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1.
Electron. j. biotechnol ; 44: 1-5, Mar. 2020. graf, tab
Artigo em Inglês | LILACS | ID: biblio-1087706

RESUMO

Background: Freeze-drying is known as one of the best methods to preserve bacterial strains. Protectant is the key factor affecting the survival rate of freeze-dried strains. In addition, salinity, bacterial suspension concentration, drying time, and other factors can also affect the survival rate of strains to varying degrees. At present, there are relatively few studies on freeze-drying preservation of marine bacteria. In the present study, we performed the freeze-drying protectant screening and optimized the preservation conditions for Pseudoalteromonas nigrifaciens, which is widely distributed in marine environment. The protective effects of the screened protectants were verified by 18 other marine bacterial strains. Results: The results indicated that the combination of 5.0% (w/v) lactose, 5.0% (w/v) mannitol, 5.0% (w/v) trehalose, 10.0% (w/v) skim milk powder, 0.5% (w/v) ascorbic acid and 0.5% (w/v) gelatin was the best choice for the preservation of P. nigrifaciens. The suggested salinity and concentration of initial cell suspension were 10 g/L NaCl and 1.0 × 109 CFU/mL, respectively. Furthermore, stationary-phase cells were the best choice for the freeze-drying process. The highest survival rate of P. nigrifaciens reached 52.8% when using 5­10% (w/v) skim milk as rehydration medium. Moreover, the other 18 marine strains belonging to Pseudoalteromonas, Vibrio, Photobacterium, Planomicrobium, Edwardsiella, Enterococcus, Bacillus, and Saccharomyces were freezedried under the abovementioned conditions. Their survival rates were 2.3­95.1%. Conclusion: Collectively, our results supported that the protectant mixture and parameters were beneficial for lyophilization of marine bacteria


Assuntos
Preservação Biológica/métodos , Pseudoalteromonas/fisiologia , Liofilização/métodos , Trealose/química , Sobrevivência Celular , Fenômenos Fisiológicos Bacterianos , Dissacarídeos/química , Viabilidade Microbiana , Salinidade , Lactose/química , Manitol/química
2.
Carbohydr Polym ; 227: 115312, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590876

RESUMO

Low molecular weight heparin (LMWH) possesses a dual function of anticoagulation and anti-inflammation. While the structures and mechanisms on its anticoagulation have been widely studied, the structural features responsible for the anti-inflammatory activity of LMWH remain to be explored. In the present study, guided by an anti-inflammation assay, a non-anticoagulant species was generated from partial desulfation of LMWH to fully retain the anti-inflammatory activity, from which five fractions were further separated and three of them were characterized by enzymatic degradation, hydrophobic labeling, C18-based HPLC and LC-MS/MS analyses. The structure-activity relationship revealed that the sulfate groups in LMWH are critical to distinguish and separate the activities of anticoagulation and anti-inflammation, leading to the identification of a synthetic heparosan-type heptasaccharide as a potent anti-inflammatory agent. The present strategy enables the simplification of complex polysaccharides to bioactive synthetic oligosaccharides for therapeutic utility.


Assuntos
Anti-Inflamatórios/farmacologia , Anticoagulantes/química , Dissacarídeos/farmacologia , Heparina de Baixo Peso Molecular/química , Sulfatos/química , Animais , Anti-Inflamatórios/química , Dissacarídeos/química , Fator Xa/química , Heparina Liase/química , Lipopolissacarídeos/farmacologia , Camundongos , Óxido Nítrico/metabolismo , Protrombina/química , Células RAW 264.7
3.
Int J Nanomedicine ; 14: 8943-8959, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819411

RESUMO

Objective: The study was designed to investigate the therapeutic potential of lactobionic acid (LA) conjugated quercetin (Q) loaded organically modified silica nanoparticles (LA-Q-ORMOSIL) with bulk quercetin to mitigate cyclophosphamide (CP) induced liver injury. Methodology: Q-ORMOSIL nanoparticles were synthesized and characterized using UV-Vis spectroscopy, TEM, Zeta sizer, FTIR and EDX. Further, encapsulation efficiency and in vitro release kinetic study was done. Q-ORMOSIL nanoparticles surface were modified with lactobionic acid, a ligand for the asialoglycoprotein receptor on the hepatocyte surface. The hepatoprotective effects of Q-ORMOSIL and LA-Q-ORMOSIL nanoparticles were evaluated in vivo. Cyclophosphamide (20 mg/kg/day, i.p) was co-administered for seven days with bulk quercetin (50mg/kg/day) and quercetin nanoparticles (50µg/kg/day). After seven days, the number of biomarkers for liver function test and oxidative stress were determined in liver homogenate. Histopathological changes were also analyzed in control and treated liver tissues. Results: Physiochemical characterization of LA-Q-ORMOSIL nanoparticles depicts that the particles formed were of approx. 80 nm, spherical, monodispersed in nature and showed sustain drug release in in vitro study. Our results further suggested that Q-ORMOSIL and LA-Q-ORMOSIL nanoparticles significantly decreased tissue TBARS, ROS levels and ALT, AST, and ALP activities compared to CP induced group. On the other hand, tissue antioxidant levels (GSH, GST, and catalase) showed a significant increase in LA-Q-ORMOSIL treated group compared to the CP treated group confirming its high therapeutic efficacy during liver injury. Conclusion: Targeted nanoquercetin demonstrated a significant hepatoprotective effect compared to bulk quercetin against CP-induced hepatotoxicity and it considerably reduced bulk quercetin dose level to many folds. Bulk quercetin has low bioavailability and thus, from obtained data we suggest that LA-Q-ORMOSIL nanoparticles provide high therapeutic value in protecting experimental animals against CP-induced liver injury. We also propose multifunctional dye-doped LA-modified ORMOSIL nanoparticles for future studies in facilitating nanoparticles uptake to hepatocytes for liver diagnosis and treatment.


Assuntos
Ciclofosfamida/efeitos adversos , Dissacarídeos/química , Fígado/patologia , Nanopartículas/química , Quercetina/farmacologia , Dióxido de Silício/química , Alanina Transaminase/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Antioxidantes/farmacologia , Aspartato Aminotransferases/metabolismo , Catalase/metabolismo , Liberação Controlada de Fármacos , Cinética , Fígado/efeitos dos fármacos , Masculino , Nanopartículas/ultraestrutura , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
4.
Nat Commun ; 10(1): 4057, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492849

RESUMO

Simultaneous imaging and treatment of infections remains a major challenge, with most current approaches being effective against only one specific group of bacteria or not being useful for diagnosis. Here we develop multifunctional nanoagents that can potentially be used for imaging and treatment of infections caused by diverse bacterial pathogens. The nanoagents are made of fluorescent silicon nanoparticles (SiNPs) functionalized with a glucose polymer (e.g., poly[4-O-(α-D-glucopyranosyl)-D-glucopyranose]) and loaded with chlorin e6 (Ce6). They are rapidly internalized into Gram-negative and Gram-positive bacteria by a mechanism dependent on an ATP-binding cassette (ABC) transporter pathway. The nanoagents can be used for imaging bacteria by tracking the green fluorescence of SiNPs and the red fluorescence of Ce6, allowing in vivo detection of as few as 105 colony-forming units. The nanoagents exhibit in vivo photodynamic antibacterial efficiencies of 98% against Staphylococcus aureus and 96% against Pseudomonas aeruginosa under 660 nm irradiation.


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Fotoquimioterapia/métodos , Antibacterianos/química , Antibacterianos/farmacocinética , Infecções Bacterianas/microbiologia , Dissacarídeos/química , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/fisiologia , Humanos , Nanopartículas/química , Porfirinas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Radiossensibilizantes/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
5.
J Agric Food Chem ; 67(38): 10744-10755, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31525900

RESUMO

We previously reported that ß-glucosidase BGL1 at low concentration (15 µg mL-1) from Coprinopsis cinerea exhibited hydrolytic activity only toward laminarioligosaccharides but not toward cellooligosaccharides and gentiobiose. This study shows that BGL1 at high concentration (200 µg mL-1) also hydrolyzed cellobiose and gentiobiose, which accounted for only 0.83 and 2.05% of its activity toward laminaribiose, respectively. Interestingly, BGL1 at low concentration (1.5 µg mL-1) showed transglycosylation but BGL1 at high concentration (200 µg mL-1) did not. BGL1 utilizes only laminarioligosaccharides but not glucose, gentiobiose, and cellobiose to synthesize the higher oligosaccharides. BGL1 transferred one glucosyl residue from substrate laminarioligosaccharide to another laminarioligosaccharide as an acceptor in a ß(1 → 3) or ß(1 → 6) fashion to produce higher laminarioligosaccharides or 3-O-ß-d-gentiobiosyl-d-laminarioligosaccharides. The BGL1-digested laminaritriose exhibited approximately 90% enhancement in the anti-oxidant activity compared to that of untreated laminaritriose, implying a potential application of BGL1-based transglycosylation for the production of high value-added rare oligosaccharides.


Assuntos
Agaricales/enzimologia , Dissacarídeos/metabolismo , Proteínas Fúngicas/química , Oligossacarídeos/metabolismo , beta-Glucosidase/química , Agaricales/química , Agaricales/genética , Sequência de Aminoácidos , Dissacarídeos/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glicosilação , Hidrólise , Cinética , Estrutura Molecular , Oligossacarídeos/química , Especificidade por Substrato , beta-Glucosidase/genética , beta-Glucosidase/metabolismo
6.
Molecules ; 24(18)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500198

RESUMO

Glycosides are ubiquitous plant secondary metabolites consisting of a non-sugar component called an aglycone, attached to one or more sugars. One of the most interesting aglycones in grapes and wine is methyl salicylate (MeSA), an organic ester naturally produced by many plants, particularly wintergreens. To date, nine different MeSA glycosides from plants have been reported, mainly spread over the genera Gaultheria, Camellia, Polygala, Filipendula, and Passiflora. From a sensorial point of view, MeSA has a balsamic-sweet odor, known as Wintergreen. MeSA was found in Vitis riparia grapes, in Vitis vinifera sp. and in the Frontenac interspecific hybrid. We found that the MeSA glycosides content in Verdicchio wines and in some genetically related varieties (Trebbiano di Soave and Trebbiano di Lugana) was very high. In order to understand which glycosides were present in wine, the methanolic extract of Verdicchio wine was injected into a UPLC-Q-TOF-HDMS and compared to the extracts of different plants rich in such glycosides. Using pure standards, we confirmed the existence of two glycosides in wine: MeSA 2-O--d-glucoside and MeSA 2-O--d-xylopyranosyl (1-6) -d-glucopyranoside (gaultherin). For the first time, we also tentatively identified other diglycosides in wine: MeSA 2-O--l-arabinopyranosyl (1-6)--d-glucopyranoside (violutoside) and MeSA 2-O--d-apiofuranosyl (1-6)--d-glucopyranoside (canthoside A), MeSA 2-O--d-glucopyranosyl (1-6)-O--d-glucopyranoside (gentiobioside) and MeSA 2-O--l-rhamnopyranosyl (1-6)--d-glucopyranoside (rutinoside). Some of these glycosides have been isolated from Gaultheria procumbens leaves by preparative liquid chromatography and structurally annotated by 1H- and 13C-NMR analysis. Two of the peaks isolated from Gaultheria procumbens leaves, namely MeSA sambubioside and MeSA sophoroside, were herein observed for the first time. Six MeSA glycosides were quantified in 64 Italian white wines, highlighting the peculiar content and pattern in Verdicchio wines and related cultivars. The total concentration in bound and free MeSA in Verdicchio wines varied in the range of 456-9796 g/L and 5.5-143 g/L, respectively, while in the other wines the bound and free MeSA was below 363 g/L and 12 g/L, respectively. As this compound's olfactory threshold is between 50 and 100 g/L, our data support the hypothesis that methyl salicylate can contribute to the balsamic scent, especially in old Verdicchio wines.


Assuntos
Glicosídeos/química , Salicilatos/química , Vitis/química , Vinho/análise , Cromatografia Líquida , Dissacarídeos/química , Dissacarídeos/isolamento & purificação , Glicosídeos/classificação , Glicosídeos/isolamento & purificação , Humanos , Extratos Vegetais/química , Folhas de Planta/química , Salicilatos/classificação , Salicilatos/isolamento & purificação
7.
Mater Sci Eng C Mater Biol Appl ; 104: 109914, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500030

RESUMO

To improve the clinical efficiency of cytotoxic anticancer drugs e.g. doxorubicin (DOX), reduce the severe off-target side effects, and allow the more biocompatible and biodegradable drug penetration into tumor cells, our research efforts developed a new DOX-conjugated protein polymer nanoconjugates (PPNCs) prodrugs delivery system. Briefly, DOX was conjugated to bovine serum albumin (BSA) and the complex was treated with lactobionic acid (LA) as well as folic acid (FA) to enhance drug endocytosis and targeting selectivity. Such functionalized BSA could be conjugated with a designed phenylboronic acid functionalized poly(N-isopropylacrylamide) (PNIPAAm) via forming a pH-sensitive borate ester bond to give the functionalized PPNCs prodrugs. The potential of the PPNCs prodrugs on tumor cells therapy was systematically evaluated in dose/time-dependent effects. In vitro results showed a rapid accumulation of the prodrugs into the MDA-MB-231 tumor cell during the first 30 min and reached maximum at 24 h. Moreover, the cell-killing effect was observed quickly after 4 h incubation with an IC50 of 0.5 mg/mL (≈4 µM/L). In general, given the efficient pH-dependent DOX release of these constructed nanoconjugates, it is anticipated to contribute a potential delivery strategy for cancer therapy.


Assuntos
Boratos/química , Sistemas de Liberação de Medicamentos , Ésteres/química , Nanoconjugados/química , Polímeros/química , Soroalbumina Bovina/química , Animais , Antineoplásicos/farmacologia , Ácidos Borônicos/química , Bovinos , Linhagem Celular Tumoral , Dissacarídeos/química , Doxorrubicina/farmacologia , Ácido Fólico/química , Humanos , Concentração de Íons de Hidrogênio , Pró-Fármacos/farmacologia , Fatores de Tempo
8.
Chem Commun (Camb) ; 55(81): 12204-12207, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31549691

RESUMO

Perfluorophenylboronic acid 1c catalyzes the direct stereoselective addition of alcohol nucleophiles to deactivated peracetylated d-galactal to give 2-deoxygalactosides in 55-88% yield with complete α-selectivity. The unprecedented results reported here also enable the synthesis of disaccharides containing the 2-deoxygalactose moiety directly from the deactivated peracetylated d-galactal. This convenient and metal-free glycosylation method works well with a wide range of alcohol nucleophiles as acceptors and tolerates a range of functional groups without the formation of the Ferrier byproduct and without the need for a large excess of nucleophiles or additives. The method is potentially useful for the synthesis of a variety of α-2-deoxygalactosides.


Assuntos
Ácidos Borônicos/química , Galactose/análogos & derivados , Galactosídeos/síntese química , Acetilação , Catálise , Dissacarídeos/química , Galactose/química , Glicosilação , Estrutura Molecular , Solventes/química , Estereoisomerismo , Temperatura
9.
J Chem Phys ; 151(3): 034504, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31325935

RESUMO

Although by now the glass transition temperature of uncrystallized bulk water is generally accepted to manifest at temperature Tg near 136 K, not much known are the spectral dispersion of the structural α-relaxation and the temperature dependence of its relaxation time τα,bulk(T). Whether bulk water has the supposedly ubiquitous Johari-Goldstein (JG) ß-relaxation is a question that has not been answered. By studying the structural α-relaxation over a wide range of temperatures in several aqueous mixtures without crystallization and with glass transition temperatures Tg close to 136 K, we deduce the properties of the α-relaxation and the temperature dependence of τα,bulk(T) of bulk water. The frequency dispersion of the α-relaxation is narrow, indicating that it is weakly cooperative. A single Vogel-Fulcher-Tammann (VFT) temperature dependence can describe the data of τα,bulk(T) at low temperatures as well as at high temperatures from neutron scattering and GHz-THz dielectric relaxation, and hence, there is no fragile to strong transition. The Tg-scaled VFT temperature dependence of τα,bulk(T) has a small fragility index m less than 44, indicating that water is a "strong" glass-former. The existence of the JG ß-relaxation in bulk water is supported by its equivalent relaxation observed in water confined in spaces with lengths of nanometer scale and having Arrhenius T-dependence of its relaxation times τconf(T). The equivalence is justified by the drastic reduction of cooperativity of the α-relaxation in nanoconfinement and rendering it to become the JG ß-relaxation. Thus, the τconf(T) from experiments can be taken as τß,bulk(T), the JG ß-relaxation time of bulk water. The ratio τα,bulk(Tg)/τß,bulk(Tg) is smaller than most glass-formers, and it corresponds to the Kohlrausch α-correlation function, exp[-(t/τα,bulk)1-n], having (1-n) = 0.90. The dielectric data of many aqueous mixtures and hydrated biomolecules with Tg higher than that of water show the presence of a secondary ν-relaxation from the water component. The ν-relaxation is strongly connected to the α-relaxation in properties, and hence, it belongs to the special class of secondary relaxations in glass-forming systems. Typically, its relaxation time τν(T) is longer than τß,bulk(T), but τν(T) becomes about the same as τß,bulk(T) at sufficiently high water content. However, τν(T) does not become shorter than τß,bulk(T). Thus, τß,bulk(T) is the lower bound of τν(T) for all aqueous mixtures and hydrated biomolecules. Moreover, it is τß,bulk(T) but not τα(T) that is responsible for the dynamic transition of hydrated globular proteins.


Assuntos
Biopolímeros/química , Modelos Químicos , Água/química , Animais , Dissacarídeos/química , Glicogênio/química , Monossacarídeos/química , Mytilus/química , Polissacarídeos/química , Ribonuclease Pancreático/química , Termodinâmica
10.
J Pharm Biomed Anal ; 174: 639-643, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31279893

RESUMO

Heparin is a carbohydrate polymer, which is clinically used as an anticoagulant for the treatment of thrombotic disorders. The anticoagulant process is mainly mediated by the interaction of heparin with antithrombin followed by inhibition of clotting factors IIa (FIIa) and Xa (FXa). The influence of polymer disaccharide structure, average molecular weight and impurity profiling (e.g., chloride and water content) was investigated by NMR spectrometry and principal component analysis (PCA) for a representative dataset of porcine heparin samples (n = 509). A significant linear dependence was found between anticoagulant activity and scores on the third principal component (PC3) based on the non-targeted analysis of 1H NMR fingerprints. The correlation between average molecular values and anticoagulant activity for the 24 porcine heparin samples from two manufacturers was linear (R = 0.85) over typical values for porcine heparin preparations. Chloride and water contents were identified as negatively influencing factors for the actual activity values as their presence decrease the "pharmaceutically active" organic part of heparin preparations. Some suggestions regarding manufacturing process are made according to the results.


Assuntos
Anticoagulantes/análise , Heparina/análise , Espectroscopia de Ressonância Magnética , Animais , Anticoagulantes/química , Cloretos/química , Dissacarídeos/química , Fator Xa/química , Inibidores do Fator Xa/análise , Inibidores do Fator Xa/química , Heparina/química , Heparina de Baixo Peso Molecular/análise , Modelos Lineares , Peso Molecular , Polímeros/química , Análise de Componente Principal , Protrombina/química , Suínos , Água/química
11.
ACS Appl Mater Interfaces ; 11(30): 26731-26744, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31268657

RESUMO

Herein, both strategies of synergistic drug combination together with dual active tumor targeting were combined for effective therapy of hepatocellular carcinoma (HCC). Therefore, based on the tumor sensitizing action, the herbal quercetin (QRC) was co-delivered with the targeted therapeutic drug sorafenib (SFB), preformulated as phospholipid complex, via protein shell-oily core nanocapsules (NCs). Inspired by the targeting action of lactoferrin (LF) via binding to LF receptors overexpressed by HCC cells, LF shell was electrostatically deposited onto the drug-loaded oily core to elaborate LF shell-oily core NCs. For dual tumor targeting, lactobionic acid (LA) or glycyrrhetinic acid (GA) was individually coupled to LF shell for binding to asialoglycoprotein and GA receptors on liver cancer cells, respectively. Compared to LF and GA/LF NCs, the dual-targeted LA/LF-NCs showed higher internalization into HepG2 cells with 2-fold reduction in half-maximal inhibitory concentration compared to free combination therapy after 48 h. Moreover, dual-targeted LF-NCs showed powerful in vivo antitumor efficacy. It was revealed as significant downregulation of the mRNA expression levels of nuclear factor-kappa B and tumor necrosis factor α as well as suppression of Ki-67 protein expression level in diethylnitrosamine (DEN)-induced HCC mice (P < 0.05). Furthermore, dual-targeted LF-NCs attenuated the liver toxicity induced by DEN in animal models. Overall, this study proposes dual-targeted LF-NCs for combined delivery of SFB and QRC as a potential therapeutic HCC strategy.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Lactoferrina/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Nanocápsulas/química , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Dietilnitrosamina/química , Dietilnitrosamina/farmacologia , Dissacarídeos/química , Sistemas de Liberação de Medicamentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ácido Glicirretínico/química , Células Hep G2 , Humanos , Antígeno Ki-67/genética , Lactoferrina/química , Lactoferrina/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos , NF-kappa B/genética , Fitoterapia
12.
J Pharm Biomed Anal ; 174: 104-114, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31163344

RESUMO

The bioproduction of lactobionic acid and its salts can be performed by enzymatic complex glucose-fructose oxidoreductase (GFOR) and glucono-δ-lactonase (GL) of Zymomonas mobilis. Considering the applicability of these compounds in pharmaceutical area, the aim of this study was to assess the accelerated and long-term stability studies of sodium, potassium, calcium lactobionate, and lactobionic acid. Furthermore, stress tests were performed to evaluate the stability against pH, temperature and oxidation. The samples submitted to degradation tests were analyzed by high-performance liquid chromatography (HPLC) and high-resolution mass spectrometry analysis (HRMS-ESI-QTOF). Sodium, potassium, and calcium lactobionate were stable for six months of analyses considering the accelerated (40 °C and 75% RH) and long-term (30 °C and 75% RH) stability studies. The presence of lactobiono-δ-lactone and a significant increase in moisture were observed for both biosynthesized and commercially available lactobionic acid samples. Against the forced degradation tests, all the lactobionate salts and lactobionic acid showed to be stable upon alkaline and acid pH conditions, at 60 and 80 °C, and also against UV light exposition. Furthermore, the presence of lactobiono-δ-lactone form was observed in lactobionic acid samples. However, the degradation of both lactobionic acid and lactobionate salts was evident in the presence of hydrogen peroxide. This degradation kinetic profile suggests, that lactobionate salts follows a zero-order reaction model and lactobionic acid follows a second-order kinetic. The MS analysis of the main degradation product suggests a molecular formula C11H20O10 resulting from the oxidative decarboxylation. This report brings an amount of results as contribution to the scarce information regarding the chemical and physical-chemical stability of sodium, potassium, calcium lactobionate, and lactobionic acid. These data may be useful and serve as reference, in view of the multipurpose applications of the cited compounds.


Assuntos
Cálcio/química , Dissacarídeos/química , Potássio/química , Sódio/química , Zymomonas/química , Reatores Biológicos , Descarboxilação , Estabilidade de Medicamentos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Cinética , Lactonas , Espectrometria de Massas , Estresse Oxidativo , Oxirredutases/química , Oxigênio/química , Temperatura , Raios Ultravioleta
13.
Appl Microbiol Biotechnol ; 103(16): 6771-6782, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31222385

RESUMO

Heparin and chondroitin sulfate are used as anti-thrombic and anti-osteoarthritis drugs, respectively, but their pharmacological actions depend on their structural characteristics such as their sulfation grade and their molecular weight. In the last years, new fermentation-based biotechnological approaches have tried to obtain heparin and chondroitin sulfate starting from the heparosan and chondroitin-like capsular polysaccharides produced by Escherichia coli K5 and K4. The study of the microbial capsular polysaccharide molecular weight is critical to obtain nature-like or structural tailor cut glycosaminoglycan homologues. However, so far, it has been scarcely investigated. In this paper, for the first time, a new protocol was set up to determine the molecular weights of the capsular polysaccharides of three wild-type and three engineered E. coli K5 and K4 strains. The protocol includes a small-scale downstream train to purify the intact polysaccharides, directly from the fermentation broth supernatants, by using ultrafiltration membranes and anion exchange chromatography, and it couples size exclusion chromatography analyses with triple detector array. In the purification high recovery (> 85.0%) and the removal of the main contaminant, the lipopolysaccharide, were obtained. The averaged molecular weights of the wild-type capsular polysaccharides ranged from 51.3 to 90.9 kDa, while the engineered strains produced polysaccharides with higher molecular weights, ranging from 68.4 to 130.6 kDa, but with similar polydispersity values between 1.1 and 1.5.


Assuntos
Condroitina/química , Dissacarídeos/química , Escherichia coli/química , Engenharia Metabólica , Polissacarídeos Bacterianos/química , Condroitina/metabolismo , Cromatografia em Gel , Meios de Cultura/química , Dissacarídeos/metabolismo , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Peso Molecular , Polissacarídeos Bacterianos/metabolismo , Ultrafiltração
14.
Acta Crystallogr F Struct Biol Commun ; 75(Pt 6): 399-404, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31204685

RESUMO

ß-1,4-Galactanases are glycoside hydrolases that are involved in the degradation of pectin and belong to family 53 in the classification of glycoside hydrolases. Previous studies have elucidated the structures of several fungal and two bacterial galactanases, while biochemical studies have indicated differences in the product profiles of different members of the family. Structural studies of ligand complexes have to date been limited to the bacterial members of the family. Here, the first structure of a fungal galactanase in complex with a disaccharide is presented. Galactobiose binds to subsites -1 and -2, thus improving our understanding of ligand binding to galactanases.


Assuntos
Aspergillus/enzimologia , Dissacarídeos/química , Dissacarídeos/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/metabolismo , Modelos Moleculares , Cristalografia por Raios X , Conformação Proteica , Especificidade por Substrato
15.
Int J Toxicol ; 38(1_suppl): 5S-38S, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31170840

RESUMO

The Cosmetic Ingredient Review Expert Panel (Panel) assessed the safety of 25 monosaccharides, disaccharides, and related ingredients and concluded these are safe in the present practices of use and concentration described in the safety assessment. Many of these ingredients are common dietary sugars, dietary sugar replacements, or very closely related analogs and salts; 7 of the ingredients are listed by the Food and Drug Administration as generally recognized as safe food substances. The most commonly reported cosmetic function is as a skin-conditioning agent; other commonly reported functions are use as a humectant or as a flavoring agent. The Panel reviewed the animal and clinical data included in this assessment, acknowledged that the oral safety of many of these ingredients has been well established, and found it appropriate to extrapolate the existing information to conclude on the safety of all the monosaccharides, disaccharides, and related ingredients.


Assuntos
Cosméticos/toxicidade , Dissacarídeos/toxicidade , Monossacarídeos/toxicidade , Animais , Qualidade de Produtos para o Consumidor , Cosméticos/química , Cosméticos/farmacocinética , Dissacarídeos/química , Dissacarídeos/farmacocinética , Humanos , Monossacarídeos/química , Monossacarídeos/farmacocinética , Exposição Ocupacional/normas , Medição de Risco
16.
J Agric Food Chem ; 67(26): 7297-7303, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31244198

RESUMO

3,6-Anhydro-l-galactose (AHG) produced from agarose in red macroalgae was recently suggested as an anticariogenic sugar to replace widely used xylitol. However, the multi-step process for obtaining monomeric sugar AHG from agarose may be expensive. Generally, it is easier to obtain oligosaccharides than monosaccharides from polysaccharides. Therefore, a one-step process to obtain agarobiose (AB) from agarose was recently developed, and here, we suggest AB as a new anticariogenic agent, owing to its anticariogenic activity against Streptococcus mutans. Among AHG-containing oligosaccharides, AB, neoagarobiose (NAB), agarooligosaccharides (AOSs), and neoagarooligosaccharides (NAOSs), AB showed higher inhibitory activity than AOSs against the growth and lactic acid production of S. mutans; no such inhibitory activity was observed for NAB and NAOSs. This inhibitory effect of AB was comparable to the previously reported inhibitory activity of AHG against S. mutans. These results suggest that AB, which can be more economically and simply produced than AHG, may serve as an anticariogenic sugar.


Assuntos
Antibacterianos/farmacologia , Dissacarídeos/farmacologia , Oligossacarídeos/farmacologia , Extratos Vegetais/farmacologia , Rodófitas/química , Alga Marinha/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Dissacarídeos/química , Dissacarídeos/isolamento & purificação , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento
17.
Biomater Sci ; 7(7): 2850-2860, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31070204

RESUMO

Glycosaminoglycans (GAGs) are important components of the extracellular matrix that have attracted great interest for drug delivery and pharmaceutical applications due to their diverse biological functions. Among GAGs, heparosan (Hep), a biosynthetic precursor of heparin, has recently emerged as a promising building block for the design of nanoparticles with stealth properties. Though this non-sulfated polysaccharide has a chemical structure very close to that of hyaluronic acid (HA), it distinguishes from HA in that it is biologically inert in the extracellular spaces in the body. In this study, we designed Hep- and HA-based nanogels (NGs) that differ only in the chemical nature of the hydrophilic shell. The nanogels were prepared in a very straightforward way from Hep and HA modified with a thermoresponsive copolymer properly designed to induce self-assembly below room temperature. This versatile synthetic approach also enabled further shell-crosslinking allowing an increase in the colloidal stability. After careful characterization of the un-crosslinked and crosslinked Hep and HA NGs in terms of size (Z-average diameters of un-crosslinked and crosslinked NGs ∼110 and 150 nm) and morphology, they were injected intravenously into tumor-bearing mice for biodistribution experiments. Interestingly, these show that the liver uptake of Hep nanogels is remarkably reduced and tumor accumulation significantly improved as compared to HA nanogels (intensity ratios of tumor-to-liver of 2.2 and 1.4 for the un-crosslinked and crosslinked Hep NGs versus 0.11 for the un-crosslinked and crosslinked HA ones). These results highlight the key role played by the shell-forming GAGs on the in vivo fate of nanogels, which correlates with the specific biological properties of Hep and HA.


Assuntos
Antineoplásicos/química , Dissacarídeos/química , Portadores de Fármacos/química , Ácido Hialurônico/química , Nanoestruturas/química , Animais , Dissacarídeos/farmacocinética , Portadores de Fármacos/farmacocinética , Interações Hidrofóbicas e Hidrofílicas , Masculino , Metacrilatos/química , Camundongos , Polietilenoglicóis/química , Temperatura , Distribuição Tecidual , Células Vero
18.
Methods Mol Biol ; 1985: 383-389, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31069747

RESUMO

Nonaqueous capillary electrophoresis (NACE) is an effective method for chiral separation. Many polyol derivatives (e.g., D-(+)-xylose, lactobionic acid, diacetone-D-mannitol, L-sorbose, and D-gluconic acid δ-lactone) can react with boric acid in methanol to produce polyol derivative-boric acid complexes which can be utilized as chiral selectors of enantioseparations. The enantiomers of more than a dozen basic analytes can be resolved under the optimized NACE using these chiral selectors.


Assuntos
Ácidos Bóricos/química , Eletroforese Capilar/métodos , Polímeros/química , Acetona/química , Dissacarídeos/química , Manitol/química , Estereoisomerismo
19.
Chemistry ; 25(39): 9272-9279, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31099933

RESUMO

There is a growing interest in the preparation of polyfluorinated carbohydrates. A limited number of fluorohexopyranosides have been used in biological investigations because of the synthetic challenge they present. Hence, we report the synthesis of fluorinated homodimer, fluorodisaccharides, C-terminal fluoroglycopeptides, lipoic acid fluoroglycoconjugate and trifluoroallopyranoside derivatives functionalized at C-6. Our strategy uses levoglucosan as inexpensive starting material and facilitates an approach to complex carbohydrate analogues with multiple C-F bonds. The challenge of our synthetic route centered around an efficient preparation of crucial 1,6-anhydro-2,4-dideoxy-difluoroglucopyranose and focused on achieving a difficult glycosylation of the trifluoroallopyranose donor. The results clearly highlight challenges related to the preparation of polyhalogenated complex organic molecules and pave the way to access novel medically relevant tools.


Assuntos
Carboidratos/química , Glucose/química , Dissacarídeos/química , Fluoretação , Glucose/análogos & derivados , Glicoconjugados/química , Piranos/química , Estereoisomerismo
20.
Eur J Med Chem ; 175: 187-200, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31078866

RESUMO

The inability to discover novel class of antibacterial agents, especially against Gram-negative bacteria (GNB), compel us to consider a broader non-conventional approach to treat infections caused by multidrug-resistant (MDR) bacteria. One such approach is the use of adjuvants capable of revitalizing the activity of current existing antibiotics from resistant pathogens. Recently, our group reported a series of tobramycin (TOB)-based hybrid adjuvants that were able to potentiate multiple classes of legacy antibiotics against various MDR GNB. Herein, we report the modification of TOB-based hybrid adjuvants by replacing TOB domain by the pseudo-disaccharide nebramine (NEB) through selective cleavage of the α-d-glucopyranosyl linkage of TOB. Potent synergism was found for combinations of NEB-based hybrid adjuvants with multiple classes of legacy antibiotics including fluoroquinolones (moxifloxacin and ciprofloxacin), tetracyclines (minocycline), or rifamycin (rifampicin) against both wild-type and MDR P. aeruginosa clinical isolates. We also demonstrated that a combination of the optimized NEB-CIP hybrid 1b and rifampicin protects Galleria mellonella larvae from the lethal effects of extensively drug-resistant (XDR) P. aeruginosa. Mechanistic evaluation of NEB-based hybrid adjuvants revealed that the hybrids affect the outer- and inner membranes of wild-type P. aeruginosa PAO1. This study describes an approach to optimize aminoglycoside-based hybrids to yield lead adjuvant candidates that are able to resuscitate the activity of partner antibiotics against MDR GNB.


Assuntos
Antibacterianos/farmacologia , Dissacarídeos/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Piranos/química , Animais , Antibacterianos/administração & dosagem , Antibacterianos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Sinergismo Farmacológico , Quimioterapia Combinada , Células HEK293 , Hemólise/efeitos dos fármacos , Humanos , Larva/efeitos dos fármacos , Lepidópteros/crescimento & desenvolvimento , Lepidópteros/microbiologia , Testes de Sensibilidade Microbiana , Espectroscopia de Prótons por Ressonância Magnética , Pseudomonas aeruginosa/efeitos dos fármacos , Rifampina/administração & dosagem , Espectrometria de Massas por Ionização por Electrospray , Suínos
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