6458-06-6Relevant articles and documents
Metal-Betaine Interactions. Part 13. Preparation and Crystal Structures of Four Polymeric Silver(I) Complexes of Betaine Derivatives
Chen, Xiao-Ming,Mak, Thomas C. W.
, p. 3253 - 3258 (1991)
Four polymeric silver(I) complexes of the betaine derivatives pyridiniopropionate (C5H5N+CH2CH2CO2-, L1) and trimethylammoniopropionate (Me3N+CH2CH2CO2-, L2) have been prepared and characterized by X-ray crystallography.The complexes 12)n>2n 1, 12(NO3)2>n> 2, 22(NO3)2>n> 3 and 22(H2O)>n>2n*nH2O 4 all contain bis(carboxylate)-bridged Ag2 dimer units which are extended into stairs-like chains via the co-ordination of each metal centre by a carboxylato oxygen atom from an adjacent unit.A pair of unidentate nitrate ligands occupy axial co-ordination sites on the same side and on opposite sides of the mean plane of the dimer in 2 and 3, respectively; the dimer in 4 has only one axial site occupied by an aqua ligand, resulting in uncommon inter-chain metal-metal contacts in the crystal .
BETA-ALANINE N-METHYLTRANSFERASE
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Page 32; 35-36; 42-43, (2008/06/13)
A beta -alanine NMTase was isolated from limonium latifolium . The purified enzyme catalyzes the N-methylation of beta -alanine, has an isoelectric point of about 5.15 and an apparent molecular weight of about 43 kilodaltons. A full-length cDNA encoding the NMTase was cloned by screening a L. latifolium cDNA library and was sequenced. Expression of the cDNA in transgenic, non- L. latifolium plants resulted in modulation of resistance to stress in the plants.
Intercharge Distance of Flexible Zwitterionic Molecules in Solution
Chevalier, Yves,Perchec, Pierre Le
, p. 1768 - 1774 (2007/10/02)
The conformation of flexible zwitterionic molecules in solutions of polar solvents is studied by means of a NMR chemical shift method.This method makes use of chemical shift changes of NMR lines, induced by the electrostatic field caused by the electrical charges of the zwitterion.The electrostatic field at the observed nucleus is calculated, taking distances of zwitterionic (trimethylammonio)alkanoates in aqueous and methanolic solutions are then deduced from the 13C NMR chemical shift data as a function of the number of methylenes linking the cationic and anionic groups of the zwitterion.The comparison of experimental data with the end to end distances predicted by the rotational isomerism state theory shows that the polymethylene chain has a more folded conformation than the free chain.Electrostatic attraction between the two zwitterionic charges is thus important, although it could be expected that it could be offset by steric hindrance, i.e., by the bulkiness of terminal charged groups.
