酸枣仁皂甙A──新型的钙调蛋白天然拮抗剂

A New Natural Calmodulin Antagonist-Jujuboside A

报导了具有宁心、安神等功效的中药酸枣仁的主要成分之一——酸枣仁皂甙Ａ， 它是钙调蛋白（ＣａＭ）的一种新型天然拮抗剂，以不含氮而区别于其它天然拮抗剂。酸 枣仁皂甙Ａ能有效地抑制ＣａＭ活化的环腺苷酸磷酸二酯酶（ＰＤＥ）的活力，其ＩＣ５０值 为 １５μｍｏｌ／Ｌ，是目前已发现的拮抗能力较强的一种 ＣａＭ天然拮抗剂。动力学研究表 明，酸枣仁皂甙Ａ对ＣａＭ活化ＰＤＥ活力的抑制是按非竞争性抑制方式进行的。

Jujuboside A, a Chinese medicine, is found to be a new natural calmodulin antagonist. Unlike most calmodulin antagonists, it does not contain nitrogen as component.Jujuboside A can inhibit the activation of calmodulin-stimulated phosphodiesterase with an IC50 value of 15μmol/L, which shows that jujubosido A is the most potent inhibitor of calmodulin.The inhibition kinetics study of jujuboside A on calmodulin indicates that this inhibition is non-competitive.