Glucosamine-6 phosphate synthase(GlmS)is the first enzyme of the hexosamine biosynthetic pathway.This enzyme catalyzes the reaction of D-fructose-6P with glutamine to afford D-glucosamine-6P and glutamate.As a checkpoint of UDP-GlcNAc synthesis,it plays a key role for the bacterial peptidoglycan,the lipopolysaccharide of Gram-negative bacteria,chitin,and mannoproteins of the fungal cell wall.The molecular mechanism of the reaction catalyzed by GlmS is complex and involves amide bond cleavage followed by ammonia channeling and sugar isomerization.Although the enzyme is also present in mammalian systems,there are substantial differences in physiological consequences of GlmS inhibition between fungi and mammals.It constitutes a firm molecular basis for the selective toxicity of specific enzyme inhibitors.As the most powerful GlmS inhibitors such as arabinose-5-phosphate oxime,5-methylenephosphono-Darabino hydroximolactone,N3-(4-methoxy-fumaroyl)-l-2,3-diaminopropanoic acid(FMDP)and 2-amino-2-deoxy-D-glucitol-6-phosphate(ADGP),these compounds exhibit very poor,if any,antifungal activity because of the restriction due to the highly inefficient uptake of these compounds by an unidentified active transport system and apparent inability to cross the membrane by free diffusion.In 2011,Shimoga et al have reported that the entagenic acid showed a high antibacterial activity against B.cereus and B.