An N-acyl anthranilic acid derivative represented by general formula (1) or a salt thereof is useful for prevention or treatment of diseases associated with excessive production of collagen. (In the formula, R
1
represents a carboxyl group or the like; R
2
represents a hydrogen atom or the like; R
3
represents an optionally substituted aryl group or the like; X
1
represents a carbonyl group; X
2
represents a bonding hand; X
3
represents a bonding hand; X
4
represents a bonding hand or the like; and A represents an optionally substituted phenyl group or the like.)
通用公式(1)表示的N-酰基
蒽酸衍
生物或其盐对预防或治疗与
胶原蛋白过度产生相关的疾病具有用处。(在该公式中,R1代表羧基或类似物;R2代表
氢原子或类似物;R3代表可选择取代的芳基或类似物;X1代表羰基;X2代表连接手;X3代表连接手;X4代表连接手或类似物;A代表可选择取代的
苯基或类似物。)