- Multigram Synthesis of Well-Defined Extended Bifunctional Polyethylene Glycol (PEG) Chains
-
A series of novel, well-defined, unsymmetrical poly(ethylene glycol) chains of the type X(OCH2-CH2)nY (where X = protecting group; Y = nucleofuge or a different protecting group; n = 3, 6, 9, 12, 15, 18, and 24) were prepared in high yields by applying orthogonal protecting groups. The purity of the compounds was fully verified by elemental and high-resolution mass spectrometry analyses.
- Loiseau, Francois A.,Hii, King Kuok,Hill, Alison M.
-
p. 639 - 647
(2007/10/03)
-
- Novel alkanoic acid derivaties
-
There are provided according to the invention compounds of the formula (I) or a salt or solvate thereof, wherein: n represents an integer 1 to 6; N represents an integer 1 to 15; R1 represents (CO)xC1-9alkyl or (CO)xC1-9fluoroalkyl, which fluoroalkyl moiety contains at least 1 fluorine atom and not more than 3 consecutive perfluorocarbon atoms wherein x represents 0 or 1; and R2 and R3 independently represent C1-3alkyl or hydrogen. There are also provided pharmaceutical aerosol formulations employing said compounds as suspension stabilising agents.
- -
-
-
- Lack of effect of the length of oligoglycine- and oligo(ethylene glycol)-derived para-substituents on the affinity of benzenesulfonamides for carbonic anhydrase II in solution
-
Using 1H NMR spectroscopy, values of T2 have been determined for the methylene protons of the oligoglycine moieties of para-substituted benzenesulfonamides having structures H2NO2SC6H4CO(Gly)(n)OH (n = 1-6) bound at the active site of bovine carbonic anhydrase II (CA, EC 4.2.1.1). These values have been correlated with measurements of dissociation constants of these complexes, in order to infer motion of these ligands when bound to the enzyme. Motion of glycines 1-3 (those closest to the aryl ring) is hindered by their proximity to the protein; motion of glycines 4-6 is relatively unhindered. Despite the restriction to motion inferred for glycines 1-3, the values of K(d) for the six compounds (n = 1-6, 1-6) are indistinguishable within experimental uncertainty (± 20%): K(d) in μM (n) 0.30 (1); 0.26 (2); 0.33 (3); 0.37 (4); 0.37 (5); 0.34 (6). There is, therefore, an unexpected compensation of the loss in conformational entropy on binding by another contributor to the free energy.
- Jain, Ahamindra,Huang, Shaw G.,Whitesides, George M.
-
p. 5057 - 5062
(2007/10/02)
-
- A Novel Procedure for the Synthesis of Ether-Bridged Perfluoro Non-Ionic Surfactants
-
An efficient procedure is described for the synthesis of perfluoro non-ionic surfactants of the type RF-CH2(OC2H4)pOH which involves the use of the principle of solid-liquid phase transfer methodology to simplify the Williamson ether synthesis usually employed in previous procedures.
- Selve, C.,Achilefu, S.,Mansuy, L.
-
p. 799 - 807
(2007/10/02)
-