PHARMACOLOGICALLY ACTIVE COMPOUNDS FROM AMPHIBIANS AND OTHER NATURAL SOURCES

天然产物提供了广泛的生物活性剂， 其中许多具有独特的药理活性特征， 治疗潜力已经鉴定出200多种生物碱， 从两栖动物皮肤中提取的物质。其中包括Batracbotoxins， 钠离子通道的有效激活剂，组胺毒素， 烟碱受体通道复合物的非竞争性阻断剂和 钾通道和pumiliotoxins，具有肌强直和心强直 活性（iii）对钠通道关闭的抑制作用。一 已从石斛中鉴定出多种其他生物碱 青蛙这些包括新的2，5-二取代的十氢喹啉 5，8-二取代的吲嗪，6，9-二取代的喹嗪， 3，5-二取代的吡咯烷，pumiliotoxins，homopumiliotoxins和 别普米利亚毒素。这些生物碱中的许多具有非竞争性活性， 肌肉型和神经节型烟碱受体通道阻滞剂。 三种三环吡咯烷酮肟和O-甲基肟的结构 根据质量分析， 光谱法、红外光谱法和核磁共振 光谱法母体成员（C（11）H（13）N（2）Cl（2））a的结构 通过分析，类似地衍生出一类新的生物碱， N-乙酰基衍生物。非石斛生物碱成分的研究 两栖动物表明某些树蛙的生物合成途径 生物碱在两栖动物的一个谱系（属）中分别进化， 蟾蜍科、蛙科和蛙科， 属于四个属。缺乏生物碱生产 在人工饲养的树蛙中， 环境和/或饮食。一种肽（30个氨基酸残基）分离 双色叶水母的粘液分泌物 行为抑郁症和刺激腺苷激动剂的结合， 脑A（1）-腺苷受体。

Natural products have provided a wide range of biologically active agents, many of which have unique profiles of pharmacological activity and therapeutic potential. Over two hundred alkaloids have been identified In extracts from amphibian skins. These include batracbotoxins, 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 (iii(- to inhibitory effects on closing of sodium channels. A variety of further alkaloids have, been characterized from dendrobatid frogs. These include new 2,5-disubstituted decahydroquinolizies 5,8-disubstited indolizidines, 6,9-disubstituted quinolizidines, 3,5-disubstituted pyrrolizidines, pumiliotoxins, homopumiliotoxins and allopumilliotoxins. Many of these alkaloids have activity as noncompetitive blockers at muscle-type and ganglionic-type nicotinic receptor-channels. Structures for three tricyclic pyrrolizidinone oximes and O-mothyloximes from a dendrobatid frog have been determined based on analysis by mass spectrometry, infrared spectroscopy and nuclear magnetic resonance spectrometry. A structure for the parent member (C(11)H(13)N(2)Cl(2) ) a new class of analgetic alkaloids has been similarly derived by analysis of an N-acetyl derivative. Characterization of alkaloids in nondendrobatid amphibians indicates that the biosynthetic pathways to certain dendrobatid alkaloids have evolved separately in one lineage (genus) of amphibians from the families Bufonidae, Myobatracidae and Ranidae and in a lineage leading to four genera in the family Dendrobatider. The lack of alkaloid production in captive-raised dendrobatid frogs now appears due to lack of natural environment and/or diet. A peptide (thirty amino acid residues) isolated from mucous secretions of a hylid frog Phyllomedusa bicolor causes profound behavioral depression land stimulates binding of adenosine agonists to brain A(1)-adenosine receptors.