Enhancement of SOD activity in boehmite supported nanoreceptors

Abstract

The binuclear Cu2+ complex of a pyridinophane polyamine ligand ranking amongst the fastest SOD mimetics so far reported displays a remarkable SOD activity enhancement when grafted to the surface of boehmite (γ-AlO(OH)) nanoparticles (BNPs).

A step forward in the development of superoxide dismutase mimetic nanozymes: the effect of the charge of the surface on antioxidant activity

“…The protonation constants of L2 obtained by potentiometric titrations, as well as those we have previously reported for L1, 24 are shown in Table 1 . The representation of the distribution diagrams as a function of the pH are shown in Fig.…”

“…L2 follows the typical protonation behaviour usually found for cyclic polyamines, already shown for L1, which is based on the electrostatic repulsions between protonated amino groups, inductive effects of the alkyl and aromatic groups and statistic effects. 29,33 The differences between the protonation constant values of L1 and L2, 24 can be explained according to minimisation of charge repulsions and inductive effects.…”

“…The Cu 2+ complexation constants of L2 determined by potentiometric titrations, as well as those of L1, 24 are shown in Table 2 . The stability constants of the pyridinophane ligands L3 and L4, 29 are collected in Table S3 of the ESI.…”

“…Regarding this point, we have recently communicated that the Cu 2+ binuclear complexes of the hexaazapyridinophane ligand L1 ( Scheme 1 ) exhibited an 8-fold enhanced SOD activity when grafted to boehmite nanoparticles (BNPs). 24 The reason for such a behaviour was in principle related to the accumulation of active sites in the surface of the BNPs. 25 However, other factors may also influence the observed behaviour such as the charge of the nanoparticle surface.…”

Stabilization of Supramolecular Networks of Polyiodides with Protonated Small Tetra-azacyclophanes

“…The synthesis of the compounds 3,6,9-triaza-1(2,6)-pyridinecyclodecaphane (L1•3HBr) [39][40][41][42], 6-(N-methyl)-3,6,9-triaza-1(2,6)-pyridinacyclodecaphane (L1-Me•3HBr) [42], 3,6,9-tris(N-methyl)-3,6,9-triaza-1(2,6)-pyridinacyclodecaphane (L1-Me 3 •3HCl) [43][44][45] (Figure 3) 4-methyl-1,7-bis(p-tolylsulfonyl)-1,4,7-triazaheptane (2•3HCl) [23,42] and 4-benzyloxy-2,6-bis(bromomethyl)pyridine (py-obn) [46][47][48] (Figure 13) were carried out following the procedure described previously in the literature. All reagents were obtained from commercial sources and used as received.…”