Abstract: The present invention provides an improved method of preparing a 4,7-di-O-alkyl chromogenic ketoside of N-acetylneuraminic acid (Neu5Ac) for use in detecting influenza virus types A and B. The ketosides are substrates that are selectively cleaved by a neuraminidase on influenza virus, but not be neuraminidases found on other viruses or on bacteria. The synthesis is efficient and provides large quantities of the ketoside for commercial development. The synthesis includes a step of alkylating the 4- and 7-hydroxyl groups of a protected alkyl ester alkyl ketoside derivative of Neu5Ac by a process that comprises contacting the derivative with a composition comprising an alkyl halide to form a 4,7-di-O-alkyl protected alkyl ester alkyl ketoside derivative of Neu5Ac. The synthesis alternatively includes protecting the 8- and 9-hydroxyl groups of an alkyl ester alkyl ketoside derivative of Neu5Ac by forming an 8,9-epoxide protected alkyl ester alkyl ketoside derivative of Neu5Ac.

Abstract: A kit for visually detecting the presence of a virus in a direct clinical specimen is provided. The kit employs a rapid and direct assay for visually detecting a virus having a characteristic enzyme in a direct clinical sample without the need for any culturing step, This assay contains the following steps: (1) the clinical sample is contacted in solution with a substrate for the enzyme which includes a chromogen that is cleaved from the substrate by the enzyme and a precipitating agent which reacts with the liberated chromogen to form a precipitate, (2) the precipitate is concentrated, and (3) the concentrated precipitate is visually observed for the characteristic color of the chromogen. The observance of the characteristic color confirms the presence of the virus in the clinical specimen.

Abstract: Chromogenic and fluorogenic 4,7-dialkoxy-N-acetylneuraminic acid substrates of the general formula ##STR1## are provided wherein R.sub.1 and R.sub.2 are alkyl groups containing 1 to 4 carbon atoms and R.sub.3 is a chromogenic or fluorogenic group. These substrates can be used to detect influenza types A and B in clinical samples or specimens. More particularly, these 4,7-dialkoxy-N-acetylneuraminic acid substrates can be used to distinguish between various viruses having neuraminidase reactivity. Thus, influenza type A and B viruses can be distinguished from parainfluenza type 1, 2, 3, and 4, and mumps using the 4,7-dialkoxy-N-acetylneuraminic acid derivatives of this invention. Diagnostic methods employing these substrates are provided to identify influenza type A and B viruses in clinical specimens and to distinguish from other viruses having neuraminidase reactivity.

Abstract: This invention relates to an improved process for the synthesis of 4-alkoxy-N-acetylneuraminic acids. According to the process of the invention, N-acetylneuraminic acid is first alkylated at C-1 and C-2 and then the vicinal hydroxyl groups at C-8 and C-9 are protected through the formation of a ketal. The resulting protected alkyl ester alkyl ketoside is then alkylated at the C-4 position whereby the hydrogen of the C-4 hydroxyl group is replaced with an alkyl group to form an alkoxy group. Deprotection is accomplished through the removal of the ketal group at C-8 and C-9 and removal of the alkyl groups at C-1 and C-2, thereby producing the 4-alkoxy-N-acetylneuraminic acid.

Abstract: A rapid and direct assay for detecting of a virus having a characteristic enzyme in clinical samples in which (1) the clinical sample is contacted in solution with a substrate for the enzyme which includes a chromogen that is cleaved from the substrate by the enzyme and a precipitating agent that reacts with the liberated chromogen to form a precipitate (2) filtering the solution to concentrate the precipitate and (3) visually observing the concentrated precipitate for the characteristic color of the chromogen.

Abstract: A new method for the production of 3,6-Di-O-methyl-D-glucose is presented.

Abstract: An improved process is described for synthesizing simple and complex 6,6'-diacyl esters of trehalose and intermediates useful therein. Novel 6,6'-diacyl esters of trehalose and novel intermediates useful in the process of the invention are also disclosed. The inventive process is capable of producing the desired compounds economically and in pure form from readily available starting materials.