THE CONSTITUTION OF A SYNTHETIC GLUCAN: II. METHYLATION STUDIES

1963 ◽  
Vol 41 (10) ◽  
pp. 2439-2446 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau
Keyword(s):  
Sulphuric Acid ◽  
Hydrolysis Of

After repeated and vigorous treatments, a fully methylated glucan was obtained. Hydrolysis of the methylated glucan with sulphuric acid gave tetra-, tri-, di-, and mono-O-methyl-D-glucoses in a 5:5:3:1 ratio. Both the furanose and pyranose tetramethyl isomers were identified. Nearly all of the possible pyranose and furanose cyclic trimethylglucoses were positively identified. An attempted resolution of the dimethylglucoses was relatively unsuccessful. The monomethylglucoses were identified by electrophoresis.

The synthesis of Cyclododecane-r-1,c-5,c-9-triamine and r-1,c-5,c-9-Tris(2,3-dimethoxybenzamido)cyclododecane

1975 ◽  
Vol 28 (3) ◽  
pp. 673 ◽  
Author(s):  
DJ Collins ◽  
C Lewis ◽  
JM Swan
Keyword(s):  
Aqueous Solution ◽  
Acid Hydrolysis ◽  
Sulphuric Acid ◽  
Sodium Carbonate ◽  
Sodium Azide ◽  
Room Temperature ◽  
Dimethyl Formamide ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium ◽  
Hydrolysis Of

Treatment of cyclododecane-r-1,c-5,c-9-triyl tris(p-toluenesulphonate) with sodium azide in dimethyl-formamide at 100� for 6 h gave the corresponding cis,cis-triazide which upon hydrogenation or reduction with lithium aluminium hydride gave cyclododecane-r-1,c-5,c-9-triamine, isolated as the tris-salicylidene derivative. Acid hydrolysis of this, removal of the salicylaldehyde, and treatment of the aqueous solution with sodium carbonate and 2,3-dimethoxybenzoyl chloride gave r-1,c-5,c- 9-tris(2,3-dimethoxybenzamido)cyclododecane. ��� Treatment of (E,E,E)-cyclododeca-1,5,9-triene with an excess of acetonitrile and sulphuric acid at room temperature for three days gave 18% of (E,E)-1-acetamidocyclododeca-4,8-diene; no di- or tri-amides were isolated.

HYDROLYSIS OF CELLULOSE ACETATE SULPHATE IN ACETONE

1954 ◽  
Vol 32 (9) ◽  
pp. 815-822 ◽  
Author(s):  
Karl Keirstead ◽  
John Myers
Keyword(s):  
Acetic Acid ◽  
Cellulose Acetate ◽  
Sulphuric Acid ◽  
Potentiometric Titration ◽  
Titration Method ◽  
Acetate Ester ◽  
Hydrolysis Of Cellulose ◽  
Potentiometric Titration Method ◽  
Hydrolysis Of

When cellulose acetate sulphate is dissolved in acetone the hydrolysis of the sulphate ester is rapid compared with that of the acetate ester. In 70% acetone the relative rates are reversed. Hydrolysis of the sulphate ester in acetone is greatly affected by the temperature. At 25 °C. or greater the hydrolysis is complete after 24 hr. A potentiometric titration method has been developed for the estimation of sulphuric acid in the presence of smaller amounts of acetic acid.

Hemtacetal formation in sulphuric acid hydrolysis of a chloro olefin

1973 ◽  
Vol 14 (8) ◽  
pp. 585-588 ◽  
Author(s):  
E.P. Woo ◽  
K.T. Mak ◽  
H.N.C. Wong
Keyword(s):  
Acid Hydrolysis ◽  
Sulphuric Acid ◽  
Hydrolysis Of

scholarly journals HIDROLISIS RUMPUT LAUT (Glacilaria sp.) MENGGUNAKAN KATALIS ENZIM DAN ASAM UNTUK PEMBUATAN BIOETANOL

Jurnal Kimia ◽  
2016 ◽  
Author(s):  
Yohanes Armawan Sandi ◽  
Wiwik Susanah Rita ◽  
Yenni Ciawi
Keyword(s):  
Gas Chromatography ◽  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Ethanol Concentration ◽  
Reducing Sugar ◽  
Optimum Concentration ◽  
Raw Material ◽  
Optimum Length ◽  
Hydrolysis Of

The aim of this research is to determine the effect of enzyme and acids concentration on the yield of glucose produced in the hydrolysis of Glacilaria sp. in the production of bioethanol. The concentrations of cellulase used were 200 units/mL, 400 units/mL, 600 units/mL, 800 units/mL and the concentration of sulphuric acid (H2SO4) and hydrochloric acid (HCl) used were 1%, 3%, 5%, 7% (w/v). The concentration of reduction sugar was determined using Anthrone and analyzed using UV-Vis spectrophotometry and the determination of ethanol concentration was carried out by using gas chromatography. The results showed that the contents of reducing sugar produced by sulphuric acid (H2SO4) hydrolysis were 26,19%; 36,69%; 41,40%; 45,0% (v/v), by hydrochloric acid (HCl) were 12,12%; 14,03%; 15,17%; 16,50% (v/v), and by cellulase enzyme were 46,15%; 46,73%; 47,68%; 48,25% (v/v). Optimum concentration of reducing sugar produced by hydrolysis using 800 units/mL cellulase was 48,25% (v/v). The optimum length of fermentation to produce bioethanol using Glacilaria sp. as raw material was 5 days. In the fermentation, inoculum with a concentrations of 5% and 10% (w/v) produced 0,85% and 1,51% (v/v) ethanol.

Kinetic studies of two-stage sulphuric acid hydrolysis of sugarcane bagasse

2015 ◽  
Vol 83 ◽  
pp. 850-858 ◽  
Author(s):  
Sachin Kumar ◽  
Pratibha Dheeran ◽  
Surendra P. Singh ◽  
Indra M. Mishra ◽  
Dilip K. Adhikari
Keyword(s):  
Acid Hydrolysis ◽  
Sulphuric Acid ◽  
Sugarcane Bagasse ◽  
Kinetic Studies ◽  
Two Stage ◽  
Hydrolysis Of

THE ACTION OF ANHYDROUS ACIDS ON ATP:CREATINE PHOSPHOTRANSFERASE

1962 ◽  
Vol 40 (5) ◽  
pp. 1018-1022 ◽  
Author(s):  
Florante A. Quiocho ◽  
Felix Friedberg
Keyword(s):  
Amino Acids ◽  
Phosphoric Acid ◽  
Formic Acid ◽  
Sulphuric Acid ◽  
Acyl Migration ◽  
Peptide Bonds ◽  
Hydrolysis Of ◽  
Anhydrous Formic Acid

Treatment of ATP:creatine phosphotransferase with anhydrous sulphuric acid permits transposition of 24% of the threonine residues and 69% of the serine residues. Treatment with anhydrous phosphoric acid yields similar results: 41% of the threonine residues and 60% of the serine residues are rearranged. Anhydrous formic acid does not induce an N- to O-acyl migration in the protein.Non-specific hydrolysis of peptide bonds or destruction of certain amino acids that might have occurred simultaneously with rearrangement during the anhydrous sulphuric or anhydrous phosphoric acid appears to be very slight. When the protein is treated with anhydrous sulphuric acid, however, phenylalanine "disappears" almost completely from the chromatogram.

Hydrolysis of titanium sulphate compounds

2008 ◽  
Vol 62 (1) ◽  
Author(s):  
Barbara Grzmil ◽  
Daniel Grela ◽  
Bogumił Kic
Keyword(s):  
Titanium Dioxide ◽  
Sulphuric Acid ◽  
Final Stage ◽  
Degree Of Hydrolysis ◽  
Commercial Preparation ◽  
Hydrated Titanium Dioxide ◽  
Starting Solution ◽  
Titanyl Sulphate ◽  
Hydrolysis Of ◽  
Hydrated Titanium

AbstractThe influence of TiOSO4 and free sulphuric acid concentrations in the starting solution on the degree of titanyl sulphate conversion to hydrated titanium dioxide and post-hydrolytic sulphuric acid was studied. Titanyl sulphate solution, an intermediate product in the commercial preparation of titanium dioxide pigments by sulphate route, was used. It was found that the degree of hydrolysis markedly depends on the studied parameters. The lower was the content of TiOSO4 in the starting solution, the higher conversion was achieved. The degree of hydrolysis at the final stage varied between 81 % (420 g TiOSO4 dm−3, 216 g H2SO4 dm−3) and 92 % (300 g TiOSO4 dm−3, 216 g H2SO4 dm−3). The same relation was obtained when changing the concentration of free H2SO4 in the starting solution. The degree of hydrolysis at the final stage varied between 49 % (261 g H2SO4 dm−3, 340 g TiOSO4 dm−3) and 96 % (136 g H2SO4 dm−3, 340 g TiOSO4 dm−3). The particle size of the obtained hydrated titanium dioxide (HTD) also depends on the initial solution composition.

Factors influencing the mode of thermal decomposition of zirconium sulphate tetrahydrate

1967 ◽  
Vol 20 (3) ◽  
pp. 415 ◽  
Author(s):  
IJ Bear
Keyword(s):  
Thermal Decomposition ◽  
Particle Size ◽  
Sulphuric Acid ◽  
Vapour Pressure ◽  
Thermal Decomposition Process ◽  
Monoclinic Zro2 ◽  
X Ray ◽  
Factors Influencing ◽  
Diffraction Patterns ◽  
Hydrolysis Of

The thermal decomposition process of zirconium sulphate tetrahydrate has been studied. Dehydration, which takes place via a crystalline monohydrate phase, is accompanied by the loss of small amounts of sulphuric acid apparently resulting from internal hydrolysis of the compound. This process gives a non-stoicheiometric zirconium sulphate which may exist in several modifications depending on the vapour pressure of the sulphuric acid around the sample during dehydration. The vapour pressure of the sulphuric acid is in turn controlled by such factors as the particle size of the tetrahydrate preparation, the size of sample, and the temperature and technique used during heating. Equilibration experiments have shown that a-Zr(SO4)2 is the stable anhydrous form. The X-ray powder diffraction patterns of a- and γ- Zr(SO4)2 have been indexed. Above 650� all forms of Zr(SO4)2 decompose to cubic ZrO2 which transforms to monoclinic ZrO2 at 800�.

Sign in / Sign up

Export Citation Format

Share Document