Home About us Contact
|
Home About us Contact | ||
|
|
||
Side Chains (side + chain)
Kinds of Side Chains Terms modified by Side Chains Selected AbstractsAir-Operable, High-Mobility Organic Transistors with Semifluorinated Side Chains and Unsubstituted Naphthalenetetracarboxylic Diimide Cores: High Mobility and Environmental and Bias Stress Stability from the Perfluorooctylpropyl Side ChainADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Byung Jun Jung Abstract N,N,-bis(3-(perfluoroctyl)propyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide (8,3-NTCDI) was newly synthesized, as were related fluorooctylalkyl-NTCDIs and alkyl-NTCDIs. The 8,3-NTCDI-based organic thin-film transistor (OTFT) on an octadecyltrimethoxysilane (OTS)-treated Si/SiO2 substrate shows apparent electron mobility approaching 0.7 cm2 V -1s -1 in air. The fluorooctylethyl-NTCDI (8,2-NTCDI) and fluorooctylbutyl-NTCDI (8,4-NTCDI) had significantly inferior properties even though their chemical structures are only slightly different, and nonfluorinated decyl and undecyl NTCDIs did not operate predictably in air. From atomic force microscopy, the 8,3-NTCDI active layer deposited with the substrate at 120 °C forms a polycrystalline film with grain sizes >4,m. Mobilities were stable in air for one week. After 100 days in air, the average mobility of three OTFTs decreased from 0.62 to 0.12 cm2 V -1s -1, but stabilized thereafter. The threshold voltage (VT) increased by 15 V in air, but only by 3 V under nitrogen, after one week. On/off ratios were stable in air throughout. We also investigated transistor stability to gate bias stress. The transistor on hexamethlydisilazane (HMDS) is more stable than that on OTS with mobility comparable to amorphous Si TFTs. VT shifts caused by ON (30 V) and OFF (,20 V) gate bias stress for the HMDS samples for 1 hour were 1.79 V and 1.27 V under N2, respectively, and relaxation times of 106 and 107 s were obtained using the stretched exponential model. These performances are promising for use in transparent display backplanes. [source] Combined Chemical-Enzymatic Assembly of Aminoglycoside Derivatives with N-1-AHB Side ChainADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2008Igor Nudelman Abstract A series of unprotected pseudo-disaccharides and pseudo-trisaccharides of 2-deoxystreptamine-containing aminoglycosides have been selectively acylated at the N-1 position with the valuable (S)-4-amino-2-hydroxybutanoyl (AHB) pharmacophore by using the recombinant BtrH and BtrG enzymes from butirosin biosynthesis in combination with a synthetic acyl donor. The process was optimized by performing two enzymatic steps in a sequential manner without purification of the intermediate product. [source] Photochromic and Photoresponsive Properties of Methacrylic Polymers Bearing Optically Active Hydroxysuccinimide in the Side ChainMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 21 2007Luigi Angiolini Abstract The photochromic and photoresponsive properties of a series of optically active azoaromatic polymers, containing in the side chain the rigid (S)- and/or (R)-hydroxysuccinimide residue, have been investigated in solution and in the solid state as thin films by observing the trans - cis photoisomerisation of the azobenzene chromophore, and the results are compared to the corresponding monomeric (S) and (R) model compounds. The presence of exciton splitting due to dipole-dipole interactions between the trans -azoaromatic rings in the CD spectra confirms the intrinsic chirality of the macromolecules. Thin films of the polymers display the same chiroptical properties as the solution, thus suggesting that the macromolecules maintain chiral conformations also in the solid amorphous state. [source] ChemInform Abstract: A New Series of Amodiaquine Analogues (I) Modified in the Basic Side Chain with in vitro Antileishmanial and Antiplasmodial Activity.CHEMINFORM, Issue 15 2010Stefano Guglielmo Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Design and Synthesis of a New Class of Arginine Analogues with an Improved Anion Binding Site in the Side Chain.CHEMINFORM, Issue 26 2005Carsten Schmuck Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of New Liquid Crystalline Compounds Containing a ,-Hydroxyketone Fragment in the Side Chain.CHEMINFORM, Issue 15 2005V. S. Bezborodov Abstract For Abstract see ChemInform Abstract in Full Text. [source] Degradation of the Side Chain of (-)-Sclareol: A Very Short Synthesis of nor-Ambreinolide (III) and Ambrox (VI).CHEMINFORM, Issue 7 2005A. F. Barrero No abstract is available for this article. [source] Isolation, Structural Elucidation, and Synthesis of RA-XVII, a Novel Bicyclic Hexapeptide from Rubia cordifolia, and the Effect of Side Chain at Residue 1 upon the Conformation and Cytotoxic Activity.CHEMINFORM, Issue 21 2004Yukio Hitotsuyanagi No abstract is available for this article. [source] Lipase-Catalyzed Transesterification of Methyl 2-Substituted 3-Hydroxy-4-pentenoates and Its Synthetic Application to the Taxol Side Chain.CHEMINFORM, Issue 5 2003Tadakatsu Mandai Abstract For Abstract see ChemInform Abstract in Full Text. [source] Modification of A and B Rings in 20-Dihydroisoxazolyl Steroids and Their Derivatives with a Functionalized Side Chain.CHEMINFORM, Issue 47 2002R. P. Litvinovskaya Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Alkyne Metathesis with Simple Catalyst Systems: Efficient Synthesis of Conjugated Polymers Containing Vinyl Groups in Main or Side Chain.CHEMINFORM, Issue 15 2001Glen Brizius Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Side Chain Mediated Electronic Contact between a Tetrahydro-4H -thiopyran-4-ylidene-Appended Polythiophene and CdTe Quantum DotsCHEMISTRY - A EUROPEAN JOURNAL, Issue 31 2006Rick van Beek Dr. Abstract The properties of a mixed CdTe quantum dot/tetrahydro-4H -thiopyran-4-ylidene-functionalized polythiophene system are reported. This system was prepared by exposing trioctylphosphine (TOP)-capped CdTe quantum dots to the polythiophene in solution. Strong fluorescence emission quenching and shortening of the fluorescence emission lifetimes of both the polythiophene and the quantum dots occur when they are mixed, indicating the occurrence of photoinduced charge separation. Photoinduced absorption spectroscopy reveals a considerable decrease in the population of the polythiophene triplet excited state in the mixed system. These results demonstrate that between the quantum dots and the polythiophene there is both physical and electronic contact, which is mediated by the tetrahydro-4H -thiopyran-4-ylidene side chains. [source] Catalytic Kinetics of the Schiff Base Metal Complexes Bearing Side Chain of Cyclic morpholine in Carboxylic Ester HydrolysisCHINESE JOURNAL OF CHEMISTRY, Issue 6 2007Shu-Lin Zhang Abstract It has been reported that two Schiff base transition metal complexes bearing the side chain of the morpholine ring were synthesized and characterized, and two complexes with the same base agent but different metal ions were used as a simulant hydrolase in the catalytic hydrolysis of p -nitrophenyl picolinate in this paper. The mechanism of PNPP catalytic hydrolysis is proposed and supported by the results of the spectral analysis and the kinetic calculation. A kinetic mathematical model, applied to the calculation of the kinetic and thermodynamics parameters of PNPP catalytic hydrolysis, has been established on the foundation of the mechanism proposed. The result of the study shows that the two complexes have a good catalytic activity in PNPP catalytic hydrolysis, and the rate of the PNPP catalytic hydrolysis was increased with the increase of the pH values in the buffer solution and affected by the polarization effect of metal ion of the complexes. [source] Basicity of Guanidines with Heteroalkyl Side Chains in AcetonitrileEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 30 2008Mirjana Eckert-Maksi Abstract The pKa values of seven novel guanidine derivatives, six of them possessing heteroalkyl substituents capable of forming intramolecular hydrogen bonds, were determined in acetonitrile (MeCN) by using the UV/Vis spectrophotometric titration method. The obtained pKa values range from 24.7 to 27.2. The most basic among the studied guanidines was found to be by ca. 4 pKa units more basic than thewell-known superbase N1,N1,N3,N3 -tetramethylguanidine (TMG). The trends in the changes in the measured pKa values were compared with the experimental (determined by the extended kinetic method) and theoretical [B3LYP/6-311+G(2df,p)//B3LYP/6-31G(d)] gas-phase proton affinities. It was shown that basicity ordering of the bases with dimethylaminopropyl substituents in acetonitrile follows the trend encountered in the gas phase. However, this is not the case for the methoxypropyl-substituted guanidines indicating that in these molecules formation of the intramolecular hydrogen bonds is to large extent hindered due to solvation by acetonitrile.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Synthesis and Glycosidase Inhibitory Activities of Pyrrolidines and Piperidines with N -(Polyhydroxyalkyl) Side ChainsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2007Sabrina Boutefnouchet Abstract Amidification of L -proline (3) with (+)-(R,R)- 6 and (,)-(S,S)-tartaric anhydride diacetate (7) gave N -substituted L -proline derivatives 8a,b, respectively. Acids 8a,b were transformed into diesters 9a,b with MeOH/HCl. Similar reactions with methyl (2S,4R)- 4 and (2R,4S)-4-acetoxypipecolate (5) led to bicyclic lactams 14a,b and 15a. Compounds 8a,b were converted into N -(trihydroxybutyl)pyrrolidine derivatives 8c,d, 10a,b and 11a,b. Methyl (2S,4R)- 20a and (2R,4S)-4-acetoxy- N -[(2S,3S)-1,2,3-trihydroxybutyl]pipecolate (20b) were obtained by displacement of (,)-(2S,2S)-2- O -benzyl-3,4- O -isopropylidene-1-deoxy-1-iodothreitol (19) by 4 and 5. Compounds 20a,b were converted into (2S,4R,2,S,2,S)- 21a and(2R,4S,2,S,3,S)-4-hydroxy-2-hydromethyl- N -(2-benzyloxy-3,4-isopropylidenedioxy)piperidine (21b) and finally into unprotected pentols 22a,b. Nonprotected (2S,2,S,3,S)- 11a and (2S,2,R,3,R)- N -(1,2,3-trihydroxybutyl)prolinol (11b), as well as 22a,b, did not inhibit any of the 13 glycosidases assayed. However, a triacetoxy derivative, (2S,3S)-2,3-diacetoxy-4-[(2R,4S)-4-acetoxy-2-(methoxycarbonyl)piperidin-1-yl]-4-oxobutanoic acid (13b) is an inhibitor (IC50 = 157 ,M) of ,- L -fucosidase from bovine kidney.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Air-Operable, High-Mobility Organic Transistors with Semifluorinated Side Chains and Unsubstituted Naphthalenetetracarboxylic Diimide Cores: High Mobility and Environmental and Bias Stress Stability from the Perfluorooctylpropyl Side ChainADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Byung Jun Jung Abstract N,N,-bis(3-(perfluoroctyl)propyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide (8,3-NTCDI) was newly synthesized, as were related fluorooctylalkyl-NTCDIs and alkyl-NTCDIs. The 8,3-NTCDI-based organic thin-film transistor (OTFT) on an octadecyltrimethoxysilane (OTS)-treated Si/SiO2 substrate shows apparent electron mobility approaching 0.7 cm2 V -1s -1 in air. The fluorooctylethyl-NTCDI (8,2-NTCDI) and fluorooctylbutyl-NTCDI (8,4-NTCDI) had significantly inferior properties even though their chemical structures are only slightly different, and nonfluorinated decyl and undecyl NTCDIs did not operate predictably in air. From atomic force microscopy, the 8,3-NTCDI active layer deposited with the substrate at 120 °C forms a polycrystalline film with grain sizes >4,m. Mobilities were stable in air for one week. After 100 days in air, the average mobility of three OTFTs decreased from 0.62 to 0.12 cm2 V -1s -1, but stabilized thereafter. The threshold voltage (VT) increased by 15 V in air, but only by 3 V under nitrogen, after one week. On/off ratios were stable in air throughout. We also investigated transistor stability to gate bias stress. The transistor on hexamethlydisilazane (HMDS) is more stable than that on OTS with mobility comparable to amorphous Si TFTs. VT shifts caused by ON (30 V) and OFF (,20 V) gate bias stress for the HMDS samples for 1 hour were 1.79 V and 1.27 V under N2, respectively, and relaxation times of 106 and 107 s were obtained using the stretched exponential model. These performances are promising for use in transparent display backplanes. [source] Helically ,-Stacked Conjugated Polymers Bearing Photoresponsive and Chiral Moieties in Side Chains: Reversible Photoisomerization-Enforced Switching Between Emission and Quenching of Circularly Polarized FluorescenceADVANCED FUNCTIONAL MATERIALS, Issue 8 2010Hiroyuki Hayasaka Abstract Novel multifunctional conjugated polymers, [poly(p -phenylene)s and poly(bithienylene-phenylene)s with (R)- and (S)-configurations], which have fluorescence, chirality, and photoresponsive properties, have been designed and synthesized. The polymers are composed of ,-conjugated main chains, where poly(p -phenylene) and poly(bithienylene-phenylene) are fluorescence moieties, and the side chains of the photochromic dithienylethene moiety are linked with chiral alkyl groups. The polymer films exhibit right- or left-handed circularly polarized fluorescence (CPF) and also show reversible quenching and emitting behaviors as a result of photochemical isomerization of the dithienylethene moiety upon irradiation with ultraviolet and visible light. This is the first report realizing the reversible switching of CPF using chirality and photoresponsive properties. [source] Self-Assembly of m -Diethynylbenzene Macrocycles Containing Exoannular Chiral Side Chains,ADVANCED FUNCTIONAL MATERIALS, Issue 12 2006Y. Tobe Abstract Induced circular dichroism (CD) spectra of the m -diethynylbenzene macrocycles (S)- 2 and (R)- 2 that have exoannular chiral side chains are observed in a methanol/chloroform (8:2) solution, indicating the formation of chiral, helical aggregates in solution. Solid films prepared on the surface of quartz substrates by spin-coating solutions of (S)- 2 also exhibit CD signals that are remarkably dependent on the solvent used for the spin-coating. The relationship between the CD spectra and the morphology of the solid films observed by atomic force microscopy is discussed. [source] Electrophilic S -Trifluoromethylation of Cysteine Side Chains in , - and , -Peptides: Isolation of Trifluoro-methylated Sandostatin® (Octreotide) DerivativesHELVETICA CHIMICA ACTA, Issue 11 2008Stefania Capone Abstract The new electrophilic trifluoromethylating 1-(trifluoromethyl)-benziodoxole reagents A and B (Scheme,1) have been used to selectively attach CF3 groups to the S-atom of cysteine side chains of , - and , -peptides (up to 13-residues-long; products 7,14). Other functional groups in the substrates (amino, amido, carbamate, carboxylate, hydroxy, phenyl) are not attacked by these soft reagents. Depending on the conditions, the indole ring of a Trp residue may also be trifluoromethylated (in the 2-position). The products are purified by chromatography, and identified by 1H-, 13C-, and 19F-NMR spectroscopy, by CD spectroscopy, and by high-resolution mass spectrometry. The CF3 groups, thus introduced, may be replaced by H (Na/NH3), an overall Cys/Ala conversion. The importance of trifluoromethylations in medicinal chemistry and possible applications of the method (spin-labelling, imaging, PET) are discussed. [source] Synthesis, and Helix or Hairpin-Turn Secondary Structures of ,Mixed' ,/, -Peptides Consisting of Residues with Proteinogenic Side Chains and of 2-Amino-2-methylpropanoic Acid (Aib)HELVETICA CHIMICA ACTA, Issue 9 2006Dieter Seebach Abstract Twelve peptides, 1,12, have been synthesized, which consist of alternating sequences of , - and , -amino acid residues carrying either proteinogenic side chains or geminal dimethyl groups (Aib). Two peptides, 13 and 14, containing 2-methyl-3-aminobutanoic acid residues or a ,random mix' of ,-, ,2 -, and ,3 -amino acid moieties were also prepared. The new compounds were fully characterized by CD (Figs.,1 and 2), and 1H- and 13C-NMR spectroscopy, and high-resolution mass spectrometry (HR-MS). In two cases, 3 and 14, we discovered novel types of turn structures with nine- and ten-membered H-bonded rings forming the actual turns. In two other cases, 8 and 11, we found 14/15 -helices, which had been previously disclosed in mixed ,/, -peptides containing unusual , -amino acids with non-proteinogenic side chains. The helices are formed by peptides containing the amino acid moiety Aib in every other position, and their backbones are primarily not held together by H-bonds, but by the intrinsic conformations of the containing amino acid building blocks. The structures offer new possibilities of mimicking peptide,protein and protein,protein interactions (PPI). [source] Do Valine Side Chains Have an Influence on the Folding Behavior of , -Substituted , -Peptides?HELVETICA CHIMICA ACTA, Issue 10 2004Alice Glättli The influence of valine side chains on the folding/unfolding equilibrium and, in particular, on the 314 -helical propensity of ,3 -peptides were investigated by means of molecular-dynamics (MD) simulation. To that end, the valine side chains in two different ,3 -peptides were substituted by leucine side chains. The resulting four peptides, of which three have never been synthesized, were simulated for 150 to 200,ns at 298 and 340,K, starting from a fully extended conformation. The simulation trajectories obtained were compared with respect to structural preferences and folding behavior. All four peptides showed a similar folding behavior and were found to predominantly adopt 314 -helical conformations, irrespective of the presence of valine side chains. No other well-defined conformation was observed at significant population in any of the simulations. Our results imply that ,3 -peptides show a structural preference for 314 -helices independent of the branching nature of the side chains, in contrast to what has been previously proposed on the basis of circular-dichroism (CD) measurements. [source] Synthesis, CD Spectra, and Enzymatic Stability of ,2 -Oligoazapeptides Prepared from (S)-2-Hydrazino Carboxylic Acids Carrying the Side Chains of Val, Ala, and LeuHELVETICA CHIMICA ACTA, Issue 12 2003Gérald Lelais , -Peptides offer the unique possibility to incorporate additional heteroatoms into the peptidic backbone (Figs.,1 and 2). We report here the synthesis and spectroscopic investigations of ,2 -peptide analogs consisting of (S)-3-aza- , -amino acids carrying the side chains of Val, Ala, and Leu. The hydrazino carboxylic acids were prepared by a known method: Boc amidation of the corresponding N -benzyl- L - , -amino acids with an oxaziridine (Scheme,1). Couplings and fragment coupling of the 3-benzylaza- ,2 -amino acids and a corresponding tripeptide (N -Boc/C -OMe strategy) with common peptide-coupling reagents in solution led to ,2 -di, ,2 -tri-, and ,2 -hexaazapeptide derivatives, which could be N -debenzylated (4,9; Schemes,2,4). The new compounds were identified by optical rotation, and IR, 1H- and 13C-NMR, and CD spectroscopy (Figs.,4 and 5) and high-resolution mass spectrometry, and, in one case, by X-ray crystallography (Fig.,3). In spite of extensive measurements under various conditions (temperatures, solvents), it was not possible to determine the secondary structure of the ,2 -azapeptides by NMR spectroscopy (overlapping and broad signals, fast exchange between the two types of NH protons!). The CD spectra of the N -Boc and C -OMe terminally protected hexapeptide analog 9 in MeOH and in H2O (at different pH) might arise from a (P)- 314 -helical structure. The N -Boc- ,2 -tri and N -Boc- ,2 -hexaazapeptide esters, 7 and 9, were shown to be stable for 48,h against the following peptidases: pronase, proteinase,K, chymotrypsin, trypsin, carboxypeptidase,A, and 20S proteasome. [source] Interactions of Enzymes and a Lectin with a Chitin-Based Graft Copolymer Having Polysarcosine Side ChainsMACROMOLECULAR BIOSCIENCE, Issue 6 2004Rikiya Nakamura Abstract Summary: The molecular-recognition abilities of a water-soluble chitin derivative, chitin- graft -polysarcosine (2) were investigated using chitinase, lysozyme, and wheat germ agglutinin (WGA). The enzymatic degradabilities of 2 were evaluated using chitinase and lysozyme. The molecular weight of those compounds of 2 with a higher affinity toward water decreased rapidly, as compared with partially deacetylated chitin (1). The 1H NMR spectrum of the low-molecular-weight fraction, yielded after lysozymic hydrolysis, indicated that saccharide residues in the chitinous backbone were specifically recognized by the lysozyme, then , -glycosidic linkages in the backbone were selectively hydrolyzed. Furthermore, the molecular-recognition ability of the chitinous backbone of graft copolymer 2 toward the lectin WGA was elucidated by the enzyme-linked lectin-binding assay (ELLA). It was revealed that the graft copolymer with a lower degree of substitution (DS) value efficiently interacted with WGA. Interestingly, a graft copolymer having longer polysarcosine side chains showed higher recognition ability toward WGA than that having short side chains. The structure of the graft copolymer, chitin- graft -polysarcosine 2, used here. [source] New Siloxane-Organic Polyesters with Azobenzene Side Chains.MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 17 2006Surface Properties, Synthesis, Thermotropic Behavior Abstract Summary: New siloxane-organic polyesters, bearing azo-type units in the side chain, were synthesized by direct solution polycondensation at room temperature, starting from 2,2,-[4-[(4-nitrophenyl)azo]phenyl]iminobisethanol (Disperse Red 19) and different siloxane diacids, using dicyclohexylcarbodiimide as an activator and 4-(N,N -dimethylamino)pyridinium- p -toluenesulfonate as the catalyst. The structure of the obtained polyesters was confirmed by 1H and 13C NMR as well as IR spectroscopy. The molecular weight and polydispersity were estimated by GPC. The thermotropic behavior was investigated by POM, DSC and TOA. The surface composition was determined by ESCA (XPS) analysis and proved enrichment in silicon for all samples. All compounds show good solubility in common organic solvents. An example of a nitroazobenzene-containing side-chain polyester with various siloxane-organic backbones. [source] Novel Polyolefins Containing Crystallizable Isotactic Polystyrene Side ChainsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 18 2008Barbara T. Gall Abstract Vinyl-terminated isotactic polystyrene macromonomers were copolymerized with ethylene and 1-octene to new polyolefin graft copolymers with crystallizable polystyrene side chains. The iPS content was varied from 4 to 78 wt.-% using different metallocene and halfsandwich catalysts. No solubility problems of the stereoregular macromonomer occured, because iPS does not crystallize during polymerization. In addition the polymers show nanophase separation of the polyolefin backbone and the iPS side chains. The crystallization of iPS, having a melting point of about 200,°C, can be achieved by annealing. This synthesis strategy allows the fabrication of a new class of thermoplastic elastomers with improved heat distortion temperatures. [source] Surfactant-Induced Helix Formation of Cylindrical Brush Polymers with Poly(L -lysine) Side ChainsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 10 2008Nikhil Gunari Abstract The complex formation of oppositely charged surfactants with some polypeptides is known to induce , -sheet or helix formation. Here, we report on the complex formation of cylindrical brush polymers with poly(L -lysine) side chains and sodium dodecylsulfate (SDS). With increasing amount of added surfactant the cylindrical polymers first adopt a helical conformation with a pitch of approximately 14,24 nm followed by a spherically collapsed structure before eventually precipitation occurs. CD measurements suggest that the helix formation of the cylindrical brush polymers is driven by the hydrophobicity of the , -sheets formed by the PLL side chain,SDS complexes. [source] Gel-to-Sol and Sol-to-Gel Transitions Utilizing the Interaction of , -Cyclodextrin with Dodecyl Side Chains Attached to a Poly(acrylic acid) BackboneMACROMOLECULAR RAPID COMMUNICATIONS, Issue 10 2005Itsuro Tomatsu Abstract Summary: By utilizing the interaction of , -cyclodextrin (, -CD) with dodecyl side chains in polymers of x mol-% dodecyl-modified poly(acrylic acid) (p(AA/C12(x))), systems that undergo gel-to-sol and sol-to-gel transitions were successfully constructed. Rheological experiments indicated that addition of , -CD to the hydrogel of p(AA/C12(5)) caused a drastic decrease in the viscosity, while addition of oligo(, -CD) to the solution of p(AA/C12(2)) led to a remarkable increase in the viscosity. Photographs for a gel-to-sol transition upon addition of , -CD to 5.0 g,·,L,1 p(AA/C12(5)). [source] Tunable, Temperature-Responsive Polynorbornenes with Side Chains Based on an Elastin Peptide Sequence,ANGEWANDTE CHEMIE, Issue 44 2009Rosemary Zufallscopolymere aus der lebenden Ringöffnungsmetathese-Polymerisation von Norbornenmonomeren, die entweder die VPGVG-Peptidsequenz von Elastin oder einen Pentaethylenglycol-Substituenten enthalten (siehe Schema; Mes=Mesityl, pyr=Pyridin), verfügen über eine untere kritische Entmischungstemperatur (LCST), die leicht durch Variieren des Monomerverhältnisses einstellbar ist. [source] Nanoparticles Featuring Amino Acid-functionalized Side Chains as DNA ReceptorsCHEMICAL BIOLOGY & DRUG DESIGN, Issue 1 2007Partha S. Ghosh A family of nanoparticles has been fabricated featuring cationic amino acid-based side chains. This controlled surface modification provides a tool to investigate the effect of various non-covalent interactions at the nanoparticle,DNA interface. The binding affinities of these nanoparticles towards DNA were determined using fluorescence, exhibiting more than threefold modulation in binding a 37-mer DNA strand. The secondary structure of the DNA strand was distorted upon nanoparticle binding, with the extent of distortion dependent on the structure of amino acid side chain. [source] ChemInform Abstract: Hetero-Double-Helix Formation by an Ethynylhelicene Oligomer Possessing Perfluorooctyl Side Chains.CHEMINFORM, Issue 51 2008Ryo Amemiya Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||