Bufadienolides, naturally occurring steroids primarily found in toads, have garnered attention for their pharmacological properties and ecological significance. In this study, we isolated and identified 21 bufadienolides from the gallbladders of Bufo gargarizans, comprising four new compounds and 17 known ones. Notably, the predominance of 15 bufadienolides with a 3α-OH configuration in toad bile differs significantly from the 3β-OH bufadienolides found in venom secreted by toad glands. Moreover, our investigation into the biotransformation of 3β-OH and 3α-OH bufadienolides in the liver and kidney tissues of toads revealed an irreversible conversion from 3β-OH to 3α-OH bufadienolides, suggesting a crucial role in toad self-detoxification. These findings provide valuable insights into the structural diversity of bufadienolides and advance our understanding of their medical and ecological significance.

Graphical Abstract

中文翻译：

---

蟾蜍胆囊中的 3α-羟基蟾蜍二烯内酯：结构见解和生物转化

蟾蜍二烯内酯是主要在蟾蜍中发现的天然类固醇，因其药理学特性和生态意义而受到关注。在本研究中，我们从中华蟾蜍胆囊中分离鉴定出 21 种蟾蜍二烯内酯，其中包括 4 种新化合物和 17 种已知化合物。值得注意的是，蟾蜍胆汁中 15 种具有 3α-OH 构型的蟾蜍二烯内酯的优势与蟾蜍腺分泌的毒液中发现的 3β-OH 蟾蜍二烯内酯显着不同。此外，我们对蟾蜍肝脏和肾脏组织中 3β-OH 和 3α-OH 蟾蜍二烯内酯的生物转化的研究揭示了从 3β-OH 到 3α-OH 蟾蜍二烯内酯的不可逆转化，这表明蟾蜍自我解毒中起着至关重要的作用。这些发现为了解蟾蜍二烯内酯的结构多样性提供了宝贵的见解，并增进了我们对其医学和生态意义的理解。

图形概要