Substrates and inhibitors of neuraminidases: Communication 1. Syntheses of O-, S-, and N-ketosides of N-acetyl-D-neuraminic acid

1. The synthesis of 2-O-p-nitrophenyl-N-acetyl-α-D-neuraminic acid, 2-deoxy-2-methylthio-N-acetyl-α-D-neuraminic acid, 2-deoxy-p-nitrophenylthio-N-a,cetyl-α-D-neuraminic acid, and 2-deoxy-2-p-nitro-phenylamino-N-acetyl-α-D-neuraminic acid was described, and their behavior in enzymatic hydrolysis by neuraminidases of cholera vibrio and influenza virus was studied. 2. 2-O-p-Nitrophenyl-N-acetyl-α-D-neurammoside is a convenient synthetic substrate in kinetic investigations of neuraminidases. N- and S-ketosides are distinguished by their stability to neuraminidases from various sources.