Isomalto-oligosaccharides (IMO) have good physiochemical properties and excellent physiological functions to make it widely used in food, medicine, feed, cosmetics and other industries. However, the procedures for industrial production of IMO are complicated. Therefore, it is necessary to develop an economical and easy-to-operate method. The genes encoding for β-amylase and α-transglucosidase were fused and co-displayed on the yeast cell surface of Yarrowia lipolytica which can convert liquefied starch to IMO in one step. The highest IMO purity of 75.3% was obtained using the displayed fusion-enzyme at 50 °C. This method showed potential application in IMO production.
Oligosaccharides ; Starch ; Yarrowia ; beta-Amylase

Most bacterial cell surface glycans are structurally unique, and have been considered as ideal target molecules for the developments of detection and diagnosis techniques, as well as vaccines. Chemical synthesis has been a promising approach to prepare well-defined oligosaccharides, facilitating the structure-activity relationship exploration and biomedical applications of bacterial glycans. L-Galactosaminuronic acid is a rare sugar that has been only found in cell surface glycans of gram-negative bacteria. Here, an orthogonally protected L-galactosaminuronic acid building block was designed and chemically synthesized. A synthetic strategy based on glycal addition and TEMPO/BAIB-mediated C6 oxidation served well for the transformation of commercial L-galactose to the corresponding L-galactosaminuronic acid. Notably, the C6 oxidation of the allyl glycoside was more efficient than that of the selenoglycoside. In addition, a balance between the formation of allyl glycoside and the recovery of selenoglycoside was essential to improve efficiency of the NIS/TfOH-catalyzed allylation. This synthetically useful L-galactosaminuronic acid building block will provide a basis for the syntheses of complex bacterial glycans.
Carbohydrates ; Glycosides ; Oligosaccharides ; Oxidation-Reduction ; Polysaccharides/chemistry*

Glycosidases are widely used in food and pharmaceutical industries due to its ability to hydrolyze the glycosidic bonds of various sugar-containing compounds including glycosides, oligosaccharides and polysaccharides to generate derivatives with important physiological and pharmacological activity. While glycosidases often need to be used under high temperature to improve reaction efficiency and reduce contamination, most glycosidases are mesophilic enzymes with low activity under industrial production conditions. It is therefore critical to improve the thermo-stability of glycosidases. This review summarizes the recent advances achieved in engineering the thermo-stability of glycosidases using strategies such as directed evolution, rational design and semi-rational design. We also compared the pros and cons of various techniques and discussed the future prospects in this area.
Glycoside Hydrolases/genetics* ; Oligosaccharides ; Polysaccharides ; Protein Engineering

Human milk oligosaccharides (HMO) are important immunoactive components found in breast milk. Scientific research proves that HMOs are significantly beneficial for infant health. 2'-fucosyllactose (2'-FL) is the major component of HMO, which obtained growing attentions from food industry. Besides, 3-fucosyllactose (3-FL) is another important fucosyllactose and it has a similar synthetic route comparing to 2'-FL. Thus, research of the two HMO components has interactive effects for each other. Recently, numerous publications are available for 2'-FL and 3-FL. The microbial cell factory is able to massively produce fucosyllactose via an efficient way, which will show considerable influences in dairy industry. In this paper, we review recent studies on 2'-FL and 3-FL, and discuss their prospects according to published literature and patents.
Female ; Humans ; Infant ; Milk, Human ; Oligosaccharides ; Trisaccharides

OBJECTIVETo study the effect of seedling quality on growth, yield and quality of Rehmannia glutinosa at harvest and build a basis for its GAP.

METHODThe seedling quality of R. glutinosa in main producing regions was surveyed to understand the current status of seedling quality. Field experiments with different varieties and seedling quality were conducted to measure dry matter accumulation with different growth of R. glutinosa and oligosaccharide content, and economic yield at harvest.

RESULTThe seedling was randomly selected by farmers in R. glutinosa producing regions. Seedling quality could significantly improve on seedling emergence rate, and promote seedling growth, especially with early stage R. glutinosa, finally increase yield at harvest. At harvest, 63% and 50% of yield with A and B seedling could be improved for variety of 85-5, and 50% and 47% of yield could be increased for variety of Beijing No. 1, compared to the C seeding.

CONCLUSIONIn cultivation, the seedlings with the diameter > 1.5 cm should be transplanted firstly.

Alginate is a group of polyuronic saccharides that are widely used in pharmaceutical and food industry due to its unique physicochemical properties and beneficial health effects. However, the low water solubility and high viscosity of alginate hampered its application. Alginate oligosaccharide (AOS) is a decomposition product of alginate and has received increasing attention due to its low molecular weight, high water solubility, safety, and non-toxicity. The wide-ranging biological functions of AOS are closely related to its structural diversity. AOS with distinct structures and biological functions can be obtained by different methods of preparation. This review summarized the biological functions of AOS reported to date, including anti-tumor, immunomodulatory, anti-inflammatory, antioxidant, prebiotic, and anti-diabetes. The preparation of AOS, as well as the relationship between the structure and biological functions of AOS were discussed, with the aim to provide a reference for further development and application of AOS.
Alginates ; Anti-Inflammatory Agents ; Antioxidants ; Molecular Weight ; Oligosaccharides

Polygalae Radix has long been used in China for calming the mind, promoting intelligence, communicating the heart and kidney, eliminating phlegm, and reducing swelling. At present, it is used to treat amnesia, insomnia, and malaise. Modern research has revealed that Polygalae Radix mainly contains triterpenoid saponins, xanthone, oligosaccharide esters, etc., with the activities of improving memory, resisting dementia, protecting the brain, relieving cough, and removing phlegm, as well as sedation and hypnosis. The present study reviews the research progress on chemical composition, pharmacological action, quality control, and metabolism of Polygalae Radix in the past 30 years, to provide a theoretical basis for further research and development.
Drugs, Chinese Herbal ; Oligosaccharides ; Plant Roots ; Polygala ; Quality Control

Heparinases can produce biologically active oligosaccharides by specifically cleaving the α-(1,4) glycosidic linkages of heparin and heparan sulphate. Heparinases are divided into heparinase and heparanase. Because heparinase is an effective biocatalyst, more and more researchers pay attention to the application of heparinase in medical field in the recent years. Combined with the related research work in our group, the application value of heparinase in the medical field was summarized, such as the determination of the structure of heparin, the preparation of low-molecular-weight heparin and ultra-low-molecular-weight heparin, tumor therapy and as a heparin antagonist. In addition, we summarized the definition, source of heparinase and its application in the medicine field. Heparinases have a great application prospect in the field of medicine.
Heparin ; Heparin Lyase ; metabolism ; Heparitin Sulfate ; Oligosaccharides ; Polysaccharide-Lyases

0.05), nor were the differences between the two experimental groups at 4 and 8 weeks. In comparison with the control group, however, both experimental groups showed superior new bone formation. Although the difference between the two experimental groups was not statistically significant, a tendency for superior new bone formation was detected with the combination of particulate dentin, plaster of Paris, and alginate. Furthermore, more fusion of woven bone and bony trabeculae formation occurred in this group, suggesting that oligosaccharides play a role in the formation and maturation of new bone. In conclusion, the treatment of bone defects by grafting with a mixture of particulate dentin and plaster of Paris alone or with alginate significantly improved the formation of new bone, both quantitatively and qualitatively. The oligosaccharide treatment appeared to improve the formation of new bone quantitatively and qualitatively.]]>
Calcium Sulfate ; Dentin ; Free Radicals ; Humans ; Oligosaccharides ; Osteogenesis ; Transplants

As a type of prebiotics and dietary fiber, inulin performs plenty of significant physiological functions and is applied in food and pharmaceutical fields. Inulosucrase from microorganisms can use sucrose as the substrate to synthesize inulin possessing higher molecular weight than that from plants. In this work, a hypothetical gene coding inulosucrase was selected from the GenBank database. The catalytic domain was remained by N- and C- truncation strategies, constructing the recombinant plasmid. The recombinant plasmid was expressed in E. coli expression system, and after purifying the crude enzyme by Ni²⁺ affinity chromatography, a recombinant enzyme with a molecular weight of approximately 65 kDa was obtained. The optimal pH and temperature of the recombinant enzyme were 5.5 and 45 °C, respectively, when sucrose was used as the sole substrate. The activity of this enzyme was inhibited by various metal ions at different degrees. After purifying the produced polysaccharide, nuclear magnetic resonance analysis was used to determine that the polysaccharide was inulin connected by β-(2,1) linkages. Finally, the conditions for the production of inulin were optimized. The results showed that the inulin production reached the maximum, approximately 287 g/L after 7 h, when sucrose concentration and enzyme dosage were 700 g/L and 4 U/mL, respectively. The conversion rate from sucrose to inulin was approximately 41%.
Escherichia coli/genetics* ; Hexosyltransferases/genetics* ; Inulin ; Oligosaccharides ; Sucrose