Safwat A. Ahmed
Suez Canal University, Egypt
Title: New antibacterial xanthone from the marine sponge-derived Micrococcus sp. EG45
Biography
Biography: Safwat A. Ahmed
Abstract
Actinomycetes are prolific producers of bioactive natural products. Xanthone natural products are fluorescent dyes that are widely distributed among plants and microorganisms. They have been used in food, cosmetics, and textile industries as coloring agents. Moreover, they exhibit a wide array of bioactivities including antioxidant, antibacterial, antimalarial, antituberculosis and cytotoxic activities. Their antibacterial action was found to be through induction of photoinactivation of bacteria via formation of reactive oxygen species such as singlet oxygen, which oxidize biological molecules including lipids, proteins and nucleic acids, leading to cell death. Microluside A [4 (19-para-hydroxybenzoyloxy-O-b-D-cellobiosyl),5(30-para-hydroxybenzoyloxy-O-b-Dglucopyranosyl) xanthone is a unique O-glycosylated disubstituted xanthone isolated from the broth culture of Micrococcus sp. EG45 cultivated from the Red Sea sponge Spheciospongia vagabunda. The structure of microluside A was determined by 1D- and 2D-NMR techniques as well as high resolution tandem mass spectrometry. The antimicrobial activity evaluation showed that 1 exhibited antibacterial potential against Enterococcus faecalis JH212 and Staphylococcus aureus NCTC 8325 with MIC values of 10 and 13 lM, respectively. This is the first report for xanthone derivatives from Micrococcus sp. which introduces this microraganism as a new source for vital antimicrobial agents espescificaly the reluctant enterobacteriacea.