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1.
Int J Mol Sci ; 22(22)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34830042

RESUMO

Shigella is a leading diarrheal cause of morbidity and mortality worldwide, especially in low- and middle-income countries and in children under five years of age. Increasing levels of antimicrobial resistance make vaccine development an even higher global health priority. S. flexneri serotype 6 is one of the targets of many multicomponent vaccines in development to ensure broad protection against Shigella. The O-antigen (OAg) is a key active ingredient and its content is a critical quality attribute for vaccine release in order to monitor their stability and to ensure appropriate immune response. Here, the optimization of two methods to quantify S. flexneri 6 OAg is reported together with the characterization of their performances. The optimized Dische colorimetric method allows a tenfold increment of the sensitivity with respect to the original method and is useful for fast analysis detecting selectively methyl-pentoses, as rhamnose in S. flexneri 6 OAg. Also, a more specific HPAEC-PAD method was developed, detecting the dimer galacturonic acid-galactosamine (GalA-GalN) coming from S. flexneri 6 OAg acid hydrolysis. These methods will facilitate characterization of S. flexneri 6 OAg based vaccines. The colorimetric method can be used for quantification of other polysaccharide containing methyl-pentoses, and the HPAEC-PAD could be extended to other polysaccharides containing uronic acids.


Assuntos
Antígenos O/química , Antígenos O/isolamento & purificação , Shigella flexneri/química , Ácidos Hexurônicos/química , Ácidos Hexurônicos/isolamento & purificação , Pentoses/química , Pentoses/isolamento & purificação
2.
Sci Rep ; 7: 44538, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28425501

RESUMO

We describe an integrated and straightforward new analytical protocol that identifies plant gums from various sample sources including cultural heritage. Our approach is based on the identification of saccharidic fingerprints using mass spectrometry following controlled enzymatic hydrolysis. We developed an enzyme cocktail suitable for plant gums of unknown composition. Distinctive MS profiles of gums such as arabic, cherry and locust-bean gums were successfully identified. A wide range of oligosaccharidic combinations of pentose, hexose, deoxyhexose and hexuronic acid were accurately identified in gum arabic whereas cherry and locust bean gums showed respectively PentxHexy and Hexn profiles. Optimized for low sample quantities, the analytical protocol was successfully applied to contemporary and historic samples including 'Colour Box Charles Roberson &Co' dating 1870s and drawings from the American painter Arthur Dove (1880-1946). This is the first time that a gum is accurately identified in a cultural heritage sample using structural information. Furthermore, this methodology is applicable to other domains (food, cosmetic, pharmaceutical, biomedical).


Assuntos
Galactanos/química , Goma Arábica/química , Mananas/química , Pinturas/história , Gomas Vegetais/química , Sequência de Carboidratos , Galactanos/isolamento & purificação , Goma Arábica/isolamento & purificação , Hexoses/química , Hexoses/isolamento & purificação , Ácidos Hexurônicos/química , Ácidos Hexurônicos/isolamento & purificação , História do Século XIX , Humanos , Mananas/isolamento & purificação , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Pentoses/química , Pentoses/isolamento & purificação , Obras Pictóricas como Assunto , Gomas Vegetais/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
3.
J Chromatogr A ; 1487: 248-253, 2017 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-28139224

RESUMO

This work presents the development of a simple and efficient analytical protocol for the direct enantioselective resolution of sugars. A racemic mixture of the C3 sugar d,l-glyceraldehyde and the C5 monosaccharides d,l-arabinose, d,l-ribose, d,l-xylose, and d,l-lyxose was subjected to derivatization with trifluoroacetic anhydride, and corresponding derivatives were separated on a ß-cyclodextrin column with excellent resolution factors. Even though each aldopentose shows beside the linear form four predominant cyclic hemiacetals being the α- and ß-furanose along with the α- and ß-pyranose, we show that the overall enantiomeric excess of each compound can be precisely determined. Moreover, the measured detection limit for derivatized aldopentoses ranges from 0.015 to 0.019pmol on the column, while the quantification limit varies from 0.5 to 0.64pmol on the column.


Assuntos
Cromatografia Gasosa/métodos , Monossacarídeos/análise , Arabinose/análise , Arabinose/isolamento & purificação , Monossacarídeos/química , Monossacarídeos/isolamento & purificação , Pentoses/análise , Pentoses/isolamento & purificação , Ribose/análise , Ribose/isolamento & purificação , Estereoisomerismo , Xilose/análise , Xilose/isolamento & purificação
4.
Anal Bioanal Chem ; 407(20): 6201-6, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26044740

RESUMO

A novel method was developed for D/L-isomeric separation of aldopentoses and aldohexoses as their (S)-(+)-4-(N,N-dimethylaminosulfonyl)-7-(3-aminopyrrolidin-1-yl)-2,1,3-benzoxadiazole derivatives using phenylboronate buffer containing sodium dodecyl sulfate as a background electrolyte. The combination of derivatization with a chiral labeling reagent and micellar electrokinetic chromatography with phenylboronate made possible the efficient separation of D/L isomers as well as epimeric isomers of aldopentoses and aldohexoses. Laser-induced fluorescence detection permitted the micromolar-level determination of monosaccharide derivatives. The limit of detection was 105 amol (300 nM), and the repeatabilities of the migration times and peak area responses were 0.8 % and 7.9 % (relative standard deviation; n = 6), respectively. The method was applied to the determination of D/L- galactose in red seaweed.


Assuntos
Ácidos Borônicos/química , Hexoses/isolamento & purificação , Oxidiazóis/isolamento & purificação , Pentoses/isolamento & purificação , Sulfonamidas/isolamento & purificação , Cromatografia Capilar Eletrocinética Micelar/métodos , Galactose/análise , Galactose/isolamento & purificação , Hexoses/análise , Oxidiazóis/análise , Pentoses/análise , Alga Marinha/química , Estereoisomerismo , Sulfonamidas/análise
5.
Rapid Commun Mass Spectrom ; 26(24): 2897-904, 2012 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-23136020

RESUMO

RATIONALE: The structural characterization of unknown oligosaccharides remains a big challenge since a large number of isomeric structures are possible even for disaccharides. In this work, electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS) was used for the differentiation of isomeric pentose disaccharides, α-(1 → 5)-L-arabinobiose (Ara(2)) and ß-(1 → 4)-D-xylobiose (Xyl(2)). METHODS: ESI-MS/MS spectra of [M + Li](+) and [M + Na](+) ions of Ara(2) and Xyl(2), as well as these precursor ions of (18)O-labelled disaccharides, were acquired using two mass spectrometers equipped with different analyzers: LIT (linear ion trap) and Q-TOF (quadrupole time-of-flight). RESULTS: Product ions observed in MS/MS spectra arise from the cleavage at the nonreducing side of the glycosidic bond (Y(1)(+)) and from cross-ring cleavages (0,1)A(2)(+), (0,2)A(2)(+), and (0,3)A(2)(+) at the reducing residue. Statistically significant differences were observed between the relative abundance of specific product ions, when comparing both disaccharides. These differences allowed discriminant models to be built and to propose a criterion using the relative abundances of selected ions capable of discriminating between the isomers for both adduct ions and spectrometers. CONCLUSIONS: Isomeric pentose disaccharides can be distinguished based on the fragmentation of both [M + Li](+) and [M + Na](+) ions and using different mass spectrometers. However, LIT instrument has a better discriminant power.


Assuntos
Dissacarídeos/química , Pentoses/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Cátions/química , Cátions/isolamento & purificação , Dissacarídeos/isolamento & purificação , Análise Discriminante , Isomerismo , Lítio/química , Modelos Moleculares , Pentoses/isolamento & purificação , Sódio/química
6.
Bioresour Technol ; 102(19): 9261-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21788133

RESUMO

Operational conditions for the hydrolysis of rape straw were optimized using the combined severity index (CS), which combines the effects of time, temperature, and acid concentration into a single parameter. The sugar recovery yield was 77.8% of the theoretical yield at a value of CS=1.3. A maximum concentration of xylose of 7.22 g/L was obtained when the straw was treated for 10 min at a low reaction temperature (150 °C) and high acid concentration (pH 1.17). The pentose-rich hydrolyzate exhibited a low concentration of fermentation-inhibiting compounds. The concept of CS can be conveniently and effectively applied for optimization of pretreatments.


Assuntos
Brassica rapa/química , Pentoses/isolamento & purificação , Caules de Planta/química , Temperatura , Ácidos , Cromatografia Líquida de Alta Pressão , Fermentação , Concentração de Íons de Hidrogênio , Hidrólise , Pentoses/análise , Fatores de Tempo
7.
Molecules ; 16(7): 5905-15, 2011 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-21760572

RESUMO

To investigate the separations of all aldopentoses (ribose, arabinose, xylose and lyxose) and aldohexoses (glucose, galactose, allose, altrose, mannose, gulose, idose and talose) on the D6 stationary phase prepared by the reaction of chloromethylated styrene-divinylbenzene copolymer and N,N,N',N'-tetramethyl-1,6-diaminohexane, we examined the effect of varying the concentration of the NaOH eluent on the elution orders. Separations of these aldoses were achieved using a 20 mM NaOH eluent. The elution behaviors of the aldoses were probably due to not only the individual pK(a) values, but also the chemical structures of the cyclic aldoses.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Diaminas/química , Hexoses/isolamento & purificação , Pentoses/isolamento & purificação , Polímeros/química , Poliestirenos/química , Arabinose/isolamento & purificação , Galactose/isolamento & purificação , Glucose/isolamento & purificação , Manose/isolamento & purificação , Ribose/isolamento & purificação , Xilose/isolamento & purificação
8.
J Chromatogr A ; 1216(44): 7415-21, 2009 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-19362721

RESUMO

Using an HPLC column packed with monodispersed vinylbenzeneboronic acid-divinylbenzene (V-D) copolymer resins, the elution behaviors of the mono- and disaccharides were studied under different pH mobile phases. The monodispersed V-D copolymer resins were prepared by the copolymerization of 4-vinylbenzeneboronic acid and divinylbenzene in the presence of template silica gel particles (particle size: 5 microm; pore size: 10 nm), followed by dissolution of the template silica gel using a NaOH solution. Similarly, styrene-divinylbenzene (S-D) copolymer resins as the control resins were also synthesized. The transmission electron micrographs of these polymer resins revealed a good monodispersity. The complexation behavior of the saccharides was evaluated by comparison of the peak area eluted through the V-D column for that through the S-D column. Four aldopentoses (D-ribose, D-arabinose, D-xylose, and D-lyxose) and four aldohexoses (D-glucose, D-mannose, D-galactose, and D-talose) were retained completely at pH 11.9. Especially, ribose and talose were totally retained even under acidic and neutral conditions. For the disaccharides, unlike sucrose and maltose, palatinose was completely retained in basic mobile phases.


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Polímeros/química , Estireno/química , Galactose/isolamento & purificação , Glucose/isolamento & purificação , Lactonas/isolamento & purificação , Manose/isolamento & purificação , Estrutura Molecular , Pentoses/isolamento & purificação , Porosidade , Ribose/isolamento & purificação , Estireno/isolamento & purificação , Xilose/isolamento & purificação
9.
J Chem Ecol ; 34(11): 1411-21, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18815840

RESUMO

Root exudates were collected over a 27 day period from defoliated and non-defoliated Lolium perenne L. plants grown under sterile conditions in microlysimeters. Eleven individual sugars, including both aldehyde and alcohol sugars, were identified and quantified with a gas chromatograph-mass spectrometer (GC-MS). There was no change in the number of sugars present between 7 and 27 days, but the exudation of alcohol sugars decreased rapidly at about day 12. Xylose and glucose were present in the largest amounts. Defoliation initially increased the total amount of sugars in the exudates, but continuous defoliation reduced total sugar exudation by 16% and induced changes in the exudation patterns of individual sugars. Defoliation enhanced exudation of erythritol, threitol, and xylitol, reduced exudation of glucose and arabitol, but had little effect on the amounts of other sugars exuded. The more complex 6 C, 5 OH aldehyde sugars, especially glucose, showed changes earlier and to a greater extent (17 days), than the 5 C, 4 OH (xylose and ribose) and 6 C 4 OH (fucose) aldehyde groups. These findings confirm the general finding that repeated defoliation reduces the quantity of total sugars exuded, but the pattern of release of individual sugars is complex and variable.


Assuntos
Álcoois/análise , Aldeídos/análise , Carboidratos/química , Lolium/metabolismo , Raízes de Plantas/metabolismo , Transporte Biológico , Carboidratos/biossíntese , Carboidratos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Hexoses/isolamento & purificação , Lolium/química , Lolium/crescimento & desenvolvimento , Pentoses/isolamento & purificação , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/química , Raízes de Plantas/crescimento & desenvolvimento , Fatores de Tempo
10.
J Chromatogr A ; 1101(1-2): 115-21, 2006 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-16253266

RESUMO

A new high performance liquid chromatographic (HPLC) method is described for the analysis of ribose, arabinose and ribulose mixtures obtained from (bio)chemical isomerization processes. These processes gain importance since the molecules can be used for the synthesis of antiviral therapeutics. The HPLC method uses boric acid as a mobile phase additive to enhance the separation on an Aminex HPX-87K column. By complexing with boric acid, the carbohydrates become negatively charged, thus elute faster from the column by means of ion exlusion and are separated because the complexation capacity with boric acid differs from one carbohydrate to another. Excellent separation between ribose, ribulose and arabinose was achieved with concentrations between 0.1 and 10 gL(-1) of discrete sugar.


Assuntos
Arabinose/isolamento & purificação , Ácidos Bóricos/química , Cromatografia Líquida de Alta Pressão/métodos , Pentoses/isolamento & purificação , Ribose/isolamento & purificação , Aldose-Cetose Isomerases/metabolismo , Arabinose/metabolismo , Cromatografia Líquida de Alta Pressão/instrumentação , Pentoses/metabolismo , Reprodutibilidade dos Testes , Estereoisomerismo
11.
Electrophoresis ; 24(21): 3828-33, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14613212

RESUMO

1-Phenyl-3-methyl-5-pyrazolone (PMP) derivatives of monosaccharides were analyzed by electrophoresis on a quartz microchip with whole-channel UV detection. Rapid separation of PMP derivatives of aldopentoses was achieved by plain-zone electrophoresis in a neutral phosphate buffer with the height equivalent to a theoretical plate at the micrometer level. Zone electrophoresis as borate complexes was also successful for the separation of PMP derivatives of a few aldoses, which were separated within 1 min. Separation by microchip electrophoresis was compared to that by capillary electrophoresis, and the difference was discussed in terms of column efficiency and sample column capacity.


Assuntos
Antipirina/análogos & derivados , Eletroforese Capilar/métodos , Monossacarídeos/química , Monossacarídeos/isolamento & purificação , Oligossacarídeos/química , Edaravone , Eletroforese Capilar/instrumentação , Sequestradores de Radicais Livres , Hexoses/química , Hexoses/isolamento & purificação , Indicadores e Reagentes , Oligossacarídeos/isolamento & purificação , Pentoses/química , Pentoses/isolamento & purificação , Reprodutibilidade dos Testes , alfa-Amilases
12.
Appl Biochem Biotechnol ; 105 -108: 547-55, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12721434

RESUMO

A new approach for the utilization of hemicellulosic hydrolysate from sugarcane bagasse is described. This approach consists of using the hydrolysate to dilute the conventional feedstock (sugarcane juice) to the usual sugar concentration (150 g/L) employed for the industrial production of ethanol. The resulting sugar mixture was used as the substrate to evaluate the performance of a continuous reactor incorporating a cell recycle module, operated at several dilution rates. An induced flocculent pentose-fermenting yeast strain was used for this bioconversion. Under the conditions used, the reactor performance was satisfactory at substrate feed rates of 30 g/(L h) or less, corresponding to an ethanol productivity of about 11.0 g/(L h) and an overall sugar conversion >95%. These results show real advantages over the existing alternatives for a better exploitation of surplus bagasse to increase industrial alcohol production.


Assuntos
Celulose/química , Etanol/metabolismo , Pentoses/metabolismo , Pichia/fisiologia , Biotecnologia/instrumentação , Biotecnologia/métodos , Etanol/isolamento & purificação , Fermentação , Hidrólise , Cinética , Pentoses/isolamento & purificação , Pichia/crescimento & desenvolvimento , Polissacarídeos/química , Polissacarídeos/metabolismo
13.
J Chromatogr A ; 873(2): 247-56, 2000 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-10757302

RESUMO

Chemically bonded silica gels were prepared in a capillary by pumping an ethanolic solution of a silylating reagent, such as octadecyltrimethoxysilane, 3-aminopropyltrimethoxysilane and dimethyloctadecyltrimethoxysilylpropylammonium chloride into a heated capillary packed with bare silica particles. The silylation reactions were completed in a short time and thus-prepared columns showed high column efficiency and high reproducibility. Examples are shown for the separation of 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives of aldopentoses on a 3-aminopropylated silica column and benzoate homologues as well as PMP derivatives of the component monosaccharides of glycoproteins on an octadecylammonium column. Since the presence of frit filters hampers high efficiency separation, an attempt was made to fix the bed of modified silica gel particles to the capillary inner wall by a cross-linking technique. The results indicated that this technique is promising.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Pentoses/isolamento & purificação , Dióxido de Silício
14.
Carbohydr Res ; 306(1-2): 291-6, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9691453

RESUMO

A lipopolysaccharide (LPS) isolated from Coxiella burnettii in virulent phase I contains in its O-polysaccharide chain two unusual sugars, virenose (6-deoxy-3-C-methylgulose) and dihydrohydroxystreptose [3-C-(hydroxymethyl)lyxose]. The sugars were isolated from LPS I, after acid hydrolysis and removal of lipid A, by a combination of HPLC and preparative paper chromatography. Their enantiomeric forms and ring conformations were established from optical rotation and NMR data. Two-dimensional COSY, HSQC, and HMBC as well as one- and two-dimensional NOEs were used to assign all proton and carbon signals in both monosaccharides. Virenose was found to be the D-gulo enantiomer with the 4C1 ring conformation and dihydrohydroxystreptose was shown to be the L-lyxo enantiomer also with the 4C1 conformation. The latter sugar was reported [S. Schramek, J. Radziejewska-Lebrecht, and H. Mayer, Eur. J. Biochem., 148 (1985) 455-461] to be present in LPS I in a furanose form, and it appears that a furanose to pyranose tautomerization took place in the course of the isolation procedure.


Assuntos
Coxiella burnetii/química , Desoxiaçúcares/química , Endotoxinas/química , Pentoses/química , Configuração de Carboidratos , Cromatografia Líquida de Alta Pressão , Desoxiaçúcares/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Rotação Ocular , Pentoses/isolamento & purificação
16.
Biochem J ; 193(2): 513-24, 1981 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-6272710

RESUMO

The D-ribulokinase and D-xylulokinase of Klebsiella aerogenes were purified to homogeneity from Escherichia coli K12 construct strains that synthesized these enzymes constitutively. The D-ribulokinase, which is encoded in the ribitol operon, is active as a dimer of 60 000 subunit mol.wt., whereas the D-xylulokinase, which is encoded in the D-arabitol operon, is active as a dimer of 54 000 subunit mol.wt. The amino acid compositions and N-terminal sequences of both pentulokinases are reported. The Kapp. values of the enzymes for their D-pentulose substrates were determined, and the D-ribulokinase was shown to have a low-affinity side-specificity for ribitol and D-arabitol. These results are discussed in the context of the evolution of the Klebsiella aerogenes pentitol operons.


Assuntos
Klebsiella pneumoniae/enzimologia , Fosfotransferases (Aceptor do Grupo Álcool) , Fosfotransferases/isolamento & purificação , Aminoácidos/análise , Eletroforese em Gel de Poliacrilamida , Cinética , Peso Molecular , Pentoses/isolamento & purificação , Especificidade por Substrato
17.
Arch Androl ; 1(1): 69-75, 1978.
Artigo em Inglês | MEDLINE | ID: mdl-570379

RESUMO

A substance apparently related to a compound consisting of phospho-peptide and ribulose-peptide in the yolk of chick embryos was isolated from acid soluble fractions of human semen by means of Dowex 1 (OH) form column chromatography. The treated precipitate of human semen was examined with an analytical ultracentrifuge by means of synthetic boundary cells and found to be a single component. The sedimentation coefficient was 0.80. The sugar component in the precipitate was identified as ribulose by paper chromatography, color reaction, absorption spectrum of the reaction product in the orcinol, and enzymatic analysis. Amino acids detected in the acid hydrolysate of the precipitate were lysine, histidine, arginine, aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, valine, isoleucine, and leucine. From the above, this substance was determined to be a ribulose-peptide.


Assuntos
Pentoses/isolamento & purificação , Peptídeos/isolamento & purificação , Sêmen/análise , Cromatografia em Papel , Humanos , Masculino
18.
J Antibiot (Tokyo) ; 29(7): 685-7, 1976 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-956053

RESUMO

A deoxypentulose has been isolated from the fermentations of a new soil isolate of Streptomyces hygroscopicus (UC-5601). It was found to inhibit weakly and specifically the growth of one strain of Mycobacterium avium (UC-159).


Assuntos
Antibacterianos/isolamento & purificação , Pentoses/isolamento & purificação , Animais , Antibacterianos/biossíntese , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Meios de Cultura , Desoxiaçúcares/isolamento & purificação , Fermentação , Camundongos , Streptomyces/metabolismo
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