12 INTEGRANTES

GRUPLAC

DESCRIPCIÓN 

Grupo de investigación en la química y la actividad biológica de plantas promisorias colombianas que busca encontrar compuestos naturales útiles para la salud, la alimentación y la industria. Aplicación de técnicas de biología molecular en la determinación de propiedades medicinales de productos naturales principalmente en cáncer. Correlación actividad –estructura molecular y aplicación de técnicas computacionales para el modelaje de estructuras moleculares. Procesos de síntesis y hemisintesis de moléculas biológicamente activas.

PRODUCTOS DESTACADOS

Synthesis of new 1,2-diaryl[2]benzopyrano[3,4-d]imidazol-5(1H)-one derivatives mediated by ceric ammonium nitrate
Fecha de publicación: 12/07/2017

Más información

Structuralandfunctionalcharacterizationoftoxicpeptidespurifiedfromthe venom of the Colombian scorpion Tityus macrochirus
Fecha de publicación: 19/11/2019

The soluble venom of the scorpion Tityus macrochirus was separated by chromatographic procedures and three homogeneous peptides were obtained and their primary structures were determined. They were called: Tma1Tma3, from the abbreviated name of the scorpion. Tma1 is a peptide containing 65 amino acids with four disulfide linkages and a molecular weight of 7386.2Da. Itis a mammalian toxin, shown to affect human sodiumchannels sub-types hNav1.6 and hNav1.4. Tma2 and Tma3 are peptides containing 69 amino acids linked by four disulfide bonds, molecular weights 7819.7 and 7830.0Da, respectively. They do not affect human sodiumchannels but are lethal to insects (crickets). A phylogenic analysis of the three peptides and those of other toxic peptides isolated from the genus Tityus and Centruroides were grouped together and analyzed, permitting to obtain a topology with two main clades, one includes most sodium-channel anti-insect scorpion toxins and others includes mostly sodium-channel scorpion toxins anti-mammalian. Tma1 segregates among a group of well-studied β-class toxins of other Tityus species such as T. discrepans, T. obscurus and T. pachyurus. Tma2 and Tma3 are associated with anti-insect toxins, particularly with one of T. obscurus. This phylogenetic analysis confirms and enforces our experimental results obtained with these three new sodium-channel scorpion toxins.


Más información

Structural and functional characterization of toxic peptides purified from the venom of the Colombian scorpion Tityus macrochirus
Fecha de publicación: 30/11/2019

The soluble venom of the scorpion Tityus macrochirus was separated by chromatographic procedures and three homogeneous peptides were obtained and their primary structures were determined. They were called: Tma1-Tma3, from the abbreviated name of the scorpion. Tma1 is a peptide containing 65 amino acids with four disulfide linkages and a molecular weight of 7386.2 Da. It is a mammalian toxin, shown to affect human sodium-channels sub-types hNav1.6 and hNav1.4. Tma2 and Tma3 are peptides containing 69 amino acids linked by four disulfide bonds, molecular weights 7819.7 and 7830.0 Da, respectively. They do not affect human sodium-channels but are lethal to insects (crickets). A phylogenic analysis of the three peptides and those of other toxic peptides isolated from the genus Tityus and Centruroides were grouped together and analyzed, permitting to obtain a topology with two main clades, one includes most sodium-channel anti-insect scorpion toxins and others includes mostly sodium-channel scorpion toxins anti-mammalian. Tma1 segregates among a group of well-studied β-class toxins of other Tityus species such as T. discrepans, T. obscurus and T. pachyurus. Tma2 and Tma3 are associated with anti-insect toxins, particularly with one of T. obscurus. This phylogenetic analysis confirms and enforces our experimental results obtained with these three new sodium-channel scorpion toxins.


Más información

Quantification of two isomeric flavones in rat colon tissue using reverse phase high performance liquid chromatography
Fecha de publicación: 07/01/2017

Background: Antineoplastic activity has been previously shown for two isomeric flavones, 5,7-dihydroxy-3,6,8-trimethoxy flavone (flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy flavone (flavone B), against colon cancer cell lines (Thomas et al. in PLoS ONE 7:e39806, 5). Here, we present modified methods for the extraction and quantification of flavones A and B in rat colon tissue after intravenous dosing via high performance liquid chromatography, from the originally described procedure for extraction and quantification in rat plasma (Whitted et al. in J Chromatogr B Analyt Technol Biomed Life Sci 1001:150-155, 7). Results: Modifications included tissue homogenization (1 g tissue: 2 mL water), filtration of the supernatant with a PVDF membrane, and the use of only one calibration curve to determine the concentration of each flavone in colon tissue. Good separation was achieved and representative equations were linear with r 2 ≥ 0.99 for both flavones. Precision and accuracy for flavone A ranged from 0.88-24.03 and 109-116%. Precision and accuracy for flavone B ranged from 1.62-33.56 and 98-113%. Concentrations of 1639 ± 601 ng/g flavone A and 5975 ± 2480 ng/g of flavone B were detected in rat colon tissue 6 h post dosing. Conclusions: Modifications to the extraction methods for flavone A and flavone B from rat colon tissue had good separation, precision, and accuracy. © 2017 The Author(s).


Más información

Purificación parcial de péptidos presentes en el veneno del escorpión Tityus macrochirus (Buthidae) y evaluación preliminar de su actividad citotóxica
Fecha de publicación: 01/06/2017

Introducción. El veneno del escorpión posee péptidos con actividad neurotóxica que actúan principalmente en los canales iónicos del sistema nervioso de insectos y mamíferos. También se ha establecido su acción citolítica y anticancerígena, características biológicas que aún no se han explorado en el veneno del escorpión Tityus macrochirus.
Objetivo. Evaluar si tanto el veneno total de T. macrochirus como la fracción de péptidos parcialmente purificados disminuyen el porcentaje de viabilidad de diferentes líneas celulares provenientes de tumores.
Materiales y métodos. Mediante métodos cromatográficos, electroforéticos y de ultrafiltración con membranas de Amicon Ultra 0.5®, se identificaron y purificaron parcialmente los péptidos del veneno de T. macrochirus obtenido mediante estimulación eléctrica. Los ensayos de actividad citotóxica del veneno y de la fracción de péptidos se hicieron en líneas celulares provenientes de tumores con el método colorimétrico de reducción de la sal de tetrazolio (Mossman’s Tetrazole Test, MTT).
Resultados. El veneno de T. macrochirus posee péptidos con pesos moleculares entre 3 y 10 kDa, los cuales se purificaron parcialmente mediante ultrafiltración y se evaluaron mediante cromatografía líquida de alta resolución en fase inversa (Reverse Phase-High Pressure Liquid Chromatography, RP-HPLC). Los ensayos de citotoxicidad del veneno total de T. macrochirus evidenciaron una mayor disminución de la viabilidad en la línea celular PC3 que en las demás líneas celulares evaluadas, en tanto que la fracción parcialmente purificada de péptidos logró disminuir la viabilidad de la línea celular HeLa.
Conclusión. Los péptidos del veneno de T. macrochirus presentaron actividad citotóxica en algunas de las líneas celulares provenientes de tumores, y se observó algún grado de selectividad frente a ellas.


Más información

GALERÍA

logo_b_n