Ru<sub>360</sub> is an oxo-bridged dinuclear ruthenium ammine complex with an absorption spectrum maximum at 360 nm. It is an analog of ruthenium red, a well-known effective inhibitor of the mitochondrial calcium uniporter.
Ru<sub>360</sub> was discovered after scientists found that commercial preparations of ruthenium red were often less than 20% pure, and that the crude mixture produced a stronger inhibition than the purified product. This component was later isolated and its structure determined, Ru<sub>360</sub> has structural formula (ü-O)[(HCO<sub>2</sub>)(NH<sub>3</sub>)<sub>4</sub>Ru]<sub>2</sub>Cl<sub>3</sub>, that is, an oxygen-linked chain only two octahedral rutheniumâÂÂammine units rather than the three of ruthenium red. One of the ruthenium atoms is in a +3 oxidation state, and the other in a +4 oxidation state. In addition to the four ammonia ligands, each ruthenium also has one formate group and there are a total of three chloride ions to balance the charge. In solution, chloride or hydroxide groups displace the formates.
Since Ru<sub>360</sub> inhibits the flow of calcium into mitochondria, which can prevent the opening of the mitochondrial permeability transition pore, it has been investigated as a therapeutic treatment for stroke and heart attack.