Alkaloid content of nursery garden seedlings and natural seedlings of Norway spruce (Picea abies)

Norway spruce (Picea abies) is an abundant and economically important plant species in northern Europe. Alongside of forestry, other ways of exploiting the wood are actively sought. Several potentially bioactive 2,6-disubstituted volatile piperidine alkaloids have been extracted from P. abies needles [1]. Since high intra-species variation seems to be typical for piperidine alkaloids in conifers [2], further investigations are needed. Spruce seedlings are traditionally planted in early summer but autumn planting is also taking place. The aim of this study was to compare the alkaloid contents of the nursery garden seedlings with the naturally regenerated, field grown seedlings over phenology (in spring and fall samples). Alkaloids from both needle and bark samples were extracted with solid phase partitioning methods and analyzed with GS-MS. Three alkaloid compounds, (+)-epidihydropinidine and two isomers of pinidine were detected in the samples. The field grown seedlings in both May and October had similar alkaloid yields than the nursery garden seedlings in May. In these samples (+)-epidihydropinidine was the main component in the needles and the only detected alkaloid in the bark. In September, the nursery garden seedlings contained 40% more alkaloids in the needles and 58% more in the bark than in May. Interestingly, also a different isomer of pinidine was detected in both needles and bark compared with that found in the natural seedling or nursery garden samples in May. These preliminary results suggest that the time of the year affects the total alkaloid amount and the quality of alkaloids in nursery garden seedlings.

References: 1. Stermitz, FR et al. (1994) Phytochemistry 35:951–953.

2. Gerson EA, et al. (2009) Ann. Bot. 103:447–457.