Abstract: It is intended to provide a novel bisphosphonic acid compound or a salt thereof which shows a remarkable inhibitory effect on ectopic calcification, and a pharmaceutical composition comprising the same. The present invention provides a bisphosphonic acid compound represented by the following formula (1) or a pharmaceutically acceptable salt thereof: wherein represents a single bond or a double bond; A represents a saturated cyclic hydrocarbon or a saturated heterocyclic ring comprising a sulfur atom or an oxygen atom; and R1 and R2 each independently represent an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a haloalkoxy group, a haloalkyl group, a halogen atom or a hydrogen atom.

Abstract: It is intended to provide a novel bisphosphonic acid compound or a salt thereof which shows a remarkable inhibitory effect on ectopic calcification, and a pharmaceutical composition comprising the same. The present invention provides a bisphosphonic acid compound represented by the following formula (1) or a pharmaceutically acceptable salt thereof: wherein represents a single bond or a double bond; A represents a saturated cyclic hydrocarbon or a saturated heterocyclic ring comprising a sulfur atom or an oxygen atom; and R1 and R2 each independently represent an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a haloalkoxy group, a haloalkyl group, a halogen atom or a hydrogen atom.