Spirocyclic derivatives as antioxidants: a review

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.

Microwave-assisted synthesis, antioxidant and antimicrobial evaluation of 2-indolinone-based bis-1,2,3-triazole derivatives

A series of 2-indolinone-based bis-1,2,3-triazole derivatives have been synthesized in excellent yields via microwave-assisted, copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction of O-, N-propargylated indolinone derivatives with in situ generated organic azides. The antioxidant activity of the synthesized compounds was evaluated by DPPH, NO and [Formula: see text] radical scavenging methods. Among the compounds screened for antioxidant activity, compounds 5e, 5f and 5o showed excellent radical scavenging activity more than the standard drugs ascorbic acid and BHT. The synthesized compounds were evaluated for their antimicrobial activity against gram-positive and gram-negative bacterial and fungal strains. Compounds 5g, 5h, 5n, 5q and 5r were found to be the most promising microbial growth inhibitory molecules.

Solvent-free microwave-assisted synthesis and biological evaluation of 2,2-dimethylchroman-4-one based benzofurans

A series of novel chroman-4-one fused benzofurans were synthesized by cyclization of the corresponding chalcones under microwave irradiation. All new compounds were characterized by IR,