The spontaneous decarboxylation of strong carboxylic acid − carboxylate mixtures and the use of carbon surfaces to trap the released free radicals

Electrochemical evidence of nitrate release from the nitrooxy compound 4-((nitrooxy) methyl)-3-nitrobenzoic acid and its antinociceptive and anti-inflammatory activities in mice

Considering the many biological activities of nitric oxide (NO), some lines of research focused on the modulation of these activities through the provision of this mediator by designing and synthesizing compounds coupled with an NO donor group. Thus, the objectives of the present study were to carry out an electrochemical investigation of the nitrooxy compound 4-((nitrooxy) methyl)-3-nitrobenzoic acid (1) and evaluate its activities and putative mechanisms in experimental models of pain and inflammation. Voltammetric studies performed in aprotic medium (mimetic of membranes) showed important electrochemical reduction mechanisms: nitroaromatic reduction, self-protonation, and finally reductive elimination, which leads to nitrate release. Systemic administration of the nitrooxy compound (1) inhibited the nociceptive response induced by heat and the tactile hypersensitivity and paw edema induced by carrageenan in mice. The activities in the models of inflammatory pain and edema were associated with reduced neutrophil recruitment and production of inflammatory cytokines, such as interleukin (IL)-1β, IL-6, tumor necrosis factor-α and CXCL-1, and increased production of IL-10. Concluding, electrochemical analysis revealed unequivocally that electron transfer at the nitro group of the nitrooxy compound (1) results in the cleavage of the organic nitrate, potentially resulting in the generation of NO. This electrochemical mechanism may be compared to a biochemical electron-transfer mediated nitrate release that, by appropriate in vivo bioreduction (enzymatic or not) would lead to NO production. Compound (1) exhibits activities in models of inflammatory pain and edema that may be due to reduced recruitment of neutrophils and production of inflammatory cytokines and increased production of IL-10. These results reinforce the interest in the investigation of NO donor compounds as candidates for analgesic and anti-inflammatory drugs.

From Langmuir-Blodgett to Grafted Films

A locally organized monolayer film strongly attached to a gold surface is obtained by transfer of a Langmuir-Blodgett (LB) film of octadecylamine (ODA) or alcohol (ODOH) onto a Au surface and simultaneous oxidative electrografting of this film still in contact with the aqueous subphase. As opposed to LB films, these films resist ultrasonication; and unlike electrografted films, they are organized monolayers by construction. They are characterized by AFM (atomic force microscopy), water contact angle, ellipsometry, XPS (X-ray photoelectron spectroscopy), IRRAS (infrared reflection absorption spectroscopy), and GIXD (grazing incidence X-ray diffraction).

Silver encapsulated copper salen complex: efficient catalyst for electrocarboxylation of cinnamyl chloride with CO2

An active catalyst, [Cu]@Ag composite, was synthesized for the first time and used as a cathode for electrocarboxylation of cinnamyl chloride with CO₂. β,γ-Unsaturated carboxylic acids were obtained with excellent yield and moderate selectivity. Moreover, reasonable yields and selectivities of carboxylic acids were also achieved with several allylic halides and aryl halides.

An active catalyst, [Cu]@Ag composite, was synthesized for the first time and used as a cathode for electrocarboxylation of cinnamyl chloride with CO₂.