A reddish crystalline compound, C14H5O2(OH)3, that is isolated from madder root for use as a biological stain and commercial dye.

• 羟基茜草素，红紫素一种从茜草属植物中提取出来用作生物染色剂和商业染料的淡红晶状化合物C14H5O2（oh）