Examination of diverse iron-chelating agents for the protection of differentiated PC12 cells against oxidative injury induced by 6-hydroxydopamine and dopamine.

Labile redox-active iron ions have been implicated in various neurodegenerative disorders, including the Parkinson's disease (PD). Iron chelation has been successfully used in clinical practice to manage iron overload in diseases such as thalassemia major; however, the use of conventional iron chelators in pathological states without systemic iron overload remains at the preclinical investigative level and is complicated by the risk of adverse outcomes due to systemic iron depletion. In this study, we examined three clinically-used chelators, namely, desferrioxamine, deferiprone and deferasirox and compared them with experimental agent salicylaldehyde isonicotinoyl hydrazone (SIH) and its boronate-masked prochelator BSIH for protection of differentiated PC12 cells against the toxicity of catecholamines 6-hydroxydopamine and dopamine and their oxidation products.

Structure-Activity Relationships of Nitro-Substituted Aroylhydrazone Iron Chelators with Antioxidant and Antiproliferative Activities.

Aroylhydrazone iron chelators such as salicylaldehyde isonicotinoyl hydrazone (SIH) protect various cells against oxidative injury and display antineoplastic activities. Previous studies have shown that a nitro-substituted hydrazone, namely, NHAPI, displayed markedly improved plasma stability, selective antitumor activity, and moderate antioxidant properties. In this study, we prepared four series of novel NHAPI derivatives and explored their iron chelation activities, anti- or pro-oxidant effects, protection against model oxidative injury in the H9c2 cell line derived from rat embryonic cardiac myoblasts, cytotoxicities to the corresponding noncancerous H9c2 cells, and antiproliferative activities against the MCF-7 human breast adenocarcinoma and HL-60 human promyelocytic leukemia cell lines.

Design, Synthesis, and Biological Evaluation of Isothiosemicarbazones with Antimycobacterial Activity.

A series of benzaldehyde and salicylaldehyde-S-benzylisothiosemicarbazones was synthesized and tested against 12 different strains of mycobacteria, Gram-positive and Gram-negative bacteria, and the significant selectivity toward mycobacteria was proved. Twenty-eight derivatives were evaluated for the inhibition of isocitrate lyase, which is a key enzyme of the glyoxylate cycle necessary for latent tuberculosis infection, and their iron-chelating properties were investigated. Two derivatives, 5-bromosalicylaldehyde-S-(4-fluorobenzyl)-isothiosemicarbazone and salicylaldehyde-S-(4-bromobenzyl)-isothiosemicarbazone, influenced the isocitrate lyase activity and caused a better inhibition at 10 μmol/L than 3-nitropropionic acid, a standard inhibitor.

Aroylhydrazone iron chelators: Tuning antioxidant and antiproliferative properties by hydrazide modifications.

Aroylhydrazones such as salicylaldehyde isonicotinoyl hydrazone (SIH) are tridentate iron chelators that may possess antioxidant and/or antineoplastic activities. Their main drawback, their low stability in plasma, has recently been partially overcome by exchanging the aldimine hydrogen for an unbranched alkyl group. In this study, ten analogs of methyl- and ethyl-substituted SIH derivatives with modified hydrazide scaffolds were synthesized to further explore their structure-activity relationships.