Modulation of drug resistance in Staphylococcus aureus by 132-hydroxy-(132-R/S)-pheophytin isolated from Sargassum polyceratium.

Efflux pumps are integral parts of the bacterial plasma membrane that are responsible for many cases of antibiotic resistance. Modulators of drug resistance are regarded as the most suitable new antibacterial therapies. We evaluated the extracts of Sargassum polyceratium and the isolated compound pheophytin (Sp-1) for antibiotic modifying activity in strains of Staphylococcus aureus with efflux pump. The minimum inhibitory concentrations (MICs) for norfloxacin, tetracycline and erythromycin were determined by the microdilution broth method, in the absence and presence of the extract at a sub-inhibitory concentration (MIC/4). The extracts and isolated compounds showed no significant antimicrobial activity, but they changed the antibiotic activity, decreasing bacterial resistance by 2 to 4x. Using a checkerboard method, it was also possible to observe the synergistic effect (ΣFIC ≤ 0.5) between Sp-1 and the antibiotics erythromycin and norfloxacin. The results indicate that the seaweed Sargassum polyceratium and pheophytin are potential sources of an antibiotic adjuvant that modulates bacterial resistance, acting as a putative efflux pump inhibitor.

Evaluación fitoquímica de hojas de Excoecaria lucida Sw. (Aité) (Euphorbiaceae) y Aislamiento e Identificación de un hemiterpenoide / Fitochemistry evaluation of leaves of Excoecaria lucida Sw. (Aité) (Euphorbiaceae) and isolation e identification of a hemiterpenoid

Introducción: excoecaria lucida Sw. (Aité), es una especie que crece en Cuba y en la región del Caribe. La misma ha sido poco estudiada por científicos a pesar de que la población la utiliza con fines medicinales, en lo principal como antiasmático, antimicrobiano y para el dolor dental. Objetivos: determinar la composición química de las hojas, así como aislar e identificar estructuralmente metabolitos secundarios. Métodos: las hojas secas y molidas, se maceraron 72 horas con etanol al 95 por ciento y se repitió el procedimiento en 4 ocasiones. Al extracto total se le determinó su composición química cualitativa y posterior se fraccionó con solventes. La fase de mayor rendimiento fue estudiada por Cromatografía Líquida de Alta Resolución y aislada la sustancia mayoritaria, la cual fue caracterizada por espectroscopía infrarroja y de Resonancia Magnética Nuclear 1H y 13C a 500 MHz (HMQC, HMBC, COSY y NOESY). Resultados: se determinó la presencia cualitativa de alcaloides, triterpenos y esteroides, quinonas, flavonoides, cumarinas, lactonas sesquiterpénicas, fenoles y taninos. De la fase de mayor rendimiento (butanólica= 23,48 g) se logró aislar e identificar el compuesto mayoritario perteneciente a un hemiterpenoide. Conclusiones: los metabolitos secundarios detectados coinciden con los reportes para otras especies del género. Se informa por primera vez para el género y la especie el aislamiento e identificación del hemiterpenoide (2E)-2-metil-2-buten-1,4-diol-1-O-β-D-glucopiranósido(AU)

Introduction: excoecaria lucida Sw. (Aité), it is a species that grow in Cuba and at the Caribbean region. It has been scientifically quite a little studied, in spite of the fact that the population utilizes it due to their medicinal properties as antiasthmatic, antimicrobial, and for the toothache treatment. Objectives: to determine the chemical composition of leaves, as well as the isolation and identification of their secondary metabolites. Methods: dried and milled leaves were macerated 72 hours with ethanol 95 percent, repeating the procedure in 4 occasions. Total extract was determined in his chemical qualitative composition and afterwards it was fragmented with solvents. The phase with greater yield was studied by High Performance Liquid Chromatography and isolated the main substance, which was characterized by infrared and Nuclear Magnetic Resonance spectroscopy: uni-dimensional 1H and 13C at 500 MHz and bi-dimensional HMQC, HMBC, COSY and NOESY. Results: the identification of Alkaloids, triterpenes and steroids, quinone, flavonoids, coumarins, sesqiterpenic lactones, tannins and phenols were accomplished. From the greater yield phase (butanol= 23.48 g) was isolated and identified the main compound, a hemiterpenoid. Conclusions: the identified secondary metabolites are in coincidence with other reports related to the genera. For first time the hemiterpene (2E)-2-methyl-2- buten-1,4-di-hydroxyl-1-O-β-D-glucopyranoside is informed in this genera and specie(AU)

Evaluación fitoquímica de hojas de Excoecaria lucida Sw. (Aité) (Euphorbiaceae) y Aislamiento e Identificación de un hemiterpenoide / Fitochemistry evaluation of leaves of Excoecaria lucida Sw. (Aité) (Euphorbiaceae) and isolation e identification of a hemiterpenoid

INTRODUCCIÓN: excoecaria lucida Sw. (Aité), es una especie que crece en Cuba y en la región del Caribe. La misma ha sido poco estudiada por científicos a pesar de que la población la utiliza con fines medicinales, en lo principal como antiasmático, antimicrobiano y para el dolor dental. OBJETIVOS: determinar la composición química de las hojas, así como aislar e identificar estructuralmente metabolitos secundarios. MÉTODOS: las hojas secas y molidas, se maceraron 72 horas con etanol al 95 % y se repitió el procedimiento en 4 ocasiones. Al extracto total se le determinó su composición química cualitativa y posterior se fraccionó con solventes. La fase de mayor rendimiento fue estudiada por Cromatografía Líquida de Alta Resolución y aislada la sustancia mayoritaria, la cual fue caracterizada por espectroscopía infrarroja y de Resonancia Magnética Nuclear 1H y 13C a 500 MHz (HMQC, HMBC, COSY y NOESY). RESULTADOS: se determinó la presencia cualitativa de alcaloides, triterpenos y esteroides, quinonas, flavonoides, cumarinas, lactonas sesquiterpénicas, fenoles y taninos. De la fase de mayor rendimiento (butanólica= 23,48 g) se logró aislar e identificar el compuesto mayoritario perteneciente a un hemiterpenoide. CONCLUSIONES: los metabolitos secundarios detectados coinciden con los reportes para otras especies del género. Se informa por primera vez para el género y la especie el aislamiento e identificación del hemiterpenoide (2E)-2-metil-2-buten-1,4-diol-1-O-ß-D-glucopiranósido.

INTRODUCTION: excoecaria lucida Sw. (Aité), it is a species that grow in Cuba and at the Caribbean region. It has been scientifically quite a little studied, in spite of the fact that the population utilizes it due to their medicinal properties as antiasthmatic, antimicrobial, and for the toothache treatment. OBJECTIVES: to determine the chemical composition of leaves, as well as the isolation and identification of their secondary metabolites. METHODS: dried and milled leaves were macerated 72 hours with ethanol 95 %, repeating the procedure in 4 occasions. Total extract was determined in his chemical qualitative composition and afterwards it was fragmented with solvents. The phase with greater yield was studied by High Performance Liquid Chromatography and isolated the main substance, which was characterized by infrared and Nuclear Magnetic Resonance spectroscopy: uni-dimensional 1H and 13C at 500 MHz and bi-dimensional HMQC, HMBC, COSY and NOESY. RESULTS: the identification of Alkaloids, triterpenes and steroids, quinone, flavonoids, coumarins, sesqiterpenic lactones, tannins and phenols were accomplished. From the greater yield phase (butanol= 23.48 g) was isolated and identified the main compound, a hemiterpenoid. CONCLUSIONS: the identified secondary metabolites are in coincidence with other reports related to the genera. For first time the hemiterpene (2E)-2-methyl-2- buten-1,4-di-hydroxyl-1-O-ß-D-glucopyranoside is informed in this genera and specie.