NEW CARDENOLIDES FROM ASCLEPIAS SPECIES

卡登内酯是一组天然存在的C23类固醇。 药用、毒理和生态方面的重要性。毒副作用 目前使用的5-αH-卡登内酯的影响 植物科玄参科和罗布麻科是主要的致病原因。 医院内药物致死的原因。最近的证据 表明在马利筋中发现的一些5-βH-卡登内酯 Asclepiadaceae科，可能有相当大的变力作用 对脊椎动物心脏的活性高于临床使用的5-α-H 化合物。通过分离、提纯和鉴定万寿菊内酯 从以前未被探索的马利筋中提取出新的卡丹内酯 可以提供具有更有利的治疗指数的 药理分析。计划进行四次探险，收集 并加工来自北美各种不同工厂的材料 马利筋。腰果内酯的分光光度测定法 每个物种的浓度和薄层层析将 用于选择物种进行进一步研究。卡德内利德将 从高浓度的物种中分离和纯化 通过各种层析技术鉴定未鉴定的卡丹内酯。 纯化后的化合物与已知化合物相比仍未鉴定 卡登内酯标准将接受结构确定 通过化学和高分辨率光谱的结合 高分辨率核磁共振等技术 实验。关于物种丰度、物候、生态的野外数据 访问过的马利筋种群的分布和传粉者 在研究过程中与参考TLC Cardenolide图谱一起 应该提供了关于这一分类的有价值的见解 难相处的植物家族。实地工作还将使采取措施 乳草寄主植物利用和卡地那内酯的固定 帝王蝶和其他植食性昆虫，提供 黄花丹化学生态学研究的重要资料及其在中国的应用 昆虫协会。

Cardenolides are a group of naturally occurring C23 steroids of medicinal, toxicological, and ecological importance. Toxic side effects from the 5-alpha H cardenolides currently used from the plant families Scrophulariaceae and Apocynaceae result in the major cause of drug induced deaths in hospitals. Recent evidence suggests that some 5-beta H cardenolides found in the milkweed family, Asclepiadaceae, may have considerably greater inotropic activity on vertebrate hearts than the clinically used 5-alpha H compounds. By isolating, purifying, and identifying cardenolides from previously unexplored milkweeds, new sources of cardenolides having a more advantageous therapeutic index may be provided for pharmacological analysis. Four expeditions are proposed to collect and process plant material from a wide variety of North American milkweeds. Spectroassay determinations of cardenolide concentrations and thin-layer chromatography of each species will be used to select species for additional study. Cardenolides will be isolated and purified from species with high concentrations of unidentified cardenolides by a variety of chromographic techniques. Purified compounds still unidentified after comparison with known cardenolide standards will be subjected to structural determination by a combination of chemical and high resolution spectrometry techniques including high resolution nuclear magnetic resonance experiments. Field data on the abundance, phenology, ecological distributions, and pollinators of the milkweed populations visited during the study along with reference tlc cardenolide profiles should provide valuable insight concerning this taxonomically difficult plant family. Field work will also enable measures of milkweed host-plant utilization and cardenolide sequestration by monarch butterflies and other phytophagous insects, providing important data on the chemical ecology of milkweeds and their insect guild.