Centaurea rupestris L.: Cytogenetics, Essential Oil Chemistry and Biological Activity

Centaurea species are used in eastern Mediterranean ethnopharmacology due to variety of bioactive compounds they comprise. Aim of this work was to characterize the Centaurea rupestris L. hydrodistilled essential oil chemical composition and test its biological activity: antimicrobial effect, antioxidant potential and inhibition of cholinesterases. Plant material authentication was by chromosome number counting and genome size assessment with the flow cytometry. Hydrodistilled essential oils were characterized using gas chromatography/mass spectrometry technique GC-MS and GC-FID. The antimicrobial effect was tested using disk diffusion and microdilution methods, antioxidant potential was tested with DPPH and FRAP methods and cholinesterases inhibition was tested with Ellman method. Genome size for C. rupestris species: sample A presented 2C=3.60 (0.10) pg and sample B 2C=3.62 (0.08) pg. The chromosome number was 2n=20 for both samples. The main essential oil constituents in isolated sample A oil, detected with GC-MS and GC-FID were: germacrene D (24.3 %), heptacosane (14.4 %), phytol (6.7 %), β-caryophyllene (5.0 %) and pentacosane (4.5 %). Sample B essential oil had the main constituents: hexadecanoic acid (18.7 %), heptacosane (13.8 %), α-linolenic acid (11.8 %), nonacosane (7.8 %) and germacrene D (5.4 %). Both samples of oil showed broad spectrum antimicrobial effect with good activity against emerging Gram-positive and Gram-negative opportunistic pathogens and pathogenic fungi which indicates the pharmaceutical potential of the C. rupestris essential oil. This work is licensed under a Creative Commons Attribution 4.0 International License

Centaurea rupestris L.: Cytogenetics, Essential Oil Chemistry and Biological Activity

Centaurea species are used in eastern Mediterranean ethnopharmacology due to variety of bioactive compounds they comprise. Aim of this work was to characterize the Centaurea rupestris L. hydrodistilled essential oil chemical composition and test its biological activity: antimicrobial effect, antioxidant potential and inhibition of cholinesterases. Plant material authentication was by chromosome number counting and genome size assessment with the flow cytometry. Hydrodistilled essential oils were characterized using gas chromatography/mass spectrometry technique GC-MS and GC-FID. The antimicrobial effect was tested using disk diffusion and microdilution methods, antioxidant potential was tested with DPPH and FRAP methods and cholinesterases inhibition was tested with Ellman method. Genome size for C. rupestris species: sample A presented 2C=3.60 (0.10) pg and sample B 2C=3.62 (0.08) pg. The chromosome number was 2n=20 for both samples. The main essential oil constituents in isolated sample A oil, detected with GC-MS and GC-FID were: germacrene D (24.3 %), heptacosane (14.4 %), phytol (6.7 %), β-caryophyllene (5.0 %) and pentacosane (4.5 %). Sample B essential oil had the main constituents: hexadecanoic acid (18.7 %), heptacosane (13.8 %), α-linolenic acid (11.8 %), nonacosane (7.8 %) and germacrene D (5.4 %). Both samples of oil showed broad spectrum antimicrobial effect with good activity against emerging Gram-positive and Gram-negative opportunistic pathogens and pathogenic fungi which indicates the pharmaceutical potential of the C. rupestris essential oil. This work is licensed under a Creative Commons Attribution 4.0 International License

Evolutionary trends in Iridaceae: new cytogenetic findings from the New World

With the present work, we aim to provide a better understanding of chromosome evolutionary trends among southern Brazilian species of Iridoideae. Chromosome numbers and genome sizes were determined for 21 and 22 species belonging to eight genera of Tigridieae and two genera of Trimezieae, respectively. The chromosome numbers of nine species belonging to five genera are reported here for the first time. Analyses of meiotic behaviour, tetrad normality and pollen viability in 14 species revealed regular meiosis and high meiotic indexes and pollen viability (>90%). The chromosome data obtained here and compiled from the literature were plotted onto a phylogenetic framework to identify major events of chromosome rearrangements across the phylogenetic tree of Iridoideae. Following this approach, we propose that the ancestral base chromosome number for Iridoideae is x=8 and that polyploidy and dysploidy events have occurred throughout evolution. Despite the variation in chromosome numbers observed in Tigridieae and Trimezieae, for these two tribes our data provide support for an ancestral base number of x=7, largely conserved in Tigridieae, but a polyploidy event may have occurred prior to the diversification of Trimezieae, giving rise to a base number of x(2)=14 (detected by maximum-parsimony using haploid number and maximum likelihood). In Tigridieae, polyploid cytotypes were commonly observed (2x, 4x, 6x and 8x), whereas in Trimezieae, dysploidy seems to have been the most important event. This feature is reflected in the genome size, which varied greatly among species of Iridoideae, 4.2-fold in Tigridieae and 1.5-fold in Trimezieae. Although no clear difference was observed among the genome sizes of Tigridieae and Trimezieae, an important distinction was observed between these two tribes and Sisyrinchieae, with the latter possessing the smallest genome sizes in Iridoideae.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP