To clarify the physiological properties of an oxophosphorus compound and provide a medicine prepared for the development of new and useful application of the compound.

The medicine contains an oxophosphorus compound expressed by general formula (R1 is a hydrocarbon group, a hydrocarbon-oxy group, a heteroaryl group, a ferrocenyl group, a silyl group, a substituted silyl group or an arylseleno group; R2 and R3 are each a hydrogen atom or a hydrocarbon group; R4 and R5 are each a hydrocarbon group or a hydrocarbon-oxy group; and n is 0 or 1) as an active component.