Water-soluble ligands, N,N,N',N'-tetramethyldiglycolamide (TMDGA), N,N,N',N'-tetraethyldiglycolamide (TEDGA), N,N,N',N'-tetrapropyldiglycolamide (TPDGA) and N,N-dipropyldiglycolamic acid (DPDGAc) were prepared and their abilities to complex with and to back-extract the metal cations were investigated. These results indicate that the DGA series and DPDGAc have a stronger complexing ability with ...

From our experimental evidence that iron lirnitation greatly increases the extracellular concentration of strong copper-complexing agents in cultures of Anabaena flos-aquae and Anabaena cyhdrica, and that the iron-algal exudate complex is much more stable than the copper complex, we conclude that strong copper-complexing agents released by filamentous blue-green algae are siderophores. Further ...

Complexing capacity of naturally occurring ligands in Vitis vinifera (Tempranillo variety) wines has been studied with respect to two target metals (Cu and Zn) by Differential Pulse Anodic Stripping Voltammetry (DPASV). Eight commercial wines of two certified brands of origin (CBO) and a young wine along its vinification process were monitored. Conditional stability constants and total complexi...

THERE IS AN EVER-increasing need for a rapid method of screening for barbiturates in the laboratory. Although the ultraviolet methods (1, ) are the most accurate, they require 0.5 to 2 h of technician time and therefore are hardly ideal for emergency-room use. Some methods have been published which depend on the complexing reaction of barbiturates in an organic solvent with a mercury salt in an...

The present work investigates the efficiency of an alkaline water electrolysis process in the presence of a complexing agent like citric acid (CA) when added directly into the electrolyte during the electrolytic process. High surface area nickel electrodes prepared by electrodeposition technique were used as the electrode to evaluate the efficiency of the oxygen evolution reaction (OER) by the ...

Rabphilin is a synaptic vesicle-associated protein proposed to play a role in regulating neurotransmitter release. Here we report the isolation and identification of a novel protein complex containing rabphilin, annexin A4 and synaptotagmin 1. We show that the rabphilin C2B domain interacts directly with the N-terminus of annexin A4 and mediates the co-complexing of these two proteins in PC12 c...

Two macrocyclic bis(ureas) 1 and 2, both based on diphenylurea, have been synthesized. Compound 1 represents the smaller ring with two ethynylene groups as linkers and 2 the larger ring with two butadiynylene groups. On thermal treatment to 130 °C molecule 1 splits up into two dihydroindoloquinolinone (3) molecules. Both compounds 1 and 2 form adducts with polar molecules such as dimethyl sulfo...

We have designed imidazolium and piperazinium salts of pyropheophorbide-a in order to develop effective photosensitizers which have good solubility in polar and non polar media and to reveal the possible influences of the piperazine and imidazole moieties on the biological activities of pyropheophorbide-a. The phototoxicity of those pyropheophorbide-a salts against A549 cells was studied in vit...

Complexing amphotericin B (AmB) with lipids or entrapping it in liposomes may increase its efficacy by reducing toxicity and affecting distribution. However, depending on the lipids involved, interference with antifungal activity has been shown. We compared the in vitro activity of AmB colloidal dispersion by cholesteryl sulfate (ABCD) to the standard AmB deoxycholate suspension (ABDS) against ...

Complexometric titrations rely on a drastic change of the pM value at the equivalence point with a water soluble chelator forming typically 1 : 1 complexes of high stability. The available chemical toolbox of suitable chelating compounds is unfortunately limited because many promising complexing agents are not water soluble. We introduce here a novel class of complexometric titration reagents, ...