Vanadium(V) Complexes with Siderophore Vitamin E-Hydroxylamino-Triazine Ligands

Abstract

Novel vitamin E chelate siderophore derivatives and their VV and FeIII complexes have been synthesised and the chemical and biological properties have been evaluated. In particular, the α- and δ-tocopherol derivatives with bis-methyldroxylamino triazine (α-tocTHMA) and (δ-tocDPA) as well their VV complexes, [V2VO3(α-tocTHMA)2] and [V2IVO3(δ-tocTHMA)2], have been synthesised and characterised by infrared (IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and ultra violet-visible (UV-Vis) spectroscopies. The dimeric vanadium complexes in solution are in equilibrium with their respefrctive monomers, H2O + [V2VO2(μ-O)]4+ = 2 [VVO(OH)]2+. The two amphiphilic vanadium complexes exhibit enhanced hydrolytic stability. EPR shows that the complexes in lipophilic matrix are mild radical initiators. Evaluation of their biological activity shows that the compounds do not exhibit any significant cytotoxicity to cells.

Biological Consequences of Vanadium Effects on Formation of Reactive Oxygen Species and Lipid Peroxidation

“…Recently new classes of vanadium coordination complexes have been reported that are mild radical initiators and should be able to initiate LPO and induce oxidation [ 14 ]. Interestingly, they are not cytotoxic to embryonic mouse fibroblasts (NIH/3T3) [ 14 ], Cal33 cells or HeLa cells.…”

“…Recently new classes of vanadium coordination complexes have been reported that are mild radical initiators and should be able to initiate LPO and induce oxidation [ 14 ]. Interestingly, they are not cytotoxic to embryonic mouse fibroblasts (NIH/3T3) [ 14 ], Cal33 cells or HeLa cells. One class of compounds is vitamin E chelate siderophores with a lipid portion and a metal ion, amphiphilic properties and hydrolytic stability [ 15 ].…”

“…The extent of oxidative stress observed depends on the ratio of compounds with oxidative damage potential relative to the defense capacity of available antioxidants ( Figure 2 ). Effects of vanadium compounds depend on whether a particular compound enhances ROS formation, in which case multiple deleterious effects on cell structure and function are observed [ 14 , 15 ]. Alternatively, vanadium compounds can decrease ROS formation, in which case they have protective effects on cells.…”

Polyoxidovanadates [MoVIVV9O28]5- and [H2PtIVVV9O28]5- interact with CHO cell plasma membrane lipids causing aggregation and activation of a G protein-coupled receptor

“…Vanadium coordination complexes have been the focus of recent work in cell systems (Scalese et al, 2019;Treviño and Diaz, 2020;Loizou et al, 2021, He et al, 2020Biswas et al, 2022;Ferretti and León, 2022;Ribeiro et al, 2022;Semiz, 2022;Althumairy et al, 2020a;Sahu et al, 2022). Our group has shown that bismaltolatodioxovanadium(IV) (BMOV) and polyoxidovanadates are able to initiate signaling by the luteinizing hormone receptor (LHR), a G-protein coupled receptor (GPCR) (Roess et al, 2008;Crans et al, 2011;Winter et al, 2012;Al-Quatati et al, 2013;Althumairy et al, 2020b;Althumairy et al, 2020c;Althumairy et al, 2020d;Samart et al, 2020).…”

Exploring Growth of Mycobacterium smegmatis Treated with Anticarcinogenic Vanadium Compounds

“…When evaluating effects of metal complexes on bacterial cells, it is, however, important to consider that these compounds are coordination complexes and many of these compounds do not remain intact during study due to their inherent hydrolytic instability in complex biological media [25][26][27][28][29]. In addition, the effects of the metal complex versus its ligand can be important, particularly in cases where the ligand has potent effects on the cells being studied [28,[30][31][32]. Here, we use a recently identified anticancer compound, a Schiff base vanadium-based catecholate complex (oxidovanadium(IV) complexed to N-(salicylideneaminato)-N -(2-hydroxyethyl)ethane-1,2-diamine 3,5-di-tertbutylcatecholato ligand) [33,34], which was found to be significantly more potent than cisplatin in several cancer lines including glioma multiforme, an aggressive brain cancer (T98g), lung cancer cells (A549), and pancreas cancer cells (PANC-1) [34].…”