Ontogenetic Changes in the Chemical Profiles of Piper Species

The chemical composition of seedlings and adult plants of several Piper species were analyzed by ¹H NMR spectroscopy combined with principal component analysis (PCA) and HPLC-DAD, HPLC-HRESIMS and GC-MS data. The chromatographic profile of crude extracts from leaves of Piper species showed remarkable differences between seedlings and adult plants. Adult leaves of P. regnellii accumulate dihydrobenzofuran neolignans, P. solmsianum contain tetrahydrofuran lignans, and prenylated benzoic acids are found in adult leaves of P. hemmendorffii and P. caldense. Seedlings produced an entirely different collection of compounds. Piper gaudichaudianum and P. solmsianum seedlings contain the phenylpropanoid dillapiole. Piper regnellii and P. hemmendorffii produce another phenylpropanoid, apiol, while isoasarone is found in P. caldense. Piper richadiaefolium and P. permucronatum contain dibenzylbutyrolactones lignans or flavonoids in adult leaves. Seedlings of P. richardiaefolium produce multiple amides, while P. permucronatum seedlings contain a new long chain ester. Piper tuberculatum, P. reticulatum and P. amalago produce amides, and their chemistry changes less during ontogeny. The chemical variation we documented opens questions about changes in herbivore pressure across ontogeny.