The ripe fruits of Vitex agnus-castus L. are traditionally used as herbal medicine for the treatment of various conditions
in women, like premenstrual syndrome, menopause and disrupted lactation. The dopaminergic
activity of some extracts is assumed to be a synergistic effect of diterpenes and
other constitutents [1]. The aim of the present study was to compare subcritical liquid
CO2 extracts of Vitex agnus-castus dried fruits with soxhlet extracts using three different solvents, namely n-hexane,
dichloromethane and methanol. Subcritical liquid extraction (25–26°C, 62–64bar) was
used because of its suitability for use in laboratory scale and minor costs compared
to supercritical fluid extraction (SFE), which has been used in prior studies [2].
The so-called periodic or soxhlet-type subcritical liquid extraction [3] allowed to
stop extraction at certain time points (15, 45, 90min and 12 hours), yielding 0.01g,
0.14g, 0.25g and 0.28g extract, respectively compared to 1.8g n-hexane, 1.3g dichloromethane
and 0.96g methanol classical soxhlet extracts. HPLC-DAD and external standards were
used for the quantification of the flavonoid casticin and the diterpene rotundifuran
[4]. The highest casticin content was found in the n-hexane soxhlet extract. Overall,
concentrations of casticin varied between 0,15 and 106,7mg/100g in the dried fruits
and between 0,13 and 1,18% in the extracts. Rotundifuran content was below limit of
quantification for the three soxhlet extracts, but showed relatively high amounts
(11,75–301,01mg/100g drug) in the subcritical CO2 extracts in comparison with literature [2], [4].
Acknowledgements: Reference standards (casticin, rotundifuran) were a kind gift from Bionorica AG.
References: 1. Meier B. et al. (2000) Phytomedicine, 7(5):373–381.
2. Cossuta D. et al. (2008)J. of Supercritical Fluids, 47: 188–194.
3. Naik S.N. et al. (1989) Fluid Phase Equilibria, 49: 115–126.
4. Hoberg E. et al. (2000) Planta Med., 66(4): 352–355.
