scholarly journals CONFORMATION-SPECIFIC IR AND UV SPECTROSCOPY OF THE AMINO ACID GLUTAMINE: AMIDE-STACKING AND HYDROGEN BONDING IN AN IMPORTANT RESIDUE IN NEURODEGENERATIVE DISEASES

2014 ◽  
Author(s):  
Patrick Walsh ◽  
Timothy Zwier ◽  
Jacob Dean
Keyword(s):  
Hydrogen Bonding ◽  
Amino Acid ◽  
Neurodegenerative Diseases ◽  
Uv Spectroscopy ◽  
Important Residue ◽  
Ir And Uv Spectroscopy

scholarly journals 7-Bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one

Molbank ◽  
10.3390/m1229 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1229
Author(s):  
Timofey N. Chmovzh ◽  
Oleg A. Rakitin
Keyword(s):  
Mass Spectrometry ◽  
Heterocyclic System ◽  
High Resolution Mass Spectrometry ◽  
Uv Spectroscopy ◽  
Hydrolysis Product ◽  
Selenium Dioxide ◽  
Biologically Active ◽  
Photovoltaic Materials ◽  
Organic Photovoltaic Materials ◽  
Ir And Uv Spectroscopy

New heterocyclic systems containing 1,2,5-chalcogenadiazoles are of great interest for the creation of organic photovoltaic materials and biologically active compounds. In this communication, 3,6-dibromopyridazine-4,5-diamine was investigated in reaction with selenium dioxide in order to obtain 4,7-dibromo-[1,2,5]selenadiazolo[3,4-d]pyridazine. We found that 7-bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one, the first representative of the new heterocyclic system, was isolated as a hydrolysis product of the corresponding 4,7-dibromoderivative. The structure of the newly synthesized compound was established by means of elemental analysis, high-resolution mass spectrometry, 1H, 13C NMR, IR and UV spectroscopy, and mass spectrometry.

Enantioselective Nucleophilic Aromatic Substitution Reaction of Azlactones to Synthesize Quaternary α-Amino Acid Derivatives

Synlett ◽  
2020 ◽  
Author(s):  
Xiaohua Liu ◽  
Yi Li ◽  
Hao Pan ◽  
Wang-Yuren Li ◽  
Xiaoming Feng
Keyword(s):  
Hydrogen Bonding ◽  
Charge Transfer ◽  
Amino Acid ◽  
Substitution Reaction ◽  
Nucleophilic Aromatic Substitution ◽  
Amino Acid Derivatives ◽  
Amino Acid Esters ◽  
Aromatic Substitution ◽  
Charge Transfer Interaction ◽  
Acid Esters

AbstractAn asymmetric organocatalytic nucleophilic aromatic substitution reaction of azlactones with electron-deficient aryls was established. A variety of α-aryl α-alkyl α-amino acid esters and peptides were obtained in decent yields and stereoselectivities. A new bifunctional catalytic mode involving charge-transfer interaction and hydrogen bonding is proposed to explain the enantioselectivity.

Cyclic Constraints on Conformational Flexibility in γ-Peptides: Conformation Specific IR and UV Spectroscopy

2013 ◽  
Vol 117 (47) ◽  
pp. 12350-12362 ◽  
Author(s):  
Patrick S. Walsh ◽  
Ryoji Kusaka ◽  
Evan G. Buchanan ◽  
William H. James ◽  
Brian F. Fisher ◽  
...  
Keyword(s):  
Uv Spectroscopy ◽  
Conformational Flexibility ◽  
Ir And Uv Spectroscopy

Quantitative determination of the vinylthio groups in divinyl sulphide copolymers by IR and UV spectroscopy

1981 ◽  
Vol 23 (7) ◽  
pp. 1845-1847
Author(s):  
L.V. Morozova ◽  
E.I. Brodskaya ◽  
D.-S.D. Taryashinova ◽  
S.V. Amosova ◽  
B.A. Trofimov
Keyword(s):  
Quantitative Determination ◽  
Uv Spectroscopy ◽  
Ir And Uv Spectroscopy

CAN SEMIEMPIRICAL QUANTUM MODELS CALCULATE THE BINDING ENERGY OF HYDROGEN BONDING FOR BIOLOGICAL SYSTEMS?

2009 ◽  
Vol 08 (04) ◽  
pp. 691-711 ◽  
Author(s):  
FENG FENG ◽  
HUAN WANG ◽  
WEI-HAI FANG ◽  
JIAN-GUO YU
Keyword(s):  
Hydrogen Bonding ◽  
Amino Acid ◽  
Amino Acid Residue ◽  
Density Functional ◽  
Biological Systems ◽  
Binding Energies ◽  
Semiempirical Model ◽  
Hydrogen Bonded Systems ◽  
High Level ◽  
Hydrogen Bonded

A modified semiempirical model named RM1BH, which is based on RM1 parameterizations, is proposed to simulate varied biological hydrogen-bonded systems. The RM1BH is formulated by adding Gaussian functions to the core–core repulsion items in original RM1 formula to reproduce the binding energies of hydrogen bonding of experimental and high-level computational results. In the parameterizations of our new model, 35 base-pair dimers, 18 amino acid residue dimers, 14 dimers between a base and an amino acid residue, and 20 other multimers were included. The results performed with RM1BH were compared with experimental values and the benchmark density-functional (B3LYP/6-31G**/BSSE) and Möller–Plesset perturbation (MP2/6-31G**/BSSE) calculations on various biological hydrogen-bonded systems. It was demonstrated that RM1BH model outperforms the PM3 and RM1 models in the calculations of the binding energies of biological hydrogen-bonded systems by very close agreement with the values of both high-level calculations and experiments. These results provide insight into the ideas, methods, and views of semiempirical modifications to investigate the weak interactions of biological systems.

Specific features of supramolecular organisation and hydrogen bonding in proline cocrystals: a case study of fenamates and diclofenac

CrystEngComm ◽  
2018 ◽  
Vol 20 (43) ◽  
pp. 6970-6981 ◽  
Author(s):  
Artem O. Surov ◽  
Alexander P. Voronin ◽  
Mikhail V. Vener ◽  
Andrei V. Churakov ◽  
German L. Perlovich
Keyword(s):  
Hydrogen Bonding ◽  
Amino Acid ◽  
Naturally Occurring ◽  
Supramolecular Organisation

New zwitterionic cocrystals of fenamate drugs and diclofenac with the naturally occurring amino acid l-proline have been obtained and thoroughly characterised by a variety of experimental and theoretical techniques.

scholarly journals Diastereo-specific conformational properties of neutral, protonated and radical cation forms of (1R,2S)-cis- and (1R,2R)-trans-amino-indanol by gas phase spectroscopy

2015 ◽  
Vol 17 (39) ◽  
pp. 25809-25821 ◽  
Author(s):  
Aude Bouchet ◽  
Johanna Klyne ◽  
Giovanni Piani ◽  
Otto Dopfer ◽  
Anne Zehnacker
Keyword(s):  
Electronic Structure ◽  
Gas Phase ◽  
Radical Cation ◽  
Amino Alcohol ◽  
Uv Spectroscopy ◽  
Conformational Properties ◽  
Gas Phase Spectroscopy ◽  
Ir And Uv Spectroscopy

The effects of ionisation and protonation on the geometric and electronic structure of a prototypical aromatic amino-alcohol with two chiral centres are revealed by IR and UV spectroscopy.

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