Synthesis of novel N-acetylneuraminic acid derivatives as substrates for rapid detection of influenza virus neuraminidase.

Two novel N-acetylneuraminic acid derivatives, luciferyl N-acetylneuraminic acid (1) and luciferyl 4,7-di-O-methyl-N-acetylneuraminic acid (2), were designed and synthesized as substrates for the rapid detection of influenza virus neuraminidase. The sensitivity and specificity of the assays with compound 1 or 2 as the substrate for detection of neuraminidases from influenza virus (H1N1 and H5N1) and bacteria (A. ureafaciens and C. perfringens) were evaluated. Compound 1 was sensitive to neuraminidases from both influenza virus and bacteria. Bioluminescent assays with this compound with H1N1 and H5N1 neuraminidases were approximately 20- and 16-fold more sensitive, respectively, than the fluorescent method with the commercial substrate 4-MUNANA. In contrast, compound 2 was only sensitive to the neuraminidases from influenza virus, showing approximately 10- and 8-fold greater sensitivity than 4-MUNANA for the detection of H1N1 and H5N1 neuraminidases, respectively. The data showed that compound 2 could be used in assays for detection of an influenza viral neuraminidase.