Among opioids, morphinans play an important role as therapeutically valuable drugs. They include pain relieving agents such as naturally occurring alkaloids (e.g. morphine, codeine), semisynthetic derivatives (e.g. oxycodone, oxymorphone, buprenorphine), and synthetic analogs (e.g. levorphanol). Currently used opioid analgesics also share a number of severe side effects, limiting their clinical usefulness. The antagonist morphinans, naloxone and naltrexone are used to treat opioid overdose, opioid dependence, and alcoholism. All these opioid drugs produce their biological actions through three receptor types, mu, delta, and kappa, belonging to the G-protein-coupled receptor family. Considerable effort has been put forward to understand the appropriate use of opioid analgesics, while medicinal chemistry and opioid pharmacology have been continuously engaged in the search for safer, more efficacious and nonaddicting opioid compounds, with the final goal to reduce complications and to improve patient compliance. Toward this goal, recent advances in chemistry, ligand-based structure activity relationships and pharmacology of 14-alkoxymorphinans are reviewed in this chapter. Current developments of different structural patterns of 14-alkoxymorphinans as research tools and their potential therapeutic opportunities are also summarized.

中文翻译：

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14-烷氧基吗啡喃衍生物的合成及其药理作用。

在阿片类药物中，吗啡喃作为具有治疗价值的药物发挥着重要作用。它们包括镇痛剂，例如天然存在的生物碱（例如吗啡、可待因）、半合成衍生物（例如羟考酮、羟吗啡酮、丁丙诺啡）和合成类似物（例如左啡诺）。目前使用的阿片类镇痛剂也有许多严重的副作用，限制了它们的临床应用。拮抗剂吗啡喃、纳洛酮和纳曲酮用于治疗阿片类药物过量、阿片类药物依赖和酒精中毒。所有这些阿片类药物均通过属于 G 蛋白偶联受体家族的三种受体类型 mu、delta 和 kappa 产生其生物学作用。为了解阿片类镇痛剂的适当使用做出了相当大的努力，而药物化学和阿片类药物药理学一直在不断地寻找更安全、更有效和非成瘾性的阿片类化合物，最终目标是减少并发症并提高患者的依从性。为实现这一目标，本章回顾了 14-烷氧基吗啡喃的化学、基于配体的结构活性关系和药理学方面的最新进展。还总结了作为研究工具的 14-烷氧基吗啡喃的不同结构模式的当前发展及其潜在的治疗机会。本章综述了 14-烷氧基吗啡喃的配体结构活性关系和药理学。还总结了作为研究工具的 14-烷氧基吗啡喃的不同结构模式的当前发展及其潜在的治疗机会。本章综述了 14-烷氧基吗啡喃的配体结构活性关系和药理学。还总结了作为研究工具的 14-烷氧基吗啡喃的不同结构模式的当前发展及其潜在的治疗机会。