Antiradical and Antioxidative Activity of Azocalix[4]arene Derivatives: Combined Experimental and Theoretical Study

Abstract

Developing antioxidants with high efficiency is fundamentally important for the protection of living cells and engineering materials against oxidative damage. In this present study, two azocalix[4]arene derivatives were synthesized via a diazo coupling reaction between calix[4]arene and diazonium salts. Their antiradical and antioxidative performances were evaluated by hydroxyl radical scavenging and pyrogallol autoxidation inhibition experiments. Combined with theoretical studies, the antiradical and antioxidative mechanisms have been explored. The results demonstrated that these two azocalix[4]arene derivatives both exhibited remarkable antiradical and antioxidative activity. The macrocyclic framework of the calix[4]arene and para-azo substituent group at the upper rim of calix[4]arene contributed synergistically and importantly to its excellent antiradical and antioxidant activity.

Macrocycles and Supramolecules as Antioxidants: Excellent Scaffolds for Development of Potential Therapeutic Agents

“…However, only recently, Silva et al reported the novel iminecalix [4]arene derivatives (42)(43)(44)(45)(46)(47) with anticandidal activity (Scheme 3) [55]. However, there are Figure 6) [52]. In this work, they developed two azocalix [4]arene derivatives by a diazo coupling reaction between calix [4]arene and diazonium salts.…”

“…Recently, Ni et al reported the antiradical and antioxidative activity of azocalix[4]arene derivatives 38 , 39 ( Figure 6 ) [ 52 ]. In this work, they developed two azocalix[4]arene derivatives by a diazo coupling reaction between calix[4]arene and diazonium salts.…”

“…General scheme for the synthesis of resorcinarene derivatives.In 2009, Vovk et al reported on the antioxidant and antiradical activities of resorcinarene tetranitroxides (Figure 8)[67]. They synthesized the resorcinarene(48,49) derivatives(50)(51)(52)(53) by the aminomethylation of resorcinarene octols with 4-amino-TEMPO TEMPO ((4-Amino-2,2,6,6-tetramethylpiperidine-1-oxyl), and studied their antioxidant activities. They found that the Tetra-TEMPO resorcinarenes(50)(51)(52)(53) are efficient scavengers of DPPH radicals and showed superoxide dismutase-like activity.…”

Supramolecular Integration of Multifunctional Nanomaterial by Mannose-Decorated Azocalixarene with Ginsenoside Rb1 for Synergistic Therapy of Rheumatoid Arthritis

“…Hydroxyl radical ( • OH) was produced by the Fenton reaction using H 2 O 2 and EDTA-Fe before being reacted with terephthalic acid (TA) to form the fluorescent compound hydroxyterephthalic acid (HTA, λ em = 425 nm). 72 In the antiradical experiment, the antioxidant competed with TA to trap • OH, thus inhibiting the production of HTA and leading to a decrease in the fluorescence intensity of HTA. The detailed procedure is outlined as follows.…”

“…49,50 Among macrocycles, calixarene was elected as the core skeleton owing to its intrinsic reactive oxygen species (ROS) scavenging capacity. 24,51 By grafting azo groups, azocalixarene with a deepened cavity provides effective drug loading and realizes hypoxia-controlled release. Mannose, as the functional group of macrophage-targeting and macrophage phenotype induction, was decorated at the upper rim of azocalixarene.…”