Abstract: The present invention provides a compound excellent in accumulation on calcified tissues and ensuring rapid excretion into urine as well as rapid clearance from blood, useful as a diagnostic agent and a therapeutic agent, etc. The compound is a compound having affinity with a calcified tissue represented by the following formula: (AC)a-MC-(LI)b. In the formula, MC is a mother nucleus and represents a residue of a compound having a plurality of functional groups selected from the group consisting of an amino group, an amide group, a hydroxyl group, a thiol group, a thioether group, a sulfonyl group, a phosphonyl group, an aldehyde group, a carboxyl group, a carbonyl group, a halogen, and a cyano group; AC is a group having affinity with a calcified tissue; LI is a ligand for binding to a metal atom; and a is an integer of 1 or more and b is 0 or an integer of 1 or more.

Abstract: An object of the present invention is to provide a bisphosphonic acid derivative and said bisphosphonic acid derivative being labeled with a radioactive nuclide, which has properties of rapid accumulation to the bone and rapid urinary excretion. The present invention relates to a bisphosphonic acid derivative and said bisphosphonic acid derivative being labeled with a radioactive nuclide, which is represented by the following general formula (1), R—Y—A  (1) wherein A is a bisphosphonic acid or a salt thereof, having P—C—P bond; Y is a bonding portion such as a methylene, an amido etc.