Abstract
A new 8-hydroxy flavone O-xyloside sulfate, isoscutellarein 7-O-
β
-xyloside-2′′-O-sulfate, along with four known metabolites, were isolated and identified from seagrass, Thalassia hemprichii, collected from the Egyptian Red sea coast. The structures of the isolated compounds were established by chemical degradation and spectral analysis. The crude extract and the new compound displayed different potent antimicrobial activity against both Gram-positive and Gram-negative bacteria as well as fungi with MIC ranging from 0.1 to 10 μg/mL.