A New Class of Water‐Soluble Aryl Sulfonium Decavanadates and Their Antioxidant Activity: Effects of Cluster Reduction and Counter Ion Substitution on Activity

• Published in: European journal of inorganic chemistry 2022-08, Vol.2022 (22), p.n/a
• Main Authors: Routh, Kousik, Kaur, Sandeep, Pradeep, Chullikkattil P.
• Format: Article
• Language: English
• Subjects: Antioxidants; Aromatic compounds; Ascorbic acid; Assaying; Biocompatibility; Clusters; Cytotoxicity; Decavanadates; Functional groups; Hydrogen peroxide; Inorganic chemistry; Lipids; Polyoxometalates; Polyoxometallates; Scavenging; Structure elucidation; Sulfonium; Toxicity
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.202200265

The development of biocompatible and water‐soluble inorganic antioxidants is important, given the increasing demand for antioxidants worldwide. Polyoxovanadate (POV) clusters have been extensively explored for several biological applications, but the antioxidant properties of POVs remain largely unexplored. Herein, we developed a series of water‐soluble aryl sulfonium decavanadate ([V10O28]6−) hybrids and studied their antioxidant properties. The hybrids were characterized by several analytical and spectroscopic techniques such as ESI‐MS, XPS, and single‐crystal XRD analyses. The antioxidant properties of these hybrids were explored under native and photochemically reduced conditions using standard in vitro antioxidant assays such as H2O2 scavenging assay, lipid peroxidation inhibitory assay, DPPH radical scavenging assay, and reducing power assay. These analyses showed that these aryl sulfonium POV hybrids exhibit comparable or better antioxidant activities than the parent [V10O28]6− cluster and the standard ascorbic acid in some of the assays studied. The cytotoxicity studies using MG‐63 cells revealed that these hybrids exhibit moderate cytotoxicity. Further, it was found that introducing a phenolic functional group on the counter ion moiety helps to improve the overall antioxidant properties of the POV‐based hybrids. The present study, therefore, reports a series of water‐soluble aryl sulfonium polyoxometalate hybrids‐based antioxidants for the first time. However, more toxicological studies using similar hybrids are required to fully understand the biocompatible nature of these systems before considering their potential biological applications. Facile synthesis of four water‐soluble aryl sulfonium decavanadate hybrids has been reported, along with the exploration of their antioxidant properties in native and photo‐reduced states. The biocompatibility of the new hybrid has also been checked using MG‐63 (Human osteosarcoma) cell lines.