Milka Todorova

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.

Ultrasound-assisted extraction of alantolactone and isoalantolactone from Inula helenium roots.

This work deals with ultrasound-assisted extraction (UAE) of alantolactone and isoalantolactone from the roots of Inula helenium L., a well-known medicinal plant. The effects of ethanol concentration, extraction time, temperature and number of extraction steps on the extraction yields of both sesquiterpene lactones were investigated. Gas chromatographic (GC) method was used for simultaneous determination of their contents in the corresponding extracts. A comparison with classical extraction methods [maceration, infusion and micro steam distillation-extraction (MSDE)] showed that the amounts of alantolactone and isoalantolactone achieved by UAE with 70 and 96% EtOH for 30 min at room temperature were higher or almost equal to those obtained by maceration for 24 hours.

Sideritis scardica Griseb., an endemic species of Balkan peninsula: Traditional uses, cultivation, chemical composition, biological activity

ETHNOPHARMACOLOGICAL RELEVANCE Sideritis scardica Griseb. is an endemic species in the Balkan Peninsula. It is used in traditional medicine as a loosening agent in bronchitis and bronchial asthma; against the common cold and lung emphysema; in the treatment of inflammation, gastrointestinal disorders and coughs; and as an active constituent of dietary supplements for the prevention of anemia. This review aims to provide a comprehensive overview of the traditional use, phytochemistry, biological activity, cultivation, and extraction of Sideritis scardica and to highlight the gaps in our knowledge which deserves further research. MATERIALS AND METHODS The present review is based on information collected from scientific journals, books, and electronic search. These sources include Scopus, Pubmed, Web of Science, and Google scholar as well as local books on ethnopharmacology and botany of this plant. RESULTS The reported data on phytochemical studies, biological activity, cultivation, extraction, and traditional uses have been reviewed. Variability in essential oil composition of wild growing and cultivated taxa depending on ecological conditions was discussed. Flavonoids, phenylethanoids, diterpenoids, aliphatic compounds, etc. identified so far have been summarized. A comparative study on the effectiveness of different methods, solvents, and parameters of extraction has also been discussed. A broad range of activities of plant extracts and fractions as antimicrobial, anti-inflammatory, cytotoxic, antioxidant, gastroprotective, antiglioma, and triple monoamine reuptake inhibition as well as cultivation of the species as an approach for conservation of the natural habitats and provision of herb with high and permanent quality has also been presented. CONCLUSIONS Sideritis scardica has become very popular and widely advertised herb in Europe. Although some of ethnobotanical uses have been proved through in vitro experiments, further studies of the individual compounds or chemical class of compounds responsible for the pharmacological effects and the mechanisms of action are necessary. In addition, the toxicity and the side effects from the use of Sideritis scardica as well as clinical trails need attention. The variability in the chemical composition of this medicinal plant depending on the origin requires development of a protocol for its standardization. For the practice it is important to improve cultivation conditions in order to increase the accumulation of biologically active compounds and to obtain herb with permanent and good quality.

New sesquiterpenoids from Achillea clypeolata

The aerial parts of Achillea clypeolata afforded, in addition to clypeotriol (5), four new polyoxigenated sesquiterpenoids of eudesmane and cyperane type. The structures were established on the basis of their spectral properties as 7α-hydroxycarisson (1), 7α-hydroxyisopterocarpolone (2), 3α-dehydroxy-3α-hydroperoxy-clypeotriol (3) and 4-oxo-cyperan-3α,7α,11-triol (4).

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.

Essential Oil Composition of Three Sideritis Species from Bulgaria

Abstract The composition of essential oils of three Sideritis species was investigated by GC and GC/MS. It was found that the oil of S. syriaca L. contained a high percentage of myrcene (50.5%), while sesquiterpenes dominated in the oils of S. scardica Griseb and S. moniana L. The major components in S. scardica oil were β-caryophyllene (18.8%) and nerolidol (12.1%), while germacrene D (41.1%) and bicyclogermacrene (10.9%) were the principal constituents of S. montana oil.

Crithmifolide: a sesquiterpene lactone from Achillea crithmifolia

Crithmifolide, a novel 1,2-seco-guaianolide hemiacetal has been isolated from the aerial parts of Achillea crithmifolia, in addition to 11 known sesquiterpene lactones. The structure of the new compound has been elucidated by spectroscopic methods.

Terpenoids from Achillea clypeolata

Abstract A new sesquiterpene alcohol named clypeotriol and characterised as eudesm-4(15)-en-3 α ,7 α , 11-triol was isolated from Achillea clypeolata collected in south-western Bulgaria. Populations of the same taxon growing in the eastern regions of Bulgaria afforded only sesquiterpene lactones two of which were the novel guaianolides 3 α ,4 α -epoxyrupicolin-A and 3 α ,4 α -epoxyrupicolin-B. The structures of the new compounds were elucidated on the basis of spectral data.

Sesquiterpene lactones in a population of Balsamita major cultivated in bulgaria

Abstract Seven C-9β-hydroxylated or esterified germacranolides were isolated from the flowers of a Balsamita major population cultivated in Bulgaria: the known 9β-propionyloxy- and 9β-isobutyryloxy-costunolides, 1α,10β-epoxyhaageanolide, 9β-hydroxyartemorin, and the new esters the propionyl-, isobutyryl- and 2-methylbutyryl1α,10β-epoxyhaageanolides. These lactones differ from the presently known eudesmanolides found in a B. major population cultivated in Poland, probably as result of the existence of chemotypes, frequently observed in the tribe Anthemideae.

Eudesmanolides from Artemisia pontica

The aerial parts of Artemisia pontica afforded seven new 5-hydroxyeudesmanolides in addition to the known sesquiterpene lactones artemin, 5-epi-artemin and 8α-hydroxytaurin. The structures of the new compounds were elucidated on the basis of the spectral findings.