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。目前已鉴定出200多种生物碱 从两栖类兽皮中提取的物质。这些毒素包括蝙蝠毒素，它是 强效的钠通道激活剂，组氨酸毒素，它是 烟碱受体通道复合体的非竞争性阻滞剂和 钾通道和短链毒素，它们具有强肌和强心作用 活性(III)对钠通道关闭的抑制作用。一个 从树枝状生物中鉴定出多种进一步的生物碱 青蛙。其中包括新的2，5-二取代十氢喹啉 5，8-二取代吲哚咪啶，6，9-二取代喹啉， 3，5-二取代吡咯里齐啶、短杆菌毒素、高乳杆菌毒素和 别粘虫毒素。其中许多生物碱的活性是非竞争性的 肌型和神经节型烟碱受体通道阻滞剂。 三种三环吡咯烷酮和O-甲氧肟的结构 根据质量分析确定了从树突蛙中分离到的 光谱、红外光谱和核磁共振 光谱分析。母体(C(11)H(13)N(2)Cl(2))a的结构 新的一类止痛生物碱类似地通过分析得到 一种N-乙酰的衍生物。非树枝状植物中生物碱的表征 两栖动物表明某些树形动物的生物合成途径 生物碱在两栖动物的一个谱系(属)中分别进化而来 蝗科、肌蜂科和蛙科，并在一个谱系中领先 隶属于Dendrobatider家族的四个属。生物碱生产的缺乏 在人工饲养的树蛙中，现在出现了由于缺乏天然的 环境和/或饮食。一种分离的多肽(30个氨基酸残基) 从一种双色青蛙的粘液分泌物中 行为抑郁土地刺激腺苷激动剂与 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.