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1.
Adv Neurobiol ; 29: 1-39, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255670

RESUMO

This chapter provides an overview of structures and functions of complex carbohydrates (commonly called glycans) that are covalently linked to proteins or lipids to form glycoconjugates known as glycoproteins, glycolipids, and proteoglycans. To understand the complexity of the glycan structures, the nature of their monosaccharide building blocks, how the monomeric units are covalently linked to each other, and how the resulting glycans are attached to proteins or lipids are discussed. Then, the classification, nomenclature, structural features, and functions of the glycan moieties of animal glycoconjugates are briefly described. All three classes of glycoconjugates are constituents of plasma membranes of all animal cells, including those of the nervous system. Glycoproteins and proteoglycans are also found abundantly as constituents of tissue matrices. Additionally, glycan-rich mucin glycoproteins are the major constituents of mucus secretions of epithelia of various organs. Furthermore, the chapter draws attention to the incredible structural complexity and diversity of the glycan moieties of cell surface and extracellular glycoconjugates. Finally, the involvement of glycans as informational molecules in a wide range of essential functions in almost all known biological processes, which are crucial for development, differentiation, and normal functioning of animals, is discussed.


Assuntos
Carboidratos , Glicoconjugados , Animais , Glicoconjugados/química , Glicoconjugados/metabolismo , Carboidratos/química , Glicoproteínas/química , Glicoproteínas/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Glicolipídeos/química , Proteoglicanas/química , Monossacarídeos , Membrana Celular/metabolismo , Mucinas
2.
Adv Neurobiol ; 29: 95-116, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255673

RESUMO

Glycoproteins carrying O-linked N-acetylgalactosamine, N-acetylglucosamine, mannose, fucose, glucose, and xylose are found in the nervous system. Lipids are glycosylated by distinct glycosylation enzymes as well. Membrane lipid, ceramide, is modified by the addition of either glucose or galactose to form glycosphingolipid, galactosylceramide, or glucosylceramide. Recent careful analyses by MS have identified glucosylated lipids of cholesterol and phosphatidic acid. These O-linked carbohydrate residues are found primarily on the outer surface of the plasma membrane or in the extracellular space. Their expression is cell or tissue specific and developmentally regulated. Due to their structural diversity, they play important roles in a variety of biological processes such as membrane transport, metabolic stress responses, cell-cell interactions and so on. Discoveries of human diseases associated with glycosylation enzyme deficits have proved modification of lipids and proteins with carbohydrates play critical roles in human health and disease in the nervous systems.


Assuntos
Acetilgalactosamina , Fucose , Humanos , Fucose/metabolismo , Acetilgalactosamina/metabolismo , Acetilglucosamina/metabolismo , Galactose/metabolismo , Manose , Glucosilceramidas , Xilose , Galactosilceramidas , Glicoconjugados/metabolismo , Carboidratos/análise , Glicoproteínas/metabolismo , Sistema Nervoso , Glucose , Ácidos Fosfatídicos
3.
Adv Neurobiol ; 29: 163-184, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255675

RESUMO

Carbohydrate chains play critical roles in cellular recognition and subsequent signal transduction in the nervous system. Furthermore, gangliosides are targets for various amyloidogenic proteins associated with neurodegenerative disorders. To better understand the molecular mechanisms underlying these biological phenomena, atomic views are essential to delineate dynamic biomolecular interactions. Nuclear magnetic resonance (NMR) spectroscopy provides powerful tools for studying structures, dynamics, and interactions of biomolecules at the atomic level. This chapter describes the basics of solution NMR techniques and their applications to the analysis of 3D structures and interactions of glycoconjugates in the nervous system.


Assuntos
Glicoconjugados , Oligossacarídeos , Humanos , Espectroscopia de Ressonância Magnética , Oligossacarídeos/química , Carboidratos , Proteínas Amiloidogênicas , Gangliosídeos
4.
Adv Neurobiol ; 29: 449-477, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255684

RESUMO

A number of viruses that have caused wide spread concern e.g. Ebola, Zika, and SARS-CoV2 (severe acute respiratory syndrome coronavirus 2 also known as COVID 19) have at various times, become newsworthy as a result of being newly discovered, mutations enabling them to more efficiently infect humans or modern modes of transportation moving them to areas with naive, susceptible populations. As more is learned about the mechanisms whereby these pathogens enter human cells it has become increasingly evident that carbohydrates expressed on the surface of either target cells or the pathogens themselves are essential. Variability in carbohydrate structures as well as the presence of carbohydrate binding receptors (lectins) provides a plethora of potential binding interactions by which infection of cells can occur. Identification of specific lipid- or protein-associated carbohydrates essential for infection provides support for research being done to develop carbohydrate related inhibitors of those interactions. This chapter (1) discusses scenarios for how carbohydrates affect the ability of specific infectious agents to interact with neural cells, (2) gives examples of problems that may result from development of antibodies to carbohydrate antigens found on pathogens that are similar to epitopes expressed on mammalian cells, and (3) provides examples of approaches either in use or under consideration for translational uses of this information.


Assuntos
COVID-19 , Infecção por Zika virus , Zika virus , Animais , Humanos , SARS-CoV-2 , RNA Viral , Carboidratos/química , Sítios de Ligação , Epitopos , Lectinas , Lipídeos , Infecção por Zika virus/tratamento farmacológico , Mamíferos
5.
J Ethnopharmacol ; 300: 115695, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36108894

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Veronicastrum Heist. ex Fabr. (Plantaginaceae) is a multifunctional plant in China and other parts of the continent. It has traditionally been used in the treatment of ascites, edema, blood stasis, pain relief, chronic nephritis injury, fever, cough, headache, arthritis, dysentery, rheumatism, pleural effusion, liver damage, and other disorders. Although research has confirmed that the genus Veronicastrum contain many active compounds, no review of its traditional uses, phytochemistry or pharmacology has been conducted to date. AIM: This review aims to systematically evaluate the traditional uses, phytochemistry, and pharmacology of the genus Veronicastrum, discuss its medicinal potential, modern scientific research, and the relationship between them, and put forward some suggestions to promote further development and utilization of Veronicastrum. MATERIALS AND METHODS: The traditional uses, phytochemical and pharmacological data related to the genus Veronicastrum from 1955 to date was compiled by surveying the ethnomedicinal books and published papers, and searching the online databases including Google Scholar, China National Knowledge Infrastructure (CNKI), Science Direct, Web of Science and World Flora Online. RESULTS: Species of the genus Veronicastrum are widely used in folkloric medicine and some of their uses have been confirmed in modern pharmacological activities. A total of 89 chemical constituents have been isolated from the genus Veronicastrum, including flavonoids, carbohydrates, iridoids, terpenoids, phytosterols, phenolic acids, and other constituents. Among the compounds isolated, iridoids, flavonoids, and terpenoids are responsible for the biological activities of this genus with significant pharmacological activities both in vitro and in vivo. The extracts and compounds isolated from this genus have been reported to contain a wide range of pharmacological activities such as immunosuppressive, antioxidant, anti-cancer, anti-inflammatory, gastro protective, and antimicrobial activity. CONCLUSION: The genus Veronicastrum is not only a great herbal remedy, but also has numerous bioactive chemicals with potential for new drug discovery. In the literature, phytochemical investigations have been undertaken on five species. Detailed scientific research is still needed to fully understand this genus. Furthermore, its bioactive chemicals' structure-activity connection, in vivo activity, and mechanism of action ought to be investigated further.


Assuntos
Anti-Infecciosos , Fitosteróis , Plantaginaceae , Antioxidantes , Carboidratos , Etnofarmacologia , Flavonoides , Iridoides , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Terpenos
6.
Food Chem ; 400: 134118, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36088890

RESUMO

Carbohydrates and their implications for human health have been the subject to a rapidly growing interest. Substantial advances in analytical methods have enabled a more effective assessment of carbohydrates and their pharmacological effects. Developing a carbohydrate profile technology would surely aid the understanding of carbohydrate dietary impacts. With the advances in technology for characterization, as well as exploration of complex structure, it is becoming more feasible to synthesize such compounds, rather than isolation. Several technological developments, including improved analytical tools, glycomics, and automation technology, have opened up new opportunities to globally assess most carbohydrates in envisaged samples. The main analytical methods applied to carbohydrates are described. And then the development of automation technology in glycan synthesis are introduced. This review concludes by considering the limitations of the existing technologies and required future developments for overcoming these limitations and improving identification score and/or yield.


Assuntos
Carboidratos , Hexoses , Carboidratos/química , Humanos , Polissacarídeos/química
7.
Methods Mol Biol ; 2555: 125-137, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36306083

RESUMO

Sustainable use of natural products is one of the key challenges for the future. An increasing focus is on marine organic matter, mostly algae. New biotechnological tools for processing high amounts of micro- and macroalgae are necessary for efficient industrial degradation of marine matter. Secreted glycosyl hydrolases can be enriched and tested on the specific algae cell wall polymers of all algae groups (Rhodophyta; Phaeophyceae; Chlorophyta/Charophyta). Metagenomic analyses established new possibilities to screen algae-associated microbiomes for novel degrading enzymes in combination with sequence-based function prediction.


Assuntos
Metagenoma , Rodófitas , Hidrolases/metabolismo , Rodófitas/metabolismo , Carboidratos , Parede Celular
8.
Gen Comp Endocrinol ; 330: 114145, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36244431

RESUMO

The adipokinetic hormone/corazonin-related peptide (ACP) is an insect neuropeptide structurally intermediate between corazonin (CRZ) and adipokinetic hormone (AKH). Unlike the AKH and CRZ signaling systems that are widely known for their roles in the mobilization of energy substrates and stress responses, respectively, the main role of ACP and its receptor (ACPR) remains unclear in most arthropods. The current study aimed to localize the distribution of ACP in the nervous system and provide insight into its physiological roles in the disease vector mosquito, Aedes aegypti. Immunohistochemical analysis and fluorescence in situ hybridization localized the ACP peptide and transcript within a number of cells in the central nervous system, including two pairs of laterally positioned neurons in the protocerebrum of the brain and a few ventrally localized neurons within the pro- and mesothoracic regions of the fused thoracic ganglia. Further, extensive ACP-immunoreactive axonal projections with prominent blebs and varicosities were observed traversing the abdominal ganglia. Given the prominent enrichment of ACPR expression within the abdominal ganglia of adult A. aegypti mosquitoes as determined previously, the current results indicate that ACP may function as a neurotransmitter and/or neuromodulator facilitating communication between the brain and posterior regions of the nervous system. In an effort to elucidate a functional role for ACP signaling, biochemical measurement of energy substrates in female mosquitoes revealed a reduction in abdominal fat body in response to ACP that matched the actions of AKH, but interestingly, a corresponding hypertrehalosaemic effect was only found in response to AKH since ACP did not influence circulating carbohydrate levels. Comparatively, both ACP and AKH led to a significant increase in haemolymph carbohydrate levels in male mosquitoes while both peptides had no influence on their glycogen stores. Neither ACP nor AKH influenced circulating or stored lipid levels in both male and female mosquitoes. Collectively, these results reveal ACP signaling in mosquitoes may have complex sex-specific actions, and future research should aim to expand knowledge on the role of this understudied neuropeptide.


Assuntos
Aedes , Hormônios de Inseto , Neuropeptídeos , Humanos , Animais , Masculino , Feminino , Aedes/genética , Aedes/metabolismo , Hibridização in Situ Fluorescente , Mosquitos Vetores , Filogenia , Hormônios de Inseto/genética , Hormônios de Inseto/metabolismo , Ácido Pirrolidonocarboxílico/metabolismo , Oligopeptídeos/genética , Oligopeptídeos/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Carboidratos
9.
J Hazard Mater ; 442: 130034, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36206716

RESUMO

The toxicity of nanoplastics (NPs) at relatively low concentrations to soil fauna at different organismal levels is poorly understood. We investigated the responses of earthworm (Eisenia fetida) to polystyrene NPs (90-110 nm) contaminated soil at a relatively low concentration (0.02 % w:w) based on multi-omics, morphological, and intestinal microorganism analyses. Results showed that NPs accumulated in earthworms' intestinal tissues. The NPs damaged earthworms' digestive and immune systems based on injuries of the intestinal epithelium and chloragogenous tissues (tissue level) and increased the number of changed genes in the digestive and immune systems (transcriptome level). The NPs reduced gut microorganisms' diversity (Shannon index) and species richness (Chao 1 index). Proteomic, transcriptome, and histopathological analyses showed that earthworms suffered from oxidative and inflammatory stresses. Moreover, NPs influenced the osmoregulatory metabolism of earthworms as NPs damaged intestinal epithelium (tissue level), increased aldosterone-regulated sodium reabsorption (transcriptome level), inositol phosphate metabolism (proteomic level) and 2-hexyl-5-ethyl-furan-3-sulfonic acid, and decreased betaine and myo-inositol concentrations (metabolic level). Transcriptional-metabolic and transcriptional-proteomic analyses revealed that NPs disrupted earthworm carbohydrate and arachidonic acid metabolisms. Our multi-level investigation indicates that NPs at a relatively low concentration induced toxicity to earthworms and suggests that NPs pollution has significant environmental toxicity risks for soil fauna.


Assuntos
Oligoquetos , Poluentes do Solo , Animais , Oligoquetos/metabolismo , Microplásticos/toxicidade , Poluentes do Solo/metabolismo , Poliestirenos/metabolismo , Proteômica , Betaína/metabolismo , Aldosterona/análise , Aldosterona/metabolismo , Ácido Araquidônico/metabolismo , Solo , Sódio , Ácidos Sulfônicos , Furanos , Carboidratos , Fosfatos de Inositol/metabolismo
10.
Chemosphere ; 310: 136790, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36220430

RESUMO

Membrane distillation (MD) is a thermally driven technology applied in desalination and water reuse with utilisation of sustainable energy. However, algal organic matter (AOM) could foul membrane critically and plague MD's long-term operational stability. In this study, the soluble extracellular polymeric substance (sEPS) and intracellular organic matter with bound extracellular polymeric substance (IOM + bEPS) of two algal species (Amphora coffeaeformis and Navicula incerta) were exposed to 60 °C, 70 °C and 80 °C for 8 h with polypropylene hydrophobic membrane, simulating heated AOMs contacted with membrane inside MD unit, to study the temperature effect on membrane fouling. The dissolved carbohydrate and protein in the sEPS and IOM + bEPS samples generally increased after being heated. Heating caused cell lysis and the release and dissolution of carbohydrate and protein from sEPS, IOM and bEPS into water. As heating temperature increased, the carbohydrate release from the AOM usually increased. The contact angle of membrane contacted with sEPS and IOM + bEPS reduced significantly after heat treatment. The reduction in IOM + bEPS was larger than sEPS, in line with SEM analysis, indicating membrane surfaces and pores with IOM + bEPS fouled more severely than sEPS. It is due to higher hydrophobicity in IOM + bEPS causing adherence to membrane and presence of amphiphiles. High protein, lipid, and saturated fats proportions also cause severe fouling. SEM-EDX analysis indicated presence of O, Na, Cl and Mg elements, pointing to carbohydrate and lipids, and salt trapped in foulants. AOM heating and composition had direct effect to the membrane integrity, dictating severity of fouling in MD operations.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Purificação da Água , Temperatura , Destilação , Membranas Artificiais , Íons , Carboidratos , Água
11.
Food Chem ; 401: 134083, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36099816

RESUMO

The impact of Spirulina, Chlorella and Phaeodactylum tricornutum (P. tricornutum) microalgal extracts obtained by pressurized liquid extraction (PLE) on antioxidant and anti-inflammatory activities, microbial growth and in vitro gut microbiota composition was evaluated. PLE, compared to conventional extraction, led to a significant (p < 0.05) increase in proteins, carbohydrates, polyphenols, and antioxidant capacities of the three microalgal extracts. Moreover, Spirulina and P. tricornutum extracts significantly (p < 0.05) reduced the in vitro activation of the inflammatory NF-κB pathway. The microalgal extracts had also an inhibitory effect on the pathogenic bacteria while potential beneficial Lactobacillus and Bifidobacterium strains increased growth. The effects of microalgal extracts on specific bacterial groups were analyzed by quantitative PCR technology, and bacterial gene copy numbers were affected by in vitro digestion process and colonic fermentation time. GC-MS results showed that microalgal biomolecules' digestion promoted the release of short-chain fatty acids (SCFAs) during in vitro colonic microbiota fermentation, particularly acetic, butanoic and propanoic, indicating that the biomolecules in microalgae extracts have potential health benefits for human gut.


Assuntos
Chlorella , Microbioma Gastrointestinal , Microalgas , Spirulina , Humanos , Chlorella/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Spirulina/metabolismo , NF-kappa B/metabolismo , Microalgas/metabolismo , Ácidos Graxos Voláteis/metabolismo , Bactérias/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/metabolismo , Carboidratos
12.
Food Chem ; 401: 134121, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36103737

RESUMO

Cactus mucilage (CMU) have been widely studied in various applications. This review addresses the sources, extraction methods, composition, biological properties and CMU applications with the help of bibliometric analysis to select scientific articles available in the Web of Science database and evaluated by VOSviewer (2001-2021). CMU are generally characterized as an arabinogalactan-type polysaccharide, a source of carbohydrates and proteins, minerals, fatty acids, essential amino acids and phenolic compounds. Such attributes contribute to its functionality as emulsifying, stabilizing, foaming and gelling agents. Therefore, it has been used in dairy, bakery, emulsified and powdered products, in addition, as microencapsulating substances, producing edible coatings and forming ecological films. Its main beneficial features consist of antioxidant, antimicrobial, prebiotic, healing, antiulcer, anti-inflammatory, anti-hyperlipidemic and slimming effects. Thus, this review provides the CMU main evidences in the literature, which reveal their scientific importance, what can boost new research for the food, pharmaceutical and cosmetic industries.


Assuntos
Opuntia , Opuntia/química , Antioxidantes/análise , Bioprospecção , Extratos Vegetais/química , Polissacarídeos , Anti-Inflamatórios , Carboidratos , Minerais , Bibliometria , Aminoácidos Essenciais
13.
Sci Total Environ ; 856(Pt 1): 159017, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36167124

RESUMO

Drought combined with extreme heatwaves has been increasingly identified as the important trigger of worldwide tree mortality in the context of climate change; nonetheless, our understanding of the potential hydraulic and thermal impairments of hot droughts to trees and the subsequent post-recovery process remains limited. To investigate the response of tree water and carbon relations to drought, heatwave, and combined drought-heatwave stresses, three-year-old potted seedlings of Fraxinus mandshurica Rupr., a dominant tree species in temperate forests of northeast China, were grown under well-watered and drought-stressed conditions and exposed to a rapid, acute heatwave treatment. During the heatwave treatment with a maximum temperature exceeding 40 °C for two days, the leaf temperature of drought-stressed seedlings was, on average, 5 °C higher than that of well-watered counterparts due to less effective evaporative cooling, indicating that soil water availability influenced leaf thermoregulatory capacity during hot extremes. Consistently, more pronounced crown damage, as shown by 13 % irreversible leaf scorch, was found in seedlings under the drought-heatwave treatment relative to sole heatwave treatment, alongside the more severe stem xylem embolism and leaf electrolyte leakage. While the heatwave treatment accelerated the depletion of non-structural carbohydrates in drought-stressed seedlings, the increase of branch soluble sugar concentration in response to heatwave might be related to the requirement for maintaining hydraulic functioning via osmoregulation under high dehydration risk. The coordination between leaf stomatal conductance and total non-structural carbohydrate content during the post-heatwave recovery phase implied that plant-water relations and carbon physiology were closely coupled in coping with hot droughts. This study highlights that, under scenarios of aggravating drought co-occurring with heatwaves, tree seedlings could face a high risk of crown decline in relation to the synergistically increased hydraulic and thermal impairments.


Assuntos
Secas , Fraxinus , Plântula , Árvores/fisiologia , Água/fisiologia , Carbono , Carboidratos
14.
Bioresour Technol ; 367: 128066, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36202284

RESUMO

Cyanobacteria-derived biofuels can be helpful in achieving a circular bioeconomy. To increase the production of biodiesel/bioethanol from cyanobacterium, Pseudanabaena mucicola GO0704, mixotrophic cultivation using volatile fatty acid (VFA), a cheap organic carbon source, was performed. The treatment of butyric acid or acetic acid enhanced the cell growth, particularly, the dry weight of the butyric acid-treated cells was 2.30-fold higher than the control. The enhancement of the growth led to the increase of metabolite (i.e., lipid and carbohydrate) productions, resulting in high amount of biodiesel and bioethanol to be produced. Butyric acid was more effective compared to acetic acid and the productions of biodiesel (52.2 mg/L) and bioethanol (132.6 mg/L) from the butyric acid-treated P. mucicola GO0704 were 2.34- and 2.17-fold higher compared to the control, respectively. This study will provide a foundation to commercialize the cyanobacteria-based carbon-neutral fuels, and ultimately, achieve a circular bioeconomy.


Assuntos
Cianobactérias , Microalgas , Biocombustíveis , Biomassa , Ácido Butírico/metabolismo , Ácidos Graxos Voláteis/metabolismo , Carbono/metabolismo , Carboidratos , Acetatos/metabolismo , Microalgas/metabolismo
15.
J Environ Manage ; 325(Pt A): 116426, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36240639

RESUMO

This study focused on how adding ionic liquids (IL) affects composting humification. During the warming and thermophilic phases, addition of IL increased precursors content, and increased the polymerization of humus (HS) at later stages. Furthermore, the final HS and humic acid (HA) content of experimental groups (T) groups 129.79 mg/g and 79.91 mg/g were higher than in control group (CK) 118.57 mg/g and 74.53 mg/g, respectively (p < 0.05). IL up-regulated the gene abundance of metabolism for carbohydrate and amino acid (AA), and promoted the contributions of Actinobacteria and Proteobacteria, which affected humification. The redundancy analysis (RDA) results showed that the citrate-cycle (TCA cycle)(ko0020), pentose phosphate pathway (ko00030), pyruvate metabolism (ko00620), glyoxylate and dicarboxylate metabolism (ko00630), propanoate metabolism (ko00640), butanoate metabolism (ko00650) positively correlated with HA and HI. HA and humification index (HI) positively correlated with AA metabolic pathways, and fulvic acid (FA) was negatively correlated with these pathways. Overall, metabolism for carbohydrate and AA metabolism favored compost humification. ILs improved metabolism for carbohydrate and amino acid metabolism, thus enhancing humification.


Assuntos
Compostagem , Líquidos Iônicos , Animais , Bovinos , Esterco , Substâncias Húmicas/análise , Solo , Aminoácidos , Redes e Vias Metabólicas , Carboidratos
16.
Methods Mol Biol ; 2566: 65-84, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36152243

RESUMO

Lectins, discovered more than 100 years ago and defined by their ability to selectively recognize specific carbohydrate structures, are ubiquitous in living organisms. Their precise functions are as yet under-explored and incompletely understood but they are clearly involved, through recognition of their binding partners, in a myriad of biological mechanisms involved in cell identity, adhesion, signaling, and growth regulation in health and disease. Understanding the complex "sugar code" represented by the "glycome" is a major challenge and at the forefront of current biological research. Lectins have been widely employed in histochemical studies to map glycosylation in cells and tissues. Here, a brief history of the discovery of lectins and early developments in their use is presented along with a selection of some of the most interesting and significant discoveries to emerge from the use of lectin histochemistry. Further, an evaluation of the next generation of lectin-based technologies is presented, including the potential for designing recombinant lectins with more precisely defined binding characteristics, linking lectin-based studies with other technologies to answer fundamental questions in glycobiology and approaches to exploring the interactions of lectins with their binding partners in more detail.


Assuntos
Glicômica , Lectinas , Carboidratos/química , Histocitoquímica , Lectinas/metabolismo , Açúcares
17.
Methods Mol Biol ; 2566: 291-310, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36152261

RESUMO

Histochemical analysis is essential for the study of plant secretory structures whose classification is based, at least partially, on the composition of their secretion. As each gland may produce one or more types of substances, a correct analysis of its secretion should be done using various histochemical tests to detect metabolites of different chemical classes. Here I describe some of the most used methods to detect carbohydrates, proteins, lipids, phenolic compounds, and alkaloids in the secretory structures.


Assuntos
Carboidratos , Estruturas Vegetais , Transporte Biológico , Carboidratos/análise , Lipídeos
18.
J Pharm Biomed Anal ; 222: 115083, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36206692

RESUMO

It is vitally important to characterize polysaccharides by monosaccharide composition method. In this study, a direct acetylation strategy combined with reversed-phase liquid chromatography electrospray tandem multiple reaction monitoring mass spectrometry (RPLC-ESI-MRM-MS) was developed for simultaneous determination of 8 aldoses (Glc, Gal, Man, Ara, Xyl, Rib, Rha and Fuc), a ketose (Fru), 2 alditols (Glc-ol and Man-ol) and 2 uronic acids (GlcA and GalA) on a high-pressure resistant reversed-phase column. Employing 1-MeIm as catalyst for direct acetylation, even though no DMSO was used to inhibit the transformation of configurations, each carbohydrate still produced a single chromatographic peak in RPLC conditions due to the ɑ- and ß- isomers merged together. Except for Fru and Man, all the other 11 carbohydrates were base-line separated in a 1.7 µm CYANO column. Therefore, correction factor method is further proposed to perfectly solve co-elution problem of Fru and Man because of occurrence of a specific Q3 ion for aldoses rather than ketose. The result was verified on a 1.7 µm Fluoro-Phenyl column with a full separation of Fru and Man. Herein, the established direct acetylation as followed RPLC-ESI-MRM-MS method was successfully applied for compositional analysis of complex polysaccharides from edible plants and fungi.


Assuntos
Cromatografia de Fase Reversa , Plantas Comestíveis , Humanos , Acetilação , Polissacarídeos/química , Monossacarídeos/análise , Espectrometria de Massas em Tandem/métodos , Carboidratos , Fungos , Cetoses , Cromatografia Líquida de Alta Pressão
19.
Food Chem ; 402: 134221, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36137386

RESUMO

Asparagine and sugars are direct precursors of acrylamide; however, proteins and fibres can also influence it. In this study, biscuits prepared replacing wheat flour with increasing concentrations (20, 40, 60%) of lupin or chickpea flour were investigated. Asparagine concentration was equalized in all formulas to isolate the effect of other flour characteristics on the acrylamide formation during baking. The results showed that replacing wheat flour with lupin flour increased acrylamide from 583.9 up to 1443 µg/kg after 9 min of baking, while 20-40% chickpea flour reduced acrylamide to 354.4-312.6 µg/kg. The acrylamide reduction using chickpea was attributed to the lower interaction between precursors resulting from both the coarser particle size and the lower reactivity of carbohydrate in presence of chickpea proteins. Chickpea addition did not affect the colour and texture of biscuits, opening the possibility for large-scale implementation of this mitigation strategy in formulas with a similar initial asparagine content.


Assuntos
Cicer , Lupinus , Farinha , Acrilamida , Asparagina , Triticum , Carboidratos , Açúcares
20.
Food Chem ; 402: 134300, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36152558

RESUMO

The effect of convective hot air and vacuum drying alone and combined with germination on alfalfa seeds' proximate composition, techno-functional, thermal and structural properties was investigated. Corresponding properties of treated alfalfa samples were compared with those of commercially available alfalfa sprouts. Both drying and combined germination and drying treatments resulted in increased carbohydrates (41.99-48.82 %), TDF (10.51-12.51 %) and Mg contents (789.49-2119.24 mg/kg), while the reduction in ash, lipid and Fe content compared to raw alfalfa seeds was observed. Alfalfa seeds subjected to combined germination and drying treatment exhibited higher water and oil binding capacities, as well as emulsions with smaller volume mean droplet diameters compared to the raw and dried samples. Conducted treatments resulted in greater thermal stability of globulins and a slight decrease in crystallinity index, although alfalfa seeds' structure did not change significantly according to FTIR analysis. Differences in applied drying techniques on alfalfa seeds' properties were not observed.


Assuntos
Microbiologia de Alimentos , Medicago sativa , Vácuo , Contagem de Colônia Microbiana , Sementes , Água/química , Lipídeos/farmacologia , Carboidratos , Germinação
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