Lambert Joseph B, Poinar George O
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Acc Chem Res. 2002 Aug;35(8):628-36. doi: 10.1021/ar0001970.
Resins are produced by woody plants on a worldwide basis. We have found several distinct classes of modern diterpenoid resins based phenomenologically on the solid-state (13)C NMR spectra of the bulk material. Resin fossilizes over millions of years into a robust material sometimes called amber. We have characterized several hundred samples of fossil resin by solid-state (13)C NMR spectroscopy. We can relate one globe-spanning group of fossil resins to the modern genus Agathis, based on spectral evolution over time. A second large group has not been related with certainty to specific modern plants. Fossil resins from Europe fall into two categories, the famous Baltic ambers and another that resembles the Agathis group. Fossil resins from the Americas and Africa are closely related to the modern genus Hymenaea. Based on spectral distinctions, fossil resin found in an archaeological context sometimes can be assigned to a specific geographical origin on the basis of its (13)C NMR spectrum.
树脂在全球范围内由木本植物产生。基于块状材料的固态（13）C NMR光谱，我们从现象学上发现了几类不同的现代二萜树脂。树脂经过数百万年石化形成一种有时被称为琥珀的坚固材料。我们通过固态（13）C NMR光谱对数百个化石树脂样本进行了表征。基于随时间的光谱演化，我们可以将一组跨越全球的化石树脂与现代贝壳杉属植物联系起来。另一大组尚未确定与特定现代植物的关系。来自欧洲的化石树脂分为两类，著名的波罗的海琥珀和另一类类似贝壳杉属植物组的树脂。来自美洲和非洲的化石树脂与现代孪叶豆属植物密切相关。基于光谱差异，在考古背景中发现的化石树脂有时可以根据其（13）C NMR光谱确定其特定的地理来源。
