In the crystal structure of the title coordination polymer, {[Zn(2)(C(24)H(18)N(4)O(10))(H(2)O)(4)]·H(2)O}(n), the mol-ecular building block (MBB), viz [Zn(2)(CO(2))(4)(H(2)O)(4)], comprises two Zn(II) cations, each bridged by three carboxyl-ate groups from different ligand mol-ecules. These two Zn(II) cations exhibit different coordination environments: a distorted trigonal-pyramidal coordinat...

The synthesis of N-acetyl-L-isoasparagine and of N-acetylL-isoglutamine is reported. The acid dissociation constants of these compounds, and those of their corresponding Ncarbobenzoxy derivatives, have been measured. Since these compounds are uncharged molecules of the type -NH-CH(-CH,COOH)-COor the corresponding glutamyl homologue, their dissociation constants represent the intrinsic dissociat...

Functionalized carbon nanotubes have tremendous potential for nanotechnology applications such as in the fabrication of polymeric carbon fibers. However, approaches to design carbon nanotube structures by using functional groups as glue and carbon nanotubes as stiff building blocks to reach superior mechanical strength and toughness at the fiber level with limited amount of materials remains po...

The reactivity of different diazoalkane reagents was examined using the coupling reaction with methyl β-Dglucopyranosiduronic acid as a model. 9H-Fluoren-2-yl-diazomethane (FDAM), prepared from its precursor 9H-fluoren2-carbaldehyde hydrazone by MnO2 oxidation, was found suitable as a new labeling agent for carboxyl groups in carbohydrate materials. The reaction with methyl β-D-glucopyranosidur...

Two industrial elemental chlorine free (ECF) bleaching sequences, D0(EOP)D1(EP)D2 and OQ(PO)DP, are compared with respect to the bulk content of lignin, carboxyl, hexeneuronic acids (HexA), and reducing groups after each bleaching stage. HexA groups contribute significantly to the total content of carboxyl groups, and their degradation during chlorine dioxide bleaching is reflected by a decreas...

The specificity of the Barrnett-Seligman method for the histochemical demonstration of alpha-acylamido carboxyl groups (C terminal) of proteins is dependent on the conversion of such groups to ketones by the action of acetic anhydride and absolute pyridine. Studies on model compounds show that the side-chain carboxyl groups also react in the method and that most of the final color developed can...

The purple membrane isolated from Halobacterium halobium contains only a single protein, bacteriorhodopsin, which functions as a light-driven proton pump. Substantial structural information has been obtained which has led to specific models of protein structure in the membrane (Engelman et al., 1982; Huang et al., 1982; Agard & Stroud, 1982). The retinal chromophore of bacteriorhodopsin is boun...

The aim of the present study was to investigate whether glycated ovalbumin (OVA) showed novel activity at the lipid-water interface. Mannosylated OVA (Man-OVA) was prepared by modification of the carboxyl groups with p-aminophenyl α-dextro (d)-mannopyranoside. An increase in the number of modified carboxyl groups increased the membrane-damaging activity of Man-OVA on cell membrane-mimicking ves...