Abstract
A systematic survey of Aralia spinosa (Araliaceae), covering an entire growing season and including aboveground organs
at various developmental stages, revealed that only about half of all samples collected
showed cyanogenesis. Cyanogenesis was detected in inflorescences and leaves but is
apparently restricted to certain harvest times or developmental stages. The structurally
unusual triglochinin, characterized by a hex-2-enedioic acid partial structure, was
the only cyanogenic glycoside detected. This is the first description of triglochinin
in this species and in the family of Araliaceae. Triglochinin is biogenetically derived
from tyrosine, which is in good agreement with the few cyanogenic glycosides previously
detected in members of the Araliaceae family. Triglochinin was identified, characterized,
and quantified by modern chromatographic methods, and the amount of enzymatically
releasable hydrocyanic acid was determined qualitatively and quantitatively. Two
isomers of triglochinin were detected chromatographically at minor levels. The
isomeric pattern agreed well with literature data from other triglochinin-containing
plants. This was confirmed in the two species, Triglochin maritima and Thalictrum aquilegiifolium, which were comparatively studied. In the case of A. spinosa, inflorescence buds harvested in July showed the highest content of triglochinin,
just under 0.2% on a dry weight basis. The detection of triglochinin adds to the knowledge
of toxicological properties and the dereplication of U(H)PLC/MS² data provides a comprehensive
phytochemical profile of A. spinosa.
Key words
Aralia spinosa
- Araliaceae - cyanogenesis - triglochinin
