118 results about "Neuraminic acid" patented technology

Compounds of formula (I) or their salts or esters:[wherein R1 is alkyl or haloalkyl; R2 and R3 each represents hydrogen or aliphatic acyl; X is hydroxy, halogen, alkoxy, or a group of formula RaO-, where Ra is aliphatic acyl; Y is a group of formula RbRcN- or RbRcN-O-, where Rb and Rc each is hydrogen or alkyl; and Z is oxygen or sulfur] have excellent sialidase inhibitory activity and are therefore useful for the treatment and prevention of influenza and other viral diseases where the replication of the virus is susceptible to sialidase inhibitors.

A composition comprising an amphoteric or pseudo-amphoteric agent and a polyhydroxy alpha hydroxyacid existing as a free acid, lactone, or salt, and isomeric or non-isomeric forms thereof is provided. The amphoteric or pseudo-amphoteric agent can be selected from amino acids, dipeptides, aminoaldonic acid, aminouronic acid, lauryl aminoproplyglycine, aminoaldaric acid, neuraminic acid desulfated heparin, deacetylated hyaluronic acid, hyalobiuronic acid, chondrosine, deacetylated chondroitin, creatine, creatinine, hydroxyproline, homocysteine, homocystine, homoserine, ornithine, citrulline, phosphatidylserine, and sphingomyelin. The composition may contain other additives, including cosmetic or pharmaceutical agents for topical treatment of dermatological disorders.

The invention provides a method for manufacturing neuraminic acid derivatives, also synthetic intermediates of the neuraminic acid derivatives and methods for their manufacture, and neuraminic acid derivatives having high purity. A synthetic intermediate compound represented by the formula (7) is provided: wherein R3 represents alkyl; R4 and R5 each represents H, alkyl, phenyl, or together represent tetramethylene, pentamethylene, oxo.

The invention discloses genetically engineered bacteria for producing N-acetylneuraminic acid as well as a construction method and application thereof. A method for preparing the genetically engineered bacteria for producing N-acetylneuraminic acid comprises the following step of: introducing genes associated with the N-acetylneuraminic acid synthesis into host bacteria so as to obtain recombinant bacteria for producing N-acetylneuraminic acid, wherein the genes associated with the N-acetylneuraminic acid synthesis are coding genes of N-acetylglucosamine and 2-isomerase and a coding gene of N-nacetylneuraminic acid aldolase. The genetically engineered bacteria for producing N-acetylneuraminic acid constructed by the invention have the following advantages that the used raw materials are relatively cheap and liable to realize industrial mass product, so that the genetically engineered bacteria play an important role in the production of N-acetylneuraminic acid in the future.

This invention discloses a sialic acid enzyme test reagent for testing sialic acid enzyme activity in vagina secreta outside the body, containing substrate on the carrier named N-acetyl neuraminate and its salt which can be its derivant or thymolphthaleic N-acetyl neuraminate and its salt, 5-Br-4-Cl-3-indolyl-alpha-D-N-acytylneuraminate and its salt. We can diagnose the bacteriogenic vagina deseases quickly and simple by testing sialic acid enzyme to vagina searate with this sialic acid ester reagent which can be used as an independent diagnosis target with good stability, extremely excellent accuracy and simple operation (one step test).

The invention discloses multipath composite neuraminic acid producing bacillus subtilis and an application thereof, and belongs to the field of genetic engineering. The expression levels of key enzymes, namely UDP-N-acetylglucosamine-2-epimerase, N-acetylglucosamine-6-phosphate isomerase, glucosamine-6-phosphoric acid-N-acetyltransferase, N-acetylglucosamine isomerase and N-acetylneuraminate synthase on genomes in three neuraminic acid synthesis paths are sequentially optimized by 10 promoters with different intensities, so that the protein synthesis pressure of enzyme expression on cells is reduced; and three neuraminic acids are further integrated into the same engineering bacillus subtilis, so that the bacillus subtilis with the increased N-acetylneuraminic acid yield is obtained, the neuraminic acid yield under the shake flask level reaches 10.4 g/L, and a foundation is laid for further increasing the NeuAc yield of the bacillus subtilis.

The present invention is directed to a process for producing CMP-N-acetylneuraminic acid (CMP-NeuAc), characterized in that the process includes adding yeast cells, N-acetylglucosamine-6-phosphate 2-epimerase (GlcNAc-6P 2-epimerase), N-acetylneuraminic acid lyase (NeuAc lyase), and CMP-N-acetylneuraminic acid synthase (CMP-NeuAc synthase) to a reaction system containing N-acetylglucosamine (GlcNAc), pyruvate, and cytidine 5′-monophosphate (CMP), and inducing reaction of the mixture. The present invention is also directed to a process for producing CMP-N-acetylneuraminic acid (CMP-NeuAc), characterized in that the process includes adding yeast cells, N-acetylglucosamine-6-phosphate 2-epimerase (GlcNAc-6P 2-epimerase), N-acetylneuraminic acid synthase (NeuAc synthase), and CMP-N-acetylneuraminic acid synthase (CMP-NeuAc synthase) to a reaction system containing N-acetylglucosamine (GlcNAc) and cytidine 5′-monophosphate (CMP), and inducing reaction of the mixture.

The invention provides a sialic acid detection kit. The kit contains a reagent R1 and a reagent R2; the reagent R1 contains the following components: a tris(hydroxymethyl)methyl aminomethane-hydrochloric acid (Tris-HCL) buffer solution, lactic dehydrogenase (LDH), N-acetylneuraminic acid aldolase, a reduced coenzyme I (NADH), a surfactant, a stabilizer, EDTA-Na2 and a preservative; and the reagentR2 contains the following components: a tris(hydroxymethyl)methyl aminomethane-hydrochloric acid (Tris-HCL) buffer solution, neuraminidase, a surfactant, a stabilizer and a preservative. A productionmethod and application of the kit are provided at the same time. The kit is a liquid kit with high stability, high anti-interference capability, high accuracy and good repeatability.

The invention belongs to the technical field of genetic engineering and particularly relates to construction and application of a genetic engineering strain for xylose-induced production of N-acetylneuraminic acid. According to the construction and the application, a N-acetylglucosamine synthesis way is integrated with a genome, a N-acetylglucosamine 2-epimerase gene bAGE and a N-acetylneuraminicacid lyase gene shNAL are introduced, a N-acetylneuraminic acid synthesis way is constructed, and a key gene nanTEK of a catabolism way of the N-acetylneuraminic acid synthesis way is knocked out. Meanwhile, metabolic ways of precursor substances required for synthesizing the N-acetylneuraminic acid are subjected to multicopy strengthening, and part of bypath metabolic ways are subjected to knockout, so that the N-acetylneuraminic acid high yielding strain is obtained. In case of shake-flask fermentation for 36h, the yield of the N-acetylneuraminic acid can reach 10.8g/L to the maximum, the production intensity can reach 0.3g/(L*h) which is the maximum value reported at present, and thus, the engineering strain has an important industrial application value.

The invention relates to dry chemical test paper for neuraminidase and a preparation method thereof, and belongs to the technical field of in-vitro diagnosis test paper. The dry chemical test paper solves the technical problem that in the prior art, a polyamine detection kit for detecting bacterial vaginosis is poor in specificity. The dry chemical test paper is filter paper with a substrate, a color developing agent, metal ions, a buffer and a surfactant dispersed, wherein the substrate is one or more of acetylneuraminic acid salt, an acetyl neuraminic acid salt derivative and 5-bromo-4-chloro-3-indolyl-alpha-D-N-acetylneuraminic acid salt, and the color developing agent is a diazonium salt. The test paper has the advantages of being high in accuracy, good in stability, simple to operateand suitable for popularization; and clinical data analysis results show that compared with an Amsel method, the chemical test paper has the advantages that the sensitivity is 89.5-90.0%, the specificity is 95.8-96%, the positive predictive value is 83.3-90.0%, the negative predictive value is 98.2-98.8%, the coincidence rate is 96.5-97%, the BV screening diagnosis requirement is basically met, and the diagnosis BV index is more objective.

The invention discloses a fermentation method for producing N-acetylneuraminic acid and relates to the technical field of N-acetylneuraminic acid production. The fermentation method for producing N-acetylneuraminic acid comprises the steps of adding supplementary feed liquid to a fermentation culture medium inoculated with N-acetyl-neuraminic acid bacteria during fermentation, wherein the feed liquid contains glycerin and an additive, the additive is selected from one or more of N-acetylglucosamine and polyphosphoric acid substances. The fermentation method improves the synthesis rate of N-acetylneuraminic acid and meanwhile improves the yield of the N-acetylneuraminic acid by optimizing the composition or use amount of the feed liquid.