.
Authors: Jiang Biao , Huang Zuo‐Gang , Cheng Ke‐Jun 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Improving Palladium‐Catalyzed Cyanation of Aryl Halides: Development of a State‐of‐the‐Art Methodology Using Potassium Hexacyanoferrate(II) as Cyanating Agent.
Authors: Schareina Thomas , Zapf Alexander , Beller Matthias 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Asymmetric Conjugate Reduction of α,β‐Unsaturated Esters with Chiral Rhodium(bisoxazolinylphenyl) Catalysts.
Authors: Tsuchiya Yasunori , Kanazawa Yoshinori , Shiomi Takushi , Kobayashi Kazuki , Nishiyama Hisao 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Stereoselective Synthesis of Functionalized β,β‐Di‐ and Trisubstituted Vinylic Sulfoxides by Cu‐Catalyzed Conjugate Addition of Organozinc Reagents.
Authors: Maezaki Naoyoshi , Sawamoto Hiroaki , Suzuki Tomoko , Yoshigami Ryoko , Tanaka Tetsuaki 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
[Ru(η3‐2‐C3H4Me)(CO)(dppf)] [SbF6]: A Mononuclear 16e‐ Ruthenium(II) Catalyst for Propargylic Substitution and Isomerization of HCCCPh2(OH).
Authors: Cadierno Victorio , Diez Josefina , Garcia‐Garrido Sergio E. , Gimeno Jose 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Convenient Synthesis of α‐Methylene‐γ‐butyrolactones from Allenyl Carbonyl Units Mediated by Mo(CO)6 Through Intramolecular Cyclocarbonylation.
Authors: Yu Chan‐Mo , Hong Young‐Taek , Lee Joon‐Hwan 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
9‐Acylation of 1‐Acyldipyrromethanes Containing a Dialkylboron Mask for the α‐Acylpyrrole Motif.
Authors: Zaidi Syeda Huma H. , Muthukumaran Kannan , Tamaru Shun‐ichi , Lindsey Jonathan S. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Stereoselective Synthesis of Bicyclic Pyrrolidines by a Rhodium‐Catalyzed Cascade Process.
Authors: Yan Ming , Jacobsen Neil , Hu Wenhao , Gronenberg Luisa S. , Doyle Michael P. , Colyer John T. , Bykowski Darren 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Reactivity of a N‐Heterocyclic Carbene, 1,3‐Di‐(1‐adamantyl) Imidazol‐2‐ylidene, with a Pseudo‐Acid: Structural Characterization of Claisen Condensation Adduct.
Authors: Grasa Gabriela A. , Singh Rohit , Scott Natalie M. , Stevens Edwin D. , Nolan Steven P. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Chemoselective Synthesis of Dialkyl 2‐(tert‐Butylamino) ‐6‐methyl‐5‐trifluoroacetyl‐4H‐pyran‐3,4‐dicarboxylates.
Authors: Asghari S. , Zaty M. , Safiri S. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Regio‐ and Diastereoselective Insertion of Allenes into Stable Oxapalladacycles with a Metal‐Bonded Stereogenic Carbon. Preparation of Contiguously Substituted 3,4‐Dihydro‐2H‐1‐Benzopyrans.
Authors: Lu Genliang , Malinakova Helena C. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Novel Redox Reaction Between 8‐Aza‐5,7‐dimethyl‐2‐trifluoromethylchromone and Alkyl Mercaptoacetates. Facile Synthesis of CF3‐Containing 2‐Pyridone Derivatives.
Authors: Sosnovskikh Vyacheslav Ya. , Barabanov Mikhail A. , Usachev Boris I. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Design of a Nonreductive Method for Chemoselective Cleavage of Hydrazines in the Presence of Unsaturations: Application to a Stereoconvergent Three‐Component Synthesis of (‐)‐Methyl Palustramate.
Authors: Toure Barry B. , Hall Dennis G. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Microwave‐Induced Synthesis of 3/4‐Substituted‐2‐thioxo/2‐oxo‐6‐thioxo‐1,2,3,4,6,7‐hexahydrothiazolo [4,5‐d]pyrimidine and Thiazole Derivatives.
Authors: Dabholkar Vijay V. , Ahmed Syed Sagir 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Regioselectivity in Cross‐Coupling Reactions of 2,6,8‐Trichloro‐9‐(tetrahydropyran‐2‐yl)purine: Synthesis of 2,6,8‐Trisubstituted Purine Bases.
Authors: Hocek Michal , Pohl Radek 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 5‐Alkyl(or aryl)pyrrolo[1,2‐a]quinoxalin‐4(5H)‐ones by Denitrocyclization of N‐Alkyl(or aryl)‐1‐(2‐nitrophenyl)‐1H‐pyrrole‐2‐carboxamides. Evidence of a Smiles Rearrangement.
Authors: Rotas Georgios , Kimbaris Athanasios , Varvounis George 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Stereostructure of Saturated Isoindolone‐Fused Hetero Tri‐, Tetra‐, and Pentacyclic Compounds.
Authors: Sohar Pal , Csampai Antal , Magyarfalvi Gabor , Szabo Angela E. , Stajer Geza 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis, NMR and Molecular Modeling Study of 4,9a‐Diaryl‐9,9a‐dihydro‐1H‐[1,4]thiazino[4,3‐a][1,3]benzimidazoles.
Authors: Karthikeyan E. , Perumal S. , Selvaraj S. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of DNA‐Interactive Pyrrolo[2,1‐c][1,4]benzodiazepines by Employing Polymer‐Supported Reagents: Preparation of DC‐81.
Authors: Kamal Ahmed , Reddy K. Laxma , Devaiah V. , Shankaraiah N. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Multicomponent Heterocyclization of Hydrazine, Hydrogen Sulfide, and Formaldehyde.
Authors: Khafizova S. R. , Akhmetova V. R. , Tyumkina T. V. , Khalilov L. M. , Kunakova R. V. , Dzhemilev U. M. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Improved Synthesis of Aryltrialkoxysilanes via Treatment of Aryl Grignard or Lithium Reagents with Tetraalkyl Orthosilicates.
Authors: Manoso Amy S. , Ahn Chuljin , Soheili Arash , Handy Christopher J. , Correia Reuben , Seganish W. Michael , DeShong Philip 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 1,1,4,4‐Tetrabromo‐2‐butenes and Related Compounds via Desilylation—Bromination of Silylated 1,3‐Butadiene Derivatives.
Authors: Xi Zhenfeng , Liu Xiaohong , Lu Jianming , Bao Fengyu , Fan Hongtao , Li Zhiping , Takahashi Tamotsu 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Reaction of 2‐Methoxy‐1,3,2‐dioxaphosphorino[4,5‐b]pyridin‐4(4H)‐one with Hexafluoroacetone.
Authors: Mironov V. F. , Burnaeva L. M. , Litvinov I. A. , Kotorova Yu. Yu. , Dobrynin A. B. , Musin R. Z. , Konovalova I. V. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Substituted 1‐Thia‐3‐aza‐4λ5‐phosphacyclohex‐2‐ene.
Authors: Pudovik M. A. , Terent'eva S. A. , Khailova N. A. , Musin R. Z. , Azancheev N. M. , Kataeva O. N. , Litvinov I. A. , Dobrynin A. B. , Pudovik A. N. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
New Oleanan‐Type Triterpene and Cincholic Acid Glycosides from Peruvian “Una de Gato” (Uncaria tomentosa).
Authors: Kitajima Mariko , Hashimoto Ken‐ichiro , Sandoval Manuel , Aimi Norio , Takayama Hiromitsu 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Convenient Synthesis and Isolation of 1‐Aminocyclopropane‐1‐carboxylic Acid (ACC) and N‐Protected ACC Derivatives.
Authors: Allwein Shawn P. , Secord Elizabeth A. , Martins Andrew , Mitten Jeffrey V. , Nelson Todd D. , Kress Michael H. , Dolling Ulf H. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of C‐Arylglycosides via Ru(II)‐Catalyzed [2 + 2 + 2] Cycloaddition.
Authors: Yamamoto Yoshihiko , Saigoku Tomoaki , Ohgai Takashige , Nishiyama Hisao , Itoh Kenji 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis, 18F‐Radiolabelling and Biological Evaluations of C‐6 Alkylated Pyrimidine Nucleoside Analogues.
Authors: Raic‐Malic Silvana , Johayem Anass , Ametamey Simon M. , Batinac Sanja , De Clercq Erik , Folkers Gerd , Scapozza Leonardo 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
New Neolignans from Spiraea formosana
Authors: Wu Tian‐Shung , Hwang Chia‐Chan , Kuo Ping‐Chung , Kuo Tsung‐Hsiao , Damu Amooru Gangaiah , Su Chung‐Ren 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
The Absolute Structures of Dihydroepiheveadride, as Characteristic Antifungal Agent Against Filamentous Fungi, and Its Related Compounds from Unidentified Fungus IFM 52672.
Authors: Hosoe Tomoo , Fukushima Kazutaka , Itabashi Takeshi , Nozawa Koohei , Takizawa Kayoko , Kawai Ken‐ichi 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A‐503083 A,B, E and F, Novel Inhibitors of Bacterial Translocase I, Produced by Streptomyces sp. SANK 62799
Authors: Muramatsu Yasunori , Ohnuki Takashi , Ishii Miyazawa , Kizuka Masaaki , Enokita Ryuzo , Miyakoshi Shunichi , Takatsu Toshio , Inukai Masatoshi 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Enzymes Inhibiting Lignans from Vitex negundo.
Authors: Azhar‐Ul‐Haq Azhar‐Ul‐Haq , Malik Abdul , Anis Itrat , Khan Sher Bahadar , Ahmed Ejaz , Ahmed Zaheer , Nawaz Sarfraz Ahmad , Choudhary Muhammad Iqbal 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Analogues of Nucleotides and Oligonucleotides Featuring Difluorophosphonate, Difluorophosphonothioate and Difluorophosphinate Functional Groups
Authors: Gautier Arnaud , Lopin Chrystel , Garipova Goulnara , Kalinina Irina , Salcedo Carmen , Balieu Sebastien , Piettre Serge R. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Recent Applications of the Amide Approach to the Synthesis of Medicinally Interesting Polyamine Analogues
Authors: Tsiakopoulos N. , Vassis S. , Militsopoulou M. , Damianakos C. , Gatos P. , Voyiatzi K. , Pantazaka E. , Papaioannou D. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Natural Product Synthesis Based on New Acyclic Stereocontrol. Stereoselective Total Syntheses of Zincophorin, the Ionophore Antibiotic, and Scytophycin C, an Antitumor Marine Macrolide
Authors: Miyashita Masaaki , Tanino Keiji 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Mucinous carcinomas of the colon and rectum show higher rates of microsatellite instability and lower rates of chromosomal instability
Authors: Kazama Yoshihiro , Watanabe Toshiaki , Kanazawa Takamitsu , Tada Tomohiro , Tanaka Junichiro , Nagawa Hirokazu 
Published: April 2005

AbstractBACKGROUNDThe clinicopathologic significance of mucinous carcinomas (Muc) of the colon and rectum has been widely discussed, but there have been few studies on Muc regarding genetic and epigenetic alterations. The current study analyzed genetic and epigenetic alterations of Muc to clarify their differences from well differentiated adenocarcinomas (WD).METHODSThirty‐nine cases of Muc and 39 cases of WD were investigated. Cases of WD were matched with cases of Muc for T classification and tumor location. Microsatellite instability (MSI) status and loss of heterozygosity (LOH) of four loci (2p, 5q, 17p, 18q) were evaluated. The methylation status of the hMLH1 promoter region in Muc was also examined.RESULTS“MSI tumors” were defined as those that showed MSI‐high, and “chromosomal instability (CIN) tumors” were defined as those that showed LOH but not MSI‐high. MSI tumors were significantly more frequent in Muc (30.8%) than in WD (5.1%). CIN tumors were significantly less frequent in Muc (53.8%) than in WD (87.2%). In Muc, MSI tumors were significantly more frequent in the proximal colon (55.6%) than in the distal colon (9.5%). Also, methylation of the hMLH1 promoter region in Muc was significantly more frequent in MSI tumors (83.3%) than in CIN tumors (27.8%) (P = 0.0077).CONCLUSIONSWhen matched for T classification and tumor location, Muc shows higher rates of MSI and lower rates of CIN than WD.. Muc shows different characteristics according to tumor location, and methylation of the hMLH1 promoter region strongly correlates with Muc tumors showing MSI. Cancer 2005. © 2005 American Cancer Society.