scholarly journals A Family of Externally-Functionalised Coordination Cages

Chemistry ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1203-1214
Author(s):  
Garrett D. Jackson ◽  
Max B. Tipping ◽  
Christopher G. P. Taylor ◽  
Jerico R. Piper ◽  
Callum Pritchard ◽  
...  
Keyword(s):  
Binding Constants ◽  
Monomethyl Ether ◽  
Terminal Alkyne ◽  
Bridging Ligands ◽  
Diverse Range ◽  
Exterior Surface ◽  
Click Reactions ◽  
Coordination Cages ◽  
Synthetic Routes ◽  
Derivatives Of

New synthetic routes are presented to derivatives of a (known) M8L12 cubic coordination cage in which a range of different substituents are attached at the C4 position of the pyridyl rings at either end of the bis(pyrazolyl-pyridine) bridging ligands. The substituents are (i) –CN groups (new ligand LCN), (ii) –CH2OCH2–CCH (containing a terminal alkyne) groups (new ligand LCC); and (iii) –(CH2OCH2)3CH2OMe (tri-ethyleneglycol monomethyl ether) groups (new ligand LPEG). The resulting functionalised ligands combine with M2+ ions (particularly Co2+, Ni2+, Cd2+) to give isostructural [M8L12]16+ cage cores bearing 24 external functional groups; the cages based on LCN (with M2+ = Cd2+) and LCC (with M2+ = Ni2+) have been crystallographically characterised. The value of these is twofold: (i) exterior nitrile or alkene substituents can provide a basis for further synthetic opportunities via ‘Click’ reactions allowing in principle a diverse range of functionalisation of the cage exterior surface; (ii) the exterior –(CH2OCH2)3CH2OMe groups substantially increase cage solubility in both water and in organic solvents, allowing binding constants of cavity-binding guests to be measured under an increased range of conditions.

scholarly journals Energetics of carbohydrate binding by a 14 kDa S-type mammalian lectin

1995 ◽  
Vol 308 (1) ◽  
pp. 237-241 ◽  
Author(s):  
R Ramkumar ◽  
A Surolia ◽  
S K Podder
Keyword(s):  
Binding Constants ◽  
Van Der Waals Interactions ◽  
Titration Calorimetry ◽  
Carbohydrate Binding ◽  
Glucose Binding ◽  
The Stability ◽  
L 14 ◽  
Derivatives Of ◽  
Binding Lectin ◽  
Site Binding

The thermodynamics of the binding of derivatives of galactose and lactose to a 14 kDa beta-galactoside-binding lectin (L-14) from sheep spleen has been studied in 10 nM phosphate/150 mM NaCl/10 mM beta-mercaptoethanol buffer, pH 7.4, and in the temperature range 285-300 K using titration calorimetry. The single-site binding constants of various sugars for the lectin were in the following order: N-acetyl-lactosamine thiodigalactoside > 4-methylumbelliferyl lactoside > lactose > 4-methylumbelliferyl alpha-D-galactoside > methyl-alpha-galactose > methyl-beta-galactose. Reactions were essentially enthalpically driven with the binding enthalpies ranging from -53.8 kJ/mol for thiodigalactoside at 301 K to -2.2 kJ/mol for galactose at 300 K, indicating that hydrogen-bonding and van der Waals interactions provide the major stabilization for these reactions. However, the binding of 4-methylumbelliferyl-alpha-D-galactose displays relatively favourable entropic contributions, indicating the existence of a non-polar site adjacent to the galactose-binding subsite. From the increments in the enthalpies for the binding of lactose, N-acetyl-lactosamine and thiodigalactoside relative to methyl-beta-galactose, the contribution of glucose binding in the subsite adjacent to that for galactose shows that glucose makes a major contribution to the stability of L-14 disaccharide complexes. Observation of enthalpy-entropy compensation for the recognition of saccharides such as lactose by L-14 and the absence of it for monosaccharides such as galactose, together with the lack of appreciable changes in the heat capacity (delta Cp), indicate that reorganization of water plays an important role in these reactions.

Synthesen von TRH-Derivaten des Typs L-Pyr-L-His-L-Pro-NH-(CH2)n-NHa (n = 4, 7,10).

1976 ◽  
Vol 31 (10) ◽  
pp. 1410-1415 ◽  
Author(s):  
Stefan Fuchs ◽  
Wolfgang Voelter
Keyword(s):  
General Structure ◽  
Biologically Active ◽  
New Class ◽  
Synthetic Routes ◽  
Derivatives Of

Synthetic routes to a new class of biologically active TRH derivatives of the general structure L—Pyr—L—His—L—Pro—NH—(CH2E)n—NH2 are described.

Monomethyl ether derivatives of 7,8-dihydroxy- and 8,9-dihydroxy-4-propyl-1,2,3,4,4a,5,6,10b-octahydrobenzo[f]quinolines as possible products of metabolism by catechol-O-methyltransferase

1990 ◽  
Vol 33 (7) ◽  
pp. 2000-2006 ◽  
Author(s):  
Joseph G. Cannon ◽  
Kathleen A. Walker ◽  
Antonio Montanari ◽  
John Paul Long ◽  
Jan R. Flynn
Keyword(s):  
Monomethyl Ether ◽  
Derivatives Of

New synthetic routes to B-halogenated derivatives of cobalt dicarbollide

1995 ◽  
Vol 34 (21) ◽  
pp. 5215-5219 ◽  
Author(s):  
Paul K. Hurlburt ◽  
Rebecca L. Miller ◽  
Kent D. Abney ◽  
Trudi M. Foreman ◽  
Raymond J. Butcher ◽  
...  
Keyword(s):  
Synthetic Routes ◽  
Derivatives Of

Synthetic plant growth regulators. The synthesis of C-o-Carboxyphenyl derivatives of some five-membered heterocycles

1977 ◽  
Vol 30 (10) ◽  
pp. 2225 ◽  
Author(s):  
RLN Harris ◽  
JL Huppatz
Keyword(s):  
Plant Growth ◽  
Benzoic Acid ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Heterocyclic Compounds ◽  
Synthetic Routes ◽  
Chloro Derivatives ◽  
Derivatives Of

Synthetic routes to o-carboxyphenyl derivatives of certain heterocyclic compounds, required for testing as plant growth regulators, were investigated. The preparation of 2-(5-phenyl-1,3,4-oxadiazol-2- yl)benzoic acid (3), 2-(5-phenyl-1,3,4-thiadiazol-2-yl)benzoic acid (4), 2-(5-phenyl-1H-1,2,4-triazol-3-yl)benzoic acid (5), 2-(3-phenyl- 1,2,4-oxadiazol-5-yl)benzoic acid (6), 2-(2-phenylthiazol-4-yl)benzoic acid (7), 2-(3-phenylisoxazol-5-yl)benzoic acid (8), 2-(5- phenylisoxazol-3-yl)benzoic acid (9) and chloro derivatives of (3), (4), (8) and (9) is described.

Sign in / Sign up

Export Citation Format

Share Document