Variability in the essential-oil composition of Sideritis scardica GRISEB. from native Bulgarian populations.

The essential-oil composition of six native populations of Sideritis scardica from Bulgaria was studied by GC-FID and GC/MS analyses. Altogether, 37 components, representing 73.1 to 79.2% of the total oil content were identified. Among them, α-pinene (4.4-25.1%), ß-pinene (2.8-18.0%), oct-1-en-3-ol (2.3-8.0%), phenylacetaldehyde (0.5-9.5%), ß-bisabolene (1.3-11.0%), benzyl benzoate (1.1-14.3%), and m-camphorene (1; 0.3-12.4%) were the main compounds. All samples were characterized by low contents of oxygenated mono- and sesquiterpenes (≤1.6 and 2.3%, resp.). Principal component analysis (PCA) and cluster analysis (CA) showed a significant variability in the chemical composition of the studied samples as well as a correlation between the oil profiles and the ecological conditions of the natural habitats of S. scardica.

Cytokinin and auxin effect on the terpenoid profile of the essential oil and morphological characteristics of shoot cultures of Artemisia alba.

The influence of plant growth regulators (PGR) on the essential oil composition and in vitro development of A. alba shoot cultures was studied. Two types of oils were determined, based on their terpenoid content. Close relations between the morphogenetic effects of PGR and the essential oil profile of the species were observed Predominance of root over shoot development was connected with a drop in the amounts of sesquiterpenoids and the direction of biosynthesis towards oxygenated monoterpenoids in the PGR-free control medium, as well in those with 1.0 mg L(-1) indole-3-butyric acid (IBA) supplementation. On the contrary, lack of root formation and stimulated callusogenesis caused by the addition of 0.2 mg L(-1) 6-benzyladenine (BA), irrespectively of the presence of IBA (either 0.5 mg L(-1) or 1.0 mg L(-1)), resulted in the strong prevalence of sesquiterpenoids in the oils. These results are indicative that the morphological development ofA. alba shoot cultures affects the terpenoid biosynthetic pathway bringing out the hypothesis for a possible root to shoot signaling.

Quantitative analysis of sesquiterpene lactones in extract of Arnica montana L. by 1H NMR spectroscopy.

(1)H NMR spectroscopy was used as a method for quantitative analysis of sesquiterpene lactones present in a crude lactone fraction isolated from Arnica montana. Eight main components - tigloyl-, methacryloyl-, isobutyryl- and 2-methylbutyryl-esters of helenalin (H) and 11α,13-dihydrohelenalin (DH) were identified in the studied sample. The method allows the determination of the total amount of sesquiterpene lactones and the quantity of both type helenalin and 11α,13-dihydrohelenalin esters separately. Furthermore, 6-O-tigloylhelenalin (HT, 1), 6-O-methacryloylhelenalin (HM, 2), 6-O-tigloyl-11α,13-dihydrohelenalin (DHT, 5), and 6-O-methacryloyl-11α,13-dihydrohelenalin (DHM, 6) were quantified as individual components.

Chemical composition of the essential oils of Rhodiola rosea L. of three different origins.

Rhodiola rosea L. (Crassulaceae), or "rose root" is a perennial herbaceous plant, distributed in the Northern Hemisphere. Pharmacological studies have shown that R. rosea exhibits different biological activities - antioxidant, antidepressant, anticancer, etc. The aim of this study was to compare the chemical composition of essential oils from rhizomes of three commercial samples of R. rosea originated from Bulgaria (sample 1), China (sample 2) and India (sample 3). The oils were analyzed by GC and GC-MS. Thus, the main volatile component in the Bulgaria and Chinese R. rosea was geraniol, followed by myrthenol in sample 1 or octanol in sample 2. Phenethylalcohol was a principal constituent in the Indian oil. Myrtenol and octanol were in significant amounts too. Aliphatic hydrocarbons were characteristic of the latter sample. It is notable that cinnamyl alcohol, which was present in large concentration in Bulgarian sample, was not detected in the other two samples. The obtained results showed considerable differences in the composition of the studied three origins of R. rosea.

Influence of the extraction method on the yield of flavonoids and phenolics from Sideritis spp. (Pirin Mountain tea).

The influence of the extraction method on the yield and composition of extracts of Sideritis (Pirin mountain tea) has been studied. Maceration, ultrasound-assisted (USAE) and microwave assisted extraction (MAE) were applied. Total phenolics and total flavonoids were quantified spectrophotometrically, and individual compounds were analyzed by HPLC-DAD-MS(n). This preliminary study reveals that the traditional way of tea preparation from Sideritis is the most appropriate in order to extract the maximum of total flavonoids and total phenolics. In the case of methanol extraction, the optimal method is USAE.

Ultrasonically assisted extraction of total phenols and flavonoids from Rhodiola rosea.

This work deals with ultrasonically assisted extraction (UAE) of biologically active compounds from rhizomes of Rhodiola rosea, a popular medicinal plant. The influence of temperature, type of solvent and solid/solvent ratio on the yield of total extracts, total phenols and flavonoids was established. The best extraction of total phenols and flavonoids was achieved by using 50% aqueous EtOH and MeOH, respectively. Five times increase of solid/solvent ratio (from 1:20 to 1:100 (w/v)) leads to slow increase of the yield of total phenols and flavonoids. The extraction effectiveness of conventional maceration with 50% EtOH and UAE performed for 1 h at 25 degrees C using the same solvent with respect of total phenols was comparable.

An iridoid and a flavonoid from Sideritis lanata L.

A new iridoid diglucoside, 10-O-(E)-p-coumaroylmelittoside (1) and a new flavone glucoside, O-(6''-O-Acetyl-)-beta-glucopyranosylchrysoeriol (2), together with four known flavone glycosides, were isolated from the aerial parts of Sideritis lanata. The structures of the new compounds were elucidated by spectroscopic methods, 2D NMR and MS.

Irregular linear sesquiterpene dilactones from Anthemis auriculata Boiss.

Seven new irregular linear sesquiterpene lactones, epi-antheindurolide A (1), epi-antheindurolide A-5,6-oxide (2), 5-hydroxy-5,6-dihydro-6,13-dehydro-epi-antheinduro lide A (3), 5-hydroperoxy-5,6-dihydro-6,13-dehydro-epi-antheindurolide A (4), epi-antheindurolide B (5), 6-hydroxy-5,6-dihydro-4,5-dehydro-epi-antheindurolide A (6) and 6-hydroperoxy-5,6-dihydro-4,5-dehydro-epi-antheindurolide A (7), were isolated from the flowers of Anthemis auriculata Bioss. Their structures were established by spectroscopic techniques. The discussed compounds were found to be stereoisomers of recently reported lactones for A. arvensis.

Sesquiterpene lactones as chemotaxonomic markers in genus Anthemis.

Sesquiterpene lactones isolated from the genus Anthemis are used as chemotaxonomic markers. The obtained results support with some exceptions the botanical classification in Flora Europaea. Discrepancy between the lactone profile, cluster analysis and classification of A. melampodina, A. macedonica and A. austriaca in the genus Anthemis is discussed. The lactone composition of the undescribed as an European species A. plutonia correlates well with the guaianolide containing group of sect. Hiorthia.

Volatiles from four Astragalus species: phenological changes and their chemotaxonomical application.

This paper shows the changes of the volatile compounds from four Astragalus species at three phenological stages: leaf development, flowering and fructification, which might be connected with the plant defense. After GC/MS analyses of Astragalus glycyphyllos L., A. hamosus L., A. cicer L. and A. spruneri Boiss., different groups of volatile compounds were found: hydrocarbons, alcohols, aldehydes and ketones, esters, terpenes, chlorinated compounds, etc. Identified volatiles were used for a cluster analysis in order to make chemotaxonomic conclusions for these evolutionary different species.

Terpenoids from Anthemis austriaca Jacq.

The aerial parts of Anthemis austriaca Jacq. afforded five new sesquiterpene lactones (two of which are dimeric guaianolides) and three new guaiane type sesquiterpene acids In addition, seven known terpenoids were also found in the studied species. Their structures were elucidated by spectral methods.

Sesquiterpene lactones from Anthemis carpatica Willd.

Four new eudesmanolides and two new guaianolides were isolated from the aerial parts of Anthemis carpatica Willd. and their structures elucidated by spectral methods. In addition, seven known sesquiterpene lactones were identified.