scholarly journals Characterization of N⋯O non-covalent interactions involving σ-holes: “electrostatics” or “dispersion”

2016 ◽  
Vol 18 (43) ◽  
pp. 29946-29954 ◽  
Author(s):  
Rahul Shukla ◽  
Deepak Chopra
Keyword(s):  
Non Covalent Interactions ◽  
Pnicogen Bonds ◽  
Covalent Interactions ◽  
Oxygen Atoms

Exploring the possibility of formation of pnicogen bonds or chalcogen bonds by utilizing the σ-holes present on nitrogen and oxygen atoms in per-halo substituted complexes.

scholarly journals The isolation and characterization of the high-molecular-weight glycoprotein from pig colonic mucus

1978 ◽  
Vol 173 (2) ◽  
pp. 569-578 ◽  
Author(s):  
T Marshall ◽  
A Allen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Quaternary Structure ◽  
Water Soluble ◽  
Isolation And Characterization ◽  
Nuclease Digestion ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Equilibrium Centrifugation

1. A high-molecular-weight glycoprotein constitutes over 80% by weight of the total glycoprotein from water-soluble pig colonic mucus. 2. It was isolated from from nucleic acid and non-covalently bound protein by nuclease digestion followed by equilibrium centrifugation in a CsCl gradient. 3. The glycoprotein has the following composition by weight: fucose 10.4%; glucosamine 23.9%; galactosamine 8.3%; sialic acid 9.9%; galactose 20.8%; sulphate 3.0%; protein 13.3%; moisture about 10%. 4. The native glycoprotein has the high mol.wt. of 15×10(6). 5. Reduction of the native glycoprotein with 2-mercaptoethanol results in a glycoprotein of mol.wt. 6×10(6). 6. Pronase digestion removes 29% of the protein (3% of the glycoprotein) but none of the carbohydrate. 7. The molecular weight of the Pronase-digested glycoprotein is 1.5×10(6), which is halved to 0.76×10(6) on reduction with 2-mercaptoethanol. 8. The contribution of non-covalent interactions, disulphide bridges and the non-glycosylated peptide core to the quaternary structure of the glycoprotein are discussed and compared with the known structure of pig gastric glycoportein.

scholarly journals Manifold Dynamic Non-Covalent Interactions for Steering Molecular Assembly and Cyclization

2021 ◽  
Author(s):  
Shaotang Song ◽  
Jie Su ◽  
Lulu Wang ◽  
Zhen Xu ◽  
Chia-Hsiu Hsu ◽  
...  
Keyword(s):  
Real Space ◽  
Molecular Assembly ◽  
Biological Processes ◽  
Chemical Transformations ◽  
Molecular Assemblies ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Space Characterization

Deciphering rich non-covalent interactions that govern many chemical and biological processes is crucial for the design of drugs and controlling molecular assemblies and their chemical transformations. However, real-space characterization of...

scholarly journals Stereodynamic tetrahydrobiisoindole “NU-BIPHEP(O)”s: functionalization, rotational barriers and non-covalent interactions

2016 ◽  
Vol 12 ◽  
pp. 1453-1458 ◽  
Author(s):  
Golo Storch ◽  
Sebastian Pallmann ◽  
Frank Rominger ◽  
Oliver Trapp
Keyword(s):  
Adduct Formation ◽  
Enantioselective Catalysis ◽  
Cellulose Derivatives ◽  
Diphosphine Ligands ◽  
Rotational Barriers ◽  
Covalent Adduct ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Stereodynamic ligands offer intriguing possibilities in enantioselective catalysis. “NU-BIPHEPs” are a class of stereodynamic diphosphine ligands which are easily accessible via rhodium-catalyzed double [2 + 2 + 2] cycloadditions. This study explores the preparation of differently functionalized “NU-BIPHEP(O)” compounds, the characterization of non-covalent adduct formation and the quantification of enantiomerization barriers. In order to explore the possibilities of functionalization, we studied modifications of the ligand backbone, e.g., with 3,5-dichlorobenzoyl chloride. Diastereomeric adducts with Okamoto-type cellulose derivatives and on-column deracemization were realized on the basis of non-covalent interactions. Enantioselective dynamic HPLC (DHPLC) allowed for the determination of rotational barriers of ΔG ‡ 298K = 92.2 ± 0.3 kJ mol−1 and 99.5 ± 0.1 kJ mol−1 underlining the stereodynamic properties of “NU-BIPHEPs” and “NU-BIPHEP(O)s”, respectively. These results make the preparation of tailor-made functionalized stereodynamic ligands possible and give an outline for possible applications in enantioselective catalysis.

Anisotropic Composites of Desaminotyrosine and Desaminotyrosyl Tyrosine Functionalized Gelatin and Bioactive Glass Microparticles

2015 ◽  
Vol 1718 ◽  
pp. 9-14
Author(s):  
Konstanze K. Julich-Gruner ◽  
Andreas Lendlein ◽  
Aldo R. Boccaccini ◽  
Axel T. Neffe
Keyword(s):  
Mechanical Properties ◽  
Bioactive Glass ◽  
Network Formation ◽  
Loss Modulus ◽  
Tensile Tests ◽  
Non Covalent Interactions ◽  
Further Development ◽  
Covalent Interactions ◽  
Thermal Stability Of

ABSTRACTFunctionalization of gelatin with desaminotyrosine (DAT) and desamino tyrosyl tyrosine (DATT) has been demonstrated to allow network formation based on non-covalent interactions of the aromatic moieties. Based on the observation that the DAT(T) groups furthermore could interact with hydroxyapatite fillers, here it was investigated whether such interactions of DAT(T) could also be employed to stabilize composites formed by functionalized gelatins and bioactive glass (BG) particles. Because of sedimentation of the BG microparticles during the gelification, anisotropic composites with two distinct layers were formed. The characterization of mechanical properties by tensile tests and rheology showed that all composites of non-functionalized and DAT(T) functionalized gelatins with BG microparticles showed an increased Young’s modulus (E) up to 3 MPa, an increased storage modulus (G’) up to 100 kPa, increased tensile strength (σmax) up to 3.4 MPa, and increased loss modulus (G’’) compared to the pure matrices. As the observed effects were more pronounced in the DAT(T) functionalized gelatins compared to non-functionalized gelatins, and a much increased thermal stability of these composites was found, it is likely that there are binding interactions between the aromatic moieties and the BG microparticles. This effect open opportunities for the further development of this type of gelatin-based composites for bone regeneration applications.

scholarly journals “Pnicogen bonds” or “chalcogen bonds”: exploiting the effect of substitution on the formation of P⋯Se noncovalent bonds

2016 ◽  
Vol 18 (20) ◽  
pp. 13820-13829 ◽  
Author(s):  
Rahul Shukla ◽  
Deepak Chopra
Keyword(s):  
Noncovalent Bonds ◽  
Non Covalent Interactions ◽  
Pnicogen Bonds ◽  
Covalent Interactions

A direct comparison of pnicogen bonds and chalcogen bonds in P⋯Se non-covalent interactions.

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