Casticin and rotundifuran content of subcritical Vitex agnus-castus CO2 fruit extracts compared with classical Soxhlet extracts

Abstract

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].