scholarly journals Novel carbazole–pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies

2011 ◽  
Vol 7 ◽  
pp. 638-647 ◽  
Author(s):  
Aamer Saeed ◽  
Madiha Irfan ◽  
Shahid Ameen Samra
Keyword(s):  
Ammonium Acetate ◽  
Laser Light ◽  
Laser Light Scattering ◽  
Economical Method ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Molecular Masses ◽  
Average Molecular Masses ◽  
Tga And Dsc ◽  
C Nmr

The synthesis, as well as spectroscopic and thermochemical studies of a novel class of carbazole-4-phenylpyridine co-polymers are described. The synthesis was carried out by a simple and cheaper method compared to the lengthy methods usually adopted for the preparation of carbazole–pyridine copolymers which involve costly catalysts. Thus, two series of polymers were synthesized by a modified Chichibabin reaction, i.e., by the condensation of diacetylated N-alkylcarbazoles with 3-substituted benzaldehydes in the presence of ammonium acetate in refluxing acetic acid. All the polymers were characterized by FTIR, 1H NMR, 13C NMR, UV–vis spectroscopy, fluorimetry, TGA and DSC. The weight average molecular masses (M w) of the polymers were estimated by the laser light scattering (LLS) technique.

Synthesis, in vitro inhibition effect of novel phthalocyanine complexes as carbonic anhydrase and paraoxonase enzyme inhibitors

2020 ◽  
Vol 24 (08) ◽  
pp. 1047-1053
Author(s):  
Emre Güzel ◽  
Barış Seçkin Arslan ◽  
Kübra Çıkrıkçı ◽  
Adem Ergün ◽  
Nahit Gençer ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Enzyme Inhibitors ◽  
Inhibition Effect ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
First Time ◽  
Ft Ir Spectroscopy ◽  
C Nmr

The preparation and assessment of carbonic anhydrase and paraoxonase enzyme inhibition properties of 3-(2-(5-amino-4-(4-bromophenyl)-3-methyl-1H-pyrazol-1-yl)ethoxy)phthalonitrile (2) and its nitrogen-containing non-peripheral phthalocyanine derivatives (3 and 4) are reported for the first time. The new phthalonitrile and its phthalocyanine derivatives have been elucidated by FT-IR spectroscopy, 1H-NMR, [Formula: see text]C-NMR, mass and UV-vis spectroscopy. The results demonstrated that all synthesized compounds moderately inhibited carbonic anhydrase and paraoxonase enzymes. Among the compounds, the most active ones were found to be compound 4 for PON (Ki : 0.14 [Formula: see text]M), compound 3 for hCA I (Ki : 22.52 [Formula: see text]M) and compound 1 for hCA II (Ki : 13.62 [Formula: see text]M).

Detection of serum proteins by high-pressure gel-permeation chromatography with low-angle laser light scattering, compared with analytical ultracentrifugation.

1986 ◽  
Vol 32 (2) ◽  
pp. 363-367 ◽  
Author(s):  
W Flapper ◽  
P J van den Oetelaar ◽  
C P Breed ◽  
J Steenbergen ◽  
H J Hoenders
Keyword(s):  
High Pressure ◽  
Light Scattering ◽  
Analytical Ultracentrifugation ◽  
Laser Light ◽  
Serum Proteins ◽  
Gel Permeation Chromatography ◽  
Laser Light Scattering ◽  
Gel Permeation ◽  
Human Sera ◽  
Molecular Masses

Abstract Human sera were subjected to analytical ultracentrifugation and "high-pressure" gel-permeation chromatography on a system of combined TSK Gel G5000 PW and G3000 SW columns. The chromatographic method produced remarkably superior resolution of the proteins, especially those exceeding 100 000 Da. We calculated the molecular masses of eluted fractions on the basis of their detection by low-angle laser light scattering and their differential refractive index. We discuss the results in relation to the clinical data.

Bioconjugation of papain with poly(N-vinylpyrrolidone): NMR characterization and study of its enzymatic activity

2021 ◽  
Vol 99 (1) ◽  
pp. 10-17
Author(s):  
L.E. Verduzco ◽  
Ana L. García-Pérez ◽  
Ramiro Guerrero-Santos ◽  
Antonio Ledezma-Pérez ◽  
Jorge Romero-García ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Chain Transfer ◽  
Gel Permeation Chromatography ◽  
Acid Group ◽  
H Nmr ◽  
Reversible Addition ◽  
Nmr Characterization ◽  
Vis Spectroscopy ◽  
C Nmr

A poly(vinylpyrrolidone) end-functionalized with a carboxylic acid group (PVP–CO2H) was synthesized by reversible addition-fragmentation chain transfer (RAFT)/macromolecular design via the interchange of xanthates (MADIX) polymerization mediated by 4-(O-ethylxanthyl)methyl benzoic acid. The molecular weight of the as-synthesized PVP–CO2H was estimated through UV–vis spectroscopy (Mn(UV–vis) = 7322 g/mol), gel permeation chromatography (GPC) (Mn(GPC) = 8670 g/mol), and 1H NMR, (Mn(NMR) = 8207 g/mol). The values obtained were close with the theoretical molecular weight (Mn(th) = 7925 g/mol). Subsequently, the preformed PVP–CO2H was activated to produce N-succinimidyl poly(vinylpyrrolidone) (PVP–NHS). This precursor was covalently coupled to papain to produce bioconjugate PVP–papain. The functional group modifications in the PVP chain-end were observed by the variations in the chemical shift values by 1H and 13C NMR and FTIR analysis at each step of the synthesis. The molecular weight of the PVP–papain was obtained by SEC–HPLC and suggests that, on average, four or five chains of PVP–CO2H were attached to one papain molecule. Compared with papain, the PVP–papain exhibited significantly improved catalytic activity, pH, and thermal stability. Additionally, the storage studies showed that the catalytic activity of PVP–papain was about 79% versus the native enzyme (29%), and this activity was maintained even when it was stored for 25 days.

One-Pot Synthesis of Functionalised 4-Spiro-1,4-Dihydropyridines Via [1+2+1+2]-Cyclisation

2017 ◽  
Vol 41 (9) ◽  
pp. 513-516 ◽  
Author(s):  
Pan Zhou ◽  
Biao Hu ◽  
Lingling Lu ◽  
Rong Huang ◽  
Fuchao Yu
Keyword(s):  
Acetic Acid ◽  
Ammonium Acetate ◽  
Water Solution ◽  
Reaction Conditions ◽  
One Pot ◽  
Efficient Approach ◽  
H Nmr ◽  
Three Component Reaction ◽  
C Nmr ◽  
Operational Simplicity

A simple and efficient approach for the synthesis of 4-spiro-1,4-DHP derivatives has been developed, involving one-pot three-component reaction of isatins, N,N-dimethylenaminones with ammonium acetate in EtOH–water solution promoted by acetic acid. Compared with the previous [1+2+3]-cyclisation method, this [1+2+1+2]-cyclisation procedure has advantages as it is more environmentally friendly, has easier operational simplicity, and requires milder reaction conditions. Moreover, these novel compounds have been obtained in moderate to good yields and their structures have been confirmed by 1H NMR, 13C NMR and IR and HRMS spectroscopy.

Zirconocene-mediated selective synthesis of 1,4-bis(alkynyl)benzenes

2020 ◽  
Vol 44 (9-10) ◽  
pp. 571-575
Author(s):  
Bo Zhang ◽  
Hongmei Qu ◽  
Zhongxuan Li ◽  
Yuanyuan Zhai ◽  
Xiaolu Zhou ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dimethyl Ester ◽  
Acid Ethyl Ester ◽  
Coupling Reactions ◽  
Benzene Derivatives ◽  
Phenylene Ethynylene ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
High Yields ◽  
C Nmr

A series of novel 1,4-bis(alkynyl)benzene derivatives were synthesized from trimethylsilyl-substituted alkynes by the mediation of zirconocene with excellent regioselectivity in high yields. The 3,6-bis(trimethylsilyl)-4,5-dialkylphthalic acid dimethyl esters were prepared by cycloaddition of 2,5-bis(trimethylsilyl)zirconacyclopentadienes to dimethyl acetylenedicarboxylate. After iodination with iodine monochloride, 3,6-diiodo-4,5-dialkylphthalic acid dimethyl esters reacted with terminal alkynes to prepare the corresponding 1,4-bis(alkynyl)benzene derivatives by Sonogashira coupling reactions. After removal of trimethylsilyl, 4,5-dibutyl-3,6-bis(ethynyl)phthalic acid dimethyl ester (compound 3) reacted with 4-iodobenzoic acid ethyl ester and 2-iodothiophene, respectively, to obtain the corresponding products 4a and 4c. Compound 3 can be extended to higher oligomers, which reacted with 1-bromo-4-iodobenzene and phenylacetylene in a stepwise manner under Sonogashira conditions to give the phenylene-ethynylene oligomer 5 in an isolated yield of 85%. The structures of the products were confirmed by 1H NMR spectroscopy, 13C NMR spectroscopy, and MS. The optical properties of the 1,4-bis(alkynyl)benzene derivatives were studied by UV-Vis spectroscopy and fluorescence spectra. The results indicated that some can be developed into potential photovoltaic materials.

scholarly journals Synthesis and Characterization of β-Diketimine Schiff Base Complexes with Ni(II) and Zn(II) Ions: Experimental and Theoretical Study

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Ibrahim A. M. Saraireh ◽  
Mohammednoor Altarawneh ◽  
Jibril Alhawarin ◽  
Mahmoud Salman ◽  
Abdel Aziz Abu-Yamin ◽  
...  
Keyword(s):  
Schiff Base ◽  
Schiff Base Complexes ◽  
H Nmr ◽  
Square Planar ◽  
Basic Set ◽  
Vis Spectroscopy ◽  
Elemental Analyses ◽  
Ft Ir ◽  
C Nmr

Schiff base diethyl 4,4-(pentane-2,4-diylidenebis(azanylylidene))benzoate (1) as a new ligand (L) was prepared by the reaction of acetylacetone with benzocaine in the ratio of 1 : 1. Two transition-metal complexes, [Ni(II)(LCl(HOEt))] (2) and [Zn(II)(LCl(HOEt))] (3), have been synthesized from metal salts with didentate Schiff base ligand (L) and characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR UV-Vis spectroscopy, and magnetic susceptibility. The biological activity of the complexes was studied. In addition, the M06-2x density function theory method and the 6-31G(d) basic set were applied to determine the optimized structures of 1–3 and to determine their IR and 1H NMR, 13C NMR spectra theoretically. The data are in good agreement with the experimental results. The geometries of complexes 2 and 3 were determined to be square-planar for 2 and tetrahedral for 3.

Functional chalcone-substituted tetrakis-metallophthalocyanines: Synthesis and spectroscopic characterization

2019 ◽  
Vol 44 (3-4) ◽  
pp. 148-151
Author(s):  
Volkan Çakır
Keyword(s):  
Spectroscopic Characterization ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
New Compounds ◽  
C Nmr

In this study, a new phthalonitrile derivative, ( E)-4-(3-(3-(3-methoxyphenyl)acryloyl)phenoxy)phthalonitrile, and four peripherally ( E)-4-(3-(3-(3-methoxyphenyl)acryloyl)phenoxy) tetrasubstituted new Ni(II), Zn(II), Co(II), and Cu(II) phthalocyanine derivatives are synthesized and characterized. ( E)-4-(3-(3-(3-Methoxyphenyl)acryloyl)phenoxy)phthalonitrile is synthesized by heating ( E)-1-(3-hydroxyphenyl)-3-(3-methoxyphenyl)prop-2-en-1-one and 4-nitrophthalonitrile in the presence of K2CO3 in dry DMF at 60°C for 96 h. The metallophthalocyanines are prepared by cyclotetramerization of ( E)-4-(3-(3-(3-methoxyphenyl)acryloyl)phenoxy)phthalonitrile with NiCl2, Zn(CH3COO)2, CoCl2, and CuCl2 in n-pentanol in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene. Characterization of the new compounds is performed by means of IR, 1H NMR, 13C NMR, and mass and UV-Vis spectroscopy techniques.

scholarly journals Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

2015 ◽  
Vol 11 ◽  
pp. 1089-1095 ◽  
Author(s):  
Yuchun Ren ◽  
Bin Wang ◽  
Xiuqing Zhang
Keyword(s):  
Nmr Spectroscopy ◽  
Crucial Role ◽  
Molecular Structures ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Thermal Phase ◽  
Reversible Gel ◽  
Phase Behaviors ◽  
Insight Into ◽  
C Nmr

A series of azobenzene–cholesterol organogel compounds (M 0 –M 12 ) with different spacers were designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial role in the gelation. Compound M 6 is the only one that can gelate in ethanol, isopropanol and 1-butanol and the reversible gel–sol transitions are also investigated. To obtain visual insight into the microstructure of the gels, the typical structures of the xerogels were studied by SEM. Morphologies of the aggregates change from flower-like, network and rod with different sizes. By using IR and XRD characterization, it is found that intermolecular H-bonding, the solvents and van der Waals interaction are the main contributions to the specific superstructure.

scholarly journals A small bifunctional chelator that modulates Aβ42 aggregation

2018 ◽  
Vol 96 (1) ◽  
pp. 78-82 ◽  
Author(s):  
Chaofeng Zhang ◽  
Luiza M.F. Gomes ◽  
Tonglu Zhang ◽  
Tim Storr
Keyword(s):  
Metal Binding ◽  
Cycloaddition Reaction ◽  
Amyloid Β ◽  
Suitable Candidate ◽  
Bifunctional Chelator ◽  
H Nmr ◽  
Multifunctional Compounds ◽  
Vis Spectroscopy ◽  
Aβ Aggregation ◽  
C Nmr

Multifunctional compounds that can modulate amyloid-β (Aβ) aggregation and interact with metal ions hold considerable promise as therapeutic agents for Alzheimer’s disease (AD). Using the copper-catalyzed azide-alkyne cycloaddition reaction, a novel bifunctional chelator 2-(1-(4-(dimethylamino)benzyl)-1H-1,2,3-triazol-4-yl)phenol (L1) was synthesized. L1 contains a bidentate metal-binding unit and a pendant dimethylamino moiety. The product was characterized by 1H NMR, 13C NMR, and MS. The metal-binding properties of L1 were probed by UV–vis spectroscopy to determine Cu:L stoichiometry. L1 was determined to limit Aβ aggregation at 48 h via a ThT assay. In addition, L1 complies with Lipinski’s rules and calculated logBB values for potential drug likeness and BBB permeability. These results suggest that L1 is a suitable candidate for further study as a multifunctional compound to treat AD.

A convenient synthesis of phthalocyanines bearing four methyl 4-hexyloxyphenyl-2-phenoxy acrylate functionalities

2009 ◽  
Vol 13 (06) ◽  
pp. 739-746 ◽  
Author(s):  
A. Aslı Esenpınar ◽  
A. Rıza Özkaya ◽  
Mustafa Bulut
Keyword(s):  
Hydroxy Group ◽  
Elemental Analysis ◽  
Lactone Ring ◽  
Redox Behavior ◽  
Synthetic Pathway ◽  
H Nmr ◽  
Maldi Tof ◽  
Convenient Synthesis ◽  
Vis Spectroscopy ◽  
C Nmr

A novel synthetic pathway for the preparation of a new phthalonitrile derivative, methyl (E)-3-[2-(3,4-dicyanophenoxy)-4-(hexyloxy)phenyl]acrylate (3), based on the opening of the lactone ring of 7-hexyloxycoumarin (2H-1-benzopyrane-2-one, 2H-chromen-2-one) and ether formation of the formed hydroxy group with 4-nitrophthalonitrile, is presented. Cyclotetramerization of this dinitrile in 2-N,N-dimethylaminoethanol gives the desired Zn(II) , Co(II) and Cu(II) phthalocyanines (4, 5 and 6) with four methyl 4-hexyloxy-2-phenoxy acrylate moiety on periphery. The complexes are characterized by IR, elemental analysis, 1 H NMR, 13 C NMR MALDI-TOF and UV-vis spectroscopy. The redox behavior of the complexes are also discussed.

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