Abstract: The present invention provides a class of biochemically-activated MRI contrast agents. The agents include a paramagnetic chelate attached via a linker arm to a relaxivity-modulating group. When the relaxivity-modulating group is removed or otherwise interacts with a targeted substance, the agents are activated by various mechanisms. The activation is detectable by an increase or decrease in the relaxivity of the metal chelate. The agents are useful in the detection of biochemical parameters in cells, tissues and subjects. Exemplary biochemical parameters are markers that are associated with disease states.

Abstract: Organic complexes of vanadium are provided, having the general structure VL3, where V is vanadium(III) and L is a monoprotic bidentate ligand that forms a five-membered, unsaturated vanadium containing ring, having vanadium coordinating oxygen or sulfur ring heteroatoms, and where the vanadium containing ring is fused to a six-membered heterocyclic ring. Preferably L is a hydroxypyrone or a hydroxypyridinone. The complexes have a number of uses, including the treatment of elevated blood glucose and related disorders, treatment of proliferative disorders, etc.