The essential oil composition of the endemic plant species Centaurea vandasii and chemotaxonomy of section Phalolepis (Asteraceae).

In the present study, the chemical composition of the essential oil from aerial parts of the endemic plant species, Centaurea vandasii Velen (sect. Phalolepis, Asteraceae), collected in its locus classicus in Rhodope Mts, Bulgaria, was evaluated by GC-MS. The main components of the oil were hexadecanoic acid (18.3%), tetradecanoic acid (13.8%), caryophyllene oxide (12.1%) and germacrene D (8.4%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to section Phalolepis, studied so far, was performed. HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analyses) were used in order to demonstrate chemotaxonomical variations in the composition of the essential oils.

Chemical composition of the essential oil of Cyanus adscendens (Bartl.) Soják and C. orbelicus (Velen.) Soják growing wild in Bulgaria, and PCA analysis of genus Cyanus Mill.

Cyanus Mill. genus, belonging to the Asteraceae family, includes more than 50 taxa, mainly growing in Central and Southern Europe, North Africa, Asia Minor, and the Caucasus. Previous investigations on Cyanus taxa have shown that they are rich source of flavonoids and phenolic compounds but, differently from species of genus Centaurea, almost devoid of sesquiterpene lactones. In the present study, the chemical composition of the essential oils from aerial parts of Cyanus adscendens (CA) and C. orbelicus (CO), collected in Bulgaria, and not previously investigated, was evaluated by GC-MS. The main components of CA were α-bergamotene (31.3%), (Z,Z,Z)-9,12,15-octadecatrien-1-ol (14.5%) and calarenepoxide (11.0%). Caryophyllene oxide (12.0%), together with α-cadinol (10.9%) and spathulenol (8.8%), were recognized as the main constituent of C. orbelicus EO. Furthermore, a complete review on the composition of all essential oils of the Cyanus taxa studied so far has been inserted and cluster analysis (PCA) was carried out.

Karyotypes and Physical Mapping of Ribosomal DNA with Oligo-Probes in Eranthis sect. Eranthis (Ranunculaceae).

A comparative karyotype analysis of four species of yellow-flowered Eranthis sect. Eranthis, i.e., E. bulgarica, E. cilicica, E. hyemalis, and E. longistipitata from different areas, has been carried out for the first time. All the studied specimens had somatic chromosome number 2n = 16 with basic chromosome number x = 8. Karyotypes of the investigated plants included five pairs of metacentric chromosomes and three pairs of submetacentric/subtelocentric chromosomes. The chromosome sets of the investigated species differ mainly in the ratio of submetacentric/subtelocentric chromosomes, their relative lengths, and arm ratios. A new oligonucleotide probe was developed and tested to detect 45S rDNA clusters. Using this probe and an oligonucleotide probe to 5S rDNA, 45S and 5S rDNA clusters were localized for the first time on chromosomes of E. cilicica, E. hyemalis, and E. longistipitata. Major 45S rDNA clusters were identified on satellite chromosomes in all the species; in E. cilicica, minor clusters were also identified in the terminal regions of one metacentric chromosome pair. The number and distribution of 5S rDNA clusters is more specific. In E. cilicica, two major clusters were identified in the pericentromeric region of a pair of metacentric chromosomes. Two major clusters in the pericentromeric region of a pair of submetacentric chromosomes and two major clusters in the interstitial region of a pair of metacentric chromosomes were observed in E. longistipitata. E. hyemalis has many clusters of different sizes, localized mainly in the pericentromeric regions. Summarizing new data on the karyotype structure of E. sect. Eranthis and previously obtained data on E. sect. Shibateranthis allowed conclusions to be formed about the clear interspecific karyological differences of the genus Eranthis.

The essential oil composition of Centaurea immanuelis-loewii Degen growing wild in Bulgaria and chemotaxonomy of section Acrocentron.

In the present study, the chemical composition of the essential oil from aerial parts of the Balkan endemic, Centaurea immanuelis-loewii Degen (sect. Acrocentron, Asteraceae), collected in Bulgaria was evaluated by GC-MS. The main components of the oil were ß-caryophyllene (23.2%), germacrene D (13.7%) and caryophyllene oxide (12.4%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to section Acrocentron, studied so far, was performed and the chemotaxonomical variations in the composition of the essential oils is discussed.[Formula: see text].

Molecular Characterization of Verbascum anisophyllum (Scrophulariaceae) Genetic Resources Through Inter-Simple Sequence Repeat (ISSR) Markers.

Verbascum (Mullein) flowers are highly valued as natural remedy for various respiratory diseases. Verbascum anisophyllum Murb. is a Balkan endemic, protected by law and included in the Bulgarian Red Data Book as "Critically Endangered". Thus, a strict conservation policy and a reliable evaluation of its genetic resources are required, considering its narrow distribution range and the increasing risk from destruction of its habitats. Here, we used Inter-simple sequence repeat (ISSR) markers to characterize the genetic diversity and to assess the genetic differentiation between the existing populations of VerbascUM anisophyllum in Bulgaria. The level of genetic diversity found herein clearly indicates a long-term potential for adaptability of this endangered plant. Our findings provide important knowledge of population genetic structure of this species, thus representing a strategy for its efficient conservation and utilization.

Chemical composition of the essential oil of the local endemics Centaurea davidovii and C. parilica (Asteraceae, sect. Lepteranthus) from Bulgaria.

In the present study the chemical compositions of the essential oils from aerial parts of Centaurea davidovii Urum. and C. parilica Stoj. & Stef., both endemic to Bulgaria, were evaluated by GC and GC-MS. The main components of C. davidovii were ß-eudesmol (13.9%), spathulenol (13.3%), caryophyllene oxide (10.1%) and (Z)-phytol (5.4%). The main components of Cparilica were hexadecanoic acid (39.2%), (Z,Z)-9,12-octadecadienoic acid (11.9%), caryophyllene oxide (6.8%) and spathulenol (6.6%). In order to compare the essential oils composition of these taxa and of related species a PCA analysis was carried out.

Sesquiterpenoids in subtribe Centaureinae (Cass.) Dumort (tribe Cardueae, Asteraceae): distribution, (13)C NMR spectral data and biological properties.

Asteraceae Bercht. & J. Presl is one of the biggest and most economically important plant families. The taxonomy and phylogeny of Asteraceae is rather complex and according to the latest and most reliable taxonomic classification of Panero & Funk, based on the analysis of nine chloroplast regions, the family is divided into 12 subfamilies and 35 tribes. One of the largest tribes of Asteraceae is Cardueae Cass. with four subtribes (Carlininae, Echinopinae, Carduinae and Centaureinae) and more than 2500 species. Susanna & Garcia-Jacas have organized the genera of Centaureinae (about 800 species) into seven informal groups, which recent molecular studies have confirmed: 1. Basal genera; 2. Volutaria group; 3. Rhaponticum group; 4. Serratula group; 5. Carthamus group; 6. Crocodylium group; 7. Centaurea group. This review summarizes reports on sesquiterpenoids from the Centaureinae subtribe of the Asteraceae family, as well as the (13)C NMR spectral data described in the literature. It further reviews studies concerning the biological activities of these metabolites. For this work, literature data on sesquiterpenes from the Centaureinae subtribe were retrieved with the help of the SciFinder database and other similar data banks. All entries from 1958 until the end of 2011 were considered. This review is addressed to scientists working in the metabolomics field such as chemists, botanists, etc., the spectroscopic data reported make this work a good tool for structural elucidation, the biological section gives useful information to those who wish to study the structure activity relationships.

Flavonoids in subtribe Centaureinae (Cass.) Dumort. (tribe Cardueae, Asteraceae): distribution and (13)C-NMR spectral data.

This review reports the occurrence of flavonoids in subtribe Centaureinae of Asteraceae family. It extensively covers the literature up to 2010 and collects all available (13)C-NMR data.

Chemical composition of the essential oils of Centaurea formanekii and C. orphanidea ssp. thessala, growing wild in Greece.

The volatile constituents of the aerial parts of Centaureaformanekii Halacsy and the aerial parts, capitula and roots of C. orphanidea Heldr. & Sart. ex Boiss. ssp. thessala (Hausskn.) Dostál from Greece were extracted by hydrodistillation and analyzed. The main components in C. formanekii were hexadecanoic acid (13.6%), delta-elemene (9.1%), and spathulenol (6.9%). The main components in C. orphanidea ssp. thessala were gamma-elemene (26.1%) and caryophyllene oxide (13.2%) in the aerial parts, hexadecanoic acid (33.5%) and heptacosane (6.3%) in the capitula, and hexadecanoic acid methyl ester (22.0%) and a-chamigrene (14.0%) in the roots. The chemotaxonomic significance with respect to other previously studied species of the same sections (Phalolepis and Achrolopus, respectively) is discussed.

Volatile components from aerial parts of Centaurea gracilenta and C. ovina ssp. besserana growing wild in Bulgaria.

The essential oils of Centaurea gracilenta Velen. (CG) and C. ovina Pall. ex Willd. ssp. besserana (DC.) Dostál (COB) growing wild in Bulgaria, were studied by GC and GC-MS. Forty-five compounds for CG, representing the 90.1% of the oil, and 68 compounds for COB, representing the 91.9% of the oil, were identified. The oils were rich in sesquiterpenoids (33.4% for CG and 27.3% for COB), hydrocarbons (28.3% for CG and 10.7% for COB) and carbonylic compounds (12.7% for CG and 13.1% for COB). Fatty acids were abundant only for COB (31.3%). beta-Eudesmol (12.8%), nonacosane (11.8%) and p-vinyl guiacol (7.5%) were recognized as the main constituents for CG, while hexadecanoic acid (21.4%), spathulenol (7.9%), beta-eudesmol (5.8%) and caryophyllene oxide (5.7%) were the main compounds for COB.

Volatile components of Centaurea bracteata and C. pannonica subsp. pannonica growing wild in Croatia.

This paper reports on the volatile components of oils from the aerial parts (CBA) and roots (CBR) of Centaurea bracteata Scop. and aerial parts of C. pannonica (Heuffel) Simonkai subsp. pannonica (CPA), two Asteraceae growing wild in Croatia. The volatile components, obtained by hydrodistillation, were determined by GC-MS analysis. The yields (w/w) of the dried oils were 0.10% (CBA), 0.22% (CBR) and 0.09% (CPA), respectively. A total of 91 compounds were identified accounting for 91.1%, 93.3% and 87.9% of the total oil for CBA, CBR and CPA, respectively. All the samples were characterized mainly by hydrocarbons (7.1-34.1%), fatty acids (9.7-45.9%), and oxygenated sesquiterpenes (15.2-16.6%). The major components of the samples were hexadecanoic acid (8.1-31.1%), nonacosane (0.6-13.4%) and caryophyllene oxide (4.5-11.9%). Monoterpenes, both hydrocarbons and oxygenated, were either absent or present in low amounts in all the oils. The similarity in the oil contents is consistent with the two species being placed in the same section, Jacea.

Volatile components of aerial parts of Centaurea nigrescens and C. stenolepis growing wild in the Balkans.

The volatile constituents of the aerial parts of Centaurea nigrescens Willd, collected in Romania and of two samples of C. stenolepis A. Kerner from Bulgaria and Romania were obtained by hydrodistillation and analyzed. The main components of C. stenolepis were caryophyllene oxide (6.9-15.6%), hexahydrofarnesyl acetone (6.5-4.4%), heptacosane (6.0-4.9%) and p-vinyl guiacol (4.3-5.0%). The main components of C. nigrescens were caryophyllene oxide (9.9%), beta-eudesmol (9.5%), spathulenol (7.6%), heptacosane (6.1%) and p-vinyl guiacol (5.5%). The chemotaxonomic significance with respect to their co-location in Sections Lepteranthus and Nigrescentes, respectively, is discussed.

Volatile constituents of aerial parts of Centaurea sibthorpii (Sect. Carduiformes, Asteraceae) from Greece and their biological activity.

The volatile constituents of the aerial parts of Centaurea sibthorpii [Sect. Carduiformes, Asteraceae] collected in Greece were extracted by hydrodistillation and analysed by GC and GC-MS. Altogether 63 components were identified. Fatty acids and sesquiterpenoidic compounds were the most abundant components in the oil. A study on the biological activity of the oil showed no action against Gram-positive and Gram-negative bacteria.