scholarly journals Hyperbranched Poly(ether-siloxane)s Containing Ammonium Groups: Synthesis, Characterization and Catalytic Activity

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 856
Author(s):  
Paweł G. Parzuchowski ◽  
Aleksandra Świderska ◽  
Marlena Roguszewska ◽  
Karolina Rolińska ◽  
Dominik Wołosz ◽  
...  
Keyword(s):  
Methyl Iodide ◽  
Raw Materials ◽  
Ethylene Carbonate ◽  
Step Procedure ◽  
Hyperbranched Poly ◽  
Epoxy Monomer ◽  
Nmr Techniques ◽  
Anionic Ring ◽  
Amine Groups ◽  
Derivatives Of

In this article we report an easy synthetic route towards hyperbranched polyglycerols (Amm-HBPGs) containing trimethylammonium groups and siloxane or hydroxyl end-groups. Siloxane derivatives of Amm-HBPGs were synthesized in an efficient five-step procedure including an anionic ring opening copolymerization of the phthalimide-epoxy monomer with glycidol, followed by reactions with allyl bromide, hydrosililation with hydrogenheptamethyltrisiloxane, hydrazinolysis of phthalimide groups and quaternization of resulting amine groups with methyl iodide. Hydroxyl derivatives were obtained by quaternization of previously reported aminated HBPG’s with methyl iodide. Polymeric products were characterized using various NMR techniques, FTIR, and elemental analysis. Both Amm-HBPGs were shown to be effective in catalysis of addition of CO2 to oxirane. The hydrophilic catalysts showed higher efficiency but synthesis of ethylene carbonate was accompanied by formation of small amounts of ethylene glycol. The siloxane-containing catalyst was easily separable from reaction mixture showing high potential in the process of converting carbon dioxide into valuable chemical raw materials.

scholarly journals Magnesium porphyrazine with peripheral methyl (3,5-dibromophenylmethyl)amino groups – synthesis and optical properties

2019 ◽  
Vol 25 (1) ◽  
pp. 1-7
Author(s):  
Ewelina Wieczorek ◽  
Jaroslaw Piskorz ◽  
Lukasz Popenda ◽  
Stefan Jurga ◽  
Jadwiga Mielcarek ◽  
...  
Keyword(s):  
Optical Properties ◽  
Singlet Oxygen ◽  
Dimethyl Sulfoxide ◽  
Amino Groups ◽  
Absorption And Emission ◽  
Emission Properties ◽  
Step Procedure ◽  
Nmr Techniques ◽  
Ft Ir ◽  
Amine Groups

AbstractNovel magnesium(II) porphyrazine with peripheral methyl(3,5-dibromophenylmethyl)amine groups was synthesized in a multi-step procedure starting from commercially available diaminomaleonitrile. All intermediates and the final macrocycle were characterized using UV–Vis, FT-IR, MS and various NMR techniques. The absorption and emission properties of the macrocycle were evaluated in N,N-dimethylformamide, dimethyl sulfoxide, and dichloromethane. The potential photosensitizing activity was evaluated by assessing the ability of the macrocycle to generate singlet oxygen in dimethyl sulfoxide and N,N-dimethylformamide.

scholarly journals The Curing Process of Epoxy/Amino-Functionalized MWCNTs: Calorimetry, Molecular Modelling, and Electron Microscopy

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
S. G. Prolongo ◽  
M. R. Gude ◽  
A. Ureña
Keyword(s):  
Molecular Simulation ◽  
Electron Microscopic ◽  
Reaction Heat ◽  
Simulation Tools ◽  
Curing Reaction ◽  
Morphological Studies ◽  
Epoxy Monomer ◽  
Curing Kinetic ◽  
Amine Groups ◽  
Functionalized Mwcnts

Curing kinetic of an epoxy resin reinforced with amino-functionalized MWCNTs has been studied by DSC and the obtained results were explained through morphological studies carried out by SEM, TEM, FEG-SEM, and molecular simulation tools. The presence of MWCNTs in the curing reaction induces a retardation effect of curing reaction and a decrease of the reaction heat. Both are associated with the adsorption of curing agent molecules inside carbon nanotubes, which was proved through the application of electron microscopic techniques and molecular simulation tools. It has been also demonstrated that there is a chemical reaction between amine groups anchored to the nanotubes and oxirane rings of epoxy monomer, which improves the nanoreinforcement/matrix interfacial adhesion, appearing a chemical interphase. The glass transition temperature (Tg) of epoxy matrix increases by the addition of MWCNTs due to the restriction of its mobility.

scholarly journals Affinity chromatography and inhibition of chorismate mutase-prephenate dehydrogenase by derivatives of phenylalanine and tyrosine

1977 ◽  
Vol 165 (1) ◽  
pp. 121-126 ◽  
Author(s):  
G D Smith ◽  
D V Roberts ◽  
A Daday
Keyword(s):  
Affinity Chromatography ◽  
Competitive Inhibitor ◽  
Chorismate Mutase ◽  
Prephenate Dehydrogenase ◽  
Step Procedure ◽  
One Step ◽  
High Degree ◽  
Sepharose 4B ◽  
Derivatives Of

Several derivatives of phenylalanine and tyrosine were prepared and tested for inhibition of chorismate mutase-prephenate dehydrogenase (EC 1.3.1.12) from Escherichia coli K12 (strain JP 232). The best inhibitors were N-toluene-p-sulphonyl-L-phenylalanine, N-benzenesulphonyl-L-phenylalanine and N-benzloxycarbonyl-L-phenylalanine. Consequently two compounds, N-toluene-sulphonyl-L-p-aminophenylalanine and N-p-aminobenzenesulphonyl-L-phenylalanine, were synthesized for coupling to CNBr-activated Sepharose-4B. The N-toluene-p-sulphonyl-L-p-aminophenylalanine-Sepharose-4B conjugate was shown to bind the enzyme very strongly at pH 7.5. The enzyme was not eluted by various eluents, including 1 M-NaCl, but could be quantitatively recovered by washing with buffer of pH9. Elution was more effective in the presence of 10 mM-1-adamantaneacetic acid, a competitive inhibitor of the enzyme. This affinity-chromatography procedure results in a high degree of purification of the enzyme and can be used to prepare the enzyme in a one-step procedure from the bacterial crude extract. Such a procedure may therefore prove useful in studying this enzyme in a state that closely resembles that in vivo.

scholarly journals Solvent- and Catalyst-free Synthesis, Hybridization and Characterization of Biobased Nonisocyanate Polyurethane (NIPU)

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1026 ◽  
Author(s):  
Xin He ◽  
Xiaoling Xu ◽  
Qian Wan ◽  
Guangxu Bo ◽  
Yunjun Yan
Keyword(s):  
Raw Materials ◽  
Ethylene Carbonate ◽  
Synthetic Method ◽  
Dimer Acid ◽  
Catalyst Free ◽  
Program Temperature ◽  
Novel Method ◽  
Nonisocyanate Polyurethane ◽  
High Degree

Nonisocyanate polyurethane (NIPU) is a research hotspot in polyurethane applications because it does not use phosgene. Herein, a novel method of solvent- and catalyst-free synthesis of a hybrid nonisocyanate polyurethane (HNIPU) is proposed. First, four diamines were used to react with ethylene carbonate to obtain four bis(hydroxyethyloxycarbonylamino)alkane (BHA). Then, BHA reacted with dimer acid under condensation in the melt to prepare four nonisocynate polyurethane prepolymers. Further, the HNIPUs were obtained by crosslinking prepolymers and resin epoxy and cured with the program temperature rise. In addition, four amines and two resin epoxies were employed to study the effects and regularity of HNIPUs. According to the results from thermal and dynamic mechanical analyses, those HNIPUs showed a high degree of thermal stability, and the highest 5% weight loss reached about 350 °C. More importantly, the utilization of these green raw materials accords with the concept of sustainable development. Further, the synthetic method and HNIPUs don’t need isocyanates, catalysts, or solvents.

scholarly journals O-Aminoalkyl-O-Trimethyl-2,3-Dehydrosilybins: Synthesis and In Vitro Effects Towards Prostate Cancer Cells

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3142 ◽  
Author(s):  
Bao Vue ◽  
Sheng Zhang ◽  
Andre Vignau ◽  
Guanglin Chen ◽  
Xiaojie Zhang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Apoptosis ◽  
Prostate Cancer Cell ◽  
Synthetic Methods ◽  
Step Procedure ◽  
Ic50 Values ◽  
In Vitro Effects ◽  
Synthetic Approaches ◽  
Derivatives Of

As part of our ongoing silybin project, this study aims to introduce a basic nitrogen-containing group to 7-OH of 3,5,20-O-trimethyl-2,3-dehydrosilybin or 3-OH of 5,7,20-O-trimethyl-2,3-dehydrosilybin via an appropriate linker for in vitro evaluation as potential anti-prostate cancer agents. The synthetic approaches to 7-O-substituted-3,5,20-O-trimethyl-2,3-dehydrosilybins through a five-step procedure and to 3-O-substituted-5,7,20-O-trimethyl-2,3- dehydrosilybins via a four-step transformation have been developed. Thirty-two nitrogen-containing derivatives of silybin have been achieved through these synthetic methods for the evaluation of their antiproliferative activities towards both androgen-sensitive (LNCaP) and androgen-insensitive prostate cancer cell lines (PC-3 and DU145) using the WST-1 cell proliferation assay. These derivatives exhibited greater in vitro antiproliferative potency than silibinin. Among them, 11, 29, 31, 37, and 40 were identified as five optimal derivatives with IC50 values in the range of 1.40–3.06 µM, representing a 17- to 52-fold improvement in potency compared to silibinin. All these five optimal derivatives can arrest the PC-3 cell cycle in the G0/G1 phase and promote PC-3 cell apoptosis. Derivatives 11, 37, and 40 are more effective than 29 and 31 in activating PC-3 cell apoptosis.

scholarly journals Ring-opening polymerization of ethylene carbonate: comprehensive structural elucidation by 1D & 2D-NMR techniques, and selectivity analysis

RSC Advances ◽  
2017 ◽  
Vol 7 (19) ◽  
pp. 11786-11795 ◽  
Author(s):  
Rubina Abdul-Karim ◽  
Abdul Hameed ◽  
Muhammad Imran Malik
Keyword(s):  
Ring Opening ◽  
Ethylene Carbonate ◽  
2D Nmr ◽  
Ring Opening Polymerization ◽  
Structural Elucidation ◽  
Nmr Techniques ◽  
Poly Ethylene

Meticulous structural elucidation and selectivity analysis of poly(ethylene ether carbonate) by multi-dimensional NMR.

N-Methylamino Acids in Peptide Synthesis. II. A New Synthesis of N-Benzyloxycarbonyl, N-Methylamino Acids

1973 ◽  
Vol 51 (12) ◽  
pp. 1915-1919 ◽  
Author(s):  
John R. McDermott ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acids ◽  
Methyl Iodide ◽  
Peptide Synthesis ◽  
Side Chains ◽  
Butyl Group ◽  
New Synthesis ◽  
Derivatives Of

Reaction of N-benzyloxycarbonyl derivatives of aliphatic amino acids, and threonine, aspartic, and glutamic acids whose side-chains were protected with the t-butyl group, gave the corresponding N-methylamino acid derivatives in good yields. The methionine derivative could be obtained by using only one mol of methyl iodide. Derivatives of threonine, and aspartic and glutamic acids whose side-chains were not protected could not be methylated. Analysis of the crude products of methylation in three cases showed that they contained 0–1% of racemized material.

Reaction of organosilicon derivatives of 1,1-dimethylhydrazine with methyl iodide

2005 ◽  
Vol 400 (4-6) ◽  
pp. 17-20
Author(s):  
M. G. Voronkov ◽  
B. A. Gostevskii ◽  
B. A. Shainyan ◽  
V. I. Rakhlin ◽  
R. G. Mirskov ◽  
...  
Keyword(s):  
Methyl Iodide ◽  
Derivatives Of
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