Synthesis of Cyclopeptides Analogues of Natural Products and Evaluation as Herbicides and Inhibitors of Cyanobacteria.

Natural products derived from plants or microorganisms have been considered as eco-friendly herbicides with application in crop protection. Several natural cyclopeptides have been reported as herbicides, while others have been identified as inhibitors of cyanobacteria. In this work, the syntheses of cyclotetrapeptides and cyclopentapeptides analogues of natural products were successfully performed by solid-phase peptide synthesis of their linear precursor and solution-phase macrolactamization. Four of the obtained peptides and cyclopeptides present phytotoxicity with more than 70% of radicle growth inhibition at 67 µg/mL. In addition, evaluation of 20 peptides and cyclopeptides, as inhibitors of cyanobacteria, rendered five active compounds that reduced the concentration of microcystins in the culture medium.

Synthesis of Cyclotetrapeptides Analogues to Natural Products as Herbicides.

The synthesis of cyclotetrapeptides analogues of the natural products tentoxin and versicotide D was achieved in good yield by solid phase peptide synthesis (SPPS) of their linear precursors and solution phase cyclization. All the cyclopeptides and several open precursors were evaluated as herbicides. Five cyclopeptides and five lineal peptides showed a significant inhibition (>70%) of Ryegrass seed's radicle growth at 67 µg/mL. The evaluation at lower concentrations (4−11 µM) indicates two cyclopeptides analogs of tentoxin, which present one (N-Methyl-d-Phe), and two N-MeAA (N-Methyl-Ala and N-Methyl-Phe), respectively, as the most active of them, showing remarkable phytotoxic activity. In two cases, the open precursors are as active as their corresponding cyclopeptide. However, many linear peptides are inactive and their cyclization derivatives showed herbicidal activity. In addition, two cyclopeptide analogues of versicotide D showed more improved activity than the natural product. The results indicate that the peptide sequence, the amino acid stereochemistry and the presence of N-methyl group have important influence on the phytotoxic activity. Moreover, several compounds could be considered as lead candidates in the development of bioherbicides.

Periodismo científico y perfil periodístico como elementos metodológicos para la construcción de historias Hipermediales / Scientific journalism and journalistic profile as methodological elements for the construction of hypermedia stories

Resumen Este artículo aborda las experiencias, metodología y aprendizajes resultantes del proyecto de investigación-creación Periodismo interactivo. Historias de investigadores en el Eje Cafetero, financiado por la Universidad de Manizales y en alianza con la Fundación Academia de Dibujo Profesional de Cali. Esta iniciativa se centró en tres elementos: una base del periodismo científico y dos columnas: el perfil como género periodístico y la hipermedialidad como canal. Luego de escoger dos historias de científicos con relevantes logros e impactos, se aplicaron los elementos del perfil como género periodístico para construir historias basadas en las experiencias, fuentes, datos y percepciones del equipo de trabajo. Igualmente se cuentan los hitos científicos con las herramientas del periodismo científico para valorar dichos impactos y transcodificarlos para audiencias no especializadas y, finalmente, se eligieron momentos, intervenciones e información relevante para construir una propuesta hipermedial que acompañará el libro que recoge ambas historias.

Abstract This article addresses the experience, methodology and learning resulting from the research-creation project Scientific Profiles and Hypermediality financed by the University of Manizales and in alliance with the Cali Professional Drawing Academy Foundation. This initiative focused on three elements: a base of scientific journalism and two columns: the profile as a journalistic genre and hypermediality as a channel. After choosing two stories of scientists with relevant achievements and impacts, the elements of the profile were applied as a journalistic genre to build stories based on the experiences, sources, data and perceptions of the work team. Likewise, scientific milestones were contracted with the tools of scientific journalism to assess those impacts and transcode them for non-specialized audiences and, finally, moments, interventions and relevant information were chosen to build an hypermedial proposal that would accompany the book that collects both stories.