PHARMACOLOGICALLY ACTIVE COMPOUNDS FROM AMPHIBIANS AND OTHER NATURAL SOURCES

天然产品提供了广泛的生物活性物质， 其中许多化合物具有独特的药理活性和 治疗潜力。三百多种生物碱已经被 从两栖动物皮肤的提取物中鉴定出来。其中包括 蝙蝠毒素是钠通道的强效激活剂， 组氨酸毒素，是尼古丁的非竞争性阻滞剂 受体通道复合体和钾通道，以及Pumilio毒素， 由于抑制作用而具有强肌和强心活性 关于钠离子通道的关闭。其他生物碱包括2，5- 二取代十氢喹啉，3，5-二取代吲哚，5，8- 双取代吲哚咪啶，1，4-二取代喹啉，3，5- 二取代的吡咯里西丁、短链毒素、高短链毒素和 别介毒素和包括吡咯里西定在内的三环生物碱 肟类、假性苯丙胺、环戊二氮喹啉、球孢菌素、 还有强效止痛药依巴替丁。这些生物碱中的大多数都是 从新热带树蛙身上检测到并表现出其特征。 肉毒杆菌毒素、喹唑烷类、吲哚利嗪类、吡咯利嗪类和 十氢喹啉类化合物现已从中华大蟾蜍中鉴定出来 Mantella属的Melanophryniscus属和扁担蛙类 马达加斯加特有。后者含有一类新的生物碱 其提出的脱氢乳杆菌毒素结构正在进行调查 综合。吡咯里西定酮和球孢菌素派生于 树突蛙从食用虫中脱颖而出的极其有效 生物碱摄取过程。吡咯里西定肟与强效止痛药 已经合成了表巴替丁，正在进行药理研究 学习。首次从鸟类中检测到的生物碱现在包括 高致死毒素，一种类似麻醉剂的生物碱，以及 行为刺激性。

Natural products provide a wide range of biologically active agents, many of which have unique profiles of pharmacological activity and therapeutic potential. Over three hundred alkaloids have been identified in extracts from amphibian skins. These included batrachotoxins, which are potent activators of sodium channels, histrionicotoxins, which are noncompetitive blockers of nicotinic receptor channel complexes and of potassium channels, and pumiliotoxins, which have myotonic and cardiotonic activity due to inhibitory effects on closing of sodium channels. Further alkaloids included 2,5- disubstituted decahydroquinolines, 3,5-disubstituted indolizidines, 5,8- disubstituted indolizidines, 1,4-disubstituted quinolizidines, 3,5- disubstituted pyrrolizidines, pumiliotoxins, homopumiliotoxins and allopumiliotoxins, and tricyclic alkaloids, including pyrrolizidine oximes, pseudophrynamines, cyclopenta[b]quinolizidines, coccinellines, and the potent analgetic epibatidine. Most of these alkaloids have been detected and characterized from neotropical dendrobatid frogs. Pumiliotoxins, quinolizidines, indolizidines, pyrrolizidines and decahydroquinolines have now been characterized from bufonid toads of the genus Melanophryniscus and in mantellid frogs of the genus Mantella endemic to Madagascar. The latter contain a new class of alkaloids whose proposed dehydropumiliotoxin structure is being probed by synthesis. Pyrrolizidine oximes and coccinellines are derived in dendrobatid frogs from dietary insects by an extremely efficient alkaloid uptake process. Pyrrolizidine oximes and the potent analgetic epibatidine have been synthesized and are undergoing pharmacological study. Alkaloids, detected for the first time from birds, now include homobatrachotoxin, an anesthetic-like alkaloid, and an alkaloid with behavioral stimulant properties.