Matsukawa M, Akizawa T, Ohigashi M, Morris J F, Butler V P, Yoshioka M
Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, Osaka, Japan.
Chem Pharm Bull (Tokyo). 1997 Feb;45(2):249-54. doi: 10.1248/cpb.45.249.
We have identified a novel cardiac steroid, 11,19-epoxy-19-methoxytelocinobufagin, named marinosin (1), in the skin of the toad, Bufo marinus (L.) Schneider. The treatment of compound 1 with 50% CH3CN containing 0.1% trifluoroacetic acid yielded a 11 alpha-hydroxyhellebrigenin (2), which has not previously been isolated from animals or plants. The structures of both compounds were established from spectral data obtained by NMR and MS, which were compared with those of a reference bufadienolide, 11 alpha-hydroxytelocinobufagin. Compounds 1 and 2 have A/B cis and C/D cis configuration, which is characteristic of bufadienolides such as bufalin and marinobufagin. However, the stereo-structure of compound 1 was characterized by a boat form of the B ring, which is different from the chair form in typical bufadienolides such as compound 2. Compounds 1 and 2 both exhibited activity, as demonstrated by inhibition of Na+, K(+)-ATPase enzymatic activity and by inhibition of the binding of [3H]ouabain to Na+, K(+)-ATPase; however, marinosin (1) was as less effective inhibitor than 2, 11 alpha-hydroxyhellebrigenin. We have identified compound 2 in toad venom, but not in the skin.
我们从海蟾蜍（Bufo marinus (L.) Schneider）的皮肤中鉴定出一种新型强心甾类化合物，11,19 - 环氧 - 19 - 甲氧基远华蟾毒精，命名为海蟾蜍素（1）。用含0.1%三氟乙酸的50%乙腈处理化合物1，得到11α - 羟基海葱苷元（2），该化合物此前尚未从动物或植物中分离得到。这两种化合物的结构通过核磁共振（NMR）和质谱（MS）获得的光谱数据确定，并与参考蟾蜍二烯羟酸内酯11α - 羟基远华蟾毒精的光谱数据进行比较。化合物1和2具有A/B顺式和C/D顺式构型，这是蟾酥灵和海蟾蜍精等蟾蜍二烯羟酸内酯的特征。然而，化合物1的立体结构以B环的船式形式为特征，这与化合物2等典型蟾蜍二烯羟酸内酯的椅式形式不同。化合物1和2均表现出活性，如抑制Na⁺,K⁺ - ATP酶活性以及抑制[³H]哇巴因与Na⁺,K⁺ - ATP酶的结合；然而，海蟾蜍素（1）作为抑制剂的效果不如2,11α - 羟基海葱苷元。我们在蟾蜍毒液中鉴定出了化合物2，但在皮肤中未鉴定出。
