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Search Results: 1 - 10 of 968 matches for " BRENDA MODAK "
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Antivirales de origen natural en la industria acuícola: Un desafío a la Fitoterapia
Brenda MODAK CANOBRA
Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas , 2011,
Abstract: En Chile el cultivo de salmones ha crecido de gran manera en los últimos a os convirtiéndose en una actividad comercial muy importante. Sin embargo, en la industria acuícola, uno de los riesgos más graves que enfrentan los sistemas de cultivo intensivo es la aparición de enfermedades infecciosas, principalmente de origen viral, debido a las altas mortalidades de los individuos y la disminución en los parámetros productivos, como resultado de la enfermedad. En el caso de la salmonicultura esto se ve aumentado por la dificultad de tener espacios cerrados y controlados, de modo de, evitar la diseminación de los patógenos a los lagos y mares. Hasta ahora, las medidas de control se limitan al uso de desinfectantes de las ovas y el diagnóstico precoz de los patógenos, así como la aplicación de algunas vacunas que han mostrado baja protección. Por lo tanto, la búsqueda de antivirales de origen natural, biodegradables e inocuos para el medio ambiente, surge como un gran desafío para los fitoquímicos.
Chemical Analysis of the Resinous Exudate Isolated from Heliotropium taltalense and Evaluation of the Antioxidant Activity of the Phenolics Components and the Resin in Homogeneous and Heterogeneous Systems
Brenda Modak,Macarena Rojas,René Torres
Molecules , 2009, DOI: 10.3390/molecules14061980
Abstract: H. taltalense (Phil.) Johnst. (Heliotropiaceae) is an endemic species of the northern coast of Chile that produces a resinous exudate that covers its foliar surface and stems. Its chemical composition was analyzed for the first time, and two aromatic geranyl derivatives: filifolinol and filifolinyl senecionate and three flavonoids – naringenin, 3-O-methylgalangin and 7-O-methyleriodictiol – were isolated. The antioxidant activity of the flavonoids and the resinous exudates was carried out by measuring the 1,1-diphenyl-2-picrylhydrazyl (DPPH) bleaching effect in ethanolic solution and in sodium dodecyl sulfate (SDS) micelles. The influence of the reaction medium was analyzed. The initial velocity reactions for the pure compounds and for the extract were higher in SDS media than in ethanolic solution. The velocity of reaction observed was interpreted in terms of the reaction medium environment in the micelle.
SEASONAL VARIATION OF THE FLAVONOIDS PINOCEMBRIN AND 3-O-METHYLGALANGIN, IN THE SURFACE COMPONENT MIXTURE (RESINOUS EXUDATES AND WAXY COATING) OF HELIOTROPIUM STENOPHYLLUM
MODAK,BRENDA; TORRES,RENé; URZúA,ALEJANDRO;
Journal of the Chilean Chemical Society , 2011, DOI: 10.4067/S0717-97072011000100002
Abstract: in this report we study the seasonal variation of the flavonoids pinocembrin and 3-o-methylgalangin in the surface component mixture (resinous exudate and waxy coating) of heliotropium stenophyllum. the quantitative analysis of the flavonoids was performed using high-performance liquid chromatography of samples collected monthly over a whole year. the results showed an increase in the spring and summer yield of surface components and a decrease during the winter. although the sum of pinocembrin and 3-o-methylgalangin did not follow a pattern related with hydric stress, uv radiation or high temperature during the year, a relationship between pinocembrin and 3-o-methylgalangin was found. on average during the months of september to august, excluding march, the amount of pinocembrin decreased wile the amount of 3-o-methylgalangin increased. the results suggest that the above compounds may play different ecophysiological functions during plant development and are consistent with the biosynthetic relationship between the two compounds.
IDENTIFICATION OF A NEW AROMATIC GERANYL DERIVATIVE IN THE RESINOUS EXUDATE OF HELIOTROPIUM FILIFOLIUM (BORAGINACEAE)
URZúA,ALEJANDRO; MODAK,BRENDA; TORRES,RENE;
Boletín de la Sociedad Chilena de Química , 2001, DOI: 10.4067/S0366-16442001000200011
Abstract: a new aromatic geranyl derivative was isolated from the resinous exudate of heliotropium filifolium. the structure was elucidated by high-resolution spectroscopic methods as filifolinyl senecionate. the compound has shown antibacterial activity against escherichia coli k-12. after irradiation of a solution of filifolinyl senecionate with uv at 366 nm, the antibacterial activity was enhanced by 100%
IDENTIFICATION OF A NEW AROMATIC GERANYL DERIVATIVE IN THE RESINOUS EXUDATE OF HELIOTROPIUM FILIFOLIUM (BORAGINACEAE)
ALEJANDRO URZúA,BRENDA MODAK,RENE TORRES
Boletín de la Sociedad Chilena de Química , 2001,
Abstract: A new aromatic geranyl derivative was isolated from the resinous exudate of Heliotropium filifolium. The structure was elucidated by high-resolution spectroscopic methods as filifolinyl senecionate. The compound has shown antibacterial activity against Escherichia coli K-12. After irradiation of a solution of filifolinyl senecionate with UV at 366 nm, the antibacterial activity was enhanced by 100% Del exudado resinoso de Heliotropium filifolium, se aisló un nuevo derivado aromático geranilado. Este compuesto se identificó por métodos espectrópicos de alta resolución como filifolinil senecionato. El compuesto mostró actividad antibacteriana contra Escherichia coli K-12. Esta actividad se vio incrementada en un 100% después de irradiar una solución de filifolinil senecionato con UV a 366 nm
SEASONAL VARIATION OF THE FLAVONOIDS PINOCEMBRIN AND 3-O-METHYLGALANGIN, IN THE SURFACE COMPONENT MIXTURE (RESINOUS EXUDATES AND WAXY COATING) OF HELIOTROPIUM STENOPHYLLUM
BRENDA MODAK,RENé TORRES,ALEJANDRO URZúA
Journal of the Chilean Chemical Society , 2011,
Abstract: In this report we study the seasonal variation of the flavonoids pinocembrin and 3-O-methylgalangin in the surface component mixture (resinous exudate and waxy coating) of Heliotropium stenophyllum. The quantitative analysis of the flavonoids was performed using high-performance liquid chromatography of samples collected monthly over a whole year. The results showed an increase in the spring and summer yield of surface components and a decrease during the winter. Although the sum of pinocembrin and 3-O-methylgalangin did not follow a pattern related with hydric stress, UV radiation or high temperature during the year, a relationship between pinocembrin and 3-O-methylgalangin was found. On average during the months of September to August, excluding March, the amount of pinocembrin decreased wile the amount of 3-O-methylgalangin increased. The results suggest that the above compounds may play different ecophysiological functions during plant development and are consistent with the biosynthetic relationship between the two compounds.
Study of the Chemical Composition of the Resinous Exudate Isolated from Heliotropium Sclerocarpum and Evaluation of the Antioxidant Properties of the Phenolic Compounds and the Resin
Brenda Modak,Melissa Salina,Jesús Rodilla,René Torres
Molecules , 2009, DOI: 10.3390/molecules14114625
Abstract: Heliotropium sclerocarpum Phil. (Heliotropiaceae) is a resinous bush that grows in the Atacama of northern Chile. The chemical composition of its resinous exudate was analyzed for the first time. One aromatic geranyl derivative: filifolinol (1), one flavanone: naringenin (2) and a new type of 3-oxo-2-arylbenzofuran derivative 3 were isolated and their structures were determined. The antioxidant activity of the phenolic compounds and resin was evaluated using the bleaching of DPPH radical method and expressed as fast reacting equivalents (FRE) and total reacting equivalents (TRE).
ANTIBACTERIAL ACTIVITY OF COMPOUNDS ISOLATED OF THE RESINOUS EXUDATE FROM HELIOTROPIUM SINUATUM ON PHYTOPATHOGENIC BACTERIA
MODAK,BRENDA; TORRES,RENé; WILKENS,MARCELA; URZúA,ALEJANDRO;
Journal of the Chilean Chemical Society , 2004, DOI: 10.4067/S0717-97072004000100001
Abstract: from the resinous exudates of heliotropium sinuatum have been isolated and characterized two compounds, pentaeicosanol 1 and 1-hydroxy-3-doeicosanone 2. those structures and previously isolated pure compounds have been tested in their antibacterial activity on phytopathogenic bacteria. ketone 2 and the flavonoid hesperetine 10 showed antibacterial activity on erwinia carotovora subsp. carotovora, while the flavonoid 3-o-methylgalangine 4 showed activity on clavibacter michiganensis subsp. michiganensis
IN VITRO SENSITIVITY OF BOTRYTIS CINéREA TO RESINOUS EXUDATES OF HELIOTROPIUM FILIFOLIUMAND GERANYL DERIVATIVES COMPOUNDS
MENDOZA,LEONORA; MODAK,BRENDA; TORRES,RENE; COTORAS,MILENA;
Journal of the Chilean Chemical Society , 2008, DOI: 10.4067/S0717-97072008000100024
Abstract: the activity of the extract ofheliotropium filifolium, of the natural compounds obtained from its resinous exudates, filifolinol and fihfohnyl senecionate, and of the synthetic derivative of filifolinol, filifolinoic acid, on the mycehal growth of the phytopathogenic fungus botrytis cinérea was analyzed in liquid and solid media. the extract of h'. filifolium, filifolinol, and filifolinoic acid reduced mycehal growth of this fungus. the effect of these compounds was dose-dependant. the compound fihfohnyl senecionate was inactive in all the tested conditions. the extract of h'. filifolium and filifolinol retarded the germination of conidia of the fungus
ACTIVIDAD ANTIBACTERIANA DE FLAVONOIDES AISLADOS DEL EXUDADO RESINOSO DE HELIOTROPIUM SINUATUM: EFECTO DEL TIPO DE ESTRUCTURA
MODAK,BRENDA; ARRIETA,ABEL; TORRES,RENE; URZUA,ALEJANDRO;
Boletín de la Sociedad Chilena de Química , 2002, DOI: 10.4067/S0366-16442002000100005
Abstract: from the resinous exudates of heliotropium sinuatum have been isolated and characterized eight flavonoids. in this paper we show the bacteride activity of resin and previously isolated flavonoids. kinetics of bacterial growth gave the generation time of bacterial population. this method let it knew a quantitative approach of the antibacterial capacity of resins and flavonoids. a discussion of the effect of flavonoids class and type of substituents is developed
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