A New Method for the Isolation of Ergosterol and Peroxyergosterol as Active Compounds of Hygrophoropsis aurantiaca and in Vitro Antiproliferative Activity of Isolated Ergosterol Peroxide.

In the present study, ergosterol peroxide and ergosterol were isolated for the first time from fresh fruit bodies of Hygrophoropsis aurantiaca (False Chanterelle). The substances were characterized mainly by spectroscopic methods (¹H-NMR, (13)C-NMR, DEPT-45, DEPT-90, DEPT-135, 2D-NMR). In our study, a new specific thin layer chromatographic method was developed for determination of ergosterol and ergosterol peroxide in H. aurantiaca extract. The method is based on the separation of n-hexane extract on silica gel (Silica Gel G) TLC plates using the optimized solvent system toluene/ethyl acetate (3:1; v/v). The main advantages of the developed method are the simplicity of operation and the low cost. The in vitro study results revealed the antiproliferative properties of ergosterol peroxide against LS180 human colon cancer cells. The described effect was attributed both to altered mitochondrial activity and decreased DNA synthesis. Additionally, in the same concentration range the investigated compound was not toxic to CCD 841 CoTr human colon epithelial cells. The present study suggests that fruit bodies of H. aurantiaca have great potential for producing substances and extracts with potential applications in medicine.

Chemotaxonomic value of magastigmane glucosides of Cichorium calvum.

Morphological characters and molecular analyses of Cichorium calvum and C. pumilum do not allow clear discrimination between these closely related wild species. Therefore, the aim of this study was to characterize the secondary metabolites of C. calvum and to select chemical markers which are unique to this species. From roots of C. calvum, ten sesquiterpene lactones were isolated, including seven lactucin-type guaianolides reported earlier from C. pumilum. Aerial parts also afforded secondary metabolites common to both species, along with the megastigmane glucosides staphylionoside D, saussureoside B and komaroveside A. This is the first report of the occurrence of these norisoprenoids in Cichorium species and the second record of their isolation from plants. Therefore, chemical discrimination of C. calvum is possible on the basis of its norisoprenoid composition.

Long-term cultured hairy roots of chicory-a rich source of hydroxycinnamates and 8-deoxylactucin glucoside.

A 12-year-old hairy root culture of Cichorium intybus L., a callus culture of the plant as well as roots and leaves of a wild plant of chicory, and roots of two C. intybus L. var. sativum cultivars were examined in respect of their hydroxycinnamate and sesquiterpene lactone compositions and contents. Total phenolics and diphenylpicrylhydrazyl radical scavenging activity of the examined plant tissues were also analyzed. The most active in radical scavenging were extracts from the hairy roots and leaves of chicory. 3,5-Dicaffeoylquinic acid was the major antioxidant present in the hairy roots. Its content in the root biomass reached 5.5 %, calculated on a dry weight basis. 8-Deoxylactucin glucoside (crepidiaside A) was the major sesquiterpene lactone in the hairy roots. Its content reached 1.4 %, calculated on a dry weight basis, and was nearly two orders of magnitude higher than that in the roots of wild chicory plant. The glucosidic derivative of 8-deoxylactucin constituted over 85 % of the total sesquiterpene lactone content in the long-term cultured hairy roots of chicory. Aglycone of this compound was reported to possess anti-inflammatory activity. The qualitative and quantitative analyses of hydroxycinnamates in callus and hairy root cultures of C. intybus were undertaken for the first time.

Sesquiterpene lactones from Lactuca canadensis and their chemotaxonomic significance.

A total of 19 sesquiterpene lactones were isolated from roots of Lactuca canadensis L., of which 10 were reported for the first time from Lactuca species and two were unknown. This is also the first report on the co-occurrence of three pairs of zaluzanin C-type guaianolides, epimeric at C-3, and on the presence of six eudesmanolides, oxygenated at C-1 and C-3, in Lactuca species. The new compounds were characterized as 3-epizaluzanin C-3-O-ß-glucopyranoside and 11,13-dehydrolactuside C using 1D and 2D NMR and high resolution mass spectroscopy. The sesquiterpene lactone profile of this species is dominated by zaluzanin C-type guaianolides (9 compounds) and eudesmanolides (8 compounds). The dissimilarity of this profile compared to that of other taxa of the genus is discussed.

Root tubers of Lactuca tuberosa as a source of antioxidant phenolic compounds and new furofuran lignans.

From the root tubers of Lactuca tuberosa, a wild edible plant species, nine phenolic compounds were isolated, including two new furofuran lignan glucosides, named lactuberin A and lactuberin B. Their structures were elucidated by spectroscopic methods, especially HRESIMS and 2D NMR techniques. This is the first time that compounds belonging to the epi series of 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane type furofuran lignans have been found in Lactuca species. The total phenolic content of the root tuber extract was evaluated and its major phenolic constituents, caffeic acid, chlorogenic acid and 3,5 dicaffeoylquinic acid, known to possess antioxidant activity, were quantified. Additionally, the root tuber extract showed DPPH radical scavenging activity implying its potential as functional food.

An unusual taxodione derivative from hairy roots of Salvia austriaca.

From a root culture of Salvia austriaca, transformed with Agrobacterium rhizogenes, a new diterpenoid was isolated and its chemical structure was determined as 7-(2-oxohexyl)-11-hydroxy-6, 12-dioxo-7,9(11),13- abietatriene [= 7-(2-oxohexyl)-taxodione] on the basis of spectroscopic methods, especially 1D and 2D NMR, and by comparison with structurally related compounds. This compound represents a hitherto unknown 2-oxohexyl diterpenoid derivative. Cytotoxic studies revealed that the new compound exhibited high cytotoxic activity against three cancer cell lines with IC(50) values ranging from 0.63 to 0.72µM. Its cytotoxic effectiveness against the cancer cells was ten fold higher than that of taxodione.

Complete NMR spectral assignments of two lactucin-type sesquiterpene lactone glycosides from Picris conyzoides.

Complete (1)H and (13)C NMR signal assignments of two lactucin-type sesquiterpene lactone glycosides, derivatives of 11ß,13-dihydrolactucin, isolated from roots of Picris conyzoides, were achieved by one- and two-dimensional NMR experiments, allowing the correction of previously published data for cichorioside B and the structure elucidation of its new ester with 3-hydroxy-2-methylpropanoic acid. In addition, seven known sesquiterpene lactones and three phenolic compounds were isolated from the plant material.

Sesquiterpenoids and phenolics from roots of Taraxacum udum.

From roots of Taraxacum udum, two new and four known sesquiterpene lactones were isolated, together with five known phenolic compounds. The new compounds were characterized as 11beta, 13-dihydrotaraxinic acid and taraxinic acid 6-O-acetyl-beta-glucopyranosyl ester by spectroscopic methods, especially 1D and 2D NMR, and by comparison with structurally related compounds. The plant material was shown to be a good source of taraxinic acid derivatives.

Structural analysis of 1L-chiro-inositol diester from Taraxacum udum.

1l-1,5-Di-O-p-hydroxyphenylacetyl-chiro-inositol was isolated from the leaves of Taraxacumudum, along with seven other secondary metabolites. Identification of the inositol derivative, based on extensive spectroscopic analyses ((1)H, (13)C and 2D NMR) in two solvents, allowed the correction of previously published data and conformational studies. This is the second report on the presence of inositol esters with p-hydroxyphenylacetic acid in plants.

Structure elucidation and complete NMR spectral assignments of two new sesquiterpene lactone xylosides from Lactuca triangulata.

Two new sesquiterpene lactone xylosides, derivatives of the guaianolides 9alpha-hydroxyleucodin and 9alpha-hydroxy-11,13-dehydroleucodin, were isolated from roots of Lactuca triangulata. Their structures were established on the basis of (1)H and (13)C NMR spectra, 2D NMR (HMQC, HMBC, COSY, NOESY) techniques and comparison with the literature data. The compounds represent the first example of sesquiterpene lactone xylosides.

Lignans and sesquiterpenoids from Lactuca sibirica.

From aerial parts of Lactuca sibirica, two new and one known furofuran lignans were isolated, together with four known lactucin-like guaianolides. On the basis of spectral data, the new lignans were characterized as acylated glucopyranosides of 4alpha, 8alpha-dihydroxypinoresinol.

The first guaian-12-oic acid glucopyranosyl ester and other constituents from Picris rhagadioloides (L.) Desf. (Asteraceae).

The first guaian-12-oic acid glucopyranosyl ester was isolated from the roots of Picris rhagadioloides (L.) Desf. (Asteraceae), in addition to five costuslactone-type guaianolides, four germacranolides and three phenolic compounds. This is the first time that the known phenolics syringaldehyde and syringaresinol, as well as the known sesquiterpene lactones glucozaluzanin C, cichorioside C and hypochoeroside A have been described from a Picris species. The compounds were characterized on the basis of physicochemical, 1D- and 2D-NMR spectroscopic, and mass spectrometric data.

Sesquiterpenoids and phenolics from roots of Cichorium endivia var. crispum.

Twelve known sesquiterpene lactones and the new guaianolide 10beta-methoxy-1alpha, 11beta,13-tetrahydrolactucin (10), together with three known phenolic acid esters were isolated from roots of Cichorium endivia var. crispum. The compounds were characterized by spectral methods.

Steroidal glycosides from the underground parts of Allium ursinum L. and their cytostatic and antimicrobial activity.

The aim of this study was the isolation and structural elucidation of steroidal glycosides from the underground parts of ramson Allium ursinum L. The structures of the isolated compounds were established based upon chromatographic methods and 1D- and 2D-NMR, MS and IR analyses. The mixture of two steroidal saponins: (25R)-spirost-5-en-3b-ol tetrasaccharide and (25R)-spirost-5, 25(27)-dien-3b-ol tetrasaccharide, along with a 3-hydroxypregna-5,16-dien-20-one glycoside were identified. The results of in vitro cytotoxic activity of the mixture of spirostanol saponins against cell lines melanoma B16 and sarcoma XC and human fibroblasts HSF are also reported. The spirostanol saponins mixture was investigated to determine its in vitro antimicrobal activity against Trichophyton mentagrophytes and Microsporum canis.

Antimicrobial activity of 10-isobutyryloxy-8,9-epoxythymol isobutyrate.

10-Isobutyryloxy-8,9-epoxythymol isobutyrate was found to be a major constituent of Inula helenium and Inula royleana root cultures. The compound showed moderate antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Escherischia coli, Pseudomonas aeruginosa and Candida albicans.

Sesquiterpenoids and phenolics from Taraxacum hondoense.

Eleven sesquiterpene lactones, including the new guaianolide 11beta-hydroxydeacetylmatricarin-8-O-beta-glucopyranoside, along with four known phenolic glucosides were isolated from Taraxacum hondoense. The compounds were characterized by spectral methods.

Quantitative structure-activity relationship of sesquiterpene lactones as inhibitors of the transcription factor NF-kappaB.

Sesquiterpene lactones (SLs) are the active compounds of a variety of traditionally used medicinal plants from the Asteraceae family. They are known to possess a considerable antiinflammatory activity in different inflammation models. They inhibit the transcription factor NF-kappaB probably by alkylating cysteine38 in the DNA binding domain of the p65 subunit. Here we investigate a set of 103 different sesquiterpene lactones representing 6 structural groups (44 germacranolides, 16 heliangolides, 22 guaianolides, 9 pseudoguaianolides, 2 hypocretenolides, 10 eudesmanolides) for their NF-kappaB inhibiting properties and the resulting IC(100)-values were submitted to a QSAR study. Properties important for the inhibition potency are discussed for the whole data set and for subsets of the different structural classes.

Thymol derivatives from a root culture of Inula helenium.

A root culture of Inula helenium L. was established from leaf explants of aseptic seedlings. An ethanol extract from the lyophilised roots was fractionated using different chromatographic techniques (CC, TLC). The main secondary metabolites found in the root culture were two thymol derivatives: 10-isobutyryloxy-8,9-epoxy-thymol isobutyrate (1) and 10-isobutyryloxy-6-methoxy-8,9-epoxy-thymol isobutyrate (2). The compounds were identified by spectral methods. Quantification of compound 1 in plant material was done by analytical RP-HPLC.

Sesquiterpene lactones from Taraxacum obovatum.

Two new guaianolide glucosides, deacetylmatricarin 8-O-beta-glucopyranoside and 11beta-hydroxyleukodin 11-O-beta-glucopyranoside, were isolated from roots of Taraxacum obovatum, along with four known sesquiterpene lactones, deacetylmatricarin, sonchuside A, taraxinic acid beta-glucopyranosyl ester and its 11beta,13-dihydro derivative. Their structures were established by spectral methods.