Linderazulen aus einer invasiven Pflanze: Delphi und sein violettes Wunder

Linderazulene, a crystalline azulene derivative, is violet due to the annulated furan ring and not blue like many other azulenes. Linderazulene occurs naturally in Gorgonians. Some plants form colourless sesquiterpenoid precursors of linderazulene. Their degradation can give rise to linderazulene as an aromatic hydrocarbon, e.g. by steam distillation. The chromatographic isolation of linderazulene in minute amounts from the essential of the seeds of Perfoliate Alexanders (Smyrnium perfoliatum) obtained by steam distillation is described. This attractive plant belongs to Apiaceae and is an invasive species in Germany. All spectra are presented with interpretations. Based on a student's project work this paper is a follow up of the recent book "Classics in Spectroscopy" by S. Berger und D. Sicker (Wiley-VCH 2009). This is the final chapter of our series on 30 natural products.