![4-(2-hydroxyethyl)-10-oxa-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione](/Databaselist/images/loading.webp)
1585-90-6Relevant academic research and scientific papers
Stereochemical effects on the mechanochemical scission of furan-maleimide Diels-Alder adducts
Wang, Zi,Craig, Stephen L.
, p. 12263 - 12266 (2019)
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.
Chlorin derivatives sterically-prevented from self-aggregation with high antitumor activity for photodynamic therapy
Linares, Irwin A.P.,de Oliveira, Kleber T.,Perussi, Janice Rodrigues
, p. 518 - 527 (2017)
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.
Glass-transition temperature governs the thermal decrosslinking behavior of Diels–Alder crosslinked polymethacrylate networks
Dobbins, Daniel J.,Scheutz, Georg M.,Sun, Hao,Crouse, Christopher A.,Sumerlin, Brent S.
, (2019)
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.
Thermodynamic and kinetic study of Diels–Alder reaction between furfuryl alcohol and N-hydroxymaleimides — An assessment for materials application
Laborie, Marie-Pierre,Roucoules, Vincent,de Oliveira, Jamerson Carneiro
, (2020)
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.
Albumin-polymer conjugate nanoparticles and their interactions with prostate cancer cells in 2D and 3D culture: Comparison between PMMA and PCL
Jiang, Yanyan,Lu, Hongxu,Dag, Aydan,Hart-Smith, Gene,Stenzel, Martina H.
, p. 2017 - 2027 (2016)
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.
A novel way to synthesize star polymers in one pot by ATRP of N-[2-(2-bromoisobutyryloxy)ethyl]maleimide and styrene
Deng, Guohua,Chen, Yongming
, p. 18 - 26 (2004)
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.
4D-Printing of Photoswitchable Actuators
Lu, Xili,Ambulo, Cedric P.,Wang, Suitu,Rivera-Tarazona, Laura K.,Kim, Hyun,Searles, Kyle,Ware, Taylor H.
, p. 5536 - 5543 (2021)
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.
Precisely albumin-hitchhiking tumor cell-activated reduction/oxidation-responsive docetaxel prodrugs for the hyperselective treatment of breast cancer
Wei, Wei,Luo, Cong,Yang, Jincheng,Sun, Bingjun,Zhao, Dongyang,Liu, Yan,Wang, Yingli,Yang, Wenqian,Kan, Qiming,Sun, Jin,He, Zhonggui
, p. 187 - 199 (2018)
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.
Efficient method for the synthesis of functionalized basic maleimides
Salewska, Natalia,Milewska, Maria J.
, p. 999 - 1003 (2014)
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.
A Catenane as a Mechanical Protecting Group
Zhang, Min,De Bo, Guillaume
, p. 5029 - 5033 (2020)
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.
