Electrophoresis of dyed polysaccharides on cellulose acetate

1968 ◽  
Vol 46 (19) ◽  
pp. 3079-3084 ◽  
Author(s):  
W. F. Dudman ◽  
C. T. Bishop

Polysaccharides have been shown to react with Procion dyes to give colored products. The degree of substitution varies with the dye to polysaccharide ratio used in the reaction and with the structure of the polysaccharide. The dyed polysaccharides give visible bands on gel filtration and on electrophoresis on cellulose acetate strips. Separations of mixtures of colored polysaccharides by the latter method are complete within 5 min and match the results obtained with the undyed polysaccharides by free-boundary, Tiselius electrophoresis.

1957 ◽  
Vol 35 (12) ◽  
pp. 1522-1533 ◽  
Author(s):  
E. P. Swan ◽  
C. B. Purves

Cellulose sodium xanthates of degree of substitution (D.S.) 0.4 to 0.66 were methylated to xanthate S-methyl esters which were then acetylated completely, the final xanthate D.S. remaining close to the original value. Dexanthation with aqueous chlorine dioxide near pH 4.5 and −5° removed almost all of the S-methyl xanthate groups, but the loss of a few acetyl groups from, and the retention of 1 to 2% of sulphur in, the resulting cellulose acetate could not be avoided. The original xanthate groups were presumably represented in this acetate as unsubstituted hydroxyl groups, and these were located by standard methods involving tosylation–iodination, tritylation, and oxidations with lead tetraacetate. Xanthate groups appeared to occupy the third and sixth, but not the second, position in the cellulose, and 53 to 61% of the substituent was in the sixth or primary position; one sample of viscose was "ripened" before the cellulose sodium xanthate was isolated, and the value was 81%. The results were of a preliminary nature, because severe technical difficulties reduced their reliability.


1973 ◽  
Vol 131 (2) ◽  
pp. 381-388 ◽  
Author(s):  
F. Reyes ◽  
R. J. W. Byrde

1. As cultures of the fungus Sclerotinia fructigena autolysed, the filtrates contained increasing quantities of a β-N-acetylglucosaminidase. 2. The enzyme was purified up to 42-fold by a combination of isoelectric focusing and gel filtration. 3. It ran as a single band in cellulose acetate strip electrophoresis and in isoelectric focusing (pI3.76). 4. The enzyme did not readily hydrolyse chitin or a glycopeptide with terminal N-acetylglucosamine residues, but rapidly degraded the N-acetylglucosamine dimer NN′-diacetylchitobiose; the monomer was readily utilized by the fungus as a nitrogen source. The Km value for hydrolysis of p-nitrophenyl β-2-acetamido-2-deoxy-d-glucopyranoside at 37°C was 2.0mm. The Sclerotinia enzyme was generally less susceptible to inhibition by 2-acetamido-2-deoxygluconolactone and other related sugars than the corresponding enzyme from other sources. Inhibition by excess of substrate was observed. 5. The culture filtrate also contained N-acetylgalactosaminidase activity; conflicting evidence was obtained as to whether the same enzyme was responsible for both hexosaminidase activities.


1996 ◽  
Vol 4 (3) ◽  
pp. 179-195 ◽  
Author(s):  
Charles M. Buchanan ◽  
Debra Dorschel ◽  
Robert M. Gardner ◽  
Ron J. Komarek ◽  
Andrew J. Matosky ◽  
...  

2021 ◽  
Vol 10 (12) ◽  
pp. e584101220761
Author(s):  
Leticia Sant'Anna Allesi ◽  
Joelen Osmari da Silva ◽  
Franciane Andrade de Pádua ◽  
Vagner Roberto Botaro

Currently, non-biodegradable polymers are produced on a large scale and cause several environmental problems, especially due to their low degradation. Cellulose acetate is a non-toxic, low-flammable and low-cost polymer, playing an important environmental role. The objective of this study was to synthesize cellulose acetate membranes from Schizolobium parahyba wood (“guapuruvu”) with particles sizes of 20 and 60 mesh. The materials were submitted to acetosolv pulping, bleaching and acetylation to produce the acetates. The yields and the degree of substitution were found. The fibers were chemically characterized and the samples obtained at each processing step were analyzed by FTIR. It was possible to prepare acetates from both granulometries wood. The FTIR analysis showed changes on the samples’ bands, indicating that the chemical processes were efficient. Cellulose acetate obtained from the 60 mesh material presented a higher degree of substitution (2.74 ± 0.12) when compared to the 20 mesh acetate (2.59 ± 0.13), showing that the particle size of the material influenced on the efficiency of the acetylation reaction. DMA tests have demonstrated that the 60 mesh membrane has higher flexibility and transparency when compared to the 20 mesh membrane.


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