1201808-31-2Relevant articles and documents
Influence of the side-chain structure and molecular weight on the re-entrant behaviors of mesogen-jacketed liquid crystalline polymers
Xiang, Zheng,Chen, Sheng,Luo, Yongbing,Li, Ping,Zhang, Hailiang
, p. 78516 - 78527 (2016)
Three series of mesogen-jacketed liquid crystalline polymers (MJLCPs) containing different terminal groups (phenmethyl, diphenylmethyl and triphenylmethyl) in the side chains, abbreviated as Pv-m-Bn, Pv-m-DPM, Pv-m-Tr (m = 2, 4, 6, 8, 10, and 12, which are the number of methylene units between the terephthalate core and terminal groups in the side chains), were designed and successfully synthesized via free-radical polymerization. Molecular characterization of the polymers was performed by 1H NMR, GPC and TG analysis. The phase structures and transitions of the polymers were investigated by a combination of techniques including DSC, POM and 1D/2D WAXD. The experimental results revealed that all the polymers exhibited excellent thermal stabilities and the re-entrant behaviors of the MJLCPs were found to be strongly dependent on the structure of the side-chain, i.e., the spacer length increased with the volume of the terminal groups when the polymers exhibited the re-entrant isotropic phase. On the other hand, a series of MJLCPs, poly{2,5-bis[(diphenylmethoxy-ethyl)oxycarbonyl]-styrenes} (Pv-2-DPMs), with different molecular weights (Mn) and narrow Mn distributions have been successfully synthesized via ATRP. The results indicated that when the Mn was below 1.73 × 104 g mol-1, only the isotropic phase was observed. When Mn was between 3.40 × 104 g mol-1 and 8.48 × 104 g mol-1, a re-entrant isotropic phase was formed at low temperatures and a columnar nematic phase at high temperatures. By further increasing the Mn to exceed 9.71 × 104 g mol-1, a stable columnar nematic phase was developed. This work provides two effective ways to design and synthesize MJLCPs with re-entrant behaviors; moreover, it is meaningful to deeply understand the structure-property relationships of MJLCPs.
Reductive cleavage of acetals/ketals with ZrCl4/NaBH4
Purushothama Chary,Santosh Laxmi,Iyengar
, p. 1257 - 1261 (1999)
Reductive cleavage of acetals/ketals with zirconium tetrachloride- sodium borohydride leading to the formation of ether alcohols is described.
A convenient synthetic route to differentially functionalized long chain polyethylene glycols
Burns,Field,Hashimoto,Petteys,Ridley,Samankumara Sandanayake
, p. 2337 - 2347 (1999)
A convenient and efficient synthetic route to differentially functionalized polyethylene glycols (PEGs) starting from cheap commercially available materials is reported. Selectively protected triethylene glycol or tetraethylene glycol have been reacted with a second PEG bearing both a protecting group and a leaving group.
Design, Synthesis, and Characterization of Brequinar Conjugates as Probes to Study DHODH Inhibition
Madak, Joseph T.,Cuthbertson, Christine R.,Chen, Wenmin,Showalter, Hollis D.,Neamati, Nouri
, p. 13875 - 13878 (2017)
Brequinar, a potent dihydroorotate dehydrogenase (DHODH) inhibitor, has been evaluated in multiple clinical trials as a potential treatment for cancer. To further understand brequinar-based DHODH inhibition and DHODH′s therapeutic relevance in cancer, we
Development of a Scalable Process for α-Amino-ω-methoxyl-dodecaethylene Glycol
Xia, Guiquan,Li, Yu,Yang, Zhigang,Jiang, Zhong-Xing
, p. 1769 - 1773 (2015)
We have developed a process for the efficient and scalable preparation of heterofunctionalized dodecaethylene glycol from the readily available tetraethylene glycol and its macrocyclic sulfate. By employing the benzyl group as both a protecting group and a separative tag, multiple chromatographic separations were avoided. With this method, α-amino-ω-methyl-dodecaethylene glycol was prepared on a 53 g scale with high purity and 61% overall yield in eight steps and one chromatographic separation.
New facts concerning the reaction of K-, K+(15-crown-5)2 with phenyl glycidyl ether: Unexpected formation of potassium cyclopropoxide
Grobelny, Zbigniew,Stolarzewicz, Andrzej,Maercker, Adalbert,Demuth, Wolfgang
, p. 153 - 157 (1999)
A new mechanism of the reaction of K-, K+(15-crown-5)2 with phenyl glycidyl ether is presented. The linear ether bond is attacked only to a small extent, if at all. As the main reaction path the oxirane bond in the β-posit
Design of nanosystems for the delivery of quorum sensing inhibitors: A preliminary study
Bortolotti, Daria,Cortesi, Rita,Esposito, Elisabetta,Hallan, Supandeep Singh,Marchetti, Paolo,Mariani, Paolo,Rizzo, Roberta,Sguizzato, Maddalena,Trapella, Claudio
, (2020)
Biofilm production is regulated by the Quorum Sensing system. Nowadays, Quorum Sensing represents an appealing target to design new compounds to increase antibiotics effects and avoid development of antibiotics multiresistance. In this research the use of liposomes to target two novel synthetic biofilm inhibitors is presented, focusing on a preformulation study to select a liposome composition for in vitro test. Five different liposome (LP) formulations, composed of phosphatidyl choline, cholesterol and charged surfactant (2:1:1, molar ratio) have been prepared by direct hydration and extrusion. As charged surfactants dicetyl phosphate didecyldimethylammonium chloride, di isobutyl phenoxy ethyl dimethyl benzyl ammonium chloride and stearylamine (SA) and have been used. Liposome charge, size and morphology were investigated by zeta potential, photon correlation spectroscopy, small angle x-ray spectroscopy and electron microscopy. LP-SA was selected for the loading of biofilm inhibitors and subjected to high performance liquid chromatography for entrapment capacity evaluation. LP-SA loaded inhibitors showed a higher diameter (223.6 nm) as compared to unloaded ones (205.7 nm) and a dose-dependent anti-biofilm effect mainly after 48 h of treatment, while free biofilm inhibitors loose activity. In conclusion, our data supported the use of liposomes as a strategy to enhance biofilm inhibitors effect.
Unexpected Cleavage of Crown Ether in the Reaction of Methyloxirane with K-,K+(15-crown-5)2
Grobelny, Zbigniew,Stolarzewicz, Andrzej,Czaja, Monika,Demuth, Wolfgang,Maercker, Adalbert
, p. 8990 - 8994 (1999)
Cleavage of oxirane and crown ether rings occurs when the supramolecular complex K-,K+(15-crown-5)2 reacts with methyloxirane in tetrahydrofuran solution. Potassium isopropoxide and potassium tetraethylene glycoxide vinyl
Development of a sensitive bioluminogenic probe for imaging highly reactive oxygen species in living rats
Kojima, Ryosuke,Takakura, Hideo,Kamiya, Mako,Kobayashi, Eiji,Komatsu, Toru,Ueno, Tasuku,Terai, Takuya,Hanaoka, Kenjiro,Nagano, Tetsuo,Urano, Yasuteru
, p. 14768 - 14771 (2015)
A sensitive bioluminogenic probe for highly reactive oxygen species (hROS), SO3H-APL, was developed based on the concept of dual control of bioluminescence emission by means of bioluminescent enzyme-induced electron transfer (BioLeT) and modulation of cell-membrane permeability. This probe enables non-invasive visualization of physiologically relevant amounts of hROS generated deep inside the body of living rats for the first time. It is expected to serve as a practical analytical tool for investigating a wide range of biological functions of hROS in vivo. The design concept should be applicable to other in vivo bioluminogenic probes. You light up my life: A sensitive bioluminogenic probe for highly reactive oxygen species (hROS) was developed based on the concept of dual control of bioluminescence emission by means of bioluminescent enzyme-induced electron transfer (BioLeT) and modulation of cell-membrane permeability. This probe enables non-invasive visualization of physiologically relevant amounts of hROS generated deep inside the body of living rats.
Fe2O3-Promoted Intermolecular Chlorotrifluoromethylthiolation of Alkenes
Jia, Yimin,Qin, Hongmei,Wang, Na,Jiang, Zhong-Xing,Yang, Zhigang
, p. 2808 - 2817 (2018)
A simple, convenient method for intermolecular chlorotrifluoromethylthiolation of alkenes by using a low-cost and more abundant iron catalyst has been developed. This protocol provides a straightforward way to synthesize a variety of useful SCF3/sub
