The saponin fraction prepared from the methanolic extract of the underground parts of Agapanthus inapertus was found to exhibit inhibitory activity on cAMP phosphodiesterase (55.2%) at a concentration of 100 μg/ml. From this fraction, four new steroidal saponins, designated as agapanthussaponin A (1), B (2), C (3) and D (4), were isolated as the active principles, along with an inactive new furostanol saponin (5). The structures of 1-5 were determined by spectroscopic data and hydrolysis. The IC50 of 1-4 on cAMP phosphodiesterase were 0.7, 1.2, 1.1 and 2.0 (×10-5M), respectively, which are more potent than that of papaverine (IC50 3.0×10-5M).
从纳丽蓝百合(Agapanthus inapertus)的地下部分
甲醇提取物中制备得到的
皂苷组分,在100 μg/ml的浓度下对c
AMP磷酸二酯酶表现出55.2%的抑制活性。从该组分中分离出四种新的甾体
皂苷,分别命名为纳丽蓝
皂苷A(1)、B(2)、C(3)和D(4),它们是活性成分,同时还分离到一个无活性的新型呋
甾醇皂苷(5)。化合物1-5的结构通过光谱数据和
水解分析确定。纳丽蓝
皂苷1-4对c
AMP磷酸二酯酶的IC50值分别为0.7、1.2、1.1和2.0(×10-5 M),这些活性均强于
罂粟碱(IC50 3.0×10-5 M)。