Design and synthesis of 3,4-methylenedioxy-6-nitrophenoxyacetylhydrazone derivatives obtained from natural safrole: New lead-agents with analgesic and antipyretic properties

Studies towards the identification of putative bioactive conformation of potent vasodilator arylidene N-acylhydrazone derivatives

“…The careful analysis of 1 H NMR spectra of the new acylhydrazone derivatives demonstrated the selective N-alkylation by the presence of a single N-methyl hydrogen signal ranging from d 3.4 to 3.6 ppm and the presence of only one imino hydrogen signal ranging from d 7.7 to 7.9 ppm (N-methyl-NAH derivatives) and d 8.3 to 8.6 ppm (NAH derivatives), attributed to the (E)-diastereomer on the basis of several previous reports from our group describing the configuration of bioactive NAH derivatives [7,8,[13][14][15][16][17], as well as an only amide hydrogen signal for the NAH derivatives ranging from d 11.6 to 11.7 ppm.…”

Discovery of Phthalimides as Immunomodulatory and Antitumor Drug Prototypes

“…Additional experiments corroborated this, as compound 3 a does not undergo N-acetylation under mild conditions; this reactivity is typical of an amide NH group (scheme S1, Supporting Information). Sulfoxide derivative 3 d was prepared using a slightly modified protocol with metachloroperoxybenzoic acid (mCPBA) as an oxidizing agent, [23] while thiosemicarbazone 4 was obtained in three steps starting from phthalic anhydride, yielding a single product. Our quantum chemical calculations, performed with the same methodology mentioned above, revealed that the energy levels of the E and Z isomers of 4 are nearly degenerate, with the E isomer only 0.11 kJ mol À1 more stable than the Z isomer ( Figure 2).…”

Involvement of electron and hydrogen transfers through redox metabolism on activity and toxicity of the nimesulide

“…These reduced and oxidized derivatives are easily obtained in experimental conditions [27,28]. In fact, electron withdrawing groups such as methyl-sulfonamide and nitro are important for the anti-inflammatory and anti-nociceptive effects of nimesulide [3,10].…”

“…Structure-activity relationship studies of nimesulide showed that the methyl-sulfonamide and nitro (NO 2 ) groups are important to its activity, such as anti-inflammatory and anti-nociceptive effects, respectively [3,10]. However, additional studies that can explain and correlate the structure and redox properties of nimesulide are required to clarify its toxicity and biological mechanism.…”