Tandem Reactions in Organic Synthesis: The Artistic Approach in Modern Organic Chemistry

The rise of the processes involving sequential reactions (tandem) is mainly due to its advantages. Although it is required high inventiveness and synthetic knowledge, this provides synthetic pathways and processes whose atomic economy is high, in addition to being inexpensive, since it can avoid many purification and separation steps during synthesis. They are also environmentally generous, avoiding the use and production of toxic substances, and the possibility to build complex molecules with high stereoselectivity. This review aims to give a few examples, from existing plethora so far, allowing illustrating and clarifying aspects related to processes involving sequential reactions with an inventiveness that borders on a level that it would be considered as art

Metabolic re-programming in confrontations of Colletotrichum graminicola and Aspergillus nidulans with Bacillus biocontrol agents

We established confrontations between two different fungi, i.e., the maize anthracnose and stalk rot pathogen Colletotrichum graminicola, and the ubiquitous fungus Aspergillus nidulans, and different biocontrol species, i.e., Bacillus subtilis, Bacillus velezensis, and Bacillus amyloliquefaciens. In all fungus–bacterium confrontations tested, growth arrest and, thus, distance inhibition was observed on solid substrata. LC–MS/MS analyses of culture filtrates suggested formation of several metabolites only synthesized in confrontations. Interestingly, microscopy of fungal hyphae grown in liquid medium showed protrusions and color changes occurred only in media harboring fungus-bacterium confrontations. These observations indicate metabolic re-programming and suggest formation of putative secondary metabolites in interactions involving microbial biocontrol agents

Estudio fitoquímico de compuestos fijos y aceite esencial de hojas de la especie Rhodostemonodaphne sp.

El presente trabajo de investigación describe los resultados obtenidos del estudio fitoquímico y biológico preliminar frente a hongos fitopatógenos, realizado con el extracto etanólico de hojas de la especie Rhodostemonodaphne sp. (Lauraceae), especie que fue clasificada en el Herbario Nacional Colombiano bajo el nombre de Rhodostemonodaphne crenaticupula. Con el fin de contribuir a las investigaciones realizadas en la familia Lauraceae, debido a que esta especie no cuenta con estudios previos. Mediante el estudio fitoquímico se aislaron alcaloides de tipo aporfínico, conocidos como leucoxina, dicentrina, ocoxilonina y ocoteina. Del aceite esencial extraído de las hojas de R. crenaticupula, se identificaron los componentes presentes comparando los índices de kovats, los espectros de masas, y con los datos reportados en la literatura, donde se pudo determinar la presencia de γ-muroleno (62,63%), biciclogermacreno (6,74%), como los sesquiterpenos con el mayor porcentaje de composición relativa dentro del cromatograma. También se evaluó la actividad antifúngica del extracto etanólico de hojas sin arrastre, los compuestos aislados y el aceite esencial frente a hongos fitopatógenos, de ellos solamente el extracto etanólico exhibió una importante actividad biológica in vitro frente al hongo fitopatógeno Fusarium oxysporum f. sp. dianthi. / Abstract. In this research work are decribed the results obtained from phytochemical analysis and the preliminary biological study on phytopatogen fungi. It was done in the ethanolic extract from the Rhodostemonodaphne sp. (Lauraceae), specie that was classified in Herbario Nacional Colombiano under the name Rhodostemonodaphne crenaticupula. The aim is to make a contribution to Lauraceae Family investigations because there are not previous reported studies on this specie. During the phytochemical analysis there were isolated these aporphine alkaloids: leucoxene, dicentrene, ocoxin and ocotein. In the essential oil extracted from R. crenaticupula leaves, there were identified the compounds comparing the Kovats index, mass spectra and literature reported data, and it could be determined the presence of gamma-murolene (62,63%), biciclegermacrene (6,74%) as the sesquiterpenes with the higher relative composition percentage in the chromatogram. Antifungal activity was also evaluated from the leaves ethanolic extract leaves by steam distillation, the isolated compounds and the essential oil was tested with the phytopathogenic fungi, from the last probes only the ethanolic extract shows an important biologycal activity in vitro with the phytopathogenic fungus Fusarium oxysporum f. sp. dianthi.Maestrí

Posconflicto y aprovechamiento de plantas invasoras para el control de cultivos agrícolas en el departamento del Tolima

This article seeks to describe a research proposal that contributes to sustainable development, through the implementation of a Local Economic Development Model, which includes obtaining chemical compounds from invasive plants present in the department of Tolima, a region included within the areas most affected by the conflict- ZOMAC. As well as a bibliographic review against invasive plants and their main chemical compounds, predominant and promising crops for the region and pests that attack these crops. In order to make agricultural production more productive and competitive in the regions affected by the armed conflictEste artículo describe una propuesta investigativa de desarrollo sostenible enfocada en la implementación de un modelo de desarrollo económico local, que incluye la obtención de compuestos químicos a partir de plantas invasoras presentes en el departamento del Tolima, región incluida dentro de las zonas más afectadas por el conflicto (ZOMAC). Igualmente, aquí se propone una revisión bibliográfica sobre plantas invasoras y sus principales compuestos químicos, cultivos predominantes y promisorios para la región y plagas que los atacan. Esto con el fin de hacer más productiva y competitiva la producción agrícola en las regiones afectadas por el conflicto armad

Tandem Reactions in Organic Synthesis: The Artistic Approach in Modern Organic Chemistry

The rise of the processes involving sequential reactions (tandem) is mainly due to its advantages. Although it is required high inventiveness and synthetic knowledge, this provides synthetic pathways and processes whose atomic economy is high, in addition to being inexpensive, since it can avoid many purification and separation steps during synthesis. They are also environmentally generous, avoiding the use and production of toxic substances, and the possibility to build complex molecules with high stereoselectivity. This review aims to give a few examples, from existing plethora so far, allowing illustrating and clarifying aspects related to processes involving sequential reactions with an inventiveness that borders on a level that it would be considered as art