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Bioactive phenols in leaves of Forsythia species
Published May 19, 2008
57-59.

Nowadays a number of lignans (arctigenin, matairesinol, pinoresinol and phillygenin) have come to the fore in research due to their various biological activities. In this paper the accumulation of these constituents in leaf extracts of Forsythia plants (F. intermedia, F. ovata 'Robusta’ and `Tetragold', F. suspensa, F. v...iridissima) was quantified using a new isolation method, supercritical CO2 fluid extraction. The total phenolic and flavonoid contents, the antioxidant capacity and the aglycone lignan profile were determined in leaf extracts of Forsythia species. Within the phenols, the flavonoids were only present in small quantities, but the amount of aglycone lignans was extremely high. F. ovata `Robusta' had the highest total lignan content (103.8 mg/g) of all the Forsythia species. The main lignan in this species is arctigenin, which normally makes up about 60% of the total lignan content, but in the case of F. ovata `Robusta' this value was 96.1%. Since this arctigenin content is outstanding compared to that of other Forsythia species, it could be promising to develop a fermentation technology for the production of this natural compound.

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Yield and composition of supercritical fluid extracts of different Lamiaceae herbs
Published May 15, 2007
79-82.

In our work the effectiveness of supercritical carbon dioxide extraction was studied on volatile components of Lamiaceae herbs. The aim of our investigations was to determine the optimal extraction parameters yielding high amount of volatiles in a desirable composition. As plant materials, dried and powdered cude drugs of Thymus vu...lgaris, Thymus pannonicus, Satureja hortensis, Ocimum basilicum, Rosmarinus officnalis and Salvia officinalis were chosen. Pressure (8-30 MPa), temperature (35-60 °C) and time (5-60 min) of extraction were regulated. Results obtained by supercritical fluid extraction (SFE) were compared to that of the conventional extraction procedur, hydrodistillation (HD). In the case of Thymus vulgaris, Thymus pannonicus and Salvia officnalis, extract yield of SFE was comparable to the essential oil amount obtained by hydrodistillation from the same drug. Essential oil rich thyme extracts were analysed by GC-FID. We have found that yield and quality of SFE extracts highly depend on the conditions of extraction.

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Yield and composition of supercritical fluid extracts of different Lamiaceae herbs: Satureja hortensis L., Ocimum basilicum L. and Melissa officinalis L.
Published December 8, 2008
75-79.

In our work the effectiveness of supercritical carbon dioxide extraction was studied on volatile and nonvolatile components of Lamiaceae herbs. The aim of our investigations was to determine the optimal extraction parameters yielding high amount of volatiles and nonvolatiles in a desirable composition. As plant materials, dried and pow...dered cude drugs of Satureja hortensis, Ocimum basilicum and Melissa officinalis were chosen. Pressure (8-50 MPa), temperature (35-60 °C), time (5-60 min) and the ratio of modifier (5-50% methanol) of extraction were regulated. Results obtained by supercritical fluid extraction (SFE) were compared to that of the conventional extraction procedure, hydrodistillation (HD). In the case of Satureja hortensis, Ocimum basilicum and Melissa officinalis extract yield of SFE was comparable to the essential oil amount obtained by hydrodistillation from the same drug. Essential oil rich extracts were analysed by GC-FID, while extracts rich in nonvolatile compounds were analysed by HPLC. We have found that yield and quality of SFE extracts highly depend on the conditions of extraction.

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Evaluation of supercritical plant extracts on volatile and non volatile biologically active lipophil components
Published June 6, 2001
78-83.

Authors dealt more than ten years with the analysis of supercritical extracts. For extraction (SFE) carbon dioxide was used as supercritical solvent. Fractionation of extracts was carried out by releasing the separations pressure at two stages. The extracts were collected as separate samples successively in time.

The traditional extract...ions were carried out with steam distillation or by using n-hexane and ethanol in Soxhlet apparatus. For the analysis of volatile compounds GC, GC-MS; of non volatile compounds TLC-densitometry and spectroscopic methods were used.

The following general characteristics were established comparing the composition of steam distillated oils with that of volatile SFE fractions. The SFE fractions were richer in monoterpene-esters and poorer in alcohols than the essential oils prepared by traditional way (clary sage, lavandel). Regarding the distributi,n of the monoterpene and sesquiterpene compounds, the SFE fractions contained sesquiterpene hydrocarbon in higher percentage than the distillated oils (e.g. 13-caryophyllene in Salvia fruticosa, (3-caryophyllene, y­muurolene, y-cadinene in Ochnum basilicum). Further the proportion of sesquiterpenes increased in SFE fractions collected successively in time.Significant difference was remarkable in respect of the optical rotationability of lovage oil and SFE fraction which was probably caused by the different ratio between the two ligustilid enantiomers. It was verified in some cases that a part of mono- and sesquiterpenes were present originally in a bounded form (glycosides) in plants. Therefore they appeared in essential oil fractions only after previous acidic treatment (Thymus, Origanum species). During the supercritical extraction the azulenogene sesquiterpene lactones did not transform to azulenes (in chamomile, yarrow), but the non volatile SFE fractions of some Asteraceae plant contained sesquiterpene--lacton of unchanged structure in high quantity (e.g. cnicin in blessed thistle, parthenolide in feverfew). Authors obtained also SFE fractions which were rich in triterpenoids and phytosterols (marigold, common dandelion).

 

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