Analysis of the chemical composition of natural carbohydrates - An overview of methods

Phenolic profiles of Australian monofloral Eucalyptus, Corymbia, Macadamia and Lophostemon honeys via HPLC-DAD analysis

Australian honey samples from four botanical genera (Lophostemon, Eucalyptus, Macadamia and Corymbia) were investigated for their phenolic content. An improved phenolic extraction and high-performance liquid chromatography-diode array detection (HPLC-DAD) analysis method allowed for the rapid and reliable identification of phenolic compounds. A concentrated liquid-liquid extraction method with an acidified aqueous solution and acetonitrile was optimised to isolate phenolic compounds from the honey matrix. The concentrated extraction method improved sensitivity and permitted the identification of phenolics present at low concentrations (LOD: 0.012-0.25 mg/kg and LOQ: 0.040-2.99 mg/kg). The optimised HPLC-DAD chromatographic conditions gave stable retention times, improved peak separation and allowed for the inexpensive detection of each of the 109 phenolic compounds at their maximum absorbance wavelength. Out of the 109 phenolic compounds included in this study, 49 were identified in the Australian honeys tested. Furthermore, 25 of the 49 compounds were determined to be markers specific to honey floral origin.

Semi-quantitative chemometric models for characterization of mixtures of sugars using infrared spectral data

Sugars (saccharides) are sweet-tasting carbohydrates that are abundant in foods and play very important roles in living organisms, particularly as sources and stores of energy, and as structural elements in cellular membranes. They are desirable therapeutic targets, as they participate in multiple metabolic processes as fundamental elements. However, the physicochemical characterization of sugars is a challenging task, mostly due to the structural similarity shared by the large diversity of compounds of this family. The need for fast, accurate enough, and cost-effective analytical methods for these substances is of extreme relevance, in particular because of the recently increasing importance of carbohydrates in Medicine and food industry. With this in view, this work focused on the development of chemometric models for semi-quantitative analysis of samples of different types of sugars (glucose, galactose, mannitol, sorbose and fructose) using infrared spectra as data, as an example of application of a novel approach, where the Principal Component Analysis (PCA) score plots are used to estimate the composition (weight-%) of the mixtures of the sugars. In these plots, polygonal geometric shapes emerge in the vectorial space of the most significant principal components, that allow grouping different types of samples on the vertices, edges, faces and interior of the polygons according to the composition of the samples. This approach was applied successfully to mixtures of up to 5 sugars and shown to appropriately extract the compositional information from the hyper-redundant complex spectral data. Thought the method has been applied here to a specific problem, it shall be considered as a general procedure for the semi-quantitative analysis of other types of mixtures and applicable to other types of data reflecting their composition. In fact, the methodology appears as an efficient tool to solve three main general problems: (i) use hyper-redundant (in variables) data, as spectral information, directly and with minimum pre-treatment, to evaluate semi-quantitatively the composition of mixtures; (ii) do this for systems which produce data that can be considered rather similar; and (iii) do it for a number of substances present in the mixtures that might be greater than that usually considered in chemistry, which in general is limited to 3 components. In addition, this work also demonstrates that, similarly to the developed analysis based on the PCA score plots, the Multivariate Curve Resolution with Alternating Least Squares (MCR-ALS) chemometric method can also be used successfully for the qualitative (when used without any previous knowledge of the components present in the samples) or semi-quantitative (when the pure components spectral profiles are provided as references) analyses of mixtures of (at least) up to 5 distinct sugars.

Ion Chromatography and Related Techniques in Carbohydrate Analysis: A Review

Ion chromatography and related techniques have been the most popular separation methods used in the determination of organic and inorganic anions and cations, predominantly in water and wastewater samples. Making progress in their development and introducing new stationary phases, methods of detection and preparation of samples for analyses have given rise to the broadening of their analytical range. Nowadays, they are also used for substances that are not ionic by nature but can convert to such forms under certain conditions. These encompass, among others, carbohydrates, whose role and significance in humans' lives and environment is invaluable. Their presence in the air is mostly due to the industrial burning of biomass for energy production purposes. In addition, the content of sugars in plants, fruits and vegetables, constituting the base of human diets, affects our health condition. Given that, there is not only a need for their determination by means of routine methods but also for searching for novel analytical solutions. Based on literature data from the past decade, this paper presents the possibilities and examples of applications regarding ion chromatography and related techniques for the determination of carbohydrates in environmental samples, biomass and plants constituting food or raw materials for food production. Attention has been paid to the virtues and limitations of the discussed separation methods in this respect. Moreover, perspectives on their development have been defined.

Food carbohydrates in the gut: structural diversity, microbial utilization, and analytical strategies

Carbohydrates, which are a vital dietary component, undergo digestion and gut fermentation through microbial enzymes to produce beneficial short-chain fatty acids. Certain carbohydrates selectively modulate the gut microbiota, impacting host health. Carbohydrate-active enzymes within the gut microbiota significantly contribute to carbohydrate utilization and microbial diversity. Despite their importance, the structural complexity of carbohydrates poses analytical challenges. However, recent advancements, notably, mass spectrometry, have allowed for their characterization and functional analysis. This review examines the intricate relationship between dietary carbohydrates and the gut microbiota, highlighting the crucial role of advanced analytical techniques in understanding their diversity and implications. These advancements provide valuable insights into carbohydrate bioactivity. Integrating high-throughput analysis with next-generation sequencing provides deeper insights into gut microbial interactions, potentially revealing which carbohydrate structures are beneficial for gut health.

Fractionation and characterisation of sialylated-mucin glycoprotein from edible birds' nest hydrolysates through anion exchange chromatography

Edible bird's nest (EBN) is made up of sialylated-mucin glycoprotein with various health benefits due to its high antioxidative activity. However, as a macromolecule with distinct charged sialic acid and amino acids, fractions with different charges would have varied physicochemical properties and antioxidant activity, which have not been studied. Therefore, this study aimed to fractionate and purify the enzymatic hydrolysed of cleaned EBN (EBNhc) and EBN by-product (EBNhbyp) through anion exchange chromatography (AEC), and determine their molecular weights, physicochemical properties, and antioxidative activities. Overall, 26 fractionates were collected from enzymatic hydrolysate by AEC, which were classified into 5 fractions. It was found that the positively charged fraction of EBNhc (CF 1) and EBNhbyp (DF 1) showed the significantly highest (p < 0.05) soluble protein contents (22.86 and 18.40 mg/g), total peptide contents (511.13 and 800.47 mg/g) and ferric reducing antioxidant power (17.44 and 6.96 mg/g) among the fractionates. In conclusion, a positively charged fraction (CF 1 and DF 1) showed more desired physicochemical properties and antioxidative activities. This research suggests the potential of AEC fractionation as a technology to purify EBN and produce positively charged EBN fractionates with antioxidative potential that could be applied as food components to provide health benefits.

Expanding the horizons of levan: from microbial biosynthesis to applications and advanced detection methods

Levan, a β-(2,6)-linked fructose polymer, exhibits diverse properties that impart versatility, rendering it a highly sought-after biopolymer with various industrial applications. Levan can be produced by various microorganisms using sucrose, food industry byproducts and agricultural wastes. Microbial levan represents the most potent cost-effective process for commercial-scale levan production. This study reviews the optimization of levan production by understanding its biosynthesis, physicochemical properties and the fermentation process. In addition, genetic and protein engineering for its increased production and emerging methods for its detection are introduced and discussed. All of these comprehensive studies could serve as powerful tools to optimize levan production and broaden its applications across various industries.

Research of saccharides and related biocomplexes: A review with recent techniques and applications

Saccharides and biocompounds as saccharide (sugar) complexes have various roles and biological functions in living organisms due to modifications via nucleophilic substitution, polymerization, and complex formation reactions. Mostly, mono-, di-, oligo-, and polysaccharides are stabilized to inactive glycosides, which are formed in metabolic pathways. Natural saccharides are important in food and environmental monitoring. Glycosides with various functionalities are significant in clinical and medical research. Saccharides are often studied with the chromatographic methods of hydrophilic interaction liquid chromatography and anion exchange chromatograpy, but also with capillary electrophoresis and mass spectrometry with their on-line coupling systems. Sample preparation is important in the identification of saccharide compounds. The cases discussed here focus on bioscience, clinical, and food applications.

Physicochemical characterization of the pod husk of Theobroma cacao L. of clones CCN51, FEAR5, and FSV41 and its agroindustrial application

In cocoa production, the harvest and postharvest processes tend to generate residues that, if not properly treated or disposed of, become a source of pests or diseases for the crop and the farmer. The residues are environmental contaminants, which are equivalent to 70%-80% of the total fruit (husk, placenta, leachates). In the case of cacao pod husk (CPH), it is hollow form contributes to the accumulation of water or leachates. These residues with no apparent profitable use may have components of agroindustrial interest, such as pectins, cellulose, and starches, in products with high added value. Thus, the physicochemical characterization CPH of clones Castro Naranjal Collection 51 (CCN51), FEDECACAO Arauquita 5 (FEAR5), and FEDECACAO San Vicente 41 (FSV41) is presented to identify different applications such as biopolymers, bioremediation, and renewable energies and their potential biotechnological use in contributing to the circular economy according to the characteristics of each clone. In conclusion, it is important to continue with the research on CPHs of the different clones and to promote the sustainable development of cocoa in the Department of Risaralda, Colombia.

Enhancing methane production and interspecies electron transfer of anaerobic granular sludge by the immobilization of magnetic biochar

Supplementation of conductive materials has been proved to be a promising approach for enhancing microbial interspecies electron transfer (IET) in anaerobic digestion systems. In this study, magnetic bamboo-based biochar was prepared at temperatures of 400-800 °C via a ball milling/carbonization method, and it immobilized in mature anaerobic granular sludge (AGS) aimed to enhance methane production by improving the IET process between syntrophic microbial communities in the AGS. Results showed that the AGS with magnetic biochar immobilization demonstrated increased glucotrophic and acetotrophic methane production by 69.54-77.56 % and 39.96-54.92 %, respectively. Magnetic biochar prepared at 800 °C with a relatively higher Fe content (0.37 g/g magnetic biochar) displayed a stronger electron charge/discharge capacity (36.66 F/g), and its immobilization into AGS promoted methane production most. The conductivity of AGS increased by 52.13-87.32 % after incorporating magnetic biochar. Furthermore, the extracellular polymeric substance (EPS) of AGS showed an increased capacitance and decreased electron transfer resistance possibly due to the binding of magnetic biochar and more riboflavin secretion in EPS, which could contribute to the accelerated IET process in the inner AGS. In addition, the immobilization of magnetic biochar could promote the production of volatile fatty acids by 15.36-22.50 %. All these improvements may jointly lead to the enhanced methane production capacity of AGS. This study provided a fundamental understanding of the role of incorporated magnetic biochar in AGS in promoting anaerobic digestion performance.

Mediating the performance of anaerobic granular sludge by exogenous flavin supplementation: Flavin binding capacity and behavior, interspecies electron transfer, and methane production

Although flavins are known as effective electron mediators, the binding capacity of exogenous flavins by anaerobic granular sludge (AGS) and their role in interspecies electron transfer (IET) remains unknown. In this study, AGS was mediated by using three exogenous flavins of riboflavin (RF), flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD). Results showed that the total amounts of flavins associated with extracellular polymeric substance (EPS) of AGS increased by 2.03-2.42 and 3.83-4.94 folds, after exposure to 50 and 200 μM of exogenous flavins, respectively. A large portion of FMN and FAD was transformed into RF by AGS. Exogenous flavin mediation also stimulated the production of EPS and cytochrome c (c-Cyts) as well as cytochrome-bound flavins. The increased abundance of these electron mediators led to a reduced electrochemical impedance of EPS and improved extracellular electron transfer capacity. The methane production of AGS after mediation with exogenous RF, FMN, and FAD increased by 19.03-31.71%, 22.86-26.04%, and 28.51-33.44%, respectively. This study sheds new light on the role of exogenous flavins in promoting the IET process of a complex microbial aggregate of AGS.

Self-assembly of maltose-albumin nanoparticles for efficient targeting delivery and therapy in liver cancer

The effective delivery and targeted release of drugs within tumor cells are critical factors in determining the therapeutic efficacy of nanomedicine. To achieve this objective, a conjugate of maltose (Mal) and bovine serum albumin (BSA) was synthesized by the Maillard reaction and self-assembled into nanoparticles with active-targeting capabilities upon pH/heating induction. This nanoparticle could be effectively loaded with doxorubicin (DOX) to form stable nanodrugs (Mal-BSA/DOX) that were sensitive to low pH or high glutathione (GSH), thereby achieving a rapid drug release (96.82 % within 24 h). In vitro cell experiments indicated that maltose-modified BSA particles efficiently enhance cellular internalization via glucose transporters (GLUT)-mediated endocytosis, resulting in increased intracellular DOX levels and heightened expression of γ-H2AX. Consequently, these results ultimately lead to selective tumor cells death, as evidenced by an IC50 value of 3.83 μg/mL in HepG2 cells compared to 5.87 μg/mL in 293t cells. The efficacy of Mal-BSA/DOX in tumor targeting therapy has been further confirmed by in vivo studies, as it effectively delivered a higher concentration of DOX to tumor tissue. This targeted delivery approach not only reduces the systemic toxicity of DOX but also effectively inhibits tumor growth (TGI, 75.95 %). These findings contribute valuable insights into the advancement of targeting-albumin nanomedicine and further support its potential in tumor treatment.

Exploring the diverse applications of Carbohydrate macromolecules in food, pharmaceutical, and environmental technologies

Carbohydrates are a class of macromolecules that has significant potential across several domains, including the organisation of genetic material, provision of structural support, and facilitation of defence mechanisms against invasion. Their molecular diversity enables a vast array of essential functions, such as energy storage, immunological signalling, and the modification of food texture and consistency. Due to their rheological characteristics, solubility, sweetness, hygroscopicity, ability to prevent crystallization, flavour encapsulation, and coating capabilities, carbohydrates are useful in food products. Carbohydrates hold potential for the future of therapeutic development due to their important role in sustained drug release, drug targeting, immune antigens, and adjuvants. Bio-based packaging provides an emerging phase of materials that offer biodegradability and biocompatibility, serving as a substitute for traditional non-biodegradable polymers used as coatings on paper. Blending polyhydroxyalkanoates (PHA) with carbohydrate biopolymers, such as starch, cellulose, polylactic acid, etc., reduces the undesirable qualities of PHA, such as crystallinity and brittleness, and enhances the PHA's properties in addition to minimizing manufacturing costs. Carbohydrate-based biopolymeric nanoparticles are a viable and cost-effective way to boost agricultural yields, which is crucial for the increasing global population. The use of biopolymeric nanoparticles derived from carbohydrates is a potential and economically viable approach to enhance the quality and quantity of agricultural harvests, which is of utmost importance given the developing global population. The carbohydrate biopolymers may play in plant protection against pathogenic fungi by inhibiting spore germination and mycelial growth, may act as effective elicitors inducing the plant immune system to cope with pathogens. Furthermore, they can be utilised as carriers in controlled-release formulations of agrochemicals or other active ingredients, offering an alternative approach to conventional fungicides. It is expected that this review provides an extensive summary of the application of carbohydrates in the realms of food, pharmaceuticals, and environment.

Optimization of HPLCCAD method for simultaneous analysis of different lipids in lipid nanoparticles with analytical QbD

Since lipid nanoparticles (LNP) have emerged as a potent drug delivery system, the objective of this study was to develop and optimize a robust high-performance liquid chromatography with charged aerosol detectors (HPLCCAD) method to simultaneously quantify different lipids in LNPs using the analytical quality by design (AQbD) approach. After defining analytical target profile (ATP), critical method attributes (CMAs) were established as a resolution between the closely eluting lipid peaks and the total analysis time. Thus, potential high-risk method parameters were identified through the initial risk assessment. These parameters were screened using Plackett-Burman design, and three critical method parameters (CMPs)-MeOH ratio, flow rate, and column temperature-were selected for further optimization. Box-Behnken design was employed to develop the quadratic models that explain the relationship between the CMPs and CMAs and to determine the optimal operating conditions. Moreover, to ensure the robustness of the developed method, a method operable design region (MODR) was established using the Monte Carlo simulation. The MODR was identified within the probability map, where the risk of failure to achieve the desired CMAs was less than 1%. The optimized method was validated according to the ICH guidelines (linearity: R2 > 0.995, accuracy: 97.15-100.48% recovery, precision: RSD < 5%) and successfully applied for the analysis of the lipid in the LNP samples. The development of the analytical method to quantify the lipids is essential for the formulation development and quality control of LNP-based drugs since the potency of LNPs is significantly dependent on the compositions and contents of the lipids in the formation.

Chemical Profiling and Biological Activity of Psydrax dicoccos Gaertn

Breast cancer is one of the deadliest diseases in women with a mortality rate of 6.6%. Adverse effects of synthetic drugs have directed research toward safer alternatives such as natural compounds. This study focused on Psydrax dicoccos Gaertn, an evergreen tree abundantly distributed in Tamil Nadu (India) for its possible application against breast cancer cells. P. dicoccos leaf methanol extract, found within a wide range of phytochemicals, demonstrated cytotoxic effects against MCF7 breast cancer cells at IC50 of 34 μg/mL. The extract exhibited good antioxidant activities against DPPH• (62%) and ABTS•+ (80%), as well as concentration-dependent (100-800 μg/mL) anti-inflammatory potential of 18-60% compared to standards, ascorbic acid or aspirin, respectively. Moreover, even low extract concentrations (10 μg/mL) inhibited the growth of Escherichia coli (1.9 ± 0.6 mm) and Pseudomonas aeruginosa (2.3 ± 0.7 mm), thus showing high antimicrobial and anti-inflammatory potential. GC-MS and LC-MS analyses identified 31 and 16 components, respectively, of which selected compounds were used to evaluate the interaction between key receptors (AKT-1, COX-2, and HER-2) of breast cancer based on binding energy (ΔG) and inhibition constant (Ki). The results indicate that bioactive compounds from P. dicoccos have potential against breast cancer cells, but further evaluations are needed.

Characterization of free oligosaccharides from garden cress seed aqueous exudate using PGC LC-MS/MS and NMR spectroscopy

Garden cress seeds produces mucilage that has found various food applications, however, there is little information on the free oligosaccharides (FOS) contents in these seeds. Herein, we explored the presence of FOS in cress seed aqueous exudate. PGC-LC MS/MS analysis indicated the presence of mainly hexose containing oligosaccharides such as raffinose, stachyose and verbascose belonging to raffinose family of oligosaccharides (RFOs). In addition, minor fraction of planteose, isomeric tri- and tetrasaccharides were also observed. Further, the structural confirmation of the abundant tri- and tetrasaccharide were obtained through 1D and 2D NMR analysis. Thus, the RFOs presence in cress seeds would enhance its bio-functionalities.

The benefits of edible mushroom polysaccharides for health and their influence on gut microbiota: a review

The gut microbiome is a complex biological community that deeply affects various aspects of human health, including dietary intake, disease progression, drug metabolism, and immune system regulation. Edible mushroom polysaccharides (EMPs) are bioactive fibers derived from mushrooms that possess a range of beneficial properties, including anti-tumor, antioxidant, antiviral, hypoglycemic, and immunomodulatory effects. Studies have demonstrated that EMPs are resistant to human digestive enzymes and serve as a crucial source of energy for the gut microbiome, promoting the growth of beneficial bacteria. EMPs also positively impact human health by modulating the composition of the gut microbiome. This review discusses the extraction and purification processes of EMPs, their potential to improve health conditions by regulating the composition of the gut microbiome, and their application prospects. Furthermore, this paper provides valuable guidance and recommendations for future studies on EMPs consumption in disease management.

Isolation of Momordica charantia seed lectin and glycosidases from the protein bodies: Lectin-glycosidase (β-hexosaminidase) protein body membrane interaction reveals possible physiological function of the lectin

Momordica charantia seeds are known to contain a galactose specific lectin that has been well characterized. Seed extracts also contain glycosidases such as the β-hexosaminidase, α-mannosidase and α-galactosidase. In the present study, lectin was affinity purified from the seed extracts and protein bodies isolated by sucrose density gradient centrifugation. From the protein bodies, lectin was identified and β-hexosaminidase was isolated by lectin affinity chromatography and subsequently separated from other glycosidases by gel filtration. In the native PAGE, the purified β-hexosaminidase migrated as a single band with a molecular weight of ∼235 kDa and by zymogram analysis using 4-methylumbelliferyl N-acetyl-β-D-glucosaminide substrate it was confirmed as β-hexosaminidase. Under reducing conditions in SDS-PAGE, the purified enzyme dissociated into three bands (Mr 33, 20 and 15 kDa). The prominent bands (20 and 15 kDa) showed immunological cross-reactivity with the human Hexosaminidase B antibody in a western blot experiment. In gel digestion of the purified enzyme, followed by proteomic analysis using tandom MS/MS revealed sequence identity as compared to the genomic sequence of the Momordica charantia with a score of 57 (24% sequence coverage). Additionally, by CD analysis the purified β-hexosaminidase showed 39.1% of α-helix. Furthermore, secondary structure variations were observed in presence of substrate, lectin and at different pH values. Protein body membrane prepared from the isolated protein bodies showed a pH dependent interaction with the purified lectin and mixture of glycosidases.

Anti-Fatigue Effects of Lycium barbarum Polysaccharide and Effervescent Tablets by Regulating Oxidative Stress and Energy Metabolism in Rats

The purpose of this study was to investigate the anti-fatigue effect of natural Lycium barbarum polysaccharide (LBP) during exercise, develop a functional anti-fatigue effervescent tablet by applying LBP to practical products, and help patients who have difficulty swallowing conventional tablets or capsules. LBP was extracted with water, and DEAE-52 cellulose was used for purification. The chemical structure and monosaccharide composition of LBP by Fourier transform infrared spectroscopy (FI-IR) and ion chromatography (IC). Lycium barbarum polysaccharide effervescent tablets (LBPT) were prepared by mixing LBP and an excipient. Animal experiments showed that LBP and LBPT significantly increased the exhaustive swimming time in rats. LBP and LBPT improved biochemical markers in rat serum, such as lactic acid and creatine kinase, enhanced the antioxidant capacity of rat muscle, and reversed the decrease in serum glucose, ATP and glycogen content caused by exercise. Transmission electron microscopy showed that LBP and LBPT increased the density of mitochondria in rat liver. In addition, molecular experiments showed that LBP and LBPT could improve oxidative stress caused by exercise by regulating the Nrf2/HO-1 signaling pathway and regulating energy metabolism via the AMPK/PGC-1α signaling pathway.