Preparation of Alkyl Esters of Pectin and Pectic Acid

Polysaccharide elementary fibrils are usually fasciated into microfibrils of from one hundred to a few hundred Angstroms wide. Cellulose microfibrils when subjected to acid treatment dissociate into component elementary fibrils. For pectic acid it was observed that variations in pH could cause a change in the fasciation of the elementary fibrils.Solutions of purified pectic acid and sodium phosphotungtate were adjusted to various pH levels with NaOH or HCl and diluted to give a final concentration of 0.5 and 1% for the polysaccharide and negative stains respectively. Micrographs were made of the samples after drying on a carbon film covered grid. The average number of elementary fibrils was determined by counting the number of elementary fibrils in each fascicle intersected by lines drawn across the micrograph.

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ACTIVATION OF THE TRANSESTERIFICATIONS PROCESS OF VEGETABLE OILS TRIGLYCERIDES WITH METHANOL UNDER THE INFLUENCE OF MAGNETIC FIELD

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v11i6.850 ◽

2015 ◽

Vol 11 (6) ◽

pp. 3630-3634

Author(s):

T.A. Mamedova ◽

Z.M. Aliyeva ◽

A.E. Aliyeva ◽

R.T. Samedov ◽

V.M. Abbasov ◽

...

Keyword(s):

Magnetic Field ◽

Fatty Acids ◽

Reaction Time ◽

Vegetable Oils ◽

High Yield ◽

Alkyl Esters ◽

Sunflower Oils ◽

The Magnetic Field

The process of producing mono-alkyl esters of fatty acids from cottonseed and sunflower oils under the influence of the magnetic field with intensity 15-45 mT was investigated . It was revealed that the use of the energy of magnetic field allows to reduce the reaction time to 10 times, the excess of used alcohol to 2 times while maintaining high yield of the desired product.

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Theoretical Computations on the Pyrolysis of Alkyl (dithio)acetates

Letters in Organic Chemistry ◽

10.2174/1570178616666190717123039 ◽

2020 ◽

Vol 17 (3) ◽

pp. 224-233

Author(s):

Xun Zhu ◽

Chen Jian ◽

Xiuqin Zhou ◽

Abdullah M. Asiri ◽

Khalid A. Alamry ◽

...

Keyword(s):

Transition States ◽

Membered Ring ◽

Pyrolysis Process ◽

Alkyl Esters ◽

Charge Distributions ◽

Theoretical Analyses

The pyrolysis of methyl alkyl esters I to III and dithioesters IV to VI were theoretically calculated. All possible pyrolysis paths were considered. Both esters and dithioesters presented three potential paths via six-, four- and five-membered ring transition states, respectively. The calculation processes were calculated using MP2/6-31G(d) set. In-depth theoretical analyses were also presented, including NBO related analyses, synchronicities, and charge distributions, to reveal the detailed pyrolysis process.

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Cross-linked pectic acid. The effect of cross-linking on cation exchange, binding of endopolygalacturonase and biodegradability

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19761879 ◽

1976 ◽

Vol 41 (7) ◽

pp. 1879-1893 ◽

Cited By ~ 19

Author(s):

R. Kohn ◽

Ľ. Rexová-Benková ◽

O. Luknár ◽

Ľ. Kuniak

Keyword(s):

Cation Exchange ◽

Cross Linking ◽

Pectic Acid

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The role of secondary alcoholic groups of D-galacturonan in its degradation with exo-D-galacturonanase

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19800427 ◽

1980 ◽

Vol 45 (2) ◽

pp. 427-434 ◽

Cited By ~ 4

Author(s):

Kveta Heinrichová ◽

Rudolf Kohn

Keyword(s):

Acetyl Derivative ◽

Competitive Inhibitor ◽

Hydroxyl Groups ◽

Pectic Acid ◽

Substrate Complex ◽

Enzyme Substrate ◽

The Individual ◽

Degradation Degree ◽

Derivatives Of

The effect of exo-D-galacturonanase from carrot on O-acetyl derivatives of pectic acid of variousacetylation degree was studied. Substitution of hydroxyl groups at C(2) and C(3) of D-galactopyranuronic acid units influences the initial rate of degradation, degree of degradation and its maximum rate, the differences being found also in the time of limit degradations of the individual O-acetyl derivatives. Value of the apparent Michaelis constant increases with increase of substitution and value of Vmax changes. O-Acetyl derivatives act as a competitive inhibitor of degradation of D-galacturonan. The extent of the inhibition effect depends on the degree of substitution. The only product of enzymic reaction is D-galactopyranuronic acid, what indicates that no degradation of the terminal substituted unit of O-acetyl derivative of pectic acid takes place. Substitution of hydroxyl groups influences the affinity of the enzyme towards the modified substrate. The results let us presume that hydroxyl groups at C(2) and C(3) of galacturonic unit of pectic acid are essential for formation of the enzyme-substrate complex.

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