Summary: An overview of current Mexican legislation regarding soil restoration and updating needs is made through the analysis of three case studies located in the southeastern México: a) soil affected by spillage of congenital waters (Zone 1), b) soil contaminated by hydrocarbons (Zone 2) and, c) a site adjacent to urban infrastructure (Zone 3). It was performed a comparative analysis of the soils conditions in the short and long term after the anthropogenic impact and restoration process that were carried out in each studied location. It was found that important properties of the soils do not recover after the weathering process, for instance in Zone 1, DR and DA as well as %Po did not reach equivalent values to the control sample and the soil texture is different even after a long recovery period. For Zone 2, it was detected important variations in the concentration of Ca, Na and K in both the impacted and recovered soils which affect the growth of plantations. In Zone 3, there were found significative differences in DA, %Po; %L, %R, %MO and CEC parameters. The current normative considers general aspects, but does not contemplate the actual site situation, there is an information gap due to this, although it was observed achievement of physical and chemical properties for the recovery soil use in each site, it was also noticed that the evaluations do not consider if these properties can change over time due to weather conditions, therefore, they could influence the success of each restoration process in the long term. The information generated can be used to make decisions about government rescue programs for the primary sector or as a starting point in the implementation of Environmental Bases Lines (LBA) for the hydrocarbon sector.

Resumen: Se realizó una visión general de la legislación mexicana vigente en materia de restauración del suelo y de las necesidades de actualización a través del análisis de tres estudios de caso ubicados en el sureste de este país: a) suelo afectado por derrames de aguas congénitas (Zona 1), b) suelo contaminado por hidrocarburos (Zona 2) y c) un sitio adyacente a infraestructura urbana (Zona 3). Se realizó un análisis comparativo a corto y largo plazo de las condiciones de los suelos después del impacto antropogénico y el proceso de restauración que se llevó a cabo en cada caso de estudio. Se encontró que propiedades importantes de los suelos no se recuperaron después del proceso de intemperizado. Por ejemplo, en la Zona 1, DA, DR y %Po no alcanzaron valores equivalentes a los del suelo testigo aun después de un tiempo prolongado de recuperación. En la Zona 2, se detectaron variaciones importantes en las concentraciones de Ca, Na y K tanto en el suelo impactado como en el recuperado, lo cual afecta el crecimiento de plantaciones. En la Zona 3, se encontraron diferencias significativas en parámetros como: DA, %Po; %L, %R, %MO y CEC. Se encontró una brecha de información en la normativa actual que considera aspectos generales, pero no considera la situación real del sitio, aunque se observó el cambio de propiedades físicas y químicas para el uso de recuperación del suelo en cada sitio, también se observó que las evaluaciones no consideran si estas propiedades pueden cambiar con el tiempo debido a las condiciones climáticas y por lo tanto podrían influir en el éxito de cada proceso de restauración a largo plazo. La información generada puede ser utilizada para tomar decisiones sobre los programas de rescate del gobierno para el sector primario o como punto de partida en la implementación de Líneas Bases Ambientales del sector de hidrocarburos.

Abstract In Mexico, soils impacted by hydrocarbons are remediated by various techniques; some reduce the concentration of the pollutant and others stabilize it, this is why the final conditions will depend on the applied process. When not considering this situation, some restored areas with an agricultural-livestock vocation use present problems such as low production of crops and/or forages. Based on the above, the present work aimed to evaluate the changes in the properties of a post-remediation soil (one month and one year) by comparing it with a control soil. Total Petroleum Hydrocarbons (TPH) were observed below the regulatory limit (600 mg∙kg-1 to 660 mg∙kg-1) and did not vary after one year; moreover, changes in soils such as pH (~6.4 to ~7.4), humidity (~14% to ~10%), apparent density (~1.1 g͎∙cm-3 to ~ 1.4 g͎∙cm-3) and real density (~2.0 g∙cm-3 to ~2.5 g∙cm-3), Cation Exchange Capacity (CEC) (~26 Cmol ∙ kg-1 to ~11 Cmol ∙ kg-1) and textures (from clayey to sandy-loam), unchanged at one year.

Resumen En México, los suelos impactados por hidrocarburos son remediados mediante diversas técnicas, algunas reducen la concentración del contaminante y otras lo estabilizan; es por ello que las condiciones finales dependerán del proceso aplicado. Al no considerar esta situación, algunas áreas restauradas con vocación de uso agrícola-ganadera presentan problemas tales como baja producción de cultivos y/o forrajes. Debido a lo anterior, el presente trabajo tuvo como objetivo evaluar los cambios en las propiedades de un suelo post-remediación (un mes y un año), comparándolo con un testigo. Se observaron Hidrocarburos Totales del Petróleo (HTP) debajo del límite normativo (600 mg∙kg-1 a 660 mg∙kg-1) y no varían después de un año; además, se observaron cambios en los suelos tales como pH (~6.4 a ~7.4), humedad (~14% a ~10%), densidad aparente (~1.1 g͎∙cm-3 a ~1.4 g͎∙cm-3) y densidad real (~2.0 g∙cm-3 a ~2.5 g∙cm-3), Capacidad de Intercambio Catiónico (CIC) (~26 Cmol∙kg-1 a ~11 Cmol∙kg-1) y texturas (de arcillosa a franco-arenosa) sin cambios después del año.

Resumen La escuaramida y sus derivados representan un importante grupo de sustancias que actualmente se están aplicando exitosamente en estrategias de organocatálisis asimétrica. En esta contribución se presenta un resumen del estado del arte relativo a la síntesis de los derivados de escuaramida y su papel como inductores de quiralidad en secuencias sintéticas relevantes. Por ello, se establece un proceso de búsqueda sistemática y selección de reportes publicados en revistas especializadas del área, con la finalidad de presentar los aspectos más notables de síntesis y la aplicación de los derivados de escuaramida en esta sustancial área de la química orgánica.

Abstract Squaramide and its derivatives represent an important group of substances that are currently being successfully applied in asymmetric organocatalitic strategies, which is why this contribution presents a summary of the state of the art related to the synthesis of escuaramide derivatives and their role as chirality inducers in relevant synthetic sequences. To this end, a process of systematic search and selection of reports published in specialized journals of the area was established in order to present the most significant aspects of synthesis and the application of escuaramide derivatives in this key area of organic chemistry.

Resumo O escuaramide e seus derivados representam um importante grupo de substâncias que atualmente estão sendo aplicadas com sucesso em estratégias de organocatálise assimétrica, razão pela qual essa contribuição apresenta um resumo do estado da arte relacionado à síntese de derivados de escuaramida e seu papel como indutores de quiralidade em sequências sintéticas relevantes. Para tanto, foi estabelecido um processo de busca sistemática e seleção de relatórios publicados em revistas especializados da área, a fim de apresentar os aspectos mais pertinentes da síntese e a aplicação de derivados de escuaramida nesta notável área da química orgânica.

The extraction of plant constituents is essential to isolate biologically active compounds, aimed to understand their role on the treatment of diabetes. This study was designed to explore the preliminary phytochemical and physicochemical analysis of Carica papaya L., Caricaceae, leaf, and further evaluation of its hypoglycemic effect on diabetic rats. C. papaya leaves were extracted using chloroform, n-hexane or ethanol. For each extract a phytochemical screening was performed. The tests were conducted in triplicate and the qualitative and quantitative determination of the various metabolites was done using analytical standards proposed by Mexican Herbal Pharmacopoeia. The chloroform extract, containing steroids and quinones as major components, was chosen to study C. papaya biological effects. The chloroform extract was evaporated to dryness, and doses 0, 31, 62, 125 mg/kg were orally administered in 300 µl polyethylene glycol to diabetic rats; and 0 and 62 mg/kg to non-diabetic rats. After a 20-day treatment with the chloroform extract, the animals were sacrificed and blood was obtained for biochemical studies. The main effect observed was a decrease in serum glucose, triglycerides and transaminases in diabetic rats after the administration of C. papaya chloroform extract. These results confirm the potential beneficial action of C. papaya to treat the symptoms of diabetic patients.