Taxonomic and chemical relationships revealed by nuclear magnetic resonance spectra of plant exudates

Exudates collected from 65 species of gymnosperms and angiosperms were examined by solid-state carbon-13 (C-13) nuclear magnetic resonance (NMR) spectroscopy. Diagnostic criteria were developed to distinguish resins, gums, and gum resins. The typology generated from the exudate spectra generally follows current taxonomic classifications, suggesting that C-13 NMR spectroscopy may have applications in exudate identification, at least at the familial level, and in some cases at the generic or specific levels.