Compounds represented by the general formula (1): (where R1 and R2 are typically a hydrogen atom; R3 and R4 are typically a hydrogen atom or a lower alkyl group; R5 is typically a hydrogen atom; X1, X2, X3 and X4 are typically a hydrogen atom or a lower alkoxy group; A is typically an optionally substituted pyridine ring; m and n are each 0 or 1) have an NOS inhibiting activity and are useful as therapeutics of cerebrovascular diseases and other pharmaceuticals.