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Search Results: 1 - 10 of 506 matches for " Betty Matsuhiro "
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SOLUBLE POLYSACCHARIDES FROM Rhodymenia: CHARACTERIZATION BY FT-IR SPECTROSCOPY
Matsuhiro,Betty; Miller,Luis G.;
Boletín de la Sociedad Chilena de Química , 2002, DOI: 10.4067/S0366-16442002000300010
Abstract: the soluble polysaccharides of few species of the family rhodymenaceae (rhodophyta) have been studied. according to the literature members of this family are agarophytes. dried samples of tetrasporic, cystocarpic and gametophytic rhodymenia howeana and tetrasporic r. corallina were analysed by ft-ir spectroscopy. results indicate that these seaweeds are not agar producers. aqueous extraction followed by chemical and ft-ir analysis showed that the extracts are very similar in composition. carrageenotype structures in the polysaccharides were not found
MODIFICACION QUIMICA DE PECTINA DE LIMON CHEMICAL MODIFICATION OF LEMON PECTIN
MATSUHIRO,BETTY; RUBIO,MARIA JOSE;
Boletín de la Sociedad Chilena de Química , 2001, DOI: 10.4067/S0366-16442001000400012
Abstract: the basic hydrolysis of the extract from lemon mesocarp afforded a pectin rich in galacturonic acid. the reaction with bromine allowed the selective oxidation of carbon 2, giving a ketone function in good yield. the reductive amination of the oxidised polysaccharide and subsequent acetylation gave an analog of the vi polysaccharide of salmonella typhi. the analogue was used as a model compound for the introduction of a side chain by amidation with caprolactam and for the conjugation of an acidic polysaccharide by amidation to the protein, bovine serum albumin
MODIFICACION QUIMICA DE PECTINA DE LIMON CHEMICAL MODIFICATION OF LEMON PECTIN
BETTY MATSUHIRO,MARIA JOSE RUBIO
Boletín de la Sociedad Chilena de Química , 2001,
Abstract: La hidrólisis básica del extracto de mesocarpio de limón dio una pectina enriquecida en ácido galacturónico. La reacción con bromo permitió la oxidación selectiva del carbono 2, dando un grupo cetónico con buen rendimiento. El polisacárido oxidado por aminación reductiva y posterior acetilación dio un análogo del polisacárido Vi de Salmonella typhi. El análogo se usó como modelo para introducir una cadena lateral por amidación con caprolactama que hiciera más accesible la conjugación de un polisacárido acídico en una segunda amidación a albúmina de suero bovino The basic hydrolysis of the extract from lemon mesocarp afforded a pectin rich in galacturonic acid. The reaction with bromine allowed the selective oxidation of carbon 2, giving a ketone function in good yield. The reductive amination of the oxidised polysaccharide and subsequent acetylation gave an analog of the Vi polysaccharide of Salmonella typhi. The analogue was used as a model compound for the introduction of a side chain by amidation with caprolactam and for the conjugation of an acidic polysaccharide by amidation to the protein, bovine serum albumin
SOLUBLE POLYSACCHARIDES FROM Rhodymenia: CHARACTERIZATION BY FT-IR SPECTROSCOPY
Betty Matsuhiro,Luis G. Miller
Boletín de la Sociedad Chilena de Química , 2002,
Abstract: The soluble polysaccharides of few species of the family Rhodymenaceae (Rhodophyta) have been studied. According to the literature members of this family are agarophytes. Dried samples of tetrasporic, cystocarpic and gametophytic Rhodymenia howeana and tetrasporic R. corallina were analysed by FT-IR spectroscopy. Results indicate that these seaweeds are not agar producers. Aqueous extraction followed by chemical and FT-IR analysis showed that the extracts are very similar in composition. Carrageenotype structures in the polysaccharides were not found Los polisacáridos solubles de muy pocas especies de la familia Rhodymenaceae (Rhodophyta) han sido estudiados. Según la literatura, estos polisacáridos presentarían la estructura de agar. El análisis por espectroscopia de IR-TF de muestras secas y molidas de individuos de las fases tetraesporofítica, cistocárpica y gametofítica de Rhodymenia howeana y de la fase tetraesporofítica de R. corallina indica que no son productoras de agar. La extracción acuosa y posterior caracterización por métodos químicos y espectroscopia de IR-TF muestran que los polisacáridos son muy similares entre sí y constituyen mezclas de polímeros sulfatados donde tampoco están presentes estructuras típicas de carragenanos
BLOCK STRUCTURE IN ALGINIC ACID FROM LESSONIA VADOSA (LAMINARIALES, PHAEOPHYTA)
MATSUHIRO,BETTY; TORRES,SIMONET E; GUERRERO,JUAN;
Journal of the Chilean Chemical Society , 2007, DOI: 10.4067/S0717-97072007000100009
Abstract: alkaline extraction of lessonia vadosa blades collected in fuerte bulnes (southern chile) afforded sodium alginate in 14.5% yield. partial acid hydrolysis of the sodium alginate gave three fractions which were characterised by one- and two-dimensional nuclear magnetic resonance techniques. fraction 1 (17.8 % yield) showed to be mainly composed of alternate heteropolymeric block (mg) and in minor proportions of polymannuronic sequences. analysis of 13c nmr and 2d hsqc spectra indicated that fraction 2 (64.5% yield) is a polymannuronic enriched fraction. the minor amount of guluronic acid residues in this fraction showed by 2d 1h/1h noesy nmr spectrum to be present in a 1→4 homopolyguluronic sequence; moreover, the interresidue correlation data indicated that mg blocks were not present. results are in agreement with data obtained by ft-ir spectroscopy in the solid state. full assignments of 1h and 13c signals in the nmr spectra indicated that fraction 3 (17.7%) presented a regular homopolyguluronic block structure
BLOCK STRUCTURE IN ALGINIC ACID FROM LESSONIA VADOSA (LAMINARIALES, PHAEOPHYTA)
BETTY MATSUHIRO,SIMONET E TORRES,JUAN GUERRERO
Journal of the Chilean Chemical Society , 2007,
Abstract: Alkaline extraction of Lessonia vadosa blades collected in Fuerte Bulnes (southern Chile) afforded sodium alginate in 14.5% yield. Partial acid hydrolysis of the sodium alginate gave three fractions which were characterised by one- and two-dimensional nuclear magnetic resonance techniques. Fraction 1 (17.8 % yield) showed to be mainly composed of alternate heteropolymeric block (MG) and in minor proportions of polymannuronic sequences. Analysis of 13C NMR and 2D HSQC spectra indicated that Fraction 2 (64.5% yield) is a polymannuronic enriched fraction. The minor amount of guluronic acid residues in this fraction showed by 2D 1H/1H NOESY NMR spectrum to be present in a 1→4 homopolyguluronic sequence; moreover, the interresidue correlation data indicated that MG blocks were not present. Results are in agreement with data obtained by FT-IR spectroscopy in the solid state. Full assignments of 1H and 13C signals in the NMR spectra indicated that Fraction 3 (17.7%) presented a regular homopolyguluronic block structure
STRUCTURAL DETERMINATION AND CHEMICAL MODIFICATIONS OF THE POLYSACCHARIDE FROM SEEDS OF Prosopis chilensis Mol. (Stuntz)
MATSUHIRO,BETTY; PRESLE,LUIS C; SAENZ,CARMEN; URZUA,CARLOS C;
Journal of the Chilean Chemical Society , 2006, DOI: 10.4067/S0717-97072006000100010
Abstract: the polysaccharide extracted from prosopis chilensis seeds in acidic medium showed by total hydrolysis and gas-liquid chromatography analysis of the alditol acetates to be composed of galactose and mannose in the molar ratio 1.0:1.9. studies by methylation and 1h and13c nmr spectroscopy indicated that the polysaccharide was a galactomannan with a chain of d-mannopyranosyl residues linked b 1 4 which carried alternatively a-d-galactopyranosyl residues at position o-6 of d-mannose units. the chemical modification of the galactomannan by reaction with sodium chloroacetate afforded in 95.3% yield, a derivative which gave a very viscous solution with water. by titration it was determined a carboxymethylation degree of 0.42 indicating that 64% of the alcoholic groups were etherified. reaction of the galactomannan with tempo-nacl-naobr system gave a water soluble polysaccharide. the dept 135o nmr spectrum indicated that the primary alcoholic groups of galactopyranosyl and unbranched mannopyranosyl residues were fully oxidised
CARBOHYDRATES FROM THE SEQUENTIAL EXTRACTION OF Lessonia vadosa (PHAEOPHYTA)
CHANDIA,NANCY P.; MATSUHIRO,BETTY; ORTIZ,JOHANNA S.; MANSILLA,ANDRES;
Journal of the Chilean Chemical Society , 2005, DOI: 10.4067/S0717-97072005000200012
Abstract: blades of lessonia vadosa were sequentially extracted with 70% ethanol, followed by 2% cacl2 solution,, diluted hcl (ph 2), and finally with 2% na2co3 solution. d-mannitol was the only low molecular weight carbohydrate obtained from the ethanolic extract. by ion-exhange chromatography of the cacl2 extract a fraction contaning 36.7% of sulfate group was obtained. chemical and spectroscopic analysis indicated the presence of a regular polymer of a-l-fucopyranose linked 1?3 and sulfated at positions o-2 and o-4. the main fraction isolated from the acidic extract by ion-exchange chromatography was shown to be composed of a complex a-l-fucan with 28.9% of sulfate. alginic acid (17.0% of dry algae) was the major polysaccharide obtained in the sequential extraction
POLI-D-GALACTOSAMINA COMO LIGANTE EN LA FORMACION DE COMPLEJOS CON Cu(II) y Ni(II)
COSTAMAGNA,JUAN; LILLO,LUIS E.; MATSUHIRO,BETTY; VILLAGRAN,MANUEL;
Boletín de la Sociedad Chilena de Química , 2000, DOI: 10.4067/S0366-16442000000300007
Abstract: the reaction of a-1?4-poly-d-galactosamine with o-salicylaldehyde afforded in good yield the schiff base which was used as ligand in the formation of complexes with cu(ii) and ni(ii). the complexes were characterized by ft-ir and electronic spectroscopies and, by cyclic voltammetry. the cu(ii) complex presented a ligand:metal ratio of 2:1 and its electrochemical behaviour was similar to that of the complex with the schiff base of the corresponding monomeric aminosugar. the ni(ii) complex showed a ligand:metal ratio of 3.3:1.0 no change in the this value was found when the schiff base of the partially degraded polysaccharide was used as ligand.
CHARACTERIZATION OF PHENOLIC ACIDS PROFILE FROM CHILEAN RED WINES BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
LEONORA MENDOZA,BETTY MATSUHIRO,MARíA J AGUIRRE,MAURICIO ISAACS
Journal of the Chilean Chemical Society , 2011,
Abstract: The success of Chilean wine in the international market has led to an important attention on the development of science and technology for wine differentiation, productivity, and quality. In order to report the profile of phenolic acid compounds in Chilean red wines, an SPE technique over ODS column was used followed by a reverse phase HPLC program that was developed to separate, characterize and quantify six phenolic acids (caffeic, gallic, p-coumaric, protocatechuic, syringic and vanillic acids) in four red Chilean wines varieties (Cabernet Sauvignon, Carménère, Merlot and Syrah) from grapes cultivated in the central zone of Chile. The separation was carried out on an RP C-18 column using a binary gradient elution and diode array detection.
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