Chemical composition and antimicrobial activity of the essential oil of the leaves of Ocotea caudata (Nees) Mez (Lauraceae) from Colombia

Ocotea is a genus that belong to Lauraceae family, which has about 56 species, distributed in Asia, Africa and mainly in America. The aim of this work was to identify the chemical composition of the essential oil from leaves of Ocotea caudata collected from Colombia. The chemical composition of the oil was determined by gas chromatography-mass spectrometry (GC-MS), being described for the first time. Thirty nine compounds (corresponding to 92.7% of the oil) were identified. The major constituents were germacrene D (55.8%), bicyclogermacrene (8.0%), β-caryophyllene (4.6%) and β-bourbonene (2.3%). Also the antibacterial activity of the oil was evaluated against two Gram (+) and two Gram (-) bacteria showing that the oil exhibited moderated activity against Gram (+) bacteria

Tidal streams in newly discovered M32 analogues: evidence for the stripping scenario

We present two newly-discovered compact elliptical (cE) galaxies, exhibiting clear evidence of tidal steams, and found during a search of SDSS DR7 for cE candidates. The structural parameters of the cEs are derived using GALFIT, giving effective radii, Re, of 388 and 263 parsecs, and B-band mean surface brightnesses within Re of 19.4 and 19.2 magnitudes per arcsec squared. We have re-analysed the SDSS spectra, which indicate that they possess young to intermediate-age stellar populations. These two cEs provide direct evidence, a "smoking gun", for the process of tidal stripping that is believed to be the origin of M32-type galaxies. Both are in small groups with a large spiral fraction, suggesting that we may be seeing the formation of such cE galaxies in dynamically young environments. The more compact of the galaxies is found in a small group not unlike the Local Group, and thus provides an additional model for understanding M32.Comment: 9 pages, 10 figures. Accepted to MNRA

A 0.8-2.4 microns spectral atlas of Active Galactic Nuclei

Aims: We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN), of all degrees of activity, in the wavelength interval of 0.8-2.4 microns, including the fluxes of the observed emission lines. We analyze the spectroscopic properties of the continuum and emission line spectra of the sources Methods: In order to exclude aperture and seeing effects we use near-infrared spectroscopy in the short cross-dispersed mode (SXD, 0.8-2.4 microns), taking the JHK-bands spectra simultaneously. Results: We present the most extensive NIR spectral atlas of AGN to date. This atlas offers a suitable database for studying the continuum and line emission properties of these objects in a region full of interesting features. The shape of the continuum of QSOs and Seyfert 1's are similar, being essentially flat in H and K band, in the J band, a strong variation is found. In Seyfert 2 galaxies, the continuum in the F_lambda X lambda space smoothly decreases from 1.2 microns redwards in almost all sources. In J, it smoothly rises bluewards in some sources while in others a small decreased in flux is observed. The spectra are dominated by strong emission features of H I, He I, He II, [S III] and conspicuous forbidden lines of low and high ionization species. Molecular lines of H2 are common features to most objects. The absence of O I and Fe II lines in Seyfert 2 galaxies give observational support to the fact that these lines are formated in the outermost portion of the broad line region. [P II] and coronal lines are detected in all degrees of activity. The [Fe II] 12570A/16436A line ratio becomes a reliable reddening indicator for the narrow-line region of Seyfert galaxies.Comment: 39 pages, 17 figures, accepted for publication in Astronomy and Astrophysics (15/05/2006

3D Lyman-alpha radiation transfer. III. Constraints on gas and stellar properties of z~3 Lyman break galaxies (LBG) and implications for high-z LBGs and Lyman-alpha emitters(LAEs)

The Aim of our study is to understand the variety of observed Lyman-alpha (Lya) line profiles and strengths in Lyman Break Galaxies (LBGs) and Lya emitters (LAEs), the physical parameters governing them, and hence deriving constraints on the gas and dust content and stellar populations of these objects. Using our 3D Lya radiation transfer code including gas and dust (Verhamme et al. 2006), we fit 11 LBGs from the FORS Deep Field with redshifts between 2.8 and 5 observed by Tapken et al. (2007). A simple geometry of a spherically expanding shell of HI is adopted. RESULTS : The variety of observed Lya profiles is successfully reproduced. Most objects show outflow velocities of 150-200 km/s; two objects are most likely quasi-static. The radial HI column density ranges from NH=2.10^{19} to 7.10^{20} cm^{-2}. Our Lya profile fits yield values of E(B-V)~0.05-0.2 for the gas extinction. We find indications for a dust-to-gas ratio higher than the Galactic value, and for a substantial scatter. The escape fraction of Lya photons is found to be determined primarily by the extinction, and a simple fit formula is proposed. Intrinsic EW(Lya)~50-100 Angstroms are found for 8/11 objects, as expected for stellar populations forming constantly over long periods (> 10-100 Myr). In three cases we found indications for younger populations. Correlations between the observed EW(Lya) and other observables such as FWHM(Lya), E(B-V),SFR(UV) etc, are reproduced. We also show that there is a clear overlap between LBGs and LAEs. Radiation transfer and dust effects explain the increase of the LAE/LBG ratio, and a higher percentage of LBGs with strong Lya emission with increasing redshift. [shortened]Comment: 26 pages, accepted for publication in A&

Galaxy bulges and their massive black holes: a review

With references to both key and oft-forgotten pioneering works, this article starts by presenting a review into how we came to believe in the existence of massive black holes at the centres of galaxies. It then presents the historical development of the near-linear (black hole)-(host spheroid) mass relation, before explaining why this has recently been dramatically revised. Past disagreement over the slope of the (black hole)-(velocity dispersion) relation is also explained, and the discovery of sub-structure within the (black hole)-(velocity dispersion) diagram is discussed. As the search for the fundamental connection between massive black holes and their host galaxies continues, the competing array of additional black hole mass scaling relations for samples of predominantly inactive galaxies are presented.Comment: Invited (15 Feb. 2014) review article (submitted 16 Nov. 2014). 590 references, 9 figures, 25 pages in emulateApJ format. To appear in "Galactic Bulges", E. Laurikainen, R.F. Peletier, and D.A. Gadotti (eds.), Springer Publishin

Alcaloides bencilisoquinolínicos del tallo de piper augustum rudge

Del extracto etanólico del tallo de P. augustum Rudge se aislaron: 3beta-hidroxi- 24-etil-delta5.22colestadieno (estigmasterol) I ; l,2-metilendioxi-6-metil-4H-dibenzo(deg) quinolina-4,5(6H)diona (Cepharadione A) II; lactama del ácido lO-amino-3,4- dimetoxifenantreno-1-carboxílico (Cepharanone B) n i y el nuevo compuesto natural: lactama del ácido N-metil-lO-amino- 4-hidroxi-2,3-dimetoxifenantreno-1 –carboxílico IV, Todos los compuestos fueron identificados mediante técnicas espectroscópicas (EM, RMN 'H y "C, IR y UV) y comparación con datos reportados en la literatura; adicionalmente I y II fueron identificados por comparación con muestras auténticas (CCF, pf, y pf, mixto). El extracto etanólico del tallo de Piper augustum Rudge presentó una moderada actividad biológica (DL50 = 350 ppm) según el ensayo de mortalidad de Artemia salina Leach (Brine Shrimp Lethality)

Genetic structure and chemical diversity of the aromatic shrub lippia origanoides h.b.k. (verbenaceae) in two populations from northern colombia

In the present study, the diversity in essential oil composition and genetic structure of two populations of Lippia origanoides from Colombia, one from the department of Magdalena on the Atlantic coast in the north, and the other from the canyon of the Chicamocha river in the northeast, were compared. Individuals were sampled in each of the two populations and ISSR (inter-simple sequence repeat) molecular markers were applied to document the distribution of the genetic diversity within and among the populations. Essential oils were extracted by steam distillation from individuals collected in the two populations and analyzed by gas chromatography and mass spectrometry (GC-MS). The results suggest that genetic diversity levels of L. origanoides in Magdalena and Chicamocha are relatively high (Hs ranged from 0.35 to 0.37) and comparable to allogamous plant species and other related species of the same genus. A rather low genetic differentiation (qII varied from 0.07 to 0.17) was found between the two populations, in spite of the relatively large geographical distance between them. The essential oils of L. origanoides can be classified as monoterpenic in type, and according to the relative amount of the major compounds, six chemotypes are proposed. Five of them (B, C, D, F and G) are present in the canyon of the Chicamocha river, while two of them (C and E) are present in Magdalena. Chemotypes B and C are similar to chemotypes previously reported. In summary, the essential oils from individuals collected in Chicamocha are rich in thymol (chemotypes C and D); carvacrol (chemotype B); Ρcymene, eucalyptol (+ Β-phellandrene trace) and thymol methyl ether (chemotype F); and thymol methyl ether, pcymene, thymol and Υ-terpinene (chemotype G); while those from Magdalena are rich in thymol (chemotype C), and eucalyptol and α-phellandrene (chemotype E). These results suggest a significant presence of genetic and essential oil diversity in this species, which should be studied further in order to make more efficient use of this promising plant resourc

Composición Química, Actividades Insecticida y Antifúngica de Aceites Esenciales de Frutos de Tres Especies Zanthoxylum de Colombia.

This study determined the chemical composition of essential oils isolated from Zanthoxylum monophyllum (Lam.) P. Wilson, Z. rhoifolium Lam., and Z. fagara (L.) Sarg. fruits by steam distillation, as well as testing antifungal and insecticidal activities of essential oils as potential pesticides. Gas chromatography-mass spectrometry (GC/MS) analysis identified 57 compounds. The main constituents in Z. rhoifolium oil were β-Myrcene (59.03%), β-phellandrene (21.47%), and germacrene D (9.28%) , the major constituents of Z. monophyllum oil were sabinene (25.71%), 1,8-cineole (9.19%), and cis-4-thujanol (9.19%), whereas fruit oil of Z. fagara mainly contained germacrene D-4-ol (21.1%), elemol (8.35%), and main constituents Zanthoxylum fagara showed the highest activity on Colletotrichum acutatum Simmonds (EC50 153.9 μL L-1 air), and Z. monophyllum was the most active against Fusarium oxysporum Schlechtend: Fr. f. sp. lycopersici (EC50 140.1 μL L-1 air). Zanthoxylum monophyllum essential oil showed significant fumigant activity against Sitophilus oryzae (L.). This study demonstrated that Zanthoxylum essential oils exhibit important fungicidal activity on F. oxysporum and C. acutatum, which could become an alternative to synthetic fung9icides to control plant fungal diseases, and Z. monophyllum oil is a potential fumigant against S. oryzae.En este estudio se determinó la composición química de los aceites esenciales de frutos de Zanthoxylum monophyllum (Lam.) P. Wilson, Z. rhoifolium Lam. y Z. fagara (L.) Sarg. obtenidos mediante destilación por arrastre con vapor y se evaluó la actividad antifúngica e insecticida de los aceites esenciales para estimar su uso como posibles plaguicidas. El análisis por cromatografía de gases-espectrometría de masas (CG/EM) permitió la identificación de 57 compuestos. β-Mirceno (59,03%), β-felandreno (21,47%) y germacreno D (9,28%) fueron los componentes principales del aceite de Z. rhoifolium; los principales componentes del aceite de Z. monophyllum fueron sabineno (25,71%), 1,8 -cineol (9,19%) y cis-4-thujanol (9,19%), mientras que el aceite de frutos de Z. fagara está compuesto principalmente por germacreno D-4-ol (21,1%), elemol (8,35%) y α-cadinol (8,22% ). Zanthoxylum fagara presentó la mayor actividad sobre Colletotrichum acutatum Simmonds (EC50 153,9 μL L-1 de aire) y Z. monophyllum fue el más activo contra Fusarium oxysporum Schlechtend: Fr. f. sp. lycopersici (EC50 140,1 μL L-1 de aire). El aceite esencial de Z. monophyllum mostró actividad insecticida significativa contra Sitophilus oryzae (L.) Este estudio demuestra que los aceites esenciales de Zanthoxylum poseen importante actividad antifúngica sobre F. oxysporum y C. acutatum y podría convertirse en una alternativa frente a los fungicidas sintéticos empleados comúnmente para el control de enfermedades de las plantas, así como el aceite de frutos de Z. monophyllum tiene un potencial para ser utilizado como fumigante contra S. oryzae