Characterization of plant exudates by principal-component and cluster analyses with nuclear magnetic resonance variables.

Principal-component and cluster analyses have been applied to nuclear magnetic resonance data for exudates derived from both conifers and angiosperms in order to classify these materials on the basis of molecular structure. The method succeeds in distinguishing resins produced by the conifer families Araucariaceae, Cupressaceae, and Pinaceae from each other and from resins produced by the angiosperm family Fabaceae. Other exudate types, including gums, gum resins, and kinos, also are distinguished from each other and from the resins.