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1.
Cell Signal ; 115: 111040, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38199596

RESUMEN

MBIP is a component of the Ada2A containing complex (ATAC) and has been identified as a susceptibility gene in several cancers. However, the role and molecular mechanism of MBIP in esophageal squamous cell carcinoma (ESCC) remain unclear. Our finding indicated that the expression level of MBIP in ESCC was higher than that in normal tissue (P < 0.05) based on the data from the Cancer Gene Atlas (TCGA) and Gene Expression Omnibus (GEO). Kaplan-Meier analysis showed that high MBIP expression was closely associated with deeper invasion and worse prognosis. Transwell assay and mouse xenograft assay demonstrated that MBIP overexpression promoted migration and invasion in vitro and in vivo, while MBIP knockdown played the opposite role. Furthermore, the results of RNA-seq, qRT-PCR, western blotting and rescue experiments revealed that MBIP promoted epithelial-mesenchymal transition (EMT) via the phosphorylation JNK/p38 in ESCC. Our study indicates that MBIP plays a significant role in the prognosis and metastasis of ESCC, suggesting that MBIP might serve as an ESCC prognostic biomarker.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Metilglicósidos , Animales , Ratones , Humanos , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas/patología , Neoplasias Esofágicas/metabolismo , Proliferación Celular/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Movimiento Celular/genética , Transición Epitelial-Mesenquimal/genética , Invasividad Neoplásica/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo
2.
Acta Crystallogr C Struct Chem ; 77(Pt 10): 668-674, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34607990

RESUMEN

Methyl ß-lactoside [methyl ß-D-galactopyranosyl-(1→4)-ß-D-glucopyranoside] monohydrate, C13H24O11·H2O, (I), was obtained via spontaneous transformation of methyl ß-lactoside methanol solvate, (II), during air-drying. Cremer-Pople puckering parameters indicate that the ß-D-Galp (ß-D-galactopyranosyl) and ß-D-Glcp (ß-D-glucopyranosyl) rings in (I) adopt slightly distorted 4C1 chair conformations, with the former distorted towards a boat form (BC1,C4) and the latter towards a twist-boat form (O5SC2). Puckering parameters for (I) and (II) indicate that the conformation of the ßGalp ring is slightly more affected than the ßGlcp ring by the solvomorphism. Conformations of the terminal O-glycosidic linkages in (I) and (II) are virtually identical, whereas those of the internal O-glycosidic linkage show torsion-angle changes of 6° in both C-O bonds. The exocyclic hydroxymethyl group in the ßGalp residue adopts a gt conformation (C4' anti to O6') in both (I) and (II), whereas that in the ßGlcp residue adopts a gg (gauche-gauche) conformation (H5 anti to O6) in (II) and a gt (gauche-trans) conformation (C4 anti to O6) in (I). The latter conformational change is critical to the solvomorphism in that it allows water to participate in three hydrogen bonds in (I) as opposed to only two hydrogen bonds in (II), potentially producing a more energetically stable structure for (I) than for (II). Visual inspection of the crystalline lattice of (II) reveals channels in which methanol solvent resides and through which solvent might exchange during solvomorphism. These channels are less apparent in the crystalline lattice of (I).


Asunto(s)
Metilglicósidos/química , Cristalografía por Rayos X , Enlace de Hidrógeno , Conformación Molecular , Solventes , Agua/química
3.
Biotechnol Appl Biochem ; 67(3): 354-365, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31746015

RESUMEN

One-pot synthesis of sugar-functionalized oligomeric caprolactone was carried out by lipase-catalyzed esterification of ε-caprolactone (ECL) with methyl-d-glucopyranoside (MGP) followed by the elongation of functionalized oligomer chain. Functionalization was performed in a custom-fabricated glass reactor equipped with Rushton turbine impeller and controlled temperature at 60 °C using tert-butanol as reaction medium. The overall reaction steps include MGP esterification of ECL monomer and its subsequent elongation by free 6-hydroxyhexanoate monomer units. A ping-pong bi-bi mechanism without ternary complex was proposed for esterification of ECL and MGP with apparent values of kinetic constant, namely maximal velocity (Vmax ), Michaelis constant for MGP (KmMGP ), and Michaelis constant for ECL (KmECL ) at 3.848 × 10-3  M H-1 , 8.189 × 10-2  M, and 6.050 M, respectively. Chain propagation step of MGP-functionalized ECL oligomer exhibits the properties of living polymerization mechanism. Linear relationship between conversion (%) and number average molecular weight, Mn (g mol-1 ), of functionalized oligomer was observed. Synthesized functionalized oligomer showed narrow range of molecular weight from 1,400 to 1,600 g mol-1 with more than 90% conversion achieved. Structural analysis confirmed the presence of covalent bond between the hydroxyl group in MGP with carboxyl end group of ECL oligomer.


Asunto(s)
Caproatos/metabolismo , Hidroxiácidos/metabolismo , Lactonas/metabolismo , Lipasa/metabolismo , Metilglicósidos/metabolismo , Biocatálisis , Caproatos/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Esterificación , Hidroxiácidos/química , Lactonas/química , Lipasa/química , Metilglicósidos/química , Estructura Molecular
4.
Int J Mol Sci ; 20(15)2019 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-31382488

RESUMEN

Galectins are a family of galactoside-recognizing proteins involved in different galectin-subtype-specific inflammatory and tumor-promoting processes, which motivates the development of inhibitors that are more selective galectin inhibitors than natural ligand fragments. Here, we describe the synthesis and evaluation of 3-C-methyl-gulopyranoside derivatives and their evaluation as galectin inhibitors. Methyl 3-deoxy-3-C-(hydroxymethyl)-ß-d-gulopyranoside showed 7-fold better affinity for galectin-1 than the natural monosaccharide fragment analog methyl ß-d-galactopyranoside, as well as a high selectivity over galectin-2, 3, 4, 7, 8, and 9. Derivatization of the 3-C-hydroxymethyl into amides gave gulosides with improved selectivities and affinities; methyl 3-deoxy-3-C-(methyl-2,3,4,5,6-pentafluorobenzamide)-ß-d-gulopyranoside had Kd 700 µM for galectin-1, while not binding any other galectin.


Asunto(s)
Galectina 1/antagonistas & inhibidores , Metilglicósidos/química , Metilglicósidos/farmacología , Sitios de Unión , Polarización de Fluorescencia , Galectina 1/química , Galectina 1/metabolismo , Humanos , Ligandos , Unión Proteica
5.
mBio ; 10(4)2019 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-31289181

RESUMEN

Neisseria gonorrhoeae is a significant threat to global health for which a vaccine and novel treatment options are urgently needed. Glycans expressed by human cells are commonly targeted by pathogens to facilitate interactions with the host, and thus characterization of these interactions can aid identification of bacterial receptors that can be exploited as vaccine and/or drug targets. Using glycan array analysis, we identified 247 specific interactions between N. gonorrhoeae and glycans representative of those found on human cells. Interactions included those with mannosylated, fucosylated, and sialylated glycans, glycosaminoglycans (GAGs), and glycans terminating with galactose (Gal), N-acetylgalactosamine (GalNAc), and N-acetylglucosamine (GlcNAc). By investigating the kinetics of interactions with selected glycans, we demonstrate that whole-cell N. gonorrhoeae has a high affinity for mannosylated glycans (dissociation constant [KD ], 0.14 to 0.59 µM), which are expressed on the surface of cervical and urethral epithelial cells. Using chromatography coupled with mass spectrometric (MS) analysis, we identified potential mannose-binding proteins in N. gonorrhoeae Pretreatment of cells with mannose-specific lectin (concanavalin A) or free mannose competitor (α-methyl-d-mannopyranoside) substantially reduced gonococcal adherence to epithelial cells. This suggests that N. gonorrhoeae targets mannosyl glycans to facilitate adherence to host cells and that mannosides or similar compounds have the potential to be used as a novel treatment option for N. gonorrhoeaeIMPORTANCE Multidrug-resistant strains of Neisseria gonorrhoeae are emerging worldwide, and novel treatment and prevention strategies are needed. Glycans are ubiquitously expressed by all human cells and can be specifically targeted by pathogens to facilitate association with host cells. Here we identify and characterize the N. gonorrhoeae host-glycan binding profile (glycointeractome), which revealed numerous interactions, including high-affinity binding to mannosyl glycans. We identify gonococcal potential mannose-binding proteins and show that N. gonorrhoeae uses mannosyl glycans expressed on the surface of cervical and urethral epithelia to facilitate adherence. Furthermore, a mannose-binding lectin or a mannoside compound was able to reduce this adherence. By characterizing the glycointeractome of N. gonorrhoeae, we were able to elucidate a novel mechanism used by this important pathogen to interact with human cells, and this interaction could be exploited to develop novel therapeutics to treat antibiotic-resistant gonorrhea.


Asunto(s)
Adhesión Bacteriana/fisiología , Cuello del Útero/citología , Células Epiteliales/microbiología , Interacciones Huésped-Patógeno , Neisseria gonorrhoeae/metabolismo , Polisacáridos/metabolismo , Uretra/citología , Adhesión Bacteriana/efectos de los fármacos , Células Cultivadas , Concanavalina A/farmacología , Células Epiteliales/efectos de los fármacos , Femenino , Gonorrea/microbiología , Humanos , Masculino , Lectina de Unión a Manosa/metabolismo , Metilglicósidos/farmacología , Análisis por Micromatrices , Neisseria gonorrhoeae/efectos de los fármacos , Neisseria gonorrhoeae/patogenicidad
6.
Carbohydr Res ; 472: 122-126, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30579118

RESUMEN

A new synthetic route for formation of a central cycloheptanone intermediate leading to the nortropane alkaloid calystegine B2 is described. The approach installs the desired ketone functionality directly in a ring-closing metathesis step. The target compound was prepared over 10 steps from commercially available methyl α-d-xylopyranoside.


Asunto(s)
Metilglicósidos/química , Nortropanos/síntesis química , Alcaloides Solanáceos/síntesis química , Cicloheptanos/química , Estructura Molecular , Nortropanos/química , Alcaloides Solanáceos/química , Estereoisomerismo , Xilosa/análogos & derivados , Xilosa/química
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 3614-3617, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30441159

RESUMEN

This paper presents an elbow training device using the Mechanically Adjustable Stiffness Actuator(MASA) for stroke survivors with hemiplegia. The MASA is a series elastic actuator whose mechanical stiffness is variable. Stiffness and the neutral position of the spring is mechanically changed using two identical actuators. Since assisting torque of the actuators is transmitted through the springs, changing stiffness of the MASA results in different level of assistance by the actuators. Then, according to the performance of the patients during given tracking tasks, the level of assistance is controlled via changing stiffness. A prototype of the rehabilitation device using the MASA is introduced and a preliminary experiments with 10 healthy subjects show the level of assistance changes.


Asunto(s)
Codo , Robótica , Diseño de Equipo , Humanos , Metilglicósidos , Torque
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 153: 363-73, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26342821

RESUMEN

A structural investigation of the organic molecules is being carried out using vibrational spectroscopy. In this study, normal co-ordinate calculations of anomers of the methyl-D-glucopyranoside and methyl-ß-D-xylopyranoside in the crystalline state have been performed using the modified Urey-Bradley-Shimanouchi force field (mUBSFF) combined with an intermolecular potential energy function. The latter includes Van der Waals interactions, electrostatic terms, and explicit hydrogen bond functions. The vibrational spectra of the compounds recorded in the crystalline state, in the 4000-500 cm(-1) spectral region for the IR spectra, and in the 4000-20 cm(-1) spectral range for the Raman spectra are presented. After their careful examination, several differences in the intensities and frequency shifts have been observed. The theoretical spectra have been obtained after a tedious refinement of the force constants. Thus, on the basis of the obtained potential distribution, each observed band in IR and in Raman has been assigned to a vibrational mode. The obtained results are indeed in agreement with those observed experimentally and thus confirm the previous assignments made for the methyl-α and ß-D-glucopyranoside, as well as for the methyl-ß-D-xylopyranoside.


Asunto(s)
Metilglucósidos/química , Metilglicósidos/química , Monosacáridos/química , Espectrometría Raman , Vibración , Xilosa/química , Conformación de Carbohidratos , Cristalización , Cristalografía por Rayos X , Enlace de Hidrógeno , Isomerismo , Metilación , Electricidad Estática , Termodinámica
9.
Clin Biochem ; 48(18): 1350-3, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26297117

RESUMEN

OBJECTIVE: We devised iduronate-2-sulfatase (IDS) enzyme activity assays by combining fluorometric substrate and LC-MS/MS based detection. DESIGN AND METHODS: 4-Methylumbelliferyl α-L-idopyranosiduronic acid 2-sulfate (IDS-S) was used as a substrate for IDS. Its enzymatic product, 4-methylumbelliferyl α-L-idopyranosiduronic acid (IDS-P) and internal standard, 4-methylumbelliferyl α-L-idopyranoside (IDS-IS), were directly measured by UPLC-MS/MS. We determined the precision of our enzyme assay and the effects of sample amounts and incubation time based on the results. Dried blood spots (DBSs) of 110 normal newborns and three patients with Hunter disease were analyzed. RESULTS: IDS-IS, IDS-P and IDS-S were fully separated using UPLC without any ion suppressions. The intra- and inter-assay precisions were 8.5-10.5% and 11.9-15.3%, respectively. The amount of product obtained was proportional to the number of DBSs and increased linearly with the incubation period from 0 to 15 h. The enzyme activities in DBSs from three patients with MPS II were markedly lower than those in the DBSs of 110 normal newborns. CONCLUSION: To the best of our knowledge, this is the first report describing the use of LC-MS/MS for the diagnosis of Hunter disease with a commercially available substrate. Our method would be a rapid and effective screening tool for the diagnosis of Hunter disease with further study.


Asunto(s)
Bioensayo , Glicoproteínas/sangre , Mucopolisacaridosis II/sangre , Tamizaje Neonatal/métodos , Biomarcadores/sangre , Cromatografía Líquida de Alta Presión , Pruebas con Sangre Seca/instrumentación , Expresión Génica , Glicoproteínas/genética , Humanos , Ácido Idurónico/análogos & derivados , Recién Nacido , Metilglicósidos/química , Mucopolisacaridosis II/diagnóstico , Mucopolisacaridosis II/genética , Espectrometría de Masas en Tándem
10.
Chin J Nat Med ; 13(7): 507-20, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26233841

RESUMEN

This paper reports a pharmacophylogenetic study of a medicinal plant family, Ranunculaceae, investigating the correlations between their phylogeny, chemical constituents, and pharmaceutical properties. Phytochemical, ethnopharmacological, and pharmacological data were integrated in the context of the systematics and molecular phylogeny of the Ranunculaceae. The chemical components of this family included several representative metabolic groups: benzylisoquinoline alkaloids, ranunculin, triterpenoid saponin, and diterpene alkaloids, among others. Ranunculin and magnoflorine were found to coexist in some genera. The pharmacophylogenetic analysis, integrated with therapeutic information, agreed with the taxonomy proposed previously, in which the family Ranunculaceae was divided into five sub-families: Ranunculoideae, Thalictroideae, Coptidoideae, Hydrastidoideae, and Glaucidioideae. It was plausible to organize the sub-family Ranunculoideae into ten tribes. The chemical constituents and therapeutic efficacy of each taxonomic group were reviewed, revealing the underlying connections between phylogeny, chemical diversity, and clinical use, which should facilitate the conservation and sustainable utilization of the pharmaceutical resources derived from the Ranunculaceae.


Asunto(s)
Alcaloides/análisis , Biodiversidad , Filogenia , Extractos Vegetales/química , Ranunculaceae/química , Saponinas/análisis , Terpenos/análisis , Alcaloides/uso terapéutico , Aporfinas/análisis , Aporfinas/uso terapéutico , Furanos/análisis , Humanos , Metilglicósidos/análisis , Fitoterapia , Extractos Vegetales/uso terapéutico , Plantas Medicinales/química , Saponinas/uso terapéutico , Terpenos/uso terapéutico
11.
Phys Chem Chem Phys ; 16(22): 10286-94, 2014 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-24569595

RESUMEN

Methyl xylopyranoside containing three 4-(pyrene-1-yl)benzoyl groups (PyXy) undergoes conformational interchange within a Langmuir monolayer upon mechanical compression. This xylose-type molecular machine PyXy was immobilized within two different matrix lipids, methyl stearate and methyl 2,3,4-tri-O-stearoyl-ß-D-xylopyranoside, which respectively form rigid and soft monolayers. Structural properties of the monolayer were characterized by assessing the compressibility, compression modulus, and ideal limiting molecular area of PyXy, all of which were estimated from the π-A isotherm measurements. Only the rigid monolayer exhibited a transition to the condensed phase with a limiting molecular area of PyXy smaller than that of the cross-sectional area of the xylopyranose ring in its C1 chair conformation. This suggests conformational interchange of PyXy from the most stable (4)C1 (C1) form to the metastable (1)C4 (1C) form. Surface-reflective fluorescence spectroscopy of the monolayer was applied to detect excimer emission resulting from the face-to-face dimerization of pyrenes attached at the O-2 and O-4 positions of xylose. Fluorescence intensity of the excimer increased abruptly in the condensed region only when the rigid monolayer was applied. These results indicate that the rigidity of the matrix monolayer is a critical aspect of the precise manipulation of molecular machines at interfaces. Consequently, this study demonstrates that including a molecular machine into a rigid lipid matrix is a promising means for the preparation of a novel nanoassembly with dynamic functionalities variable depending on a mechanical stimulus.


Asunto(s)
Metilglicósidos/química , Agua/química , Aire , Metilglicósidos/síntesis química , Conformación Molecular
12.
Int J Food Microbiol ; 165(3): 209-13, 2013 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-23803568

RESUMEN

Corn tortillas are a staple in the diet among the Mexican population, and are traditionally produced through a process known as nixtamalization. This traditional process involves steeping whole-kernel corn in an alkaline solution overnight and then grinding the corn into dough (masa), which is then baked. While the masa is held before baking, significant microbial change can occur which leads to fermentation and spoilage. The objective of this research was to characterize and identify the microflora of nixtamalized corn masa from six different commercial tortilla mills throughout Guadalajara, Mexico. The identification of samples was conducted using the microbial identification system (MIS), which analyzes cellular fatty acids via gas chromatography to identify bacterial species. Lactic acid bacteria and aerobic mesophiles were the predominant organisms, with both groups having counts ranging from 10(4) to 10(7)cfu/g across all mills. Coliform populations were observed at counts of 10(2) to 10(3)cfu/g, while yeast and mold counts were typically less than 10(1)cfu/g. Some mills showed no presence of coliforms or yeast or mold. Streptococcus bovis and Lactobacillus oris were isolated from all mills, and were the most prevalent organisms representing 43% and 17% of all lactic acid bacteria isolated, respectively. S. bovis was also isolated on the aerobic tryptic soy plates and was the most prevalent species representing 19% of the total organisms from these aerobic plates.


Asunto(s)
Biodiversidad , Manipulación de Alimentos , Microbiología de Alimentos , Zea mays/microbiología , Técnicas de Tipificación Bacteriana , Recuento de Colonia Microbiana , Lactobacillus/aislamiento & purificación , Metilglicósidos/química , México , Levaduras/aislamiento & purificación , Zea mays/química
13.
Chemistry ; 18(38): 12059-67, 2012 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-22893559

RESUMEN

The interactions between 3-O-methyl-mannose polysaccharides (MMPs), extracted from Mycobacterium smegmatis (consisting of a mixture of MMP-10, -11, -12 and -13) or obtained by chemical synthesis (MMP-5(s), -8(s), -11(s) and -14(s)), and linear saturated and unsaturated fatty acids (FAs), and a commercial mixture of naphthenic acids (NAs) in aqueous solution at 25 °C and pH 8.5 were quantified by electrospray ionization mass spectrometry (ESI-MS). Association constants (K(a)) for MMP binding to four FAs (myristic acid, palmitic acid, stearic acid and trans-parinaric acid) were measured by using an indirect ESI-MS assay, the "proxy protein" method. The K(a) values are in the 10(4)-10(5) M(-1) range and, based on results obtained for the binding of the synthetic MMPs with palmitic acid, increase with the size of the carbohydrate. Notably, the measured affinity of the extracted MMPs for trans-parinaric acid is two orders of magnitude smaller than the reported value, which was determined by using a fluorescence assay. Using a newly developed competitive binding assay, referred to as the "proxy protein/proxy ligand" ESI-MS method, it was shown that MMPs bind specifically to NAs in aqueous solution, with apparent affinities of approximately (5×10(4)) M(-1) for the mixture of NAs tested. This represents the first demonstration that MMPs can bind to hydrophobic species more complex than those containing linear alkyl/alkenyl chains. Moreover, the approach developed here represents a novel method for probing carbohydrate-lipid interactions.


Asunto(s)
Carbohidratos/química , Ácidos Carboxílicos/química , Lípidos/química , Metilglicósidos/química , Metilmanósidos/química , Mycobacterium/química , Ácidos Palmíticos/química , Polisacáridos/química , Soluciones/química , Conformación Molecular , Estructura Molecular , Espectrometría de Masa por Ionización de Electrospray
14.
J Chem Ecol ; 38(8): 996-1002, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22711029

RESUMEN

Growing evidence suggests that the freely accessible pollen of some plants is chemically protected against pollen-feeding flower visitors. For example, a diet of pollen from buttercup plants (Ranunculus) recently was shown to have a deleterious effect on developing larvae of several bee species not specialized on Ranunculus. Numerous Ranunculus species contain ranunculin, the glucosyl hydrate form of the highly reactive and toxic lactone protoanemonin, that causes the toxicity of these plants. We tested whether the presence of ranunculin is responsible for the lethal effects of R. acris pollen on the larvae of two bee species that are not Ranunculus specialists. To investigate the effect on bee larval development, we added ranunculin to the pollen provisions of the Campanula specialist bee Chelostoma rapunculi and the Asteraceae specialist bee Heriades truncorum, and allowed the larvae to feed on these provisions. We quantified ranunculin in pollen of R. acris and in brood cell provisions collected by the Ranunculus specialist bee Chelostoma florisomne. We demonstrated that although ranunculin was lethal to both tested bee species in high concentrations, the concentration in the pollen of R. acris was at least fourfold lower than that tolerated by the larvae of C. rapunculi and H. truncorum in the feeding experiments. Ranunculin concentration in the brood cells of C. florisomne was on average even twentyfold lower than that in Ranunculus pollen, suggesting that a mechanism different from ranunculin intoxication accounts for the larval mortality reported for bees not specialized on Ranunculus pollen.


Asunto(s)
Abejas/efectos de los fármacos , Furanos/toxicidad , Metilglicósidos/toxicidad , Polen/química , Animales , Abejas/crecimiento & desarrollo , Furanos/química , Estimación de Kaplan-Meier , Larva/efectos de los fármacos , Metilglicósidos/química , Ranunculus/metabolismo
15.
Carbohydr Res ; 353: 92-5, 2012 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-22533917

RESUMEN

The protecting group tetraisopropyldisiloxane-1,3-yl has been investigated for simultaneous protection of two hydroxyls on pentopyranosides. Methyl α-D-xylopyranoside is protected in excellent regioselectivity and high yield to form the 2,3-protected xylopyranoside whereas methyl ß-D-xylopyranoside gives the 3,4-protected product also with excellent regioselectivity.


Asunto(s)
Silanos/química , Metilglicósidos/química , Estructura Molecular , Estereoisomerismo , Especificidad por Sustrato , Xilosa/química
16.
J Agric Food Chem ; 60(9): 2309-15, 2012 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-22296272

RESUMEN

Isoflavones are known to possess immunomodulating and antiallergic activities. Previously we identified novel isoflavone methyl-glycosides (daidzein 7-O-ß-d-glucoside 4″-O-methylate (CDGM), glycitein 7-O-ß-D-glucoside 4″-O-methylate (CGLM), genistein 7-O-ß-D-glucoside 4″-O-methylate (CGNMI) and genistein 4'-O-ß-D-glucoside 4″-O-methylate (CGNMII)) from Cordyceps militaris grown on germinated soybeans (GSC). The biological activity of novel isoflavone methyl-glycosides, however, remains unknown. In this study, CGNMII showed the strongest inhibition of degranulation. Additionally, the release of interleukin (IL)-4 and tumor necrosis factor (TNF)-α was decreased by CGNMII in antigen-stimulated RBL-2H3 cells. To elucidate the antiallergic mechanism of CGNMII, we examined whether it affected levels of signaling molecules responsible for degranulation. The levels of activated Lyn, Syk, PLCγ1 and LAT proteins were reduced in CGNMII treated RBL-2H3 cells. CGNMII also inhibited the activation of AKT and ERK1/2 proteins. These results suggest that CGNMII might be used as a therapeutic agent for allergic diseases.


Asunto(s)
Antialérgicos/farmacología , Cordyceps/crecimiento & desarrollo , Glycine max/crecimiento & desarrollo , Isoflavonas/farmacología , Mastocitos/inmunología , Metilglicósidos/farmacología , Animales , Células de la Médula Ósea , Degranulación de la Célula/efectos de los fármacos , Células Cultivadas , Cordyceps/química , Activación Enzimática/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Germinación , Inmunoglobulina E/inmunología , Interleucina-4/metabolismo , Masculino , Mastocitos/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Células Neoplásicas Circulantes , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Factor de Necrosis Tumoral alfa/metabolismo
17.
Acta Crystallogr C ; 66(Pt 7): o321-3, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20603556

RESUMEN

In methyl beta-D-fructopyranoside, C(7)H(14)O(6), the thermodynamically most stable methyl glycoside of the ketose D-fructose, the pyranose ring is close to being an ideal (2)C(5) chair. The compound forms bilayers involving a complex hydrogen-bonding pattern of five independent hydrogen bonds. Graph-set analysis was applied to distinguish the hydrogen-bond patterns at unary and higher level graph sets.


Asunto(s)
Cristalografía por Rayos X , Metilglicósidos/química , Enlace de Hidrógeno , Estructura Molecular , Termodinámica
18.
Acta Crystallogr C ; 66(Pt 2): o67-70, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20124684

RESUMEN

Methyl beta-D-galactopyranosyl-(1-->4)-alpha-D-mannopyranoside methanol 0.375-solvate, C(13)H(24)O(11).0.375CH(3)OH, (I), was crystallized from a methanol-ethanol solvent system in a glycosidic linkage conformation, with varphi' (O5(Gal)-C1(Gal)-O1(Gal)-C4(Man)) = -68.2 (3) degrees and psi' (C1(Gal)-O1(Gal)-C4(Man)-C5(Man)) = -123.9 (2) degrees , where the ring is defined by atoms O5/C1-C5 (monosaccharide numbering); C1 denotes the anomeric C atom and C6 the exocyclic hydroxymethyl C atom in the betaGalp and alphaManp residues, respectively. The linkage conformation in (I) differs from that in crystalline methyl alpha-lactoside [methyl beta-D-galactopyranosyl-(1-->4)-alpha-D-glucopyranoside], (II) [Pan, Noll & Serianni (2005). Acta Cryst. C61, o674-o677], where varphi' is -93.6 degrees and psi' is -144.8 degrees . An intermolecular hydrogen bond exists between O3(Man) and O5(Gal) in (I), similar to that between O3(Glc) and O5(Gal) in (II). The structures of (I) and (II) are also compared with those of their constituent residues, viz. methyl alpha-D-mannopyranoside, methyl alpha-D-glucopyranoside and methyl beta-D-galactopyranoside, revealing significant differences in the Cremer-Pople puckering parameters, exocyclic hydroxymethyl group conformations and intermolecular hydrogen-bonding patterns.


Asunto(s)
Cristalografía por Rayos X , Metilglicósidos/química , Metilmanósidos/química , Metanol , Modelos Moleculares
19.
Acta Crystallogr C ; 65(Pt 12): o601-6, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19966440

RESUMEN

Methyl beta-allolactoside [methyl beta-D-galactopyranosyl-(1-->6)-beta-D-glucopyranoside], (II), was crystallized from water as a monohydrate, C(13)H(24)O(11).H(2)O. The betaGalp and betaGlcp residues in (II) assume distorted (4)C(1) chair conformations, with the former more distorted than the latter. Linkage conformation is characterized by phi' (C2(Gal)-C1(Gal)-O1(Gal)-C6(Glc)), psi' (C1(Gal)-O1(Gal)-C6(Glc)-C5(Glc)) and omega (C4(Glc)-C5(Glc)-C6(Glc)-O1(Gal)) torsion angles of 172.9 (2), -117.9 (3) and -176.2 (2) degrees , respectively. The psi' and omega values differ significantly from those found in the crystal structure of beta-gentiobiose, (III) [Rohrer et al. (1980). Acta Cryst. B36, 650-654]. Structural comparisons of (II) with related disaccharides bound to a mutant beta-galactosidase reveal significant differences in hydroxymethyl conformation and in the degree of ring distortion of the betaGlcp residue. Structural comparisons of (II) with a DFT-optimized structure, (II(C)), suggest a link between hydrogen bonding, pyranosyl ring deformation and linkage conformation.


Asunto(s)
Disacáridos/química , Metilglicósidos/química , Conformación de Carbohidratos , Cristalografía por Rayos X , Enlace de Hidrógeno , Modelos Moleculares
20.
Biochemistry ; 48(49): 11678-91, 2009 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-19877716

RESUMEN

The cestodes constitute important but understudied human and veterinary parasites. Their surfaces are rich in carbohydrates, on which very little structural information is available. The tissue-dwelling larva (hydatid cyst) of the cestode Echinococcus granulosus is outwardly protected by a massive layer of carbohydrate-rich extracellular matrix, termed the laminated layer. The monosaccharide composition of this layer suggests that its major carbohydrate components are exclusively mucin-type O-glycans. We have purified these glycans after their release from the crude laminated layer and obtained by MS and NMR the complete structure of 10 of the most abundant components. The structures, between two and six residues in length, encompass a limited number of biosynthetic motifs. The mucin cores 1 and 2 are either nondecorated or elongated by a chain of Galpbeta1-3 residues. This chain can be capped by a single Galpalpha1-4 residue, such capping becoming more dominant with increasing chain size. In addition, the core 2 N-acetylglucosamine residue is in cases substituted with the disaccharide Galpalpha1-4Galpbeta1-4, giving rise to the blood P(1)-antigen motif. Larger, also related, glycans exist, reaching at least 18 residues in size. The glycans described are related but larger than those previously described from an Echinococcus multilocularis mucin [Hulsmeier, A. J., et al. (2002) J. Biol. Chem. 277, 5742-5748]. Our results reveal that the E. granulosus cyst exposes to the host only a few different major carbohydrate motifs. These motifs are composed essentially of galactose units and include the elongation by (Galpbeta1-3)(n) and the capping by Galpalpha1-4, novel in animal mucin-type O-glycans.


Asunto(s)
Equinococosis/metabolismo , Equinococosis/parasitología , Echinococcus granulosus/química , Galactosa/química , Mucinas/química , Polisacáridos/química , Animales , Conformación de Carbohidratos , Secuencia de Carbohidratos , Bovinos , Cromatografía en Gel , Matriz Extracelular/química , Interacciones Huésped-Parásitos , Espectroscopía de Resonancia Magnética , Metilglicósidos/química , Datos de Secuencia Molecular , Oligosacáridos/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Alcoholes del Azúcar/química
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