Anti-inflammatory action of sulfoaryl 3,3-disubstituted triazenes in rat experimental edema models.

The acute toxicity and anti-inflammatory activity of eleven potassium salts of sulfobenzene and sulfonaphthalene 3,3-disubstituted triazenes have been examined in rats with carrageenin- and bentonite-induced edema using a 50 mg/kg p.o. dose. All compounds were found to exhibit anti-inflammatory activity significantly exceeding that of acetylsalicylic acid and ibuprofen, and were less toxic than these reference drugs. The most pronounced anti-inflammatory activity was shown by the potassium salt of 4-(piperazin-1-ylazo)benzenesulfonic acid.

Anion effect on mediated electron transfer through ferrocene-terminated self-assembled monolayers.

Inorganic anions strongly influence the electron transfer rate from the ascorbate to the ferrocene-terminated self-assembled monolayer (SAM) composed of 9-mercaptononyl-5'-ferrocenylpentanoate (Fc(CH2)4COO(CH2)9SH, MNFcP). At the 1 M concentration level of the supporting anion (sodium salt electrolyte), a more than 10-fold increase in the electrocatalytic oxidation rate constant of the ascorbate is observed in the following sequence: PF6-, ClO4-, BF4-, NO3-, Cl-, SO4(2-), NH2SO3- (sulfamate), and F-. The sequence corresponds to the direction of increasing hydration energy of the corresponding anion, suggesting that highly hydrated ions promote electrocatalytic electron transfer to the ferrocene-terminated SAMs, while poorly hydrated ions inhibit it. Fourier transform surface-enhanced Raman spectroscopy (FT-SERS), in combination with cyclic voltammetry, indicates the formation of surface ion pairs between the ferricinium cation (Fc+) and low hydration energy anions, while, on the contrary, no ion pairs were observed in the electrolytes dominated by the high hydration energy anions. Though it is evident that the ion-pairing ability of hydrophobic anions is directly responsible for the electrocatalytic electron transfer inhibition, an estimate of the free, ion-unpaired Fc+ surface concentration shows that it cannot be directly related to the electron transfer rate. This suggests that the principal reason of the anion-induced electron transfer rate modulation might be related to the molecular level changes of the physical and chemical properties as well as the structure of the self-assembled monolayer.