An integrated membrane system for the biocatalytic production of 3'-sialyllactose from dairy by-products.

An integrated membrane system was investigated for the production of 3'-sialyllactose by an engineered sialidase using casein glycomacropeptide (CGMP) and lactose as substrates. CGMP was purified by ultrafiltration (UF) to remove any small molecules present and then an enzymatic membrane reactor (EMR) was used to separate the product and reuse the enzyme. A PLCC regenerated cellulose membrane was found to be the most suitable for both the UF purification and EMR. Subsequently, nanofiltration (NF) was conducted to increase the purity of the 3'-sialyllactose by removing the excess lactose present. The NTR7450 membrane outperformed others in NF due to its high retention of 3'-sialyllactose (98%) and relatively low rejection of lactose (40%). The lactose in the permeate could be concentrated by the NF45 membrane and recycled into the EMR. The described integrated membrane system enables a more economic and efficient enzymatic production of 3'-sialyllactose.

[Research progress of anti-influenza virus agents].

Influenza is a major threat to millions of people worldwide. Vaccines and antiviral agents are two main options available to reduce the impact of the influenza virus, while anti-influenza agents are the most effective means to prevent the transmission of the highly contagious virus and to treat the epidemics of disease. At present, four anti-influenza agents have been approved by the FDA for the treatment of influenza, including two M2 protein ion channel inhibitors-amantadine and rimantadine and two neuraminidase inhibitors-zanamivir and oseltamivir. Arbidol hydrochloride, launched in Russia, is a potent inhibitor of influenza virus, too. Neuraminidase inhibitors could be classified generally by structure into six different kinds: sialic acid derivatives, benzoic acid derivatives, cyclohexene derivatives, cyclopentane derivatives, pyrrolidine derivatives and natural products. In this paper, recent progress in the research of the action mechanisms and structure-activity relationships of these anti-influenza virus agents were reviewed.