The secondary metabolites of three plant species (Betonica officinalis, Stachys sylvatica and Colchicum autumnale) were analysed.
The aim of this work was to study the chemical composition of the essential oils, total phenolic compounds, total flavonoids, the alkaloid content and antioxidant activity and to evaluate their natural variation between different plants organs collected from different wild populations. The essential oils were obtained by micro-distillation and analysed using gas chromatography equipped with a FID detector (GC-FID), gas chromatography and mass spectrometry (GC-MS). Total flavonoids, total phenolics, and antioxidant activities were analysed by UV/Vis spectrophotometric methods. Colchicine alkaloid was determined by HPLC.
Sixty-nine constituents were identified in the essential oil of B.
officinalis. The main compounds of the essential oil were [alpha]-pinene, 1-octen-3-ol, [beta]-bourbonene, [beta]-caryophyllene, trans-[alpha]-farnesene and germacrene D. In the essential oil of Stachys sylvatica twenty-eight volatile constituents were identified.
The main constituents were [alpha]-pinene, [beta]-pinene and germacrene-D. The concentration of total phenolics and total flavonoids in the leaves of B. officinalis was about 3-fold higher than in the roots.
Consequently, the highest antioxidant activity was also found in the leaves. In general no ssignificant differences were found between locations. In S. sylvatica total phenolics, total flavonoids and DPPH shows significant differences, between organs and populations too, whereas the FRAP antioxidant activity showed less variability.
The concentrations of the flavonoids and phenolic compounds showed a very high positive correlation in both antioxidative systems in both plant species.
The colchicine content in the flowers of Colchicum autumnale was about 2-fold higher than in the bulbs in all localities. The highest content of colchicine was found in the flowers and bulbs collected in the Duhle location.
Hajdari, A; Novak, J; Mustafa, B; Franz, C
(2012): Essential oil composition and antioxidant activity of Stachys sylvatica L. (Lamiaceae) from different wild populations in Kosovo.
Nat Prod Res. 2012; 26(18):1676-1681