In recent years, spiro compounds have attracted significant interest in medicinal chemistry due to their numerous biological activities attributed primarily to their versatility and structural similarity to important pharmacophore centers. Currently, the development of drugs with potential antioxidant activities is of great importance since numerous investigations have shown that oxidative stress is involved in the development and progression of numerous diseases such as cancer, senile cataracts, kidney failure, diabetes, high blood pressure, cirrhosis, and neurodegenerative diseases, among others. This article provides an overview of the synthesis and various antioxidant activities found in naturally occurring and synthetic spiro compounds. Among the antioxidant activities reviewed are DPPH, ABTS, FRAP, anti-LPO, superoxide, xanthine oxidase, peroxide, hydroxyl, and nitric oxide tests, among others. Molecules that presented best results for these tests were spiro compounds G14, C12, D41, C18, C15, D5, D11, E1, and C14. In general, most active compounds are characterized for having at least one oxygen atom; an important number of them (around 35%) are phenolic compounds, and in molecules where this functional group was absent, aryl ethers and nitrogen-containing functional groups such as amine and amides could be found. Recent advances in the antioxidant activity profiles of spiro compounds have shown that they have a significant position in discovering drugs with potential antioxidant activities.

The chalcone and bis-chalcone derivatives have been synthesized under sonication conditions via Claisen-Schmidt condensation with KOH in ethanol at room temperature (20-89%). The structures were established on the basis of NMR, IR, Single-crystal XRD, and MS. The best compound 3u had inhibitory activity (IC50 = 7.50 µM). The synthesis, the antioxidative properties, chemical reactivity descriptors supported in Density Functional Theory (DFT), acetylcholinesterase (AChE) inhibition and their potential binding modes, and affinity were predicted by molecular docking of a number of morpholine-chalcones and quinoline-chalcone. A series of bis-chalcones are also reported. Molecular docking and an enzyme kinetic study on compound 3u suggested that it simultaneously binds to the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. Moreover, the pharmacokinetic profile of these compounds was investigated using a computational method.

New N‐allyl/propargyl 4‐substituted 1,2,3,4‐tetrahydroquinolines derivatives were efficiently synthesized using acid‐catalyzed three components cationic imino Diels–Alder reaction (70–95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl‐cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC₅₀ = 72 μm) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl‐cholinesterase was exhibited by compound 4ae (IC₅₀ = 25.58 μm) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl‐cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets.

Keeping in mind the concept of green chemistry, this research aims to synthesize and characterize new ionic liquids (ILs) derived from N-cinnamyl imidazole with different sizes of alkyl chains (1, 6, 8, and 10 carbon atoms), and evaluate their antibacterial activity against Skin and soft tissue infections (SSTIs) causative bacteria. The antibacterial screening was carried out by agar well diffusion and the Minimum Inhibitory Concentration (MIC) and Half Maximum Inhibitory Concentration (IC₅₀) of the different ILs were determined by microdilution in broth, also Molecular dynamics simulations were performed to study the interaction mechanism between ILs and membranes. The MIC value in Gram-positive bacteria showed that as the hydrocarbon chain increases, the MIC value decreases with a dose-dependent effect. Furthermore, Gram-negative bacteria showed high MIC values, which were also evidenced in the antibacterial screening. The molecular dynamics showed an incorporation of the ILs with the longer chain (10 C), corresponding to a passive diffusion towards the membrane surface, for its part, the ILs with the shorter chain due to its lack of hydrophobicity was not incorporated into the bilayer. Finally, the new ILs synthesized could be an alternative for the treatment of Gram-positive bacteria causative of SSTIs.

Pyrazolo[3,4- b ]pyridines derivatives have been synthesized via one-pot condensation of 3-methyl-1-phenyl-1 H -pyrazolo-5-amine ( 1 ), paraformaldehyde ( 2 ) and β-diketones ( 3 ) under microwave irradiation in aqueous media catalyzed by InCl ₃ .

(E)-2-(benzo[d]thiazol-2-yl)-3-heteroarylacrylonitriles are described as a new class of selective inhibitors of acetylcholinesterase (AChE). The most potent compound in the series exhibited good AChE inhibitory activity (IC₅₀ = 64 µM). Compound 7f was found to be more selective than galanthamine in inhibiting AChE and it showed a moderate selectivity index. Kinetic studies on AChE indicated that a competitive type of inhibition pattern exist for these acrylonitrile derivates. Molecular docking models of the ligand-AChE complexes suggest that compound 7g is located on the periphery of the AChE active site.