PURPOSE: To provide a carbon monoxide synthetase inhibitor useful for therapy and prevention of shock, hypotension, chronic articular rheumatism, ulcerative colitis, ischemic encephalopathy, tumor, insulin dependent diabetes mellitus, etc.
CONSTITUTION: This carbon monoxide synthetase inhibitor contains a compound of formula I {R1 is H or an alkyl; R2 is ACOR3 [A is an alkylene which may be substituted; R3 is OR4, NHR5 (R4 and R5 are each R1, etc.)], (CH2)mGR8 [(m) is 0 to 4; E is phenylene which may be substituted; G is O, S, (CH2)nR10 (n) is 0 to 4; R10 is COO, SO2, NH, etc.], formula II, etc.], formula III [L is an alkylene, an alkylene-S, etc.; R17 is formula IV, formula V (R18 is R1)], MR19 (M is a single bond, an alkylene, N=CH, NHSO2, etc.; R19 is an alkyl which may be substituted, formula TV, etc.), formula VI [Q is an alkylene or phenylene; T is COO, COS, etc.; R24 is (CH2)tCOOR25 or SO2NR26R27 [(t) is 0 to 4; R25 to R27 are each R1)]} or a compound of formula VII as the active component.
