Bioguided isolation of antimicrobial polyphenols from Cuspidaria convoluta leaves and thei

Bioguided isolation of antimicrobial polyphenols from Cuspidaria convoluta leaves and their

synergistic effect with antibiotics

Carola A.Torres; Mario A.Sturla; Ana M.Romero; María A.Judis

【期刊名称】《亚太热带生物医学杂志：英文版》 【年(卷),期】2019(000)010

【摘要】Objective:To identify and isolate phenolic compounds from Cuspidaria convoluta,and to evaluate their antibacterial activity and synergistic effect with antibiotics.Methods:The crude extract was prepared by maceration with methanol(5%).The dry extract was suspended in water and fractionated successively.The most active extract was selected by its antibacterial activity and its total phenol content was determined by spectrophotometry and by HPLC-MS/MS.Bioactive fractions of the most active extract were separated by column chromatography and evaluated by bioautography.Isolated compounds were identified.Minimum inhibitory concentration(MIC)of these compounds was determined by microdilution broth method,and synergism with antibiotics(ampicillin,gentamicin and oxacillin)was tested by

checkerboard

and

time-kill

assays.Results:Coumaric

acid,catechin/epicatechin,and luteolin were purified and identified from the extract.There was an increase in the antibacterial activity of antibiotics when they were combined with these compounds.The