Showing papers on "Cestrum published in 2007"

Distribution of a Ty3/gypsy-like retroelement on the A and B-chromosomes of Cestrum strigilatum Ruiz & Pav. and Cestrum intermedium Sendtn. (Solanaceae)

Abstract: Retroelements are a diversified fraction of eukaryotic genomes, with the Ty1/copia and Ty3/gypsy groups being very common in a large number of plant genomes. We isolated an internal segment of the Ty3/gypsy retroelement of Cestrum strigilatum (Solanaceae) using PCR amplification with degenerate primers for a conserved region of reverse transcriptase. The isolated segment (pCs12) was sequenced and showed similarity with Ty3/gypsy retroelements of monocotyledons and dicotyledons. This segment was used as probe in chromosomes of C. strigilatum and Cestrum intermedium. Diffuse hybridization signals were observed along the chromosomes and more accentuated terminal signals in some chromosome pairs, always associated with nucleolus organizer regions (NORs). The physical relationship between the hybridization sites of pCs12 and pTa71 ribosomal probes was assessed after sequential fluorescence in situ hybridization (FISH). Hybridization signals were also detected in the B chromosomes of these species, indicating an entail among the chromosomes of A complement and B-chromosomes.

Aislamiento de ácido ursólico de las hojas de Cestrum laurifolium L'Herit.

Abstract: Ursolic acid has shown a wide biological activity, its potential as anticarcinogenic, anti - inflammatory, anti - microbial and antiviral has been proven, also, it has been used as emulsifying agent in pharmaceuticals, cos- metics and foods preparations all of that makes to this substance very interest- ing. This acid has been isolated from two species of the Cestrum genus, which appears in Cuba represented by 15 species of which seven are endemics and therefore it is a wide source to study with the objective of determining the pres- ence or not of ursolic acid. The study of Cestrum laurifolium LiHerit leaves was carried out, species that is in different regions of Cuba. The dry and powdered vegetable material was submitted to an extraction process with ethanol. The obtained alcoholic extract was concentrated at reduced pressure, then it was diluted with water and later on it was extracted with benzene-ether (1 : 1 (v/v)). The benzene phase was concentrated and the obtained crude was fractioned by chromatographic column using neutral aluminium oxide, as mobile phase a mixture of chloroform-ethyl acetate (80 : 20 (v/v)) was used and start- ing from the fractions for 55 to 84 a product was isolated. It was crystal- lized from chloroform achieving a white solid with a melting temperature of 284 to 285" C and 1.55 % of yield. For the structural confirmation of this compound a derivative was synthe- sized and the compounds were char- acterized by means of the spectro- scopic techniques (infrared, Mass, nuclear magnetic resonance of carbon). The isolated substance was identified as ursolic acid.

EXTRACTOS VEGETALES CON ACTIVIDAD SOBRE CEPAS MUTADAS DE Saccharomyces cerevisiae CON DEFICIENCIA EN EL MECANISMO DE REPARACION DEL ADN

Abstract: One hundred thirty eight extracts derived from plant belonging to six botanical families collected in natural reserves from the Eje Cafetero Ecorregion (ECE, Colombia) were assayed against engineered yeast Saccharomyces cerevisiae strains RS 322N, R52Y and RS 321 by the agar well diffusion method to identify novel bioactive extracts with DNAdamaging and/or topoisomerase I and II activities. From this study the methanol extracts from the Solanaceae Browallia speciosa, Cestrum olivaceum, and Solanum brevifolium, showed selectivity toward DNA-repair-deficient yeast mutant Saccharomyces cerevisiae, evidencing topoisomerase I activity; in addition, the dichloromethane one of the Solanaceae, Solanum deflexiflorum exhibited topoisomerase II activity.

Una nueva especie de Cestrum (Solanaceae)

Abstract: Cestrum cristinae (Solanaceae), a new species from Costa Rica and Panama that is closely related to Cestrum fragile Francey, Cestrum lewisii D'arcy and Cestrum salicifolium Jacq. is described and illustrated. The etymology of the name, distribution and its taxonomic relationships are discussed.