Iliana María Ramírez Velásquez

Prof. Iliana María Ramírez Velásquez

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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 March 2022 in Molecules
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IVIliana María Ramírez Velásquez
Iliana María Ramírez Velásquez
EVEderley Vélez
Ederley Vélez
ÁBÁlvaro Hernan Bedoya-Calle
Álvaro Hernan Bedoya-Calle
FCFrancisco J. Caro-Lopera
Francisco J. Caro-Lopera
Betanin and betanidin are compounds with extensive interest; they are effectively free radical scavengers. The present work aims to elucidate the differences between the mechanism of the antioxidant activity of betanin, betanidin, and their respective C15-epimers. Shape Theory establishes comparisons between the molecules’ geometries and determines parallelisms with the descriptors BDE, PA, ETE IP, PDE, and infrared spectra (IR) obtained from the molecule simulations. Furthermore, the molecules were optimized using the B3LYP/6-31+G(d,p) protocol. Finally, the molecular docking technique analyzes the antioxidant activity of the compounds in the complex with the therapeutic target xanthine oxidase (XO), based on a new proposal for the geometrical arrangement of the ligand atoms in the framework of Shape Theory. The results obtained indicate that the SPLET mechanism is the most favorable in all the molecules studied and that the first group that loses the hydrogen atom in the four molecules is the C17COOH, presenting less PA the isobetanidin. Furthermore, regarding the molecular docking, the interactions of these compounds with the target were favorable, standing out to a greater extent the interactions of isobetanidin with XO, which were analyzed after applying molecular dynamics.

29 January 2019 in trilogía Ciencia Tecnología Sociedad
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JCJorge Contreras-Germán
Jorge Contreras-Germán
APAlberto Piedrahita-Ospina
Alberto Piedrahita-Ospina
IVIliana María Ramírez Velásquez
Iliana María Ramírez Velásquez
El presente artículo presenta el proceso de desarrollo y validación del instrumento: Escala de Valoración de Competencias Digitales (EVCD), aplicado a estudiantes de educación media de la ciudad de Medellín Colombia. Para llevar a cabo esta investigación de tipo cuantitativo, se realiza un proceso de validación de contenidos a través del juicio de expertos y el cálculo del Índice de Validez de Contenido, luego se realiza una ratificación de constructo a través de análisis factorial exploratorio y confirmatorio, y finalmente, se hace un análisis de fiabilidad a través de la aplicación de la prueba de Alpha de Cronbach. Como producto del estudio, se obtiene un instrumento con 6 dimensiones y 30 ítems que evalúa las competencias digitales de estudiantes en Colombia, de manera confiable y precisa.

6 December 2022 in ACS Omega
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IVIliana María Ramírez Velásquez
Iliana María Ramírez Velásquez
ÁBÁlvaro Hernan Bedoya-Calle
Álvaro Hernan Bedoya-Calle
EVEderley Vélez
Ederley Vélez
FCFrancisco J. Caro-Lopera
Francisco J. Caro-Lopera
Automatic search of cavities and binding mode analysis between a ligand and a 3D protein receptor are challenging problems in drug design or repositioning. We propose a solution based on a shape theory theorem for an invariant coupled system of ligand-protein. The theorem provides a matrix representation with the exact formulas to be implemented in an algorithm. The method involves the following results: (1) exact formulae for the shape coordinates of a located-rotated invariant coupled system; (2) a parameterized search based on a suitable domain of van der Waals radii; (3) a scoring function for the discrimination of sites by measuring the distance between two invariant coupled systems including the atomic mass; (4) a matrix representation of the Lennard-Jones potential type 6-12 and 6-10 as the punctuation function of the algorithm for a molecular docking; and (5) the optimal molecular docking as a solution of an optimization problem based on the exploration of an exhaustive set of rotations. We apply the method in the xanthine oxidase protein with the following ligands: hypoxanthine, febuxostat, and chlorogenic acid. The results show automatic cavity detection and molecular docking not assisted by experts with meaningful amino acid interactions. The method finds better affinities than the expert software for known published cavities.

14 May 2018 in TecnoLógicas
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MBMaría D. Bustamante-Rodríguez
María D. Bustamante-Rodríguez
APAlberto A. Piedrahita-Ospina
Alberto A. Piedrahita-Ospina
IVIliana María Ramírez Velásquez
Iliana María Ramírez Velásquez
La valoración de textos escritos es una tarea que considera principalmente dos aspectos: el sintáctico y el semántico. El primero de ellos, se enfoca en la forma del texto y el segundo en el significado. La puesta en marcha de dicha tarea realizada en forma manual implica un esfuerzo en tiempo y recursos, que se puede reducir si parte del proceso se lleva a cabo de forma automática. De acuerdo con los antecedentes revisados en la corrección automática de textos, se identifican diferentes técnicas, entre ellas la lingüística, la cual se centra en los elementos sintácticos, semánticos y pragmáticos. Así, la investigación en curso se orienta a la revisión automática de textos escritos en español desde el punto de vista de la sintaxis, como punto de partida para garantizar la coherencia y la cohesión en la composición de textos, lo que puede ser de utilidad e impacto en el medio académico. Con el propósito de llevar a cabo este estudio se recolectó y analizó un conjunto de textos de estudiantes de un programa académico, al cual se le aplicó técnicas de procesamiento de lenguaje natural y aprendizaje de máquina. Adicionalmente, se realizó una corrección manual con la finalidad de comparar ambos resultados. De esta manera, se determinó que hay correspondencia entre ellos, lo cual permitió concluir que el método automático sirve de apoyo en el proceso de corrección sintáctica de un texto escrito en español.

10 January 2023 in Molecules
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JBJohann E. Bedoya-Cardona
Johann E. Bedoya-Cardona
MRMarcela Rubio-Carrasquilla
Marcela Rubio-Carrasquilla
IVIliana María Ramírez Velásquez
Iliana María Ramírez Velásquez
MVMario S. Valdés-Tresanco
Mario S. Valdés-Tresanco
EMErnesto Moreno
Ernesto Moreno
Invasive fungal infections represent a public health problem that worsens over the years with the increasing resistance to current antimycotic agents. Therefore, there is a compelling medical need of widening the antifungal drug repertoire, following different methods such as drug repositioning, identification and validation of new molecular targets and developing new inhibitors against these targets. In this work we developed a structure-based strategy for drug repositioning and new drug design, which can be applied to infectious fungi and other pathogens. Instead of applying the commonly accepted off-target criterion to discard fungal proteins with close homologues in humans, the core of our approach consists in identifying fungal proteins with active sites that are structurally similar, but preferably not identical to binding sites of proteins from the so-called “human pharmacolome”. Using structural information from thousands of human protein target-inhibitor complexes, we identified dozens of proteins in fungal species of the genera Histoplasma, Candida, Cryptococcus, Aspergillus and Fusarium, which might be exploited for drug repositioning and, more importantly, also for the design of new fungus-specific inhibitors. As a case study, we present the in vitro experiments performed with a set of selected inhibitors of the human mitogen-activated protein kinases 1/2 (MEK1/2), several of which showed a marked cytotoxic activity in different fungal species.

Verified
Journal Article
Open access
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IVIliana María Ramírez Velásquez
Iliana María Ramírez Velásquez
ÁBÁlvaro Hernan Bedoya-Calle
Álvaro Hernan Bedoya-Calle
EVEderley Vélez
Ederley Vélez
FCFrancisco J. Caro-Lopera
Francisco J. Caro-Lopera
Betanidin (Bd) is a nitrogenous metabolite with significant bioactive potential influenced by pH. Its free radical scavenging activity and deprotonation pathway are crucial to studying its physicochemical properties. Motivated by the published discrepancies about the best deprotonation routes in Bd, this work explores all possible pathways for proton extractions on that molecule, by using the direct approach method based on pKa. The complete space of exploration is supported by a linear relation with constant slope, where the pKa is written in terms of the associated deprotonated molecule energy. The deprotonation rounds 1, …, 6 define groups of parallel linear models with constant slope. The intercepts of the models just depend on the protonated energy for each round, and then the pKa can be trivially ordered and explained by the energy. We use the direct approximation method to obtain the value of pKa. We predict all possible outcomes based on a linear model of the energy and some related verified assumptions. We also include a new measure of similarity or dissimilarity between the protonated and deprotonated molecules, via a geometric–chemical descriptor called the Riemann–Mulliken distance (RMD). The RMD considers the cartesian coordinates of the atoms, the atomic mass, and the Mulliken charges. After exploring the complete set of permutations, we show that the successive deprotonation process does not inherit the local energy minimum and that the commutativity of the paths does not hold either. The resulting clusterization of pKa can be explained by the local acid and basic groups of the BD, and the successive deprotonation can be predicted by using the chemical explained linear models, which can avoid unnecessary optimizations. Another part of the research uses our own algorithm based on shape theory to determine the protein’s active site automatically, and molecular dynamics confirmed the results of the molecular docking of Bd in protonated and anionic form with the enzyme aldose reductase (AR). Also, we calculate the descriptors associated with the SET and SPLET mechanisms.