Anti-tumour activity of fatty acid maltotriose esters

The anti-tumour properties of two fatty acid esters of maltotriose, 6’’-O-lauroylmaltotriose and 6’’-O-palmitoylmaltotriose, in which the 6-OH at the non-reducing end of the maltotriose has been regioselectively acylated, were studied. Both compounds were synthesised by transesterification of vinyl laurate or vinyl palmitate with maltotriose, in presence of immobilized lipase from Thermomyces lanuginosus. A mixture formed by 2-methyl-2-butanol and dimethylsulfoxide (80:20 v/v) was the reaction medium. Their cytotoxic activities against two human cancer cell lines, Hep-G2 and HeLa, were studied. 6’’-O-palmitoylmaltotriose showed 50% inhibition values (IC50) of 2.3 M (1.7 g/ml) for Hep-G2 and 3.6 M (2.7 g/ml) for HeLa cells, whereas 6’’-O-lauroylmaltotriose displayed a lower inhibitory effect. 6’’-O-palmitoylmaltotriose showed a marginal cytotoxicity to rat hepatocytes, confirming its potential as a new anti-tumour agent.We thank Prof. Manuel Bernabé (Instituto de Química Orgánica, CSIC, Madrid) for help with NMR analysis. This work was supported by European Union (project MERG-CT-2004-505242) and the Spanish CICYT (Project BIO2002-00337).Peer reviewe

Paleoecology and paleoenvironment of the Early Cretaceous theropod-dominated ichnoassemblage of the Los Corrales del Pelejón tracksite, Teruel Province, Spain

The earliest Cretaceous (mid-late Berriasian) tracksite Los Corrales del Pelejón is an important dinosaur trackway site in Teruel Province in Spain. The ichnoassemblage occurs in the Galve Formation (Galve sub-basin, Maestrazgo Basin) and comprises around 40 tracks assigned to theropods and ornithopods. In this paper, we undertake a paleoenvironmental analysis of the succession, which includes the overbank deposits of a fluvial environment, and discuss the implications of these findings for trackway preservation and orientation. The track-bearing unit is composed of fine- to very fine-grained, thinly bedded sandstone layers with wave ripples and traces of the Mermia ichnofacies, which were deposited as splay deposits within an ephemeral overbank pond. Two different theropod ichnotaxa (Megalosauripus cf. transjuranicus and Grallatoridae indet.) of three different size classes occur as small-, medium-, and large-sized tracks. The ornithopod tracks are classified as cf. Iguanodontipus isp. Five theropod trackways (M. cf. transjuranicus) show a bimodal orientation pattern with a similar orientation to NE-SW wave ripple crests, suggesting that these animals were walking parallel to the shoreline of the ephemeral overbank pond. Three of them walked in a similar subparallel orientation, but there is no evidence suggesting gregarious behavior as they have slightly different orientations and/or speed values. The Los Corrales del Pelejón site is an example of environmental influence on dinosaur behavior

Combined use of electron and light microscopy techniques reveals false secondary shell units in Megaloolithidae eggshells

Abnormalities in the histo- and ultrastructure of the amniote eggshell are often related to diverse factors, such as ambient stress during egg formation, pathologies altering the physiology of the egg-laying females, or evolutionarily selected modifications of the eggshell structure that vary the physical properties of the egg, for example increasing its strength so as to avoid fracture during incubation. When dealing with fossil materials, all the above hypotheses are plausible, but a detailed taphonomical study has to be performed to rule out the possibility that secondary processes of recrystallization have occurred during fossilization. Traditional analyses, such as optical microscopy inspection and cathodoluminescence, have proven not to be enough to understand the taphonomic story of some egg-shells. Recently, electron backscatter diffraction has been used, in combination with other techniques, to better understand the alteration of fossil eggshells. Here we present a combined study using scanning electron microscopy, optical microscopy, cathodoluminescence and electron backscatter diffraction of eggshell fragments assigned to Megaloolithus cf. siruguei from the Upper Cretaceous outcrops of the Cameros Basin. We focus our study on the presence of secondary shell units that mimic most aspects of the ultrastructure of the eggshell mammillae, but grow far from the inner surface of the eggshell. We call these structures extra-spherulites, describe their crystal structure and demonstrate their secondary origin. Our study has important implications for the interpretation of secondary shell units as biological or pathological structures. Thus, electron backscatter diffraction complements other microscope techniques as a useful tool for understanding taphonomical alterations in fossil eggshells

Paleohistología en dinosaurios ornitópodos del Barremiense de Ladruñán (Teruel)

La presente memoria corresponde al Trabajo fin de Grado (TFG) del Grado en Geología impartido en la Universidad de Zaragoza, y plantea como objetivo fundamental el estudio paleohistológico de nueve muestras de huesos fósiles encontrados en dos yacimientos de macrovertebrados del Barremiense (Cretácico Inferior) de Ladruñán (provincia de Teruel).<br /

Procedimiento para la acilación específica enzimática de un hidroxilo secundario de la sacarosa

Referencia OEPM: P9702602.-- Fecha de solicitud: 15/12/1997.-- Titular: Consejo Superior de Investigaciones Científicas (CSIC).Procedimiento para la acilación específica enzimática de un hidroxilo secundario de la sacarosa. Es un procedimiento enzimático para la acilación regioespecífica de un hidroxilo secundario de la sacarosa. En esencia, consiste en hacer reaccionar la sacarosa con el éster vinílico de un ácido graso en un disolvente orgánico, en presencia de una lipasa de un hongo filamentoso, preferiblemente inmovilizada. Permite obtener tensioactivos con una estructura química distinta a los obtenidos industrialmente (químicamente los hidroxilos más reactivos son los primarios). Además, se trata de un proceso notablemente más sencillo para la acilación específica de un hidroxilo secundario de la sacarosa. Aplicaciones en farmacia, cosmética, alimentación y detergentes.Peer reviewe

Sedimentología y registro fósil de vertebrados de la Formación El Castellar en la subcuenca de Galve.

This work consists of a detailed sedimentological-paleontological study of a stratigraphic section of the lower Barremian El Castellar Formation located in Galve (Teruel province), which includes the Escarpe-Pelejón fossil site. It consists on a 30 m thick series of palustrine-lacustrine limestones, lutites and marls with abundant fossil content. The detailed field and laboratory work, has allowed differentiating 12 facies based on lithology, sedimentary structures and fossil remains, which characterize 3 main depositional environments. The lower part of the unit is dominated by lutites, marly lutites and discrete sandstone beds, whose deposition took place in an alluvial-palustrine transition subenvironment with fluvial influence. In this context, a fossil-bearing bed with a great paleodiversity has been found, whose origin is given by the superposition of subenvironments due to lake dynamics during a lake expansion event. This fossil site named Escarpe-Pelejón, bear remains of organisms (vertebrates, charophytes, ostracods, mollusks…) with different lifestyles (aquatic, land and amphibious). Those remains are broken, disarticulated and dispersed, and some of them, look like allochthonous. The middle and upper part of the unit is formed by marls and marly limestones, with different proportions of charophytes, ostracods and mollusks and traces suggesting aerial exposure (nodules, root traces). These facies formed in a plaustrine subenvironment with energy flood events. Finally, the bioclastic limestones (with charophytes, ostracods, mollusks, fishes remains…) mostly bioturbated were deposited in a shallow lacustrine subenvironment with variations in energy and periods of subaerial exposure. Overall, the studied unit reflects the evolution from an alluvial environment with small ponds to a shallow lake environment. The highest paleodiversity is found in lutites-marly lutites facies in the alluvial-palustrine transition subenvironment.<br /

Synthesis of methyl Alpha-D-Glucoolicosaccharides by Entrapped Dextransucrase from Leuconostoc mesenteroides B-1299

The synthesis of methyl alpha-D-glucooligosaccharides, using sucrose as glucosyl donor and methyl alpha-D-glucopyranoside as acceptor, was studied with dextransucrase from Leuconostoc mesenteroides NRRL B-1299. The enzyme was immobilized by entrapment in alginate. By NMR and mass spectrometry we identified three homologous series (S1-S3) of methyl alpha-D-glucooligosaccharides. Series S2 and S3 were characterized by the presence of alpha(1-2) linkages, in combination with alpha(1-6) bonds. Two parameters, sucrose to acceptor concentration ratio (S/A) and the total sugar concentration (TSC) determined the yield of methyl alpha-D-glucooligosaccharides. The maximum concentration achieved of the first acceptor product, methyl alpha-D-isomaltoside, was 65 mM using a S/A 1:4 and a TSC of 336 g l-1. When increasing temperature, a shift of selectivity towards compounds containing alpha(1-2) bonds was observed. The formation of leucrose as a side process was very significant (reaching values of 32 g l-1) at high sucrose concentrations.We are very grateful to Profs. P. Monsan and M. Remaud-Simeon (INSA, Toulouse) for providing us with dextransucrase. We thank Prof. A. Cortés (ICP, CSIC) for helpful comments. We thank Gobierno Vasco and Instituto Danone for research fellowships. This work was supported by the Spanish Education and Science Ministry (Project BIO2004-03773-C04-01).Peer reviewe

A multi-ootaxic assemblage from the Lower Cretaceous of the Cameros Basin (La Rioja; Northern Spain)

Here we describe the new fossil site of El Horcajo in the vicinity of Trevijano (La Rioja, Spain). It is located in the palustrine facies of the Enciso Group (Cameros Basin). This new locality has provided dozens of eggshell fragments, together with other vertebrate remains and charophyte fructifications, which allow dating of the locality as Valanginian-Hauterivian. Five ootaxa have being recognized: 1) the Spheroolithidae Guegoolithus turolensis; 2) a surprisingly thick Prismatoolithidae indet., with certain affinities to the oogenus Sankofa, that may represent a new oogenus and oospecies for this oofamily; 3) the Krokolithida

Análisis bioeconómico del cultivo de dorada en Canarias y en el Mediterráneo

[EN] Aquaculture is an expanding industry, which represents an altemative to the limited fishing resources. This paper develops a bioeconomic model for the production of gilthead seabream, a species with large market potential. The model is based on a biological growth submodel, where fish growth is related to fish weight, ration size, and temperature. Random factors are introduced through the functions for temperatura and market price. A dynamic system methodology is utilised for analysing the temporal evolution of the biological and economic relationships. Since plant localisation is determined by environmental factors, and therefore has an influence on firm retums, the model is utilised for evaluating the impact of two altemative scenarios: the Mediterranean and the Canary Islands. As a main conclusion, it is obtained that competitiveness in the Canaries depends on the production of 750g. extralarge size, which is not profitable in the Mediterranean sea due to large costs. The results also show increasing retums to scale, and the efficient plant capacity for the representative firm.[ES] La acuicultura es una industria en continua expansión, representando una alternativa a los limitados recursos pesqueros. En este trabajo se desarrolla un modelo bioeconómico para la producción de dorada, la cual es una de las especies con mayor potencial de mercado. El modelo incorpora un submodelo biológico de crecimiento, que relaciona el crecimiento del pez con su peso, la ración alimentaria, y la temperatura. Los factores aleatorios entran a formar parte del modelo a través de la temperatura y el precio de mercado. Se utiliza la metodología de la dinámica de sistemas para representar la evolución temporal de las relaciones biológicas y económicas. Dado que la localización de la empresa determina los factores ambientales y, por tanto, influye significativamente en los resultados, el modelo se utiliza para analizar el impacto de dos escenarios alternativos: el Mediterráneo y Canarias. Como principal conclusión, se obtiene que la competitividad en Canarias depende de la producción de la talla súper de 750 g, la cual no es viable en aguas del Mediterráneo debido a los altos costes incurridos. También se obtienen rendimientos de escala crecientes, así como el tamaño de planta eficiente para la empresa representativa.Gasca-Leyva, E.; León, C.; Hernández, JM.; Vergara, JM. (2001). Análisis bioeconómico del cultivo de dorada en Canarias y en el Mediterráneo. Economía Agraria y Recursos Naturales - Agricultural and Resource Economics. 1(1):55-76. doi:10.7201/earn.2001.01.03SWORD55761