Resumen Aplicamos un enfoque de dominios ambientales para identificar las características ambientalmente heterogéneas que definen una matriz del paisaje. Construimos capas ambientales a 3 escalas, nacional, regional y local, para considerar las diferentes escalas que pueden tener distintos estudios. Utilizamos una clasificación numérica jerárquica para datos espaciales y una clasificación multivariada. Con base en los dominios obtenidos, construimos mapas de heterogeneidad ambiental y determinamos las variables asociadas para cada escala. Probamos específicamente la idoneidad de nuestro enfoque para definir estrategias de muestreo para estudios de genética del paisaje, usando como especie focal al roedor Heteromys pictus. Así, de los dominios obtenidos en la escala local seleccionamos sitios de muestreo que incluyeran la más amplia heterogeneidad del hábitat, los cuales corroboramos en campo. La matriz del paisaje que generamos fue utilizada con datos genéticos previamente obtenidos para H. pictus. Nuestro protocolo nos permitió identificar variables significativamente asociadas con la dispersión (flujo génico) de los individuos en su hábitat natural. Demostramos así su pertinencia para definir eficientemente localidades de muestreo (matriz del paisaje) que abarquen la mayor heterogeneidad ambiental, en paisajes explorados e inexplorados, e identificar de forma rápida localidades y sus características ambientales en sitios con poca información previa.

Abstract We apply an environmental domains approach to identify environmentally heterogeneous characteristics defining a landscape matrix. We built environmental layers for national, regional, and local scales, considering the different scales studies can have. We used a numerical classification of explicit spatial layers and performed a multivariate classification. Based on the domains obtained, we mapped the landscape’s climatic heterogeneity and identified a comprehensive set of environmental variables that defined the landscape matrix at each scale. We specifically tested our approach for its suitability to define a sampling strategy for a landscape genetics study, using as focal species the rodent Heteromys pictus. Namely, from the domains obtained at the local scale, we selected sampling localities that comprised the broadest habitat heterogeneity, which we corroborated in the field. The landscape matrix thus generated was used with genetic data previously obtained for H. pictus. Our approach allowed identification of environmental variables significantly associated with dispersal (gene flow) of H. pictus individuals in their natural habitat. We demonstrate its adequacy to efficiently determine sampling localities -or landscape sites- that encompass the highest environmental heterogeneity, in explored and unexplored landscapes, enabling rapid identification of localities and their environmental characteristics where in situ information is scarce.

Gold compounds engage an important place in the field of medicinal chemistry due to their therapeutic properties. Since the last four decades, Au(I) and Au(III) complexes have attracted the attention of researchers due to their anti-tumor proprieties and the different mechanisms of action they display in comparison to conventional anticancer platinum compounds. Au(I/III) complexes can inhibit the activity of enzymes containing thiols including thioredoxin reductase; nevertheless, the affinity for several therapeutic targets has been confirmed in recent years. The properties conferred by auxiliary ligands such as phosphines (PR3) and N-heterocyclic carbenes (NHCs) to gold complexes have been key to the development of more promising anticancer compounds. In the same way, it has happened with the inclusion of some multidentate ligands in Au(III) complexes, increasing their stability and selectivity for tumor cells. In this review, we discuss the anticancer effects of Au(I) complexes containing PR3 and NHCs ligands as well as Au(III) complexes containing multidentate ligands especially those that have high cytotoxicity and information on the mechanism of action, as well as attempts to target identification and validation.

Abstract Background: Analyzing interactions between vegetation and environmental factors at regional scales provide information for the understanding of species assemblages. Hypotheses: Environmental restrictions at higher elevations produce a decreasing species richness pattern along an elevational gradient and the climatic variables related to temperature and precipitation are the main filters of species distribution. Objectives: (1) To identify the different assemblages of tree species occurring in a biodiversity hotspot; (2) to analyze the pattern of tree species richness along an elevational gradient; and (3) to analyze the environmental filters that determine the species distribution. Study site: Serranías Meridionales of Jalisco in western Mexico. Period of study: 2016-2018. Methods: Thirty-three rectangular 0.1 ha plots were established for vegetation and environmental characterization. Cluster and canonical correspondence analyses were conducted to analyze tree species composition. We defined three groups of variables (climatic, relief and soil) to evaluate the influence of environmental filters. We used generalized linear models to assess the contribution of each group to the spatial variation in species richness. Results: A total of 63 tree species were recorded. The cluster analysis defined eight groups within three forest types. The species richness showed a hump-shaped pattern along the elevational gradient and the climatic and soil variables explained a considerable amount of variation in the species richness. Conclusions: The tree species richness in the Serranías Meridionales of Jalisco is dominated by a striking number of Pinus and Quercus species. This biodiversity hotspot is an important site for the understanding of tree ecological diversification in Mexico.

Resumen Antecedentes: El análisis de las interacciones entre la vegetación y el ambiente a escalas regionales permite entender el ensamblaje de especies. Hipótesis: Restricciones ambientales en sitios elevados generan un patrón decreciente de riqueza de especies en gradientes altitudinales y la temperatura y la precipitación son los principales filtros de la distribución de especies. Objetivos: (1) Identificar los diferentes ensamblajes de especies de árboles en una región crítica de biodiversidad; (2) analizar la riqueza de especies arbóreas en un gradiente altitudinal; (3) analizar los filtros ambientales que determinan la distribución de especies. Sitio de estudio: Serranías Meridionales of Jalisco, México. Período de estudio: 2016-2018. Métodos: Se establecieron 33 parcelas de 0.1 ha para la caracterización de la vegetación y las variables ambientales. Se realizaron análisis de clasificación y canónicos de correspondencia. Utilizamos tres grupos de variables (climáticas, relieve y suelo) y modelos lineales generalizados para estimar las contribuciones de estas variables a la variación espacial en la riqueza de especies. Resultados: Se registraron 63 especies de árboles. El análisis de agrupación definió ocho grupos dentro de tres tipos de bosques. La riqueza de especies presenta un patrón de joroba en el gradiente altitudinal y las variables climáticas y de suelo explicaron la variación de la riqueza de especies. Conclusiones: La riqueza de árboles en las Serranías Meridionales of Jalisco es dominado por un número notable de especies de Pinus y Quercus. Este hotspot de biodiversidad es un sitio importante para el entendimiento de la diversificación de árboles en México.

Abstract. A new azasterol 22-hydrazine-imidazolin-2-yl-chol-5-ene-3β-ol (AH3) and their derivatives [Au(AH3)Cl] (1) and [Cu(AH3)2(H2O)2](NO3)2 (2) were synthesized and characterized by a combination of elemental analyses, 1H and 13C -NMR, UV-vis and infrared spectroscopies. The interactions with two targets DNA and TrxR were investigated. The results from these studies suggested that these metal-azasterol complexes interact with DNA most probably by covalent binding. Complex 1 showed also the ability to strongly inhibit TrxR. Additionally, their activities against yeast cells of Sporothrix spp. were evaluated; finding that complex 1 was the most active, even better than itraconazole.

Resumen. Un nuevo azasterol 22-hidrazina-imidazolin-2-il-col-5-en-3β-ol (AH3) y sus derivados [Au(AH3)Cl] (1) y [Cu(AH3)2(H2O)2](NO3)2 (2) fueron sintetizados y caracterizados por técnicas espectroscopias como RMN 1H ,13C, UV-vis, infrarrojo y análisis elemental. Se investigaron las interacciones de estos compuestos sobre dos blancos moleculares el ADN y la TrxR. Los resultados encontrados sugirieren que estos complejos metal-azasterol interactúan con el ADN covalentemente. El complejo 1 también mostró tener la capacidad de inhibir fuertemente la TrxR. Además, fueron evaluadas sus actividades contra Sporothrix spp., encontrando que complejo 1 fue el más activo, incluso mejor que el itraconazol.

Two new gold(I) -chloroquine complexes, Au(CQ)(Cl) (1) and Au(CQ)(tgta) (2), were prepared and their most probable structure were established through a combination of different spectroscopic and analytical techniques. Their interaction with two important targets of action, DNA and thioredoxin reductase (TrxR), were investigated. These studies showed that complexes 1 and 2 displayed two types of interaction with DNA, covalent binding through the metal center, and additionally a non-covalent interaction that is electrostatic in the case of complex 1, but intercalative for complex 2, which is similar to that displayed by free CQ. The experimental data indicated that these gold-CQ complexes also possess the ability to inhibit TrxR. These results led us to test their cytotoxicity against 6 tumor cell lines. The complexes displayed cytotoxic activity against the PC-3, SKBR-3, HT-29, LoVo and B16/BL6 lines. These finding suggest that gold(I)-CQ compounds, particularly [Au(CQ)(PPh3)]PF6, are promising chemotherapeutic alternatives in the search of anticancer agents.

Dos nuevos complejos de oro(I)-cloroquina: Au(CQ)(Cl) (1) y Au(CQ)(tgta) (2) fueron sintetizados, la estructura más probable para cada uno de ellos fue establecida a través de la combinación de diversas técnicas espectroscópicas. Se evaluó la interacción de cada uno de estos nuevos compuestos con dos importantes blancos de acción: ADN y tioredoxina reductasa (TrxR). Dichos estudios indicaron que 1 y 2 son capaces de interaccionar con el ADN a través de dos vía: covalentemente a través del centro metálico, y no covalentemente, en el caso del complejo 1 es del tipo electrostática mientras que para el complejo 2 es del tipo intercalativa. Además, la data experimental indicó que ambos complejos 1 y 2 tienen la capacidad de inhibir el sistema TrxR. Estos resultados motivaron la evaluación de sus actividad citotóxica contra 6 líneas celulares tumorales, encontrándose que, los complejos mostraron actividad citotoxica contra las líneas PC-3, SKBR-3, HT-29, LoVo y B16/BL6. Estos alentadores resultados sugieren que los complejos Au(I)-CQ, particularmente el [Au(CQ)(PPh3)]PF6 son una alternativa prometedora en la búsqueda de agentes anti cancerígenos.

Este trabalho descreve a busca de novos agentes com potencial quimioterápico baseados em complexos de metais de transição com ligantes planares. Neste estudo, complexos polipiridilpaládio foram sintetizados e caracterizados por análise elementar e por espectroscopias de RMN e de absorção no UV-visível e no infravermelho. A interação dos complexos com DNA também foi investigada por métodos espectroscópicos. Todas as bandas de transferência de carga do metal para os ligantes (TCML) dos complexos polipiridilpaládio exibiram hipocromismo e deslocamento para o vermelho na presença de DNA. A constante de formação e os dados de viscosidade sugeriram que os complexos [PdCl2(phen)] e [PdCl2(phendiamine)] interagem com DNA por forças eletrostáticas. Adicionalmente, estes complexos induziram um efeito leishmaniostático importante sobre promastigotos de L. (L.) mexicana na concentração final de 10 µmol L-1 em 48 h.

This paper describes the search for new potential chemotherapeutic agents based on transition metal complexes with planar ligands. In this study, palladium polypyridyl complexes were synthesized and characterized by elemental analysis, NMR, UV-VIS and IR spectroscopies. The interaction of the complexes with DNA was also investigated by spectroscopic methods. All metal-to-ligand charge transfer (MLCT) bands of the palladium polypyridyl complexes exhibited hypochromism and red shift in the presence of DNA. The binding constant and viscosity data suggested that the complexes [PdCl2(phen)] and [PdCl2(phendiamine)] interact with DNA by electrostatic forces. Additionally, these complexes induced an important leishmanistatic effect on L. (L.) mexicana promastigotes at the final concentration of 10 µmol L-1 in 48 h.