The present work is devoted to the study of antiradical and antimicrobial activities of phenolic compounds extracted from different grapevine varieties grown in the Bekaa plane-Lebanon. The amount of phenolic compound...The present work is devoted to the study of antiradical and antimicrobial activities of phenolic compounds extracted from different grapevine varieties grown in the Bekaa plane-Lebanon. The amount of phenolic compounds in selected grape extracts was determined by the Folin-Ciocalteau method. Phenolic composition was specified by high performance liquid chromatography. Free radical scavenging activity was examined by using the (2,2’-diphenyl-1-picrylhy-drazyl) DPPH assay. The potential antimicrobial activity was studied using a new quantitative method developed during this work. This activity was tested against several microbial pathogens, including a Gram-positive strain (Listeria monocytogenes), two Gram-negative strains (Escherichia coli and Salmonella arizonae) and a fungal strain (Candida albicans). According to the results of the present screening study, a great variability in the composition of phenolic com-pounds in red grape extracts was detected. All phenolic compounds extracts, demonstrated important scavenging properties and antimicrobial effect against bacterial and fungal strains. Yet, a different response degree was noticed depending on the tested microorganism and the phenolic composition of grape extracts. Antimicrobial activity was more effective against Gram-positive than Gram-negative and yeast strains. Furthermore, our results highlighted a significant role of synergistic effect between various phenolic compounds in the free radical scavenging and antimicrobial activities.展开更多
Bunches of plump dark purple grapes hang from trellises in a vineyard in Siba Town in southwest China's Guangxi zhuang Autonomous Region.Tracing the grapevines to the ground,one can see that they are rooted in sto...Bunches of plump dark purple grapes hang from trellises in a vineyard in Siba Town in southwest China's Guangxi zhuang Autonomous Region.Tracing the grapevines to the ground,one can see that they are rooted in stone cracks rather than soft soil.展开更多
Eutypella vitis is reported for the first time on several new host trees viz.Fagus grandifolia,Fraxinus pennsylvanica and Syringa reticulata with associated branch dieback symptoms in the Niagara Region of Southern On...Eutypella vitis is reported for the first time on several new host trees viz.Fagus grandifolia,Fraxinus pennsylvanica and Syringa reticulata with associated branch dieback symptoms in the Niagara Region of Southern Ontario,Canada.Morphological characteristics and phylogenetic analyses of ITS sequence data confirmed the species identification.Eutypella vitis is known as a woody plant pathogen causing dieback of grapevines and other economically important fruit trees widely cultivated in Ontario.The fungus ability to infect several alternate new hosts can promote its faster and wider spread across vineyards and consequently increase a dieback hazard to viticulture in Canada.展开更多
文摘The present work is devoted to the study of antiradical and antimicrobial activities of phenolic compounds extracted from different grapevine varieties grown in the Bekaa plane-Lebanon. The amount of phenolic compounds in selected grape extracts was determined by the Folin-Ciocalteau method. Phenolic composition was specified by high performance liquid chromatography. Free radical scavenging activity was examined by using the (2,2’-diphenyl-1-picrylhy-drazyl) DPPH assay. The potential antimicrobial activity was studied using a new quantitative method developed during this work. This activity was tested against several microbial pathogens, including a Gram-positive strain (Listeria monocytogenes), two Gram-negative strains (Escherichia coli and Salmonella arizonae) and a fungal strain (Candida albicans). According to the results of the present screening study, a great variability in the composition of phenolic com-pounds in red grape extracts was detected. All phenolic compounds extracts, demonstrated important scavenging properties and antimicrobial effect against bacterial and fungal strains. Yet, a different response degree was noticed depending on the tested microorganism and the phenolic composition of grape extracts. Antimicrobial activity was more effective against Gram-positive than Gram-negative and yeast strains. Furthermore, our results highlighted a significant role of synergistic effect between various phenolic compounds in the free radical scavenging and antimicrobial activities.
文摘Bunches of plump dark purple grapes hang from trellises in a vineyard in Siba Town in southwest China's Guangxi zhuang Autonomous Region.Tracing the grapevines to the ground,one can see that they are rooted in stone cracks rather than soft soil.
文摘Eutypella vitis is reported for the first time on several new host trees viz.Fagus grandifolia,Fraxinus pennsylvanica and Syringa reticulata with associated branch dieback symptoms in the Niagara Region of Southern Ontario,Canada.Morphological characteristics and phylogenetic analyses of ITS sequence data confirmed the species identification.Eutypella vitis is known as a woody plant pathogen causing dieback of grapevines and other economically important fruit trees widely cultivated in Ontario.The fungus ability to infect several alternate new hosts can promote its faster and wider spread across vineyards and consequently increase a dieback hazard to viticulture in Canada.
