scholarly journals Synthesis and properties of oligochitosan ascorbate from Bombyx mori

2021 ◽  
Vol 101 (1) ◽  
pp. 91-98
Author(s):  
K.K. Pirniyazov ◽  
◽  
V.E. Tikhonov ◽  
S.Sh. Rashidova ◽  
◽  
...  
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
Bombyx Mori ◽  
Antimicrobial Properties ◽  
A Value ◽  
Optimal Duration ◽  
Physicochemical Methods ◽  
Composition Structure ◽  
Hydrolysis Of ◽  
High Molecular Weight Chitosan

Oligochitosan samples were obtained by acid hydrolysis of high molecular weight chitosan isolated from Bombyx mori (B.M.). Carrying out acid hydrolysis for 6 hours, it was found that after 4 hours and further with increasing duration, the molecular weight of chitosan decreases to a value corresponding to the ranges of mo-lecular weights of oligochitosan 2–16 kDa. It has been seen that the optimal duration of hydrolysis, leading to the production of oligochitosan with a molecular weight of less than 16 kDa, should be considered 4–5 hours. Depolymerization of chitosan with a molecular weight of 177 kDa was carried out using sodium nitrite in so-lution to obtain oligochitosan with a molecular weight of 6 kDa. On the basis of oligochitosan samples ob-tained by two methods, their ascorbates were received. Under constant conditions with varying the ratio of the components (ChS:AA) and the pH of the solution, the reaction of chitosan ascorbate formation was car-ried out on the basis of the suspension method. The composition, structure, and molecular weight characteris-tics of oligochitosan ascorbate and oligochitosan Bombyx morisamples were confirmed by physicochemical methods. It has been seen that the obtained samples have antimicrobial properties against Fuzarium oxysporum.

"Colloidal" Phosphorus Errors in Gel Chromatography

1983 ◽  
Vol 40 (10) ◽  
pp. 1614-1621 ◽  
Author(s):  
B. Kent Burnison
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
High Molecular Weight ◽  
Gel Chromatography ◽  
Chemical Analyses ◽  
Molybdophosphoric Acid ◽  
Molybdenum Blue ◽  
Soluble Reactive Phosphate ◽  
Colloidal Phosphorus ◽  
Hydrolysis Of

Gel chromatography has been used for the separation of 32PO4 and a high molecular weight "colloidal" 32P-labeled fraction from 32PO4-labeled lakewater. When the labeled filtrate is treated with reagents required for the molybdenum blue method for orthophosphate analysis, only a small fraction of the "colloidal" peak is hydrolyzed to orthophosphate. As the reduced molybdophosphoric acid is strongly adsorbed to the dextran gel, quantitative elution of 32PO4 can be achieved with 0.05 mol∙L−1 NaOH and 0.3% NaCl. In hardwater lakes, care must be taken to eliminate the possibility of orthophosphate precipitation at higher pH. In these lakes, it is unlikely that the discrepancy between 32PO4 bioassays and chemical analyses can be solely attributed to acid hydrolysis of "colloidal" phosphorus. Microparticulate apatite also has the potential to release soluble reactive phosphate when the acidic molybdenum blue method is used.

scholarly journals Ultrasound-Assisted Ultra-Mild-Acid Hydrolisis of -Carrageenan

REAKTOR ◽  
2018 ◽  
Vol 17 (4) ◽  
pp. 191
Author(s):  
Ratnawati Ratnawati ◽  
Nita Indriyani
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
Average Molecular Weight ◽  
Weight Fraction ◽  
Number Average Molecular Weight ◽  
Hydrolysis Process ◽  
Higher Temperature ◽  
Ultrasound Assisted ◽  
Hydrolysis Of ◽  
Mild Acid

The low molecular weight fraction of κ-carrageenan is useful in biomedical applications. An ultrasound-assisted acid hydrolysis of κ-carrageenan has been studied. κ-carrageenan with an initial number-average molecular weight of 629 kDa was dispersed in distilled water to form a 5 g/l solution. The pH (3 and 6) of the solution was adjusted by adding HCl solution. The depolymerization reaction was carried out in an ultrasonic device at various temperatures (30, 40, 50, and 60°C) and times (8, 16, 24, and 32 min). The experimental results showed that ultrasound positively contributed to acid hydrolysis process. The number-average molecular weight of the treated k-carrageenan was lower or the percentage of reduction was higher at lower pH, longer reaction time, and higher temperature. The lowest number-average molecular weight (14 kDa) or the highest percent of molecular weight reduction reduction (97.7%) was achieved after ultrasonic irradiation at 60°C and pH 3 for 32 min. Keywords: depolymerization; midpoint scission; ultrasonication

A MANNAN PRODUCED BY BACILLUS POLYMYXA

1959 ◽  
Vol 37 (6) ◽  
pp. 1012-1017 ◽  
Author(s):  
D. H. Ball ◽  
G. A. Adams
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
Periodate Oxidation ◽  
Methylation Data ◽  
Bacillus Polymyxa ◽  
Hydrolysis Of

During the fermentation of glucose, sucrose, or lactose by Bacilluspolymyxa, a mixture of polysaccharides is formed, one of which has been isolated by mild procedures and shown to contain mannose as the only sugar together with approximately 13% protein. Acid hydrolysis of the methylated mannan gave 2,3,4,6-tetra-O-methyl-D-mannose, 2,4,6-tri-O-methyl-D-mannose, 3,4,6-tri-O-methyl-D-mannose, and 3,4-di-O-methyl-D-mannose in the approximate ratio 2:1:1:2. Periodate oxidation results are in agreement with the methylation data and indicate a molecular weight of approximately 3000.

scholarly journals Enzymatic Hydrolysis of Marine Collagen and Fibrinogen Proteins in the Presence of Thrombin

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 208 ◽  
Author(s):  
Ludmila L. Semenycheva ◽  
Marfa N. Egorikhina ◽  
Victoria O. Chasova ◽  
Natalya B. Valetova ◽  
Yulia L. Kuznetsova ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Main Part ◽  
Room Temperature ◽  
A Value ◽  
Hydrolysis Products ◽  
Native Collagen ◽  
Before And After ◽  
Molecular Fraction ◽  
Hydrolysis Of

Enzymatic hydrolysis of native collagen and fibrinogen was carried out under comparable conditions at room temperature. The molecular weight parameters of proteins before and after hydrolysis by thrombin were monitored by gel-penetrating chromatography (GPC). An analysis of the experiment results shows that the molecular weight parameters of the initial fibrinogen (Fn) and cod collagen (CC) are very similar. High molecular CC decays within the first minute, forming two low molecular fractions. The main part (~80%) falls on the fraction with a value of Mw less than 10 kDa. The initial high molecular fraction of Fn with Mw ~320–340 kDa is not completely hydrolyzed even after three days of control. The presence of low molecular fractions with Mw ~17 and Mw ~10 kDa in the solution slightly increases within an hour and noticeably increases for three days. The destruction of macromolecules of high molecular collagen to hydrolysis products appears almost completely within the first minute mainly to the polymer with Mw ~10 kDa, and enzymatic hydrolysis of fibrinogen proceeds slower than that of collagen, but also mainly to the polymer with Mw ~10 kDa. Comparative photos of the surfaces of native collagen, fibrinogen and the scaffold based on them were obtained.

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