The present invention provides a novel medicament for preventing and treating diseases related to the activity of human chymosin. A human chymosin inhibitor containing a compound as shown in the following general formula (A) as an effective component shows selectivity for human chymosin and has an excellent enzyme activity inhibiting effect. Preferably, more than one component of this compound is selected from a group consisting of quercitrin, isoquercitrin, hyperoside, kaempferol and luteolin. A medicament containing the human chymosin inhibitor is a medicine used for preventing and treating various diseases related to the activity of human chymosin by means of a human chymosin activity inhibiting effect. (In the general formula (A), R1 to R5 respectively and independently represent hydroxyl or methoxyl, and X1 represents hydroxyl or -OG group. In addition, G represents a carbohydrate chain).本發明係提供新穎的與人類凝乳酶的活性相關疾病之預防治療用藥劑。含有下述一般式(A)所示之化合物作為有效成分之人類凝乳酶阻礙劑，係對人類凝乳酶顯示出選擇性且優異的酵素活性阻礙作用。即便是在該化合物之中，係以從槲皮苷(quercitrin)、異槲皮苷(isoquercitrin)、金絲桃苷(hyperoside)、山奈酚(kaempferol)及木犀草素(luteolin)所組成之群組中選出之1種以上者為佳。含有該人類凝乳酶阻礙劑之藥劑，係藉由抑制人類凝乳酶的活性而有用於作為與人類凝乳酶的活性相關之各種疾病之預防及治療中所使用之醫藥。(一般式(A)中，R1~R5各自獨立地表示羥基或甲氧基，X1表示羥基或-OG基。另外，G表示糖鏈)。
