Synthesis Of Oligosaccharides Research Articles

Effects of Latilactobacillus sakei LZ217 on Gastric Mucosal Colonization, Metabolic Interference, and Urease Expression in Helicobacter pylori Infection.

Emerging evidence suggests differential antagonism of lactic acid-producing bacteria (LAB) to Helicobacter pylori, posing challenges to human health and food safety due to unclear mechanisms. This study assessed 21 LAB strains from various sources on H. pylori growth, urease activity, and coaggregation. Composite scoring revealed that Latilactobacillus sakei LZ217, derived from fresh milk, demonstrates strong inhibitory effects on both H. pylori growth and urease activity. L. sakei LZ217 significantly reduced H. pylori adherence of gastric cells invitro, with inhibition ratios of 47.62%. Furthermore, invivo results showed that L. sakei LZ217 alleviated H. pylori-induced gastric mucosa damage and inflammation in mice. Metabolomic exploration revealed metabolic perturbations in H. pylori induced by L. sakei LZ217, including reduced amino acid levels (e.g., isoleucine, leucine, glutamate, aspartate, and phenylalanine) and impaired carbohydrate and nucleotide synthesis, contributing to the suppression of ureA (28.30%), ureE (84.88%), and ureF (59.59%) expressions in H. pylori. This study underscores the efficacy of LAB against H. pylori and highlights metabolic pathways as promising targets for future interventions against H. pylori growth and colonization.

Integrated multi-omic analysis reveals the carbon metabolism-mediated regulation of polysaccharide biosynthesis by suitable light intensity in Bletilla striata leaves

Bletilla striata, valued for its medicinal and ornamental properties, remains largely unexplored in terms of how light intensity affects its physiology, biochemistry, and polysaccharide formation. In this 5-month study, B. striata plants were exposed to three different light intensities: low light (LL) (5–20 μmol m−2·s−1), middle light (ML) (200 μmol m−2·s−1), and high light (HL) (400 μmol m−2·s−1). The comprehensive assessment included growth, photosynthetic apparatus, chlorophyll fluorescence electron transport, and analysis of differential metabolites based on the transcriptome and metabolome data. The results indicated that ML resulted in the highest plant height and total polysaccharide content, enhanced photosynthetic apparatus performance and light energy utilization, and stimulated carbon metabolism and carbohydrate accumulation. HL reduced Chl content and photosynthetic apparatus functionality, disrupted OEC activity and electron transfer, stimulated carbon metabolism and starch and glucose accumulation, and hindered energy metabolism related to carbohydrate degradation and oxidation. In contrast, LL facilitated leaf growth and increased chlorophyll content but decreased plant height and total polysaccharide content, compromised the photosynthetic apparatus, hampered light energy utilization, stimulated energy metabolism related to carbohydrate degradation and oxidation, and inhibited carbon metabolism and carbohydrate synthesis. Numerous genes in carbon metabolism were strongly related to polysaccharide metabolites. The katE and cysK genes in carbon metabolism were strongly related not only to polysaccharide metabolites, but also to genes involved in polysaccharide biosynthesis. Our results highlight that light intensity plays a crucial role in affecting polysaccharide biosynthesis in B. striata, with carbon metabolism acting as a mediator under suitable light intensity conditions.

New synthesis of oligosaccharides modelling the M epitope of the Brucella O-polysaccharide.

Brucellosis is a dangerous zoonotic disease caused by bacteria of the genus Brucella. Diagnosis of brucellosis is based on the detection in animal and human sera of antibodies to the O-polysaccharide of Brucella lipopolysaccharide. The currently employed serodiagnosis of brucellosis relies on the use of the Brucella O-polysaccharide as a diagnostic antigen. However, the existence of bacterial species, which also express O-polysaccharides structurally similar to that of Brucella, may decrease the specificity of the brucellosis detection due to false-positive test results. It has been shown that the efficiency of the test can be significantly improved by using synthetic oligosaccharides that correspond to the so-called M epitope of the Brucella O-antigen. This epitope is characterized by an α-(1→3)-linkage between d-perosamine units and is unique to Brucella. Here we report on an efficient approach to the synthesis of oligosaccharides that model the M epitope of the Brucella O-polysaccharide. The approach is based on the use of the α-(1→3)-linked disaccharide thioglycoside as the key donor block. Its application allowed the straightforward assembly of a set of four protected oligosaccharides, which includes a disaccharide, two trisaccharides, and a tetrasaccharide, in five glycosylation steps. The synthesized oligosaccharides are planned to be used in the development of diagnostic tools for identifying brucellosis in humans and domestic animals, as well as a potential vaccine against it.

HPLC-Based Automated Synthesis and Purification of Carbohydrates.

Reported herein is a new HPLC-based automated synthesizer (HPLC-A) capable of a temperature-controlled synthesis and purification of carbohydrates. The developed platform allows to perform various protecting group manipulations as well as the synthesis of O- and N-glycosides. A fully automated synthesis and purification was showcased in application to different carbohydrate derivatives including glycosides, oligosaccharides, glycopeptides, glycolipids, and nucleosides.

Kinetics and products of Thermotoga maritima β-glucosidase with lactose and cellobiose

Galacto-oligosaccharides (GOS) are prebiotic compounds that are mainly used in infant formula to mimic bifidogenic effects of mother’s milk. They are synthesized by β-galactosidase enzymes in a trans-glycosylation reaction with lactose. Many β-galactosidase enzymes from different sources have been studied, resulting in varying GOS product compositions and yields. The in vivo role of these enzymes is in lactose hydrolysis. Therefore, the best GOS yields were achieved at high lactose concentrations up to 60%wt, which require a relatively high temperature to dissolve. Some thermostable β-glucosidase enzymes from thermophilic bacteria are also capable of using lactose or para nitrophenyl-galactose as a substrate. Here, we describe the use of the β-glucosidase BglA from Thermotoga maritima for synthesis of oligosaccharides derived from lactose and cellobiose and their detailed structural characterization. Also, the BglA enzyme kinetics and yields were determined, showing highest productivity at higher lactose and cellobiose concentrations. The BglA trans-glycosylation/hydrolysis ratio was higher with 57%wt lactose than with a nearly saturated cellobiose (20%wt) solution. The yield of GOS was very high, reaching 72.1%wt GOS from lactose. Structural elucidation of the products showed mainly β(1 → 3) and β(1 → 6) elongating activity, but also some β(1 → 4) elongation was observed. The β-glucosidase BglA from T. maritima was shown to be a very versatile enzyme, producing high yields of oligosaccharides, particularly GOS from lactose.Key points• β-Glucosidase of Thermotoga maritima synthesizes GOS from lactose at very high yield.• Thermotoga maritima β-glucosidase has high activity and high thermostability.• Thermotoga maritima β-glucosidase GOS contains mainly (β1-3) and (β1-6) linkages.Graphical

Effects of Aspergillus flavus infection on multi-scale structures and physicochemical properties of maize starch during storage

This study systematically analyzed the effect of Aspergillus flavus infection on the maize starch multi-scale structure, physicochemical properties, processing characteristics, and synthesis regulation. A. flavus infection led to a decrease in the content of starch, an increase in the content of reactive oxygen species (ROS) and malondialdehyde (MDA), a significant decrease in the activities of peroxidase (POD) and superoxide dismutase (SOD). In addition, A. flavus infection had a significant destructive effect on the double helix structure, relative crystallinity and lamellar structure of starch, resulting in the reduction of starch viscosity, affecting the viscoelastic properties of starch, and complicating the gel formation process. However, the eugenol treatment group significantly inhibited the growth of A. flavus during maize storage, protecting the multi-scale structure and processing characteristics of maize starch from being damaged. Transcriptome analysis showed that genes involved in carbohydrate synthesis in maize were significantly downregulated and genes involved in energy synthesis were significantly upregulated, indicating that maize converted its energy storage into energy synthesis to fight the invasion of A. flavus. These results of this study enriched the mechanism of quality deterioration during maize storage, and provide theoretical and technical support for the prevention of A. flavus infection during maize storage.

Physiological and genetic responses of the benthic dinoflagellate Prorocentrum lima to polystyrene microplastics

Microplastics are well known as contaminants in marine environments. With the development of biofilms, most microplastics will eventually sink and deposit in benthic environment. However, little research has been done on benthic toxic dinoflagellates, and the effects of microplastics on benthic dinoflagellates are unknown. Prorocentrum lima is a cosmopolitan toxic benthic dinoflagellate, which can produce a range of polyether metabolites, such as diarrhetic shellfish poisoning (DSP) toxins. In order to explore the impact of microplastics on marine benthic dinoflagellates, in this paper, we studied the effects of polystyrene (PS) on the growth and toxin production of P. lima. The molecular response of P. lima to microplastic stress was analyzed by transcriptomics. We selected 100 nm, 10 μm and 100 μm PS, and set three concentrations of 1 mg L−1, 10 mg L−1 and 100 mg L−1. The results showed that PS exposure had limited effects on cell growth, but increased the OA and extracellular polysaccharide content at high concentrations. After exposure to PS MPs, genes associated with DSP toxins synthesis, carbohydrate synthesis and energy metabolism, such as glycolysis, TCA cycle and pyruvate metabolism, were significantly up-regulated. We speculated that after exposure to microplastics, P. lima may increase the synthesis of DSP toxins and extracellular polysaccharides, improve the level of energy metabolism and gene expression of ABC transporter, thereby protecting algal cells from damage. Our findings provide new insights into the effects of microplastics on toxic benthic dinoflagellates.

Cultivation of a Novel Strain of Chlorella vulgaris S2 under Phototrophic, Mixotrophic, and Heterotrophic Conditions, and Effects on Biomass Growth and Composition

Microalgal biomass is an excellent platform for producing food, feed, nutraceuticals, pharmaceuticals, and biofuels. This study aimed to investigate the effect of the trophic mode of cultivation (phototrophic, heterotrophic, and mixotrophic) on the growth and biomass composition of Chlorella vulgaris S2. The contents of lipids and carbohydrates, as well as the fatty acid composition of total lipids, were studied. The effects of the carbon-to-nitrogen ratio (C:N) and the organic carbon concentration of the growth media under mixotrophic and heterotrophic conditions were also investigated. The C:N ratio of 30 mol mol−1 favoured lipid synthesis, and the C:N ratio of 10 mol mol−1 favoured carbohydrate synthesis. Maximal lipid and biomass productivities (2.238 and 0.458 g L−1 d−1, respectively) were obtained under mixotrophic conditions at the C:N ratio of 50 mol mol−1 and glucose concentration of 50 g L−1. Fed-batch cultivation conducted in a stirrer tank bioreactor under heterotrophic growth conditions increased biomass (2.385 g L−1 d−1, respectively) and lipid (0.339 L−1 d−1) productivities ~50 and ~60 times compared to the fed-batch phototrophic cultivation, respectively. The trophic mode, growth phase, and growth medium composition significantly influenced the fatty acid composition. Under mixotrophic and heterotrophic growth conditions, lipid accumulation is associated with an increase in oleic acid (C18:1) content. Mixotrophically grown biomass of Chlorella vulgaris S2 under optimised conditions is a suitable source of lipids for biodiesel production.

Management of Secondary Metabolite Synthesis and Biomass in Basil (Ocimum basilicum L.) Microgreens Using Different Continuous-Spectrum LED Lights.

Different LED light spectra (LS) are absorbed by different plant photoreceptors and can control biomass and plant secondary metabolite synthesis. In this study, the effects of continuous-spectrum LED lights (red, blue, white, red + blue, and 12 h blue + 12 h red) on the production value, antioxidant compounds, and biomass of basil (Ocimum basilicum L.) microgreens (Red Rubin, Violeto, and Kapoor cultivars and the Ablagh genotype) were investigated. The results showed significant effects of LS on cultivar (Cv) and the interaction of LS and Cv on the studied traits. The highest quantitys of chlorophyll a, total chlorophyll, and nitrate were obtained in Violeto under blue lighting. Red lighting enhanced starch synthesis in Red Rubin and flavonoids in the Violeto Cv. The highest biomass (4.54 kg m-2) was observed in the Ablagh genotype and the highest carbohydrate synthesis in Violeto Cv in the red + blue treatment. The highest anthocyanin content (26.33 mg 100 g-1 FW) was observed for Red Rubin Cv under 12 h blue + 12 h red light. The greatest antioxidant capacity (83.57% inhibition), the highest levels of phenolic compounds (2027.25 mg GA 100 g-1 FW), vitamin C (405.76 mg 100 g-1 FW), proline, antioxidant potential composite index (APCI), and the greatest production values were obtained for the Ablagh genotype under blue lighting. Taken together, the experiment findings indicate that growing the Ablagh genotype under continuous blue lighting can increase the antioxidant capacity, phenolic compounds, and vitamin C and that this LED light spectrum can be used as a practical method to produce basil microgreens with high nutritional health value.

Integrated multiple-omics reveals the regulatory mechanism underlying the effects of homologous Bacillus tequilensis (GCB-3) on growth performance of grass carp (Ctenopharyngodon idellus)

The purpose of this study was to investigate the regulatory mechanism of Bacillus tequilensis (GCB-3) in improving the growth performance of grass carp by microbiome and targeted metabolomics analysis. Fish were fed with different amounts of GCB-3 including B0 (0 CFU/g), B6 (1×106 CFU/g), B7 (1×107 CFU/g), B8 (1×108 CFU/g), and B9 (1×109 CFU/g) for 8 weeks. The results indicate that with the increase of dietary GCB-3 concentration, grass carp showed a significant linear trend in growth performance, and appetite factors showed a significant linear and quadratic trend, the growth performance and appetite-promoting factors in the B8 group reach their maximum value in the B8 group. Microbiome analysis found that Proteobacteria and Actinobacteria were the most abundant phylum in the gut microbiota of grass carp. The functional potential predicted that GCB-3 affected the synthesis and degradation of carbohydrates, amino acids, fatty acids and lipids. It found that GCB-3 also affected the tricarboxylic acid (TCA) cycle VII (acetate-producers) pathway. The results of targeted metabolomics showed a significant linear and quadratic increase in intestinal acetate with GCB-3 concentration and a maximum in the B8 group. The results of the correlation analysis showed a significant positive correlation between Actinobacteria abundance and acetic acid content, and also between TCA cycle VII (acetate-producers) pathway abundance and Actinobacteria abundance and acetic acid content. In B8 group, grass carp showed a faster regulation speed of blood glucose levels after glucose injection, and the GLP-1 content remained stable. The activities of glycolytic enzymes, lipolytic enzymes, protein metabolism enzymes, and their related mRNA expression levels in grass carp showed a linear or quadratic increasing trend. However, the expression levels of gluconeogenic enzymes and fatty acid synthesis enzyme related mRNA showed an opposite trend. In summary, the addition of 1×108 CFU/g GCB-3 in grass carp feed can improve the abundance of dominant bacterial phyla in the intestine, especially Actinobacteria, increase the concentration of intestinal acetate, provide substrate for the TCA cycle VII (acetate-producers) pathway, thereby regulating the nutrient metabolism of grass carp and ultimately promoting growth.

Glycan synthesis: An update

Carbohydrate synthesis presents several challenges due to the intricate nature of molecules and their complex structures. Since certain pathogens are difficult to culture in the laboratory under some circumstances, and the isolation of glycans in pure structural forms is an arduous undertaking, the medicinal chemistry approach offers a fascinating and attractive option. The efforts being made to develop an automated system for oligosaccharide synthesis are expected to produce immense effects and revolutionize the understanding of the role of carbohydrates in biological systems. Glycovaccines aid in saving millions of lives around the world annually by protecting children and adults from bacterial infections. These vaccines further expand the therapeutic armamentarium against several microbial infectious diseases. This review highlights the different clinical applications of glycan and the progress made in their synthetic process.

Possible Roles of Carbohydrate Management and Cytokinin in the Process of Defoliation-Regrowth Cycles in Rice.

Defoliation is an inevitable abiotic stress for forage and turf grasses because harvesting, grazing, and mowing are general processes for their production and management. Vegetative regrowth occurs upon defoliation, a crucial trait determining the productivity and persistence of these grasses. However, the information about the molecular regulation of this trait is limited because it is still challenging to perform molecular analyses in forage and turf grasses. Here, we used rice as a model to investigate vegetative regrowth upon defoliation at physiological and molecular levels. This study analyzed stubble and regrown leaves following periodic defoliation using two rice varieties with contrasting regrowth vigor. Vigorous regrowth was associated with maintained chlorophyll content and photosystem II performance; a restricted and promoted mRNA accumulation of sucrose synthase (SUS) I and III subfamilies, respectively; and reduced enzymatic activity of SUS. These results suggest that critical factors affecting vegetative regrowth upon defoliation are de novo carbohydrate synthesis by newly emerged leaves and proper carbohydrate management in leaves and stubble. Physiological and genetic analyses have demonstrated that the reduced sensitivity to and inhibited biosynthesis of cytokinin enhance regrowth vigor. Proper regulation of these metabolic and hormonal pathways identified in this study can lead to the development of new grass varieties with enhanced regrowth vigor following defoliation.

Improve Cannabis sativa micropropagation through increasing air change rate in photoautotrophic and traditional tissue culture

Micropropagation is essential for pathogen-free plant materials. However, the conventional in-vitro micropropagation approach poses challenges for optimal growth and development. This study enhances Cannabis sativa micropropagation by implementing a photoautotrophic tissue culture with increased air change rates. This method relies exclusively on photosynthesis for carbohydrate synthesis, eliminating the need for exogenous sugar supplementation. To overcome the limitations of conventional in vitro culture, the photoautotrophic culture requires higher air exchange in the vessel to supply CO2 for photosynthesis. The research evaluates the effects of varying air change rates, comparing conventional tissue culture (TC) with photoautotrophic micropropagation (PAM). Nodal explants, each with 3–4 fully expanded leaves, were transferred to PAM or TC media in Magenta boxes, undergoing four distinct air change rate treatments: 0.5 (control), 4.1, 7.9, and 14.5 air change per hour. Magenta boxes were placed under controlled chamber conditions, including a photosynthetic photon flux density of 100 µmol·m−2·s−1, 18-hour photoperiod, 25 °C temperature, 70 % relative humidity, and CO2 concentration of 553 µmol·mol−1; data were collected after a 28-day period. Increasing the air change rate in TC (from 0.5 to 7.9 h−1) and PAM (from 0.5 to 14.5 h−1) resulted in a significant 25.1 % and 146.6 % increase in shoot dry mass, respectively. The number of axillary buds per plant exhibited a linear increase response to increasing air change rates only under PAM; as well as a significant difference between PAM (11.5) and TC (8.3) under an air change rate of 7.9 h−1. Particularly advantageous for PAM was simultaneous root growth, escalating from 5.2 to 44.3 mg as the air change rate rose from 0.5 to 14.5 h−1. Implementing the photoautotrophic culture practice not only accelerated Cannabis micropropagation but also maintained outcomes comparable to traditional sugar-based tissue culture, contributing to cost-effective cultivation practices in the Cannabis and tissue culture industries.

Parametric Analysis of Donor Activation for Glycosylation Reactions.

The chemical synthesis of complex oligosaccharides relies on efficient and highly reproducible glycosylation reactions. The outcome of a glycosylation is contingent upon several environmental factors, such as temperature, acidity, the presence of residual moisture, as well as the steric, electronic, and conformational aspects of the reactants. Each glycosylation proceeds rapidly and with a high yield within a rather narrow temperature range. For better control over glycosylations and to ensure fast and reliable reactions, a systematic analysis of 18 glycosyl donors revealed the effect of reagent concentration, water content, protecting groups, and structure of the glycosyl donors on the activation temperature. With these insights, we parametrize the first step of the glycosylation reaction to be executed reliably and efficiently.

Asymmetric Pd/Organoboron-Catalyzed Site-Selective Carbohydrate Functionalization with Alkoxyallenes Involving Noncovalent Stereocontrol.

Herein, we demonstrate the robustness of a synergistic chiral Pd/organoboron system in tackling a challenging suite of site-, regio-, enantio- and diastereoselectivity issues across a considerable palette of biologically relevant carbohydrate polyols, when prochiral alkoxyallenes were employed as electrophiles. In view of the burgeoning role of noncovalent interactions (NCIs) in stereoselective carbohydrate synthesis, our mechanistic experiments and DFT modeling of the reaction path unexpectedly revealed that NCIs such as hydrogen bonding and CH-π interactions between the resting states of the Pd-π-allyl complex and the borinate saccharide are critically involved in the stereoselectivity control. Our strategy thus illuminates the untapped potential of harnessing NCIs in the context of transition metal catalysis to tackle stereoselectivity challenges in carbohydrate functionalization.

Asymmetric Pd/Organoboron‐Catalyzed Site‐Selective Carbohydrate Functionalization with Alkoxyallenes Involving Noncovalent Stereocontrol

AbstractHerein, we demonstrate the robustness of a synergistic chiral Pd/organoboron system in tackling a challenging suite of site‐, regio‐, enantio‐ and diastereoselectivity issues across a considerable palette of biologically relevant carbohydrate polyols, when prochiral alkoxyallenes were employed as electrophiles. In view of the burgeoning role of noncovalent interactions (NCIs) in stereoselective carbohydrate synthesis, our mechanistic experiments and DFT modeling of the reaction path unexpectedly revealed that NCIs such as hydrogen bonding and CH‐π interactions between the resting states of the Pd‐π‐allyl complex and the borinate saccharide are critically involved in the stereoselectivity control. Our strategy thus illuminates the untapped potential of harnessing NCIs in the context of transition metal catalysis to tackle stereoselectivity challenges in carbohydrate functionalization.

Enzymatic synthesis of Artemisia capillaris-derived prebiotic oligosaccharide using Leuconostoc mesenteroides MKSR dextransucrase and its potential health functional effects

This study focuses on the enzymatic synthesis of prebiotic oligosaccharide from Artemisia capillaris (AC) using Leuconostoc mesenteroides MKSR dextransucrase and explores their antidiabetic, antidementia, and antioxidant effects through in vitro experiments. A Box-Behnken design was used to optimize transglycosylation conditions to produce Artemisia capillaris-derived oligosaccharide (ACOD) containing isomaltooligosaccahrides (IMO), dextran, and A. capillaris-derived substances with high α-glucosidase inhibition (AGI). The optimized conditions were 3.62 brix of AC, 182.54 mM sucrose, and 11.304 mM maltose. ACOD completely inhibited α-glucosidase activity, with 1.52-fold increase compared to other samples, such as OD (IMO and dextran, transglycosylated by dextransucrase without AC) and AC + OD (a simple mixture of AC and OD). Additionally, ACOD showed noteworthy acetylcholinesterase (103.91%) and butyrylcholinesterase (103.30%) inhibitory activity and potent antioxidant properties in terms of DPPH radical scavenging activity (70.04%), reducing power (100%), and ferric reducing antioxidant power (FRAP). ACOD (3.60) showed a higher prebiotic index compared with AC (-23.11), OD (-2.27), and AC + OD (-9.12). In conclusion, ACOD offers enhanced multi-biological activities as a potential health-functional prebiotic. These findings hold promise for applications in functional foods and pharmaceuticals, expanding our understanding of prebiotic functionality.

Production of recombinant glycosidases fused with Usp45 and SpaX to avoid the purification and immobilization stages

The elucidation of the physicochemical properties of glycosidases is essential for their subsequent technological application, which may include saccharide hydrolysis processes and oligosaccharide synthesis. As the application of cloning, purification and enzymatic immobilization methods can be time consuming and require a heavy financial investment, this study has validated the recombinant production of the set of Lacticaseibacillus rhamnosus fucosidases fused with Usp45 and SpaX anchored to the cell wall of Lacticaseibacillus cremoris subsp cremoris MG1363, with the aim of avoiding the purification and stabilization steps. The cell debris harboring the anchored AlfA, AlfB and AlfC fucosidases showed activity against p-nitrophenyl α-L-fucopyranoside of 6.11 ± 0.36, 5.81 ± 0.29 and 9.90 ± 0.58 U/mL, respectively, and exhibited better thermal stability at 50 °C than the same enzymes in their soluble state. Furthermore, the anchored AlfC fucosidase transfucosylated different acceptor sugars, achieving fucose equivalent concentrations of 0.94 ± 0.09 mg/mL, 4.11 ± 0.21 mg/mL, and 4.08 ± 0.15 mg/mL of fucosylgalatose, fucosylglucose and fucosylsucrose, respectively.

Revolutionizing Renewable Resources: Cutting-Edge Trends and Future Prospects in the Valorization of Oligosaccharides

Lignocellulosic wastes, primarily from agricultural by-products, are a renewable resource increasingly used in the sustainable production of oligosaccharides, significantly contributing to the growing bioeconomy. This innovative utilization of biological resources aligns with the global shift towards sustainable development, focusing on creating products such as food, feed, and bioenergy from renewable sources. Oligosaccharides, specialized carbohydrates, are synthesized either chemically or more eco-friendly, biologically. Biological synthesis often involves enzymes or whole-cell systems to transform lignocellulosic wastes into these valuable sugars. As functional food supplements, oligosaccharides play a crucial role in human and animal health. They serve as prebiotics, indigestible components that promote the proliferation of beneficial gut microbiota, especially within the colon. This positive impact on gut flora is essential for boosting the immune system and regulating physiological functions. Important prebiotics, including galactooligosaccharides (GOS), xylooligosaccharides (XOS), fructooligosaccharides (FOS), mannan-oligosaccharides (MOS), and isomaltooligosaccharides (IMOS), are produced through methods involving enzymes or the use of whole cells, with agricultural waste as substrates. Recent advancements focus on refining these biological processes for oligosaccharide synthesis using lignocellulosic substrates, emphasizing the principles of a circular bioeconomy, which promotes resource reuse and recycling. This review highlights the potential and challenges in the biological synthesis of oligosaccharides from renewable resources. It underscores the need for innovation in process optimization and commercialization strategies to fully exploit lignocellulosic wastes. This approach not only contributes to sustainable product development, but also opens new avenues for the profitable and environmentally friendly utilization of agricultural residues, marking a significant step forward in the bio-based industry.

Organocatalyzed Stereoselective Glycosylation: An Overview of the Last Decade

Abstract: Even though there has been an important evolution in the synthesis of oligosaccharides, the efficient and stereoselective study of glycosidic bonds through non-toxic, moderate, and inexpensive techniques is one of the most challenging fields in organic synthesis. Glycosyl reactions play a fundamental role in biological material and structure-activity relationships, having numerous medicinal chemistry applications. For this, interesting strategies have evolved over the years to control the stereoselectivity of glycosidic bonds, including the manipulation of different reaction elements, mainly promoters or catalysts, but also involving the nature of donors and solvents. This review looks at glycosylation methodologies in the last decade resulting in the specific formation of alpha or beta glycosidic bonds.