- Stereochemical effects on the mechanochemical scission of furan-maleimide Diels-Alder adducts
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Clarifying the correlation between the chemical structure of mechanophores and their mechanical reactivity informs the design of mechanochemical systems. One specific correlation that has received much recent attention is that between stereoisomerism and mechanical reactivity. Here, we report previously unobserved differences in the mechanical reactivity of furan-maleimide Diels-Alder (DA) stereoisomers. We evaluated the internal competition between the mechanically triggered retro-DA reaction and the mechanochemical ring opening of gem-dichlorocyclopropane mechanophores in the pulsed sonication of polymer solutions. The relative extent of the two sonomechanochemical reactions in the same polymer shows that the endo DA isomer exhibits greater mechanical lability than its exo isomer. This result contrasts with recent measurements of the relative rates of scission in a similar system and points to potential enhanced sensitivity obtained through the use of internal competition as opposed to absolute rates in assessing mechanical reactivity in sonication studies.
- Wang, Zi,Craig, Stephen L.
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- Chlorin derivatives sterically-prevented from self-aggregation with high antitumor activity for photodynamic therapy
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In this study two new chlorin derivatives sterically prevented from aggregation were synthesised by the Diels-Alder reaction between protoporphyrin IX dimethyl ester and 1-(2-hydroxyethyl)maleimide. The compounds were fully characterised by 1H NMR, 13C NMR, UV-Vis and high-resolution mass spectroscopy (HRMS) and their photochemical properties such as singlet oxygen quantum yield (?0), fluorescence quantum yield (?f) and photodegradation were also evaluated. Furthermore, the partition coefficient (log P) revealed that these compounds present amphiphilic properties. Studies of the photodynamic action in tumour cells (HEp-2 and HeLa) and non-tumour cells (Vero) were also performed in order to confirm the photodynamic therapy (PDT) activity that was indicated by the preliminary photophysical studies. Those phototoxicity results were 55–77% higher than the results obtained with the commercial photosensitiser verteporfin. Finally, cytotoxic assays were performed with the new photosensitiser candidates and cell death was determined using fluorescence microscopy, which provided information about the mechanisms of cell death. In general, we have obtained improved and accessible compounds for PDT studies, as highlighted by the research presented here.
- Linares, Irwin A.P.,de Oliveira, Kleber T.,Perussi, Janice Rodrigues
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- Glass-transition temperature governs the thermal decrosslinking behavior of Diels–Alder crosslinked polymethacrylate networks
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A series of Diels–Alder (DA) crosslinked polymethacrylate networks covering a broad range of glass-transition temperatures (Tg) was prepared to establish the relationship between the Tg and the thermal decrosslinking behavior of these networks. A series of permanently crosslinked and uncrosslinked analogues were also prepared to better understand the thermoset-to-thermoplastic transition occurring in the DA networks at elevated temperatures. The network series were studied using dynamic mechanical analysis, which established an inverse relationship between Tg and decrosslinking ability. Differential scanning calorimetry confirmed the viability of the DA linkages in all formulations, and a trapping experiment with 9-anthracenemethanol demonstrated that even the least responsive network was capable of undergoing decrosslinking given appropriate thermal treatment. While polymer chain mobility has long been understood to be a critical factor in healable materials, this work verifies the importance of this parameter in the decrosslinking of DA networks.
- Dobbins, Daniel J.,Scheutz, Georg M.,Sun, Hao,Crouse, Christopher A.,Sumerlin, Brent S.
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- Thermodynamic and kinetic study of Diels–Alder reaction between furfuryl alcohol and N-hydroxymaleimides — An assessment for materials application
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The study of Diels–Alder reactions in materials science is of increasing interest. The main reason for that is the potential thermoreversibility of the reaction. Aiming to predict the behavior of a material modified with maleimido and furyl moieties, 1H NMR and UV-Vis solution studies of the Diels–Alder reaction between furfuryl alcohol and two N-hydroxymaleimides are explored in the present study. Rate constants, activation energy, entropy, and enthalpy of formation were determined from each technique for both reacting systems. Endo and exo isomers were distinguished in 1H NMR, and the transition from a kinetic, controlled Diels–Alder reaction to a thermodynamic one could be observed in the temperature range studied. A discussion on the effect of that on the application in a material was performed. The approach selected considers a simplified equilibrium of the Diels–Alder reaction as the kinetic model, allowing materials scientists to evaluate the suitability of using the reacting molecules for the creation of thermoresponsive materials. The proposed approach determines the kinetic constants without the direct influence of the equilibrium constant value, thereby allowing a more objective data analysis. The effects of the selection of kinetic model, analytical method, and data treatment are discussed.
- Laborie, Marie-Pierre,Roucoules, Vincent,de Oliveira, Jamerson Carneiro
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- Albumin-polymer conjugate nanoparticles and their interactions with prostate cancer cells in 2D and 3D culture: Comparison between PMMA and PCL
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Using proteins as the hydrophilic moiety can dramatically improve the biodegradability and biocompatibility of self-assembled amphiphilic nanoparticles in the field of nanomedicine. In this study, we fabricated and evaluated curcumin loaded albumin-polycaprolactone nanoparticles as a novel drug delivery system for prostate carcinoma therapeutics and compared their performance to poly(methyl methacrylate) (PMMA), a non-degradable and amorphous polymer. The maleimide functionalized poly(ε-caprolactone) (PCL) was obtain using ring opening polymerization (ROP) of ε-caprolactone where N-(2-hydroxyethyl)maleimide was used as an initiator. The resorbable albumin-polymer conjugate was prepared by conjugating the hydrophobic maleimide-terminated PCL to the hydrophilic bovine serum albumin (BSA) via a simple Michael addition reaction. PMMA was conjugated in a similar manner. The amphiphilic BSA-polymer conjugates can self-assemble into nanoparticles, displaying well-defined structure, prolonged storage stability, and excellent biocompatibility. The BSA nanoparticles, with encapsulated curcumin, exhibited highly enhanced antitumor activity compared to free curcumin. Furthermore, the high efficacy of the curcumin loaded nanoparticles was verified by effectively inhibiting the growth of three-dimensional LNCaP multicellular tumour spheroids. The cytotoxicity was attributed to the efficient cellular uptake of the nanoparticles through caveolic endocytosis. The direct comparison between PCL and the PMMA revealed that drug loading and release as well as cytotoxicity is not significantly affected by the nature of the polymer. However, it seems that nanoparticles based on PMMA penetrate quicker into LNCaP multicellular tumour spheroids thanks to the increased stability. The faster penetration was found to reduce the toxicity of the nanoparticles as evidenced by the lower number of dead cells. In contrast, the fully degradable PCL-based nanoparticles were more efficient in delivering the drug, thus limiting the growth of LNCaP multicellular tumour spheroids.
- Jiang, Yanyan,Lu, Hongxu,Dag, Aydan,Hart-Smith, Gene,Stenzel, Martina H.
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- A novel way to synthesize star polymers in one pot by ATRP of N-[2-(2-bromoisobutyryloxy)ethyl]maleimide and styrene
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A one-pot approach to synthesize star polymers by atom transfer radical polymerization (ATRP) of N-[2-(2-bromoisobutyryloxy)ethyl]maleimide (BiBEMI) with a large excess of styrene (St) was described. It was based on preferential consumption of BiBEMI, as an inimer, through its copolymerization with St, to form a branched intermediate in situ as the multifunctional core, which initiated homopolymerization of the excessive St to produce a star polymer. The kinetic studies exhibited two polymerization stages corresponding to the formation of the core with a faster propagating rate and the formation of arms by homopolymerization of St, respectively. 1H NMR spectra showed that in core formation stage random copolymer was formed. Analysis of the basic hydrolyzed products of the core by MALDI-TOF mass spectroscopy confirmed the branched structure of the core. A 6 -shaped polystyrene was also formed simultaneously, and its structure was confirmed by MALDI-TOF mass spectroscopy. Lowering the reaction temperature and using less excessive St could decrease the content of this polymer. Star polymers were characterized by 1H NMR, hydrolysis, and intrinsic viscosity.
- Deng, Guohua,Chen, Yongming
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- 4D-Printing of Photoswitchable Actuators
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Shape-switching behavior, where a transient stimulus induces an indefinitely stable deformation that can be recovered on exposure to another transient stimulus, is critical to building smart structures from responsive polymers as continue power is not needed to maintain deformations. Herein, we 4D-print shape-switching liquid crystalline elastomers (LCEs) functionalized with supramolecular crosslinks, dynamic covalent crosslinks, and azobenzene. The salient property of shape-switching LCEs is that light induces long-lived, deformation that can be recovered on-demand by heating. UV-light isomerizes azobenzene from trans to cis, and temporarily breaks the supramolecular crosslinks, resulting in a programmed deformation. After UV, the shape-switching LCEs fix more than 90 % of the deformation over 3 days by the reformed supramolecular crosslinks. Using the shape-switching properties, we print Braille-like actuators that can be photoswitched to display different letters. This new class of photoswitchable actuators may impact applications such as deployable devices where continuous application of power is impractical.
- Lu, Xili,Ambulo, Cedric P.,Wang, Suitu,Rivera-Tarazona, Laura K.,Kim, Hyun,Searles, Kyle,Ware, Taylor H.
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- Precisely albumin-hitchhiking tumor cell-activated reduction/oxidation-responsive docetaxel prodrugs for the hyperselective treatment of breast cancer
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The anticancer efficacy of chemotherapy is greatly limited by short blood circulation and poor tumor selectivity. Thus, anticancer prodrugs with prolonged systemic circulation, tumor-specific distribution and bioactivation, could significantly strengthen the chemotherapy efficacy. Herein, we design two novel tumor cell reduction/oxidation-responsive docetaxel (DTX) prodrugs, DTX-maleimide conjugates with disulfide bond (DSSM) or thioether bond (DSM) linkages, to evaluate the roles of different sensitive linkages in drug release, pharmacokinetics and therapeutic efficacy. An ester bond-linkage prodrug (DM) is utilized as a non-sensitive control. DSSM and DSM show reduction- or oxidation-sensitive release behavior, respectively, and exhibit hyperselective bioactivation and cytotoxicities between cancerous and normal cells. They could instantly hitchhike blood circulating albumin after i.v. administration with albumin-binding half-lives as short as 1 min, resulting in prolonged systemic circulation, increased tumor accumulation. In response to the upregulated reduction/oxidation environment within tumor cells, DSSM and DSM exhibit selectively release capacity in tumor tissues, their TAITumor/Liver values are over 30-fold greater than DM. Combining the above delivery advantages into one, DSSM and DSM achieve enhanced antitumor efficacy of DTX. Such a uniquely developed strategy, integrating high albumin-binding capability and reduction/oxidation-sensitive drug superselective release in tumors, has great potential to be applied in clinical cancer therapy.
- Wei, Wei,Luo, Cong,Yang, Jincheng,Sun, Bingjun,Zhao, Dongyang,Liu, Yan,Wang, Yingli,Yang, Wenqian,Kan, Qiming,Sun, Jin,He, Zhonggui
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- Efficient method for the synthesis of functionalized basic maleimides
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A three-step procedure involving Diels-Alder condensation of maleic anhydride with furane, formation of N-substituted imide upon reaction with appropriate diamine, and a final retro Diels-Alder regeneration of the maleic carbon-carbon double bond is proposed for an unequivocal synthesis of N-substituted basic maleimides. The novel method is characterized by mild reaction conditions, easy work-up, high yields, and no need for additional catalysis.
- Salewska, Natalia,Milewska, Maria J.
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- A Catenane as a Mechanical Protecting Group
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Mechanophores (mechanoresponsive molecules) offer great promises for the development of smart force-responsive materials. The activity of a mechanophore can be tuned by altering its structure or the composition of the actuating polymer. Here we show that a [2]catenane can act as a mechanical protecting group by diverting tensional forces away from a mechanically active functional group embedded in one of its rings. This property emerges from the mobility of the two rings of the catenane, which are able to rotate along each other until the tension equalizes over the entirety of the catenated framework. This approach provides a new way to control the mechanical activity of a mechanophore.
- Zhang, Min,De Bo, Guillaume
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- Self-healing polyurethanes with shape recovery
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Two new thermoresponsive self-healing polyurethanes (1DA1T and 1.5DA1T) based on the Diels-Alder (DA) reaction between furan and maleimide moieties are developed that use the shape-memory effect to bring crack faces into intimate contact such that healing can take place. Unlike other self-healing polymers, these polymers do not require external forces to close cracks but rather they use the shape-memory effect to autonomously close the crack. Both polyurethanes have a stable polymer structure and comparable mechanical properties to commercial epoxies. A differential scanning calorimeter is employed to check the glass transition temperature of the polymers as well as the DA and retro-DA (rDA) reaction temperatures. These DA and rDA reactions are confirmed with variable-temperature proton nuclear magnetic resonance. Healing efficiency is calculated using a measurement of the failure load from compact tension testing. The results show that the shape-memory effect can replace external forces to close two crack surfaces and the DA reaction can be repeatedly employed to heal the cracks.
- Heo, Yunseon,Sodano, Henry A.
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- Reversible-Addition Fragmentation Chain Transfer Step-Growth Polymerization
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Reversible-addition fragmentation chain transfer (RAFT) polymerization has been widely explored since its discovery due to its structural precision, versatility, and efficiency. However, the lack of tunability of the polymer backbone limits some applications. Herein, we synergistically combine RAFT and step-growth polymerization mechanisms, by employing a highly selective insertion process of a single monomer with a RAFT agent, to achieve RAFT step-growth polymerization. A unique feature of the RAFT step-growth polymers is that each backbone repeat unit bears a pendant RAFT agent, which can subsequently graft side chains in a second polymerization step and afford molecular brush polymers. Enabled by cleavable backbone functionality, we demonstrate transformation of the resulting brushlike polymers into linear chains of uniform size upon a stimulus.
- Archer, Noel Edward,Grant, Michael Jeffery,Tanaka, Joji,You, Wei
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supporting information
p. 15918 - 15923
(2021/10/21)
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- Controlled Covalent Functionalization of 2 H-MoS2 with Molecular or Polymeric Adlayers
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Most air-stable 2D materials are relatively inert, which makes their chemical modification difficult. In particular, in the case of MoS2, the semiconducting 2 H-MoS2 is much less reactive than its metallic counterpart, 1T-MoS2. As a consequence, there are hardly any reliable methods for the covalent modification of 2 H-MoS2. An ideal method for the chemical functionalization of such materials should be both mild, not requiring the introduction of a large number of defects, and versatile, allowing for the decoration with as many different functional groups as possible. Herein, a comprehensive study on the covalent functionalization of 2 H-MoS2 with maleimides is presented. The use of a base (Et3N) leads to the in situ formation of a succinimide polymer layer, covalently connected to MoS2. In contrast, in the absence of base, functionalization stops at the molecular level. Moreover, the functionalization protocol is mild (occurs at room temperature), fast (nearly complete in 1 h), and very flexible (11 different solvents and 10 different maleimides tested). In practical terms, the procedures described here allow for the chemist to manipulate 2 H-MoS2 in a very flexible way, decorating it with polymers or molecules, and with a wide range of functional groups for subsequent modification. Conceptually, the spurious formation of an organic polymer might be general to other methods of functionalization of 2D materials, where a large excess of molecular reagents is typically used.
- Quirós-Ovies, Ramiro,Vázquez Sulleiro, Manuel,Vera-Hidalgo, Mariano,Prieto, Javier,Gómez, I. Jénnifer,Sebastián, Víctor,Santamaría, Jesús,Pérez, Emilio M.
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supporting information
p. 6629 - 6634
(2020/04/07)
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- N-substituted maleimide compound based on drug intermediate as well as preparation and antibacterial activity study thereof
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The invention discloses an N-substituted maleimide compound shown as a formula (I), a preparation method of the compound and application of the compound for inhibiting riziocotinia solani or sclerotinia sclerotiorum. The preparation method comprises the following steps: taking anhydride shown as a formula (II) and organic amines as raw materials, dissolving the raw materials in a solvent acetone, magnetically stirring, completely reacting at room temperature, performing rotary evaporation to remove the solvent acetone, adding methylbenzene to serve as a solvent, carrying out an amidation reaction and a closed-loop dehydration reaction under the actions of stabilizers and a dehydrating agent, separating and purifying the reaction solution after the reaction is ended, thereby obtaining the N-substituted maleimide compound shown as the formula (I). The organic amines refer to chlorobenzylamine, ethanol amine, propanolamine, aminophenol or (R)-(+)-1-(4-metoxybenzene) ethylamine; the stabilizers comprise hydroquinone and anhydrous sodium acetate; the dehydrating agent is triethylamine. The N-substituted maleimide compound disclosed by the invention is simple in preparation method and convenient to operate and has excellent effects on rice sheath blight disease and sclerotinia stem rot. The structural formula is as shown in the specification.
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Paragraph 0091-0093
(2017/10/07)
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- 9,10-Dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones: Synthesis and Investigation of Their Effects on Carbonic Anhydrase Isozymes I, II, IX, and XII
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N-substituted maleimides were synthesized from maleic anhydride and primary amines. 1,4-Dibromo-dibenzo[e,h]bicyclo-[2,2,2]octane-2,3-dicarboximide derivatives (4a-f) were prepared by the [4+2] cycloaddition reaction of dibromoanthracenes with the N-substituted maleimide derivatives. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the new derivatives were assayed against the human (h) isozymes hCA I, II, IX, and XII. All tested bicyclo dicarboximide derivatives exhibited excellent inhibitory effects in the nanomolar range, with Ki values in the range of 117.73-232.87 nM against hCA I and of 69.74-111.51 nM against hCA II, whereas they were low micromolar inhibitors against hCA IX and XII. A series of 9,10-dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones (4a-f) were synthesized from N-substituted maleimide derivatives and 9,10-dibromoanthracene. Compounds 4a-f were assayed against human carbonic anhydrases (hCA) IX and XII, which are the two tumor-associated isozymes, and hCA I and II, which represent the most common off-targets for the development of selective anticancer CA inhibitors.
- G?ksu, Haydar,Topal, Meryem,Keskin, Ali,Gültekin, Mehmet S.,?elik, Murat,Gül?in, Ilhami,Tanc, Muhammet,Supuran, Claudiu T.
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p. 466 - 474
(2016/06/09)
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- NANOPARTICLES FOR DRUG DELIVERY COMPRISING ALBUMIN HAVING A POLYMER CHAIN COUPLED THERETO
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The invention provides a dispersion of assemblies. The assemblies comprise an albumin derivative comprising albumin having a polymer chain coupled thereto, wherein the assemblies comprise a core comprising the polymer chains and a shell comprising the albumin. A process for making the dispersion and methods of using the dispersion are also described.
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- Synthesis of a bridging ligand with a non-denatured protein pendant: Toward protein encapsulation in a coordination cage
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Toward protein encapsulation by a synthetic host, we synthesized an ubiquitin-dangled ligand, a potential precursor of a nanoscale coordination cage. The key step is the addition of a C-terminal Cys76 SH group, which was introduced by Gly76Cys mutation, to a maleimide acceptor on the ligand. The C-terminal mutation and the SH addition to the ligand did not damage the ubiquitin moiety at all, neither structurally nor conformationally.
- Fujita, Daishi,Suzuki, Kosuke,Sato, Sota,Yagi-Utsumi, Maho,Kurimoto, Eiji,Yamaguchi, Yoshiki,Kato, Koichi,Fujita, Makoto
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supporting information; scheme or table
p. 313 - 315
(2012/06/01)
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- TETRAZINE-TRANS-CYCLOOCTENE LIGATION FOR THE RAPID CONSTRUCTION OF RADIONUCLIDE LABELED PROBES
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A Diels-Alder adduct of a irans-cyclooctene with a tetrazine is provided, wherein the adduct bears a substituent labeled with a radionuclide. A method of producing a PET or other image of an organ in an animal or human includes forming the Diels-Alder adduct in the animal or human. Trans-cyclooctenes and tetrazines suitable for preparing the adducts are provided.
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Page/Page column 36 - 37
(2012/02/05)
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- Maleimide-dimethylfuran exo adducts: Effective maleimide protection in the synthesis of oligonucleotide conjugates
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The reaction of maleimide-containing compounds with 2,5-dimethylfuran gives a mixture of exo and endo isomers from which the exo cycloadduct can be easily isolated taking advantage of its stability in concentrated aqueous ammonia. Bifunctional compounds incorporating a dimethylfuran-protected maleimide (exo adduct) have been attached to resin-linked oligonucleotide chains. Removal of protecting groups masking oligonucleotide functionalities followed by retro-Diels-Alder maleimide deprotection affords maleimido-oligonucleotides suitable for conjugation, as assessed by their reaction with different thiols.
- Sanchez, Albert,Pedroso, Enrique,Grandas, Anna
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supporting information; scheme or table
p. 4364 - 4367
(2011/10/18)
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- Dendrimeric alkylated polyethylenimine nano-carriers with acid-cleavable outer cationic shells mediate improved transfection efficiency without increasing toxicity
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Purpose. Improved polycation-based non-viral DNA vectors were sought by preparing dendrimers with polyethylenimine cores surrounded by various shells incorporating structural features intended to facilitate steps in transfection mechanisms. Dendrimeric vectors were designed with (a) an outer oligocation shell, intended to facilitate DNA release inside cells, (b) a hydrophobic C-16 alkyl shell, and (c) a polycationic core, the latter two intended to combine lipid-depletion and osmotic burst endosome escape mechanisms, respectively, and were (d) attached through an a acid-cleavable linker reported to hydrolyze at endosomal pH values. Methods. Vectors and DNA complexes were characterized by dynamic and static light scattering. Flow cytometry was used to quantitate transfection activity and cytotoxicity in CHO-Kl cells. Results. About 5-fold increased transfection activity was obtained for a vector constructed with an outer shell of oligocations attached through acid-cleavable linkers, relative to a control dendrimer with an acidstable linker. The most effective oligocation component of outer shells tested was spermine. Neither modification was associated with increased cytotoxicity. This vector design did not permit an evaluation of the benefit of combining endosome release mechanisms. Conclusion. Using acid-cleavable linkers to attach an outer shell of short, highly-charged oligocations to a PEI-based dendrimeric vector substantially increased transfection efficiency without increasing cytotoxicity.
- Steele, Terry W. J.,Shier, Wayne Thomas
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experimental part
p. 683 - 698
(2011/03/20)
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- Photosensitized oxidations of substituted pyrroles: Unanticipated radical-derived oxygenated products
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(Chemical Equation Presented) Photooxidation of pyrrole adducts 7-10 has been investigated in order to establish a general reaction pattern andmechanism for the formation of the resulting oxygenated products. The reactions were performed in several solvents utilizing both type I and type II sensitizers. In most cases, photooxidations gave complex mixture of products. Among these products, 5,5- or 6,5-bicyclic lactams (11, 15, and 19), maleimide 12 unsaturated γ-lactams (16 and 20), 5-hydroxylactams (13, 17, and21), and 5-methoxylactams (14, 18, and22) wereisolated and characterized. Photooxidation of 2,5-dimethyl-substituted pyrrole 10 in aprotic solvents unexpectedly afforded aldehyde 23 as the major product. Moreover, photooxidation of pyrrole adduct 10 in protic solvents exclusively gave the unprecedented solvent-trapped products 24-27. The formation of products 11-22 was rationalized by the intermediacy of a commonendoperoxide intermediate, whichcould be formedby both type I and type II mechanisms. Compounds 23-27 were most probably formed via an electron-transfer mechanism. 2009 American Chemical Society.
- Alberti, Mariza N.,Vougioukalakis, Georgios C.,Orfanopoulos, Michael
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experimental part
p. 7274 - 7282
(2010/01/16)
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- PROCESSES FOR THE PRODUCTION OF HYDROXYALKYLMALEIMIDES
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A process is provided for producing high purity hydroxyalkylmaleimides in high yields. Hydroxyalkylmaleimides can be represented by: Formula (I) wherein R is an aliphatic, substituted aliphatic, cycloaliphatic or substituted cycloaliphatic linkage having 1 to 12 carbon atoms.
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Page/Page column 10
(2010/11/27)
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- A thermally-cleavable linker for solid-phase synthesis
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Oxabicyclo[2.2.1]norbornenes constitute a convenient and readily cleaved linker for solid-phase organic synthesis. A simple and inexpensive furfuryl-substituted resin has been shown to capture and release maleimide dienophiles under conditions compatible with intermediate synthetic steps. The synthesis of β-amino, -thiophenoxy, and -hydrazino alcohols by epoxide ring opening, and maleimide-functionalized Leu-enkephalin by standard peptide coupling techniques, are described to illustrate the utility of the solid-phase synthesis methodology.
- Keller, Keith A.,Guo, Jianhua,Punna, Sreenivas,Finn
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p. 1181 - 1184
(2007/10/03)
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- Synthesis and antimicrobial activities of N-substituted imides
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In the field of our research programs concerning novel antimicrobial agents, a series of N-substituted imides was synthesized. These compounds were obtained by cyclization of amido-acids in acetic anhydride/sodium acetate or hexamethyldisilazane/zinc bromide for the hydroxy-aromatic derivatives. The hydroxy-alkyl maleimides were directly prepared by condensation of the corresponding amino-alcohol with maleic anhydride in boiling toluene. Most of N-substituted maleimides showed an interesting antimicrobial activity towards bacteria from the ATCC collection (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853) but the MIC values for P. aeruginosa were always high (128 μg/ml). The imides with alkyl substituents showed higher activities than aromatic analogues with MIC values in the range of 8-32 μg/ml. Comparatively, succinimides were practically inactive.
- Zentz, Frederic,Valla, Alain,Le Guillou, Regis,Labia, Roger,Mathot, Anne-Gabrielle,Sirot, Danielle
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p. 421 - 426
(2007/10/03)
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- Synthesis of New Bifunctional Maleimide Compounds for the Preparation of Chemoimmunoconjugates
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Bifunctional maleimide compounds are suitable for binding small molecules to carrier proteins in that they bind to the sulfhydryl group of proteins through the double bond of the maleimide group and to molecules of low molecular weight (e.g. anticancer drugs) through a functional group X. 18 maleimide compounds of the general formula Maleimid-R-X (R = phenylene, benzyl-, methylene-, ethylene, or a m-benzoylethylamide group and X = hydroxy-, amino-, hydrazino-, carboxylic acid-, carboxylic anhydride-, carboxylic acid chloride-, carboxylic acid hydrazide-, oxycarbonylchloride-, aldehyde, keto-, or p-toluenesulfonate-group) were synthesized and characterized through 1H- and 13C-NMR-spectroscopy, elemental analysis, and mass spectrometry.
- Beyer,Krüger,Schumacher,Unger,Kratz
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