5426-09-5Relevant articles and documents
Organoseleno cytostatic derivatives: Autophagic cell death with AMPK and JNK activation
Garnica, Pablo,Encío, Ignacio,Plano, Daniel,Palop, Juan A.,Sanmartín, Carmen
, p. 234 - 246 (2019)
Selenocyanates and diselenides are potential antitumor agents. Here we report two series of selenium derivatives related to selenocyanates and diselenides containing carboxylic, amide and imide moieties. These compounds were screened for their potency and selectivity against seven tumor cell lines and two non-malignant cell lines. Results showed that MCF-7 cells were especially sensitive to the treatment, with seven compounds presenting GI50 values below 10 μM. Notably, the carboxylic selenocyanate 8b and the cyclic imide 10a also displayed high selectivity for tumor cells. Treatment of MCF-7 cells with these compounds resulted in cell cycle arrest at S phase, increased levels of pJNK and pAMPK and caspase independent cell death. Autophagy inhibitors wortmannin and chloroquine partially prevented 8b and 10a induced cell death. Consistent with autophagy, increased Beclin1 and LC3-IIB and reduced SQSTM1/p62 levels were detected. Our results point to 8b and 10a as autophagic cell death inducers.
New polymer systems based on alicyclic polyimides
Zhubanov,Kravtsova,Mukhamedova,Bekmagambetova
, p. 1869 - 1874 (2006)
Specific features of modification of some alicyclic polyimides with polyamido acids derived from aromatic tetracarboxylic acid dianhydrides were studied. The possibility of preparing new polymer systems with improved characteristics was demonstrated.
Synthesis, crystal structure, spectroscopic properties and potential anti-cancerous activities of four unsaturated bis-norcantharimides
Cheng, Shuang-Shuang,Shi, Yan,Ma, Xiao-Na,Xing, Dian-Xiang,Liu, Lian-Dong,Liu, Yun,Zhao, Yun-Xue,Sui, Qi-Cheng,Tan, Xue-Jie
, p. 228 - 240 (2016)
Four unsaturated norcantharimide (UNCI) dimers were synthesized and characterized by elemental analysis, ESI-QTOF-MS, FT/IR, UV-Vis, 1H and 13C NMR as well as single crystal X-ray diffraction. In addition, theoretical studies have been investigated to compare with the experimental findings. Introduction of various lengths of single bond link chains provides high conformational flexibility and thus unusual molecular and crystal structures for dimers. Two of the four dimers twist into helicate, but crystallize into centrosymmetric lattice; one adopts approximately centrosymmetric conformer, but packs into non-centrosymmetric polar space group (P21). Moreover, in vitro cytotoxic activities of four UNCI dimers and their corresponding saturated NCI dimers were evaluated. All four UNCI dimers are inactive and one NCI dimer shows modest cytotoxicity. These findings were compared with the relevant results in literature. It is found that the antitumor properties of UNCI/NCI dimers depend mainly on the length of link chains (the longer chain, the higher therapeutic efficacy) and have relationship with the double bond, which requires more experimental support.
New Dielectric Elastomers with Variable Moduli
Hu, Wei,Ren, Zhi,Li, Junpeng,Askounis, Erin,Xie, Zhixin,Pei, Qibing
, p. 4827 - 4836 (2015)
Dielectric elastomers have been widely investigated for muscle-like soft actuators and capacitive sensors. Mechanical properties play a central role in the performances of the active material. Most elastomers have specific moduli pre-determined by the polymers' molecular structures, which are not suitable for applications in changing working conditions as natural muscles are capable of. Here new dielectric elastomers are described exhibiting variable moduli controlled via thermal treatment. The elastomers contain furan-maleimide Diels-Alder adduct moieties to administer the crosslinking densities of the elastomeric networks via reversible Diels-Alder/retro-Diels-Alder cycloaddition reaction, resulting in changes in the elastomers' moduli. One of the synthesized elastomers has moduli that can be controlled between 0.17 and 0.52 MPa incrementally and reversibly. Capacitive strain sensors based on this elastomer can be operated in both rigid and soft modes to achieve variable sensing response up to 30% linear strain. Actuators were fabricated and operated in both high strain mode (35% actuation area strain at 65 MV m-1) and high force output mode (0.55 MPa at 104 MV m-1). The elastomers can exhibit a range of stress-strain outputs in similar fashion as muscle.
ACCELERATION OF A DIELS-ALDER REACTION IN AN ULTRACENTRIFUGE
Dolata, Daniel P.,Bergman, Rolf
, p. 707 - 708 (1987)
The reaction rate for the Diels-Alder reaction between maleic anhydride and furan is increased when performed in an ultracentrifuge.
Synthesis and reactivity of a fluorinated N-alkylmaleimide towards free-radical grafting and polymerization reactions
Castelvetro, Valter,Aglietto, Mauro,Ciardelli, Francesco,Spagnoli, Federica
, p. 315 - 328 (2004)
A new fluorinated N-alkylmaleimide, N-(2-pentadecafluoro-n-octanoyloxy)- ethyl)maleimide (FOMI), was synthesized from perfluorooctyl carboxylic acid (FOCA) by reaction of the furan adduct of maleic anhydride (MAH) with ethanolamine and esterification of the resulting alcohol-imide. The reactivity of FOMI in free-radical reactions such as copolymerization with butyl vinyl ether (BVE) and grafting onto olefin copolymers (OCP) was investigated. Copolymerization with 2/1 molar excess BVE yields a copolymer with 63 mol% FOMI in moderate conversion, indicating that homopropagation of the maleimide prevails over comonomer alternation. The thermal stability of FOMI is quite poor, with onset of the pyrolytic loss of the N-perfluoroalkylcarboxyethyl moiety just above 100 °C, similarly to that of FOCA. This restricts the possibilities for direct melt functionalization of OCP with FOMI. To bypass this limitation three distinct approaches were preliminarly investigated. These were respectively based on either direct grafting of FOMI at low temperature, or reaction of a MAH-grafted polyolefin with a low molecular weight amine or amino-terminated oligomer bearing the perfluoroheptyl group. A functionalization degree FD=2% was achieved by solution grafting of a linear very low density polyethylene (VLDPE) with FOMI and Perkadox 16 as the free-radical initiator. The relatively high grafting efficiency was attributed to the growth of some oligomeric FOMI grafts onto the OCP. The alternative routes of post-modification of VLDPE- g -MAH by imidization with an amidoamine obtained by amidation of FOCA with a diamine or an amino-terminated FOMI/BVE oligomer, respectively, were also preliminarly investigated.
Albumin-micelles via a one-pot technology platform for the delivery of drugs
Jiang, Yanyan,Liang, Mingtao,Svejkar, Domenic,Hart-Smith, Gene,Lu, Hongxu,Scarano, Wei,Stenzel, Martina H.
, p. 6394 - 6397 (2014)
A new micelle delivery platform based on albumin coated nanoparticles is able to selectively deliver the payload to cancerous cells while healthy cells remain less affected. The technology is simple and can be used in a one-pot procedure. the Partner Organisations 2014.
Reversible-Addition Fragmentation Chain Transfer Step-Growth Polymerization
Archer, Noel Edward,Grant, Michael Jeffery,Tanaka, Joji,You, Wei
supporting information, p. 15918 - 15923 (2021/10/21)
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.
Bridging from the Sequence to Architecture: Graft Copolymers Engineering via Successive Latent Monomer and Grafting-from Strategies?
Zhang, Yajie,Cao, Xiaohuan,Gao, Yang,Xie, Yujie,Huang, Zhihao,Zhang, Zhengbiao,Zhu, Xiulin
supporting information, p. 1273 - 1280 (2021/05/04)
The on-demand building copolymer structures, from sequence to architecture, is crucial in understanding the relation between polymer structure and property, meanwhile motivating the innovation of polymer hierarchy. However, the challenge is conspicuous for complicated polymer structures from inherently intricate polymerization. In this work, copolymers with tailored grafting density and distributions were achieved using successive latent monomer and grafting-from strategies. The hydroxyl group functionalized furan/maleimide adduct (FMOH) was selected as the latent monomer for RAFT polymerization of an array of copolymers with tailored localization of hydroxyl group along the main chain. The hydroxyl group further initiated the ring opening polymerization (ROP) of L-lactide or ε-caprolactone, resulting in a library of multicomponent copolymers via grafting-from strategy. The initiating efficiency reached to ~100% with variable molecular weight (21300—58600 Da) and narrow distributions (DM 1.25), indicating that such graft copolymers possessed controlled density and distribution of side chains as its linear template. The investigation on thermal properties of the well-defined graft copolymers implied that the precise tailoring over copolymer structures at the molecule level could lead to tunable chemical/physical properties. This work bridged polymer from sequence to architecture, unveiled a new method in creating graft copolymers with programmable structures and provided the insight into the structure/property relationship.
A Mechanochemical Reaction Cascade for Controlling Load-Strengthening of a Mechanochromic Polymer
Boulatov, Roman,Pan, Yifei,Tian, Yancong,Wang, Chenxu,Weng, Wengui,Xiang, Shishuai,Xu, Piaoxue,Zhang, Huan
supporting information, p. 21980 - 21985 (2020/10/02)
We demonstrate an intermolecular reaction cascade to control the force which triggers crosslinking of a mechanochromic polymer of spirothiopyran (STP). Mechanochromism arises from rapid reversible force-sensitive isomerization of STP to a merocyanine, which reacts rapidly with activated C=C bonds. The concentration of such bonds, and hence the crosslinking rate, is controlled by force-dependent dissociation of a Diels–Alder adduct of anthracene and maleimide. Because the adduct requires ca. 1 nN higher force to dissociate at the same rate as that of STP isomerization, the cascade limits crosslinking to overstressed regions of the material, which are at the highest rate of material damage. Using comb polymers decreased the minimum concentration of mechanophores required to crosslinking by about 100-fold compared to previous examples of load-strengthening materials. The approach described has potential for controlling a broad range of reaction sequences triggered by mechanical load.
