Jiang Zuodong, Kempinski Chase, Chappell Joe
Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536-0596.
Curr Protoc Plant Biol. 2016;1:345-358. doi: 10.1002/cppb.20024. Epub 2016 Jun 10.
Terpenes/terpenoids constitute one of the largest classes of natural products, this is due to the incredible chemical diversity that can arise from the biochemical transformations of the relatively simple prenyl diphosphate starter units. All terpenes/terpenoids comprise a hydrocarbon backbone that is generated from the various length prenyl diphosphates (a polymer chain of prenyl units). Upon ionization (removal) of the diphosphate group, the remaining allylic carbocation intermediates can be coaxed down complex chemical cascades leading to diverse linear and cyclized hydrocarbon backbones, which can then be further modified with a wide range of functional groups (. alcohol, ketones, .) and substituent additions (. sugars, fatty acids). Because of this chemical diversity, terpenes/terpenoids have great industrial uses as flavors, fragrances, high grade lubricants, biofuels, agricultural chemicals and medicines. The protocols presented here focus on the extraction of terpenes/terpenoids from various plant sources and have been divided into extraction methods for terpenes/terpenoids with various levels of chemical decoration, from the relative small, nonpolar, volatile hydrocarbons to substantially large molecules with greater physical complexity due to their chemical modifications.
萜类化合物是最大的天然产物类别之一，这归因于相对简单的异戊二烯基二磷酸起始单元的生化转化所能产生的令人难以置信的化学多样性。所有萜类化合物都包含一个由各种长度的异戊二烯基二磷酸（异戊二烯单元的聚合物链）生成的碳氢化合物骨架。在二磷酸基团离子化（去除）后，剩余的烯丙基碳正离子中间体可以被引导进入复杂的化学级联反应，从而产生各种线性和环状的碳氢化合物骨架，然后这些骨架可以用广泛的官能团（如醇、酮等）和取代基添加物（如糖、脂肪酸）进行进一步修饰。由于这种化学多样性，萜类化合物在香料、香精、高档润滑剂、生物燃料、农用化学品和药物等方面具有巨大的工业用途。这里介绍的方案重点是从各种植物来源中提取萜类化合物，并已根据萜类化合物化学修饰程度的不同分为不同的提取方法，从相对较小、非极性、挥发性的碳氢化合物到由于化学修饰而具有更大物理复杂性的大分子。
