天然产物绝对构型的确定(英文)

Determination of the absolute configuration of natural products

天然产物结构研究一直是天然药物化学相关领域最重要的工作之一,尤其对天然产物绝对构型(AC)的确定更是具有挑战性的研究内容,目前得到国内外学者越来越多的关注。在过去的几十年里已发展了许多技术和方法用来确定天然产物的绝对构型,包括直接法(或绝对方法),例如X射线单晶衍射(XRD)、电子圆二色谱(ECD)、振动圆二色谱(VCD)及拉曼光学活性(ROA);使用已知绝对构型的参照物或衍生化试剂的间接法(或相对方法),例如利用经验规则的圆二色谱,以及利用手性衍生化试剂各向异性效应的核磁共振法(NMR)。但由于这些方法适用的化合物类型和结构不尽相同,目前尚没有一种通用技术涵盖所有类型天然产物绝对构型的测定,我们只能灵活应用各种技术和方法才能确定大部分天然产物的绝对构型。本综述总结了大多数当前天然产物绝对构型测定中常用的以及具有潜在前景的技术和方法,并简要介绍了它们的原理及特点。

Structural elucidation of natural products is always one of the most important tasks for natural product researchers in related fields. Particularly, the absolute configuration （AC）, being a great challenge for natural product chemists, has attracted much attention. During the past few decades, many techniques and approaches have been developed to determine the AC of natural products, including direct （or absolute） methods, e.g. X-ray diffraction （XRD）, electronic and vibrational circular dichroism （ECD and VCD）, and Raman optical activity （ROA）, as well as indirect （or relative） methods using a reference or a derivatizing agent with known AC, e.g. CD with empirical rules and nuclear magnetic resonance （NMR） utilizing anisotropic effects of chiral derivatizing agents. How- ever, none of the currently applied techniques is capable of dominating AC determination, since they each have their respective limita- tions corresponding to the different structural features. This mini review summarizes most of the techniques and methods which are commonly used in AC assignment of natural products, or have potential application prospects, and briefly describes their principles, advantages and limitations.