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1.
J Agric Food Chem ; 68(10): 3250-3259, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32045528

RESUMO

Arabinoxylan oligosaccharides (AXOS) are a complex mixture of cereal derived, water-soluble prebiotics, obtained by enzymatic hydrolysis of arabinoxylan, a group of dietary fibers exerting numerous nutritional and health-beneficial effects. Such complex biomolecular mixtures are notoriously difficult to characterize without initial physical fractionation. Here we present the in situ analysis of AXOS using a variety of state-of-the-art sensitivity-enhanced 13C-DOSY methods, enabling virtual separation and identification of the components. Three dimensional correlation plots displaying 13C diffusivity (DOSY: Diffusion Ordered SpectroscopY), relaxation parameters (TOSY: raTe of relaxation Ordered SpectrscopY), and chemical shift offer a unique way to elucidate the composition of mixtures. We have demonstrated this multifaceted 13C probed correlation strategy in standard mixtures of aliphatic and aromatic compounds, before implementing it on AXOS. These 3D-DOSY-TOSY plots in combination with 2D-NMR correlation experiments offer unprecedented clarity for assigning chemical functions, molecular size distribution, and dynamics of oligosaccharide mixtures.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Oligossacarídeos/química , Prebióticos/análise , Análise Espectral/métodos , Hidrólise , Tamanho da Partícula , Xilanos/química
2.
J Agric Food Chem ; 68(10): 3184-3194, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32105462

RESUMO

Enzymatic hydrolysis of xylan represents a promising way to produce xylooligosaccharide (XOS), which is a novel ingredient in functional food. However, the recalcitrance of xylan in natural lignocellulosic biomass entails effective and robust xylanases. In the present study, we reported the isolation of a thermophilic Streptomyces sp. B6 from mushroom compost producing high xylanase activity. Two xylanases of Streptomyces sp. B6 belonging to GH10 (XynST10) and GH11 (XynST11) families were thus identified and biochemically characterized to be robust enzymes with high alkaline- and thermostability. Direct hydrolysis of neutralized viscose fiber production waste using XynST10 and XynST11 showed that while XynST10 produced 23.22 g/L XOS with a degree of polymerization (DP) of 2-4 and 9.27 g/L xylose, XynST11 produced much less xylose (1.19 g/L) and a higher amounts of XOS with a DP = 2-4 (28.29 g/L). Thus, XynST11 holds great potential for the production of XOS from agricultural and industrial waste.


Assuntos
Proteínas de Bactérias/química , Endo-1,4-beta-Xilanases/química , Glucuronatos/química , Oligossacarídeos/química , Streptomyces/enzimologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biocatálise , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismo , Estabilidade Enzimática , Glucuronatos/metabolismo , Temperatura Alta , Concentração de Íons de Hidrogênio , Resíduos Industriais/análise , Oligossacarídeos/metabolismo , Streptomyces/química , Streptomyces/genética , Xilose/química , Xilose/metabolismo
3.
Chem Commun (Camb) ; 56(18): 2767-2770, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32022009

RESUMO

We synthesized "glyco-arylopeptides", whose folding structure significantly changes depending on the kind of saccharide in their side chain. The saccharide moiety interacts with the main chain via hydrogen bonding, and the non-natural polypeptides form two well-defined architectures-(P)-31- and (M)-41-helices-depending on the length of the saccharide chains and even the configuration of a single stereo-genic center in the epimers.


Assuntos
Glicopeptídeos/química , Oligossacarídeos/química , Peptídeos/síntese química , Teoria da Densidade Funcional , Estrutura Molecular , Peptídeos/química , Dobramento de Proteína
4.
J Agric Food Chem ; 68(3): 838-844, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31896254

RESUMO

Maltooligosaccharide-forming amylases (MFAses) are promising tools for a variety of food industry applications because they convert starch into functional maltooligosaccharides. The MFAse from Bacillus stearothermophilus STB04 (BstMFAse) is a thermostable enzyme that preferentially produces maltopentaose and maltohexaose. An X-ray crystal structure of the BstMFAse-acarbose complex suggested that mutation of glycine 109 would increase its maltohexaose specificity. Using site-directed mutagenesis, glycine 109 was replaced with several different amino acids. Mutant-containing asparagine (G109N), aspartic acid (G109D), and phenylalanine (G109F) produced 36.1, 42.4, and 39.0% maltohexaose from starch, respectively, which was greater than that produced by the wild-type (32.9%). These mutants also exhibited substantially altered oligosaccharide hydrolysis patterns in favor of maltohexaose production. Homology models suggested that the mutants form extra interactions with the substrate at subsite -6, which were responsible for the enhanced maltohexaose specificity of BstMFAse. The results of this study support the proposition that binding of the substrate's nonreducing end in the nonreducing end-subsite of the MFAse active center plays a crucial role in its product specificity.


Assuntos
Amilases/genética , Amilases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Geobacillus stearothermophilus/enzimologia , Oligossacarídeos/metabolismo , Amilases/química , Proteínas de Bactérias/química , Sítios de Ligação , Geobacillus stearothermophilus/genética , Mutagênese Sítio-Dirigida , Oligossacarídeos/química , Engenharia de Proteínas , Amido/química , Amido/metabolismo , Especificidade por Substrato
5.
J Agric Food Chem ; 68(7): 2174-2182, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31985220

RESUMO

Goat milk oligosaccharides are complex carbohydrates with a variety of biological functions. Free oligosaccharides from goat milk show more similarity to human milk than cow milk. At present, changes in goat milk glycoconjugates at different parities remain poorly studied. Herein, we qualitatively and quantitatively compared the goat milk glycoprotein N/O-glycome at different parities using a stable isotope labeling followed by electrospray ionization mass spectrometry and online hydrophilic interaction chromatography. N-Glycans were mainly fucosylated and nonfucosylated nonsialylated, and both fucosylation and sialylation gradually increased with parity, amounting (at the third parity) to 1.25 times and 3.3 times those of the first parity, respectively. O-Glycans were mostly nonfucosylated and nonsialylated, and sialylation increased with increasing parity, and Neu5Ac-sialylated was up to 9 times higher in the third parity than in the first parity, whereas Neu5Gc-sialylated was 5.5 times higher. This study provides a reference for exploring an alternative milk source closest to human milk and for the development of humanized formula milk.


Assuntos
Colostro/química , Polissacarídeos/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Feminino , Glicosilação , Cabras , Humanos , Leite Humano/química , Oligossacarídeos/química , Espectrometria de Massas em Tandem
6.
Chem Asian J ; 15(4): 450-462, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-31895493

RESUMO

Carbohydrates contain numerous hydroxyl groups and sometimes amine functionalities which lead to a variety of complex structures. In order to discriminate each hydroxyl group for the synthesis of complex oligosaccharides, protecting group manipulations are essential. Although the primary role of a protecting group is to temporarily mask a particular hydroxyl/amino group, it plays a greater role in tuning the reactivity of coupling partners as well as regioselectivity and stereoselectivity of glycosylations. Several protecting groups offer anchimeric assistance in glycosylation. They also alter the solubility of substrates and thereby influence the reaction outcome. Since oligosaccharides comprise branched structures, the glycosyl donors and acceptors need to be protected with orthogonal protected groups that can be selectively removed one at a time without affecting other groups. This minireview is therefore intended to provide a discussion on new protecting groups for amino and hydroxyl groups, which have been introduced over last ten years in the field of carbohydrate synthesis. These protecting groups are also useful for synthesizing non-carbohydrate target molecules as well.


Assuntos
Oligossacarídeos/química , Benzoatos/química , Compostos de Benzilideno/química , Ésteres/química , Éter/química , Glicosídeos/química , Glicosilação , Oligossacarídeos/síntese química , Estereoisomerismo
7.
Chem Commun (Camb) ; 56(3): 344-347, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31808481

RESUMO

Exploiting synergistic remote participation effects of acyl groups at the O3 and O6 positions was key to the complete α-selectivity during the total synthesis of the unique (1 → 2)- and (1 → 3)-linked α-oligoglucosides from the Helicobacter pylori O2 O-antigen. Acyl remote participation and solvent effects were found to counteract during α-stereoselective glucosylations for the first time. The resulting antigen is a lead for the development of a carbohydrate-conjugate vaccine.


Assuntos
Helicobacter pylori/metabolismo , Antígenos O/química , Oligossacarídeos/síntese química , Oligossacarídeos/química , Sorogrupo , Solventes/química , Estereoisomerismo , Vacinas Conjugadas/química
8.
J Agric Food Chem ; 68(5): 1207-1212, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31755264

RESUMO

Human noroviruses (HuNoVs) are among the main pathogens causing acute nonbacterial gastroenteritis. Histo-blood group antigens (HBGAs) are widely accepted receptors for HuNoV specific binding. HBGA-like substances in produce are also considered as the critical ligands for capture of HuNoVs. However, the composition of viral ligands from food substrates remains unknown. In this study, an oligosaccharide (H2N2F2) was captured and isolated from romaine lettuce extract by a bacterial surface display system. Using electrospray ionization mass spectrometry and tandem mass spectrometry, it was shown that H2N2F2 was most likely to be a chimera of type A, H, and Lewis a HBGAs. The composition was consistent with our ELISA results using a panel of monoclonal antibodies against HBGAs. Our results revealed a possible interaction mechanism between HuNoVs and romaine lettuce. Better understanding of the interaction of HuNoVs with easily contaminated produce will ultimately aid in the control of and reduction in disease outbreaks.


Assuntos
Antígenos de Plantas/metabolismo , Antígenos de Grupos Sanguíneos/metabolismo , Alface/virologia , Norovirus/fisiologia , Receptores Virais/metabolismo , Ligação Viral , Antígenos de Plantas/química , Antígenos de Plantas/genética , Antígenos de Grupos Sanguíneos/química , Antígenos de Grupos Sanguíneos/genética , Infecções por Caliciviridae/genética , Infecções por Caliciviridae/metabolismo , Infecções por Caliciviridae/virologia , Humanos , Alface/química , Alface/genética , Alface/metabolismo , Espectrometria de Massas , Norovirus/genética , Oligossacarídeos/química , Oligossacarídeos/genética , Oligossacarídeos/metabolismo , Ligação Proteica , Receptores Virais/química , Receptores Virais/genética
9.
J Agric Food Chem ; 68(1): 4-16, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31829005

RESUMO

Obesity has an important influence on health conditions, causing a multitude of complications and comorbidities, and drug therapy is considered to be one of the treatment strategies. Nowadays, there is increasing interest in the study of intestinal microbiota regulation of obesity; also, an increasing number of agricultural and sideline products have been found to have anti-obesity potential. In the present review, we summarize an overview of current known and potential anti-obesity oligosaccharides and their molecular structures. We describe their anti-obesity potential activity and the molecular structure associated with this activity, the regulation of intestinal microbiota composition and its mechanism of action, including regulation of the short-chain fatty acid (SCFA) pathway and altering bile acid (BA) pathway. This review will provide new ideas for us to develop new anti-obesity functional foods.


Assuntos
Fármacos Antiobesidade/administração & dosagem , Obesidade/tratamento farmacológico , Oligossacarídeos/administração & dosagem , Animais , Fármacos Antiobesidade/química , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Ácidos Graxos Voláteis/metabolismo , Microbioma Gastrointestinal , Humanos , Obesidade/metabolismo , Obesidade/microbiologia , Oligossacarídeos/química , Prebióticos/administração & dosagem , Prebióticos/análise
10.
J Dairy Sci ; 103(1): 72-86, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31677836

RESUMO

The aim of this study was to characterize minor lipids in methanol fraction extracted from raw camel milk after loading it on a water-preconditioned short C18 open column and fractionating with a gradient of methanol/water. The C18 column showed high fractionation efficiency of minor lipids, such as glycosphingolipids, lipopolysaccharides, or oligosaccharides, when compared with other constituents, in particular polysaccharides, proteins, and free fatty acids. Liquid chromatography electrospray ionization tandem mass spectrometry in negative ion mode was used to identify 21 new glycosphingolipids, lipopolysaccharides, and oligosaccharides. Electrospray ionization tandem mass spectrometry was qualified to provide relevant data for recognizing the molecular mass, glycosylation sequences, and structure of saccharide moieties for the revealed compounds. The sequence of combinations of one selected lipopolysaccharide, which was considered the backbone of the remaining lipopolysaccharides, was confirmed in a density functional theory study. The obtained results showed that the tested fraction is a rich source of glycosphingolipids, lipopolysaccharides, and oligosaccharides with antioxidant activity.


Assuntos
Camelus , Lipídeos/farmacologia , Leite/química , Oligossacarídeos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray/veterinária , Animais , Humanos , Lipídeos/química , Oligossacarídeos/química , Plasma , Espectrometria de Massas por Ionização por Electrospray/métodos
11.
Anal Bioanal Chem ; 412(3): 533-537, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31853603

RESUMO

Glycosaminoglycans (GAGs) are a physio- and pharmacologically highly relevant class of complex saccharides, possessing a linear sequence and strongly acidic character. Their repetitive linear core makes them seem structurally simple at first glance, yet differences in sulfation and epimerization lead to an enormous structural diversity with only a few GAGs having been successfully characterized to date. Recent infrared action spectroscopic experiments on sulfated mono- and disaccharide ions show great promise. Here, we assess the potential of two types of gas-phase action spectroscopy approaches in the range from 1000 to 1800 cm-1 for the structural analysis of complex GAG oligosaccharides. Synthetic tetra- and pentasaccharides were chosen as model compounds for this benchmark study. Utilizing infrared multiple photon dissociation action spectroscopy at room temperature, diagnostic bands are largely unresolved. In contrast, cryogenic infrared action spectroscopy of ions trapped in helium nanodroplets yields resolved infrared spectra with diagnostic features for monosaccharide composition and sulfation pattern. The analysis of GAGs could therefore significantly benefit from expanding the conventional MS-based toolkit with gas-phase cryogenic IR spectroscopy. Graphical abstract.


Assuntos
Glicosaminoglicanos/química , Oligossacarídeos/química , Espectrofotometria Infravermelho/métodos , Animais , Temperatura Baixa , Hélio/química , Humanos , Íons/química , Isomerismo , Espectrofotometria Infravermelho/instrumentação , Sulfatos/análise
12.
Meat Sci ; 159: 107936, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518708

RESUMO

The substitution of dietary fiber and probiotic strains to reduce fat content of fermented sausages has been used for the development of innovative and healthier meat products. For this study, pork back fat was partially replaced by fructooligosaccharides (FOS) and the probiotic strains Lactobacillus paracasei and Lactobacillus rhamanosus. The fat replacement resulted in a significant decrease (P ≤ .05) in fat content (29%) compared with the control formulation (no fat substitution). The addition of FOS did not have a significant effect on microbial counts; however, reductions in Enterobacteriaceae and yeast were observed when Lactobacillus strains were also incorporated. The inclusion of FOS and probiotic strains did not show any significant effect on lipid oxidation and proteolysis. The partial fat replacement and the addition of Lactobacillus rhamanosus GG as probiotic strain in Spanish Salchichón can be considered a successful reformulation strategy for the meat product market.


Assuntos
Lactobacillus/fisiologia , Produtos da Carne/normas , Oligossacarídeos/química , Probióticos , Animais , Fermentação , Humanos , Peroxidação de Lipídeos , Produtos da Carne/análise , Produtos da Carne/microbiologia , Sensação , Suínos , Fatores de Tempo
13.
Carbohydr Polym ; 227: 115356, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590850

RESUMO

Chitosan oligosaccharide-valylvaline-stearic acid (CSO-VV-SA) nanomicelles were designed for topical ocular drug delivery, based on peptide transporter-1 (PepT-1) active targeting. Hydrogenated castor oil-40/octoxynol-40 (HCO-40/OC-40) mixed nanomicelles were also prepared according to Cequa, just approved by FDA. Both nanomicelles produced no significant cytotoxicity and difference in human corneal epithelial cells (HCEpiC) and human conjunctival epithelial cells (HConEpiC). The active transport of CSO-VV-SA nanomicelles by PepT-1 was illustrated in the inhibitory test. Ex vivo fluorescence images of frozen sections indicated that the nanomicelles entered the posterior segment mainly through conjunctival route. In vivo precorneal retention study suggested dexamethasone from both nanomicelles could be detected for more than 3 h in rabbit tears. In vivo distribution evaluation of rabbits' eyes showed the delivering efficiency of CSO-VV-SA nanomicelles was not inferior to that of HCO-40/OC-40 mixed nanomicelles. These findings indicated that CSO-VV-SA nanomicelles could become promising candidates for further clinical application.


Assuntos
Anti-Inflamatórios/administração & dosagem , Quitosana/administração & dosagem , Dexametasona/administração & dosagem , Sistemas de Liberação de Medicamentos , Micelas , Nanopartículas/administração & dosagem , Oligossacarídeos/administração & dosagem , Administração Oftálmica , Animais , Anti-Inflamatórios/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Dexametasona/química , Dipeptídeos/administração & dosagem , Dipeptídeos/química , Liberação Controlada de Fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Olho/citologia , Olho/metabolismo , Humanos , Masculino , Nanopartículas/química , Oligossacarídeos/química , Transportador 1 de Peptídeos/metabolismo , Coelhos , Ratos Sprague-Dawley , Ácidos Esteáricos/administração & dosagem , Ácidos Esteáricos/química
14.
Food Microbiol ; 86: 103336, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703861

RESUMO

Plant derived galactomannooligosaccharides (GMOS) are an emerging class of prebiotics, but no information is available on their utilization in lactobacilli at the molecular level. The current study aimed at identifying the genetic loci involved in the transport and catabolism of locust bean gum derived GMOS in Lactobacillus plantarum WCFS1. Substrate depletion study showed that L. plantarum WCFS1 can metabolize only short chain GMOS (degree of polymerization; DP ≤ 3). Global transcriptome microarray profiling of L. plantarum WCFS1 revealed differential expression when GMOS or control sugars (glucose, galactose, and mannose) were used as a sole carbohydrate source. Two genetic loci involved in cellobiose (~3.2 kb) and oligo-sucrose (~7.3 kb) utilization in L. plantarum WCFS1 were highly up-regulated up to 8.3 and up to 6.7-fold, respectively by GMOS utilization. qRT-PCR studies of the selected gene clusters showed correlation with microarray data. Altogether, transcriptome and qRT-PCR studies of L. plantarum WCFS1 suggested that un-substituted mannobiose (DP2) might be metabolized by proteins encoded by the cellobiose operon while, substituted DP2 (galactomannose) and DP3 (galactomannobiose) were most likely transported and catabolized by the oligo-sucrose utilization loci encoded proteins.


Assuntos
Proteínas de Bactérias/genética , Lactobacillus plantarum/genética , Lactobacillus plantarum/metabolismo , Oligossacarídeos/metabolismo , Proteínas de Bactérias/metabolismo , Galactose/metabolismo , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Glucose/metabolismo , Manose/metabolismo , Família Multigênica , Oligossacarídeos/química , Óperon
15.
Food Chem ; 306: 125641, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31606628

RESUMO

Temperature fluctuation is a common problem in the frozen storage of shrimp products. This study investigated the influence of carrageenan oligosaccharide (CO) and xylooligosaccharide (XO) on the growth and recrystallization of ice crystals in frozen peeled shrimp exposed to temperature fluctuations. Shrimp soaked with water and 3.0% (w/v) Na4P2O7 solution were designated as the negative and positive controls, respectively. Our data revealed that both CO- and XO-soaked shrimp had significant improvements in thawing and cooking loss, myofibrillar protein content, Ca2+-ATPase activity, and textural variables when exposed to temperature fluctuations compared to control samples. Microstructural imaging indicated that soaking the shrimp in CO and XO slowed the progression of damage caused to tissue myofibrils by large ice crystals, as well as inhibited the growth and recrystallization of ice crystals in muscle tissues. SDS-PAGE analysis confirmed that treatment with the oligosaccharides exhibited marked effects on the stability of muscle proteins and inhibited the degradation of muscle proteins affected by the temperature fluctuations. Based on these data, we hypothesize that the incorporated CO and XO may bind to muscle proteins and capture water molecules in the myofibrillar network through hydrogen bonding, thereby suppressing the myofibrillar denaturation and tissue structure destruction induced by the growth and recrystallization of ice crystals.


Assuntos
Carragenina/química , Glucuronatos/química , Oligossacarídeos/química , Penaeidae/química , Animais , Congelamento , Ligações de Hidrogênio , Gelo/análise , Temperatura Ambiente , Água/química
16.
Int J Nanomedicine ; 14: 6917-6932, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695366

RESUMO

Aim: To determine whether the use of a mixed polymeric micelle delivery system based on vitamin E succinate (VES)-grafted-chitosan oligosaccharide (CSO)/VES-grafted-chitosan (CS) mixed micelles (VES-g-CSO/VES-g-CS MM) enhances the delivery of C-DMSA, a theranostic fluorescent probe, for Hg2+ detection and detoxification in vitro and in vivo. Methods: Mixed micelles self-assembled from two polymers, VES-g-CSO and VES-g-CS, were used to load C-DMSA and afforded C-DMSA@VES-g-CSO/VES-g-CS MM for cell and in vivo applications. Fluorescence microscopy was used to assess C-DMSA cellular uptake and Hg2+ detection in L929 cells. C-DMSA@VES-g-CSO/VES-g-CS MM was then administered intravenously. Hg2+ detection was assessed by fluorescence microscopy in terms of bio-distribution while detoxification efficacy in Hg2+-poisoned rat models was evaluated in terms of mercury contents in blood and in liver. Results: The C-DMSA loaded mixed micelles, C-DMSA@VES-g-CSO/VES-g-CS MM, significantly enhanced cellular uptake and detoxification efficacy of C-DMSA in Hg2+ pretreated human L929 cells. Evidence from the reduction of liver coefficient, mercury contents in liver and blood, alanine transaminase and aspartate transaminase activities in Hg2+ poisoned SD rats treated with the mixed micelles strongly supported that the micelles were effective for Hg2+ detoxification in vivo. Furthermore, ex vivo fluorescence imaging experiments also supported enhanced Hg2+ detection in rat liver. Conclusion: The mixed polymeric micelle delivery system could significantly enhance cell uptake and efficacy of a theranostic probe for Hg2+ detection and detoxification treatment in vitro and in vivo. Moreover, this nanoparticle drug delivery system could achieve targeted detection and detoxification in liver.


Assuntos
Quitosana/química , Fígado/metabolismo , Mercúrio/análise , Micelas , Oligossacarídeos/química , Succímero/química , alfa-Tocoferol/farmacologia , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Morte Celular/efeitos dos fármacos , Linhagem Celular , Quitosana/síntese química , Liberação Controlada de Fármacos , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Humanos , Inativação Metabólica/efeitos dos fármacos , Masculino , Mercúrio/sangue , Camundongos Endogâmicos BALB C , Nanopartículas/química , Oligossacarídeos/síntese química , Ratos Sprague-Dawley , Succímero/síntese química , alfa-Tocoferol/síntese química , alfa-Tocoferol/química
17.
J Agric Food Chem ; 67(50): 13969-13977, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31747272

RESUMO

Various ß-galactosidase enzymes catalyze the trans-glycosylation reaction with lactose. The resulting galactooligosaccharide (GOS) mixtures are widely used in infant nutrition to stimulate growth of beneficial gut bacteria. GOS consists mainly of compounds with a degree of polymerization (DP) varying from 2-8 and with diverse glycosidic linkages. In recent years, we have elucidated in detail the composition of several commercial GOS mixtures in terms of DP and the structural identity of the individual compounds. In this work, 13 (single) probiotic strains of gut bacteria, belonging to 11 different species, were grown to stationary phase with a Vivinal GOS-derived sample purified to remove lactose and monosaccharides (pGOS). Growth among the probiotic strains varied strongly between 30 and 100% of OD600nm relative to positive controls with glucose. By identifying the components of the pGOS mixture that remain after growth, we showed that strains varied in their consumption of specific GOS compounds. All strains commonly used most of the GOS DP2 pool. Lactobacillus salivarius W57 also utilized the DP3 branched compound ß-d-Galp-(1 → 4)-[ß-d-Galp-(1 → 2)]-d-Glc. Bifidobacterial strains tended to use GOS with higher DP and branching than lactobacilli; Bifidobacterium breve DSM 20091, Lactobacillus acidophilus W37, and Bifidobacterium infantis DSM 20088 were exceptional in using 38, 36, and 35 compounds, respectively, out of the 40 different structures identified in pGOS. We correlated these bacterial GOS consumption profiles with their genomic information and were able to relate metabolic activity with the presence of genome-encoded transporters and carbohydrate-active enzymes. These detailed insights may support the design of synbiotic combinations pairing probiotic bacterial strains with GOS compounds that specifically stimulate their growth. Such synbiotic combinations may be of interest in food/feed and/or pharmacy/medicine applications.


Assuntos
Bifidobacterium/metabolismo , Lactobacillus/metabolismo , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Bifidobacterium/crescimento & desenvolvimento , Lactobacillus/crescimento & desenvolvimento , Lactobacillus acidophilus/crescimento & desenvolvimento , Lactobacillus acidophilus/metabolismo , Prebióticos/análise , Probióticos/metabolismo
18.
Int J Nanomedicine ; 14: 6691-6706, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31692515

RESUMO

Purpose: Amentoflavone, robustaflavone, 2'',3''-dihydro-3',3'''-biapigenin, 3',3'''-binaringenin and delicaflavone are five major active ingredients in the total biflavonoids extract from Selaginella doederleinii (TBESD) with favorable anticancer properties. However, the natural-derived potent antitumor agent of TBESD is undesirable due to its poor solubility. The present study was to develop and optimize a proliposomal formulation of TBESD (P-TBESD) to improve its solubility, oral bioavailability and efficacy. Materials and methods: P-TBESD containing a bile salt, a protective hydrophilic isomalto-oligosaccharides (IMOs) coating, were successfully prepared by thin film dispersion-sonication method. The physicochemical and pharmacokinetic properties of P-TBESD were characterized, and the antitumor effect was evaluated using the HT-29 xenograft-bearing mice models in rats. Results: Compared with TBESD, the relative bioavailability of amentoflavone, robustaflavone, 2'',3''-dihydro-3',3'''-biapigenin, 3',3'''-binaringenin and delicaflavone from P-TBESD were 669%, 523%, 761%, 955% and 191%, respectively. The results of pharmacodynamics demonstrated that both TBESD and P-TBESD groups afforded antitumor effect without systemic toxicity, and the antitumor effect of P-TBESD was significantly superior to that of raw TBESD, based on the tumor growth inhibition and histopathological examination. Conclusion: Hence, IMOs-modified proliposomes have promising potential for TBESD solving the problem of its poor solubility and oral bioavailability, which can serve as a practical oral preparation for TBESD in the future cancer therapy.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Biflavonoides/administração & dosagem , Lipossomos/administração & dosagem , Extratos Vegetais/administração & dosagem , Selaginellaceae/química , Administração Oral , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacocinética , Biflavonoides/farmacocinética , Biflavonoides/farmacologia , Ácidos e Sais Biliares/química , Disponibilidade Biológica , Células HT29 , Humanos , Lipossomos/química , Lipossomos/farmacocinética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oligossacarídeos/química , Extratos Vegetais/química , Ratos Sprague-Dawley , Solubilidade , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Org Biomol Chem ; 17(43): 9456-9466, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31642455

RESUMO

Many clinically-relevant biofilm-forming bacterial strains produce partially de-N-acetylated poly-ß-(1→6)-N-acetyl-d-glucosamine (dPNAG) as an exopolysaccharide. In Gram-negative bacteria, the periplasmic protein PgaB is responsible for partial de-N-acetylation of PNAG prior to its export to the extracellular space. In addition to de-N-acetylase activity found in the N-terminal domain, PgaB contains a C-terminal hydrolase domain that can disrupt dPNAG-dependent biofilms and hydrolyzes dPNAG but not fully acetylated PNAG. The role of this C-terminal domain in biofilm formation has yet to be determined in vivo. Further characterization of the enzyme's hydrolase activity has been hampered by a lack of specific dPNAG oligosaccharides. Here, we report the synthesis of a defined mono de-N-acetylated dPNAG penta- and hepta-saccharide. Using mass spectrometry analysis and a fluorescence-based thin-layer chromatography (TLC) assay, we found that our defined dPNAG oligosaccharides are hydrolase substrates. In addition to the expected cleavage site, two residues to the reducing side of the de-N-acetylated residue, minor cleavage products on the non-reducing side of the de-N-acetylation site were observed. These findings provide quantitative data to support how PNAG is processed in Gram-negative bacteria.


Assuntos
Acetilglucosamina/farmacologia , Amidoidrolases/metabolismo , Proteínas de Escherichia coli/metabolismo , Oligossacarídeos/farmacologia , Acetilação , Acetilglucosamina/síntese química , Acetilglucosamina/química , Biofilmes/efeitos dos fármacos , Hidrólise , Conformação Molecular , Oligossacarídeos/síntese química , Oligossacarídeos/química
20.
Int J Mol Sci ; 20(20)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614552

RESUMO

The incidence of diabetes mellitus (DM) is increasing rapidly and is associated with changes in dietary habits. Although restrictions in the use of sweeteners may prevent the development of DM, this might reduce the quality of life of patients with DM. Therefore, there has been a great deal of research into alternative sweeteners. In the search for such sweeteners, we analyzed the carbohydrate content of maple syrup and identified a novel oligosaccharide composed of fructose and glucose, linked at the C-4 of glucose and the C-6 of fructose. This oligosaccharide inhibited the release of fructose from sucrose by invertase (IC50: 1.17 mmol/L) and the decomposition of maltose by α-(1-4) glucosidase (IC50: 1.72 mmol/L). In addition, when orally administered together with sucrose to rats with DM, the subsequent plasma glucose concentrations were significantly lower than if the rats had been administered sucrose alone, without having any effect on the insulin concentration. These findings suggest that this novel oligosaccharide might represent a useful alternative sweetener for inclusion in the diet of patients with DM and may also have therapeutic benefits.


Assuntos
Acer/química , Diabetes Mellitus Tipo 2/dietoterapia , Oligossacarídeos/administração & dosagem , Sacarose/administração & dosagem , Administração Oral , Animais , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Humanos , Insulina/sangue , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Extratos Vegetais/química , Ratos , Sacarose/farmacologia
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