Orthovanadic

Orthovanadic is an adjective used to describe compounds containing the orthovanadate ion, VO4^3−, or relating to orthovanadic acid. The orthovanadate ion is a tetrahedral vanadium(V) species that in water exists in several protonation states depending on pH, including VO4^3−, HVO4^2−, and H2VO4−.

Common orthovanadate salts include sodium orthovanadate Na3VO4, potassium orthovanadate K3VO4, and ammonium orthovanadate (NH4)3VO4. They are typically prepared by neutralization of orthovanadic acid or from vanadate solutions. In solution, orthovanadates are typically water-soluble and can form hydrates. The chemistry of orthovanadate is relevant to its behavior as a phosphoryl analog in biological contexts.

In biochemistry and cell biology, orthovanadate compounds are widely used as inhibitors of protein phosphatases, especially protein tyrosine phosphatases, by mimicking phosphate groups and preventing dephosphorylation. They serve as tools to study phosphorylation signaling and enzyme regulation. The effectiveness and specificity of inhibition depend on pH, concentration, and the particular enzyme studied, and off-target effects can occur.

Safety and handling: vanadium compounds, including orthovanadates, can be toxic and should be handled with appropriate protective equipment and proper disposal in accordance with regulations. Prolonged exposure or ingestion should be avoided.

Orthovanadic chemistry thus sits at the intersection of vanadium chemistry and phosphate mimicry, with primary practical relevance in biochemical research and as a laboratory reagent.