scholarly journals Production of Low Molecular Weight Chitosan and Chitooligosaccharides (COS): A Review

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2466
Author(s):  
Cleidiane Gonçalves ◽  
Nelson Ferreira ◽  
Lúcia Lourenço
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
High Specificity ◽  
Added Value ◽  
Limiting Factor ◽  
Low Molecular Weight ◽  
Hydrolysis Time ◽  
Power Intensity ◽  
Low Molecular Weight Chitosan ◽  
Long Time

Chitosan is a biopolymer with high added value, and its properties are related to its molecular weight. Thus, high molecular weight values provide low solubility of chitosan, presenting limitations in its use. Based on this, several studies have developed different hydrolysis methods to reduce the molecular weight of chitosan. Acid hydrolysis is still the most used method to obtain low molecular weight chitosan and chitooligosaccharides. However, the use of acids can generate environmental impacts. When different methods are combined, gamma radiation and microwave power intensity are the variables that most influence acid hydrolysis. Otherwise, in oxidative hydrolysis with hydrogen peroxide, a long time is the limiting factor. Thus, it was observed that the most efficient method is the association between the different hydrolysis methods mentioned. However, this alternative can increase the cost of the process. Enzymatic hydrolysis is the most studied method due to its environmental advantages and high specificity. However, hydrolysis time and process cost are factors that still limit industrial application. In addition, the enzymatic method has a limited association with other hydrolysis methods due to the sensitivity of the enzymes. Therefore, this article seeks to extensively review the variables that influence the main methods of hydrolysis: acid concentration, radiation intensity, potency, time, temperature, pH, and enzyme/substrate ratio, observing their influence on molecular weight, yield, and characteristic of the product.

scholarly journals PREPARATION AND CHARACTERIZATION OF LOW MOLECULAR WEIGHT CHITOSAN WITH DIFFERENT DEGREES OF DEACETYLATION BY THE ACID HYDROLYSIS METHOD

2021 ◽  
pp. 153-164
Author(s):  
NAWZAT D. AL-JBOUR ◽  
M. D. H. BEG ◽  
JOLIUS GIMBUN ◽  
A. K. M. MOSHIUL ALAM
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
Water Solubility ◽  
Skeletal Structure ◽  
Low Molecular Weight ◽  
Molecular Weights ◽  
Hydrolysis Method ◽  
Significant Difference ◽  
Low Molecular Weight Chitosan ◽  
Pharmaceutical Industries

Objective: The objective of this research is to prepare Low Molecular Weight Chitosan (LMWC) by the acid hydrolysis method, using dilute hydrochloric acid (2M). LMWC has superior properties compared to the High Molecular Weight Chitosan (HMWC), especially in terms of water solubility, antibacterial and antifungal properties. These could open new potential applications for LMWC in sectors such as the cosmetics, food, and pharmaceutical industries. Methods: In this work, the acid hydrolysis method was used to produce LMWC with different molecular weights starting from 500 kDa and 93% degree of deacetylations (DDA). The molecular weights of the produced grades were determined by applying Mark-Houwink equation while the %DDA was determined and verified by the use of the 1st derivative UV method and 1HNMR method, respectively. The depolymerization reactions were carried out with different time intervals to produce totally deacetylated LMWC of 30 kDa, 15 kDa, and 7.5 kDa. The LMWC was characterized by FTIR, XRD, and DSC to evaluate the functionality, microstructure and thermal properties. Results: The FTIR spectra revealed that there is no significant difference in the main skeletal structure of the LMWC and HMWC. On the other hand, the XRD and DSC results showed that the LMWC of different molecular weights and degrees of deacetylation are of semi-crystalline structure, similar to the HMWC. Conclusion: The obtained results showed that the used acid hydrolysis procedure can produce LMWC grades of desired specifications, yields, and quality which are suitable for use in different applications.

Preparation of low-molecular-weight chitosan by enzymatic hydro-lysis for use in peliculture

2021 ◽  
pp. 31-33
Author(s):  
Элана Игоревна Ковалева ◽  
Марина Алексеевна Фролова ◽  
Алексей Иванович Албулов ◽  
Валерий Петрович Варламов ◽  
Анатолий Константинович Елисеев
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Environmental Factors ◽  
Low Molecular Weight ◽  
Technological Parameters ◽  
Low Molecular Weight Chitosan

Хитозан и его производные обладают множеством свойств, которые позволяют применять его в пчеловодстве. Он повышает устойчивость организма пчел к неблагоприятным факторам внешней среды и к возбудителям различных заболеваний. В результате проведенных исследований разработаны технологические параметры получения низкомолекулярного хитозана методом ферментативного гидролиза. Chitosan and its derivatives have many properties that allow them to be used in beekeeping. It increases the resistance of the bee organism to adverse environmental factors and to pathogens of various diseases. As a result of the conducted research, the technological parameters for the production of low-molecular-weight chitosan by enzymatic hydrolysis were developed.

Liposome coated with low molecular weight chitosan and its potential use in ocular drug delivery

2009 ◽  
Vol 379 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Ning Li ◽  
Chunyang Zhuang ◽  
Mi Wang ◽  
Xiyang Sun ◽  
Shufang Nie ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Molecular Weight ◽  
Ocular Drug Delivery ◽  
Low Molecular Weight ◽  
Low Molecular Weight Chitosan ◽  
Potential Use

Searching for synergistic effects of low-molecular weight chitosan derivatives, chitosan and copper nanoparticles for wound healing ointment

2021 ◽  
Vol 12 (3) ◽  
pp. 035016
Author(s):  
Natalya Nikolaevna Glushchenko ◽  
Olga Alexandrovna Bogoslovskaya ◽  
Balzhima Tsyrendorzhievna Shagdarova ◽  
Alla Victorovna Il’ina ◽  
Irina Pavlovna Olkhovskaya ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Wound Healing ◽  
Copper Nanoparticles ◽  
Synergistic Effects ◽  
Low Molecular Weight ◽  
Chitosan Derivatives ◽  
Low Molecular Weight Chitosan

The use of enzymatic preparation for the production of low molecular-weight chitosan from the king crab hepatopancrease

2009 ◽  
Vol 45 (4) ◽  
pp. 374-379 ◽  
Author(s):  
A. V. Ilyina ◽  
D. S. Zagorskaya ◽  
A. N. Levov ◽  
A. I. Albulov ◽  
N. P. Kovacheva ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Enzymatic Preparation ◽  
King Crab ◽  
Low Molecular Weight Chitosan

γ-Ray Irradiation Practical Conditions for Low Molecular Weight Chitosan Material Production

2003 ◽  
Vol 792 ◽  
Author(s):  
Rangrong Yoksan ◽  
Mitsuru Akashi ◽  
Mikiji Miyata ◽  
Siriratana Biramontri ◽  
Suwabun Chirachanchai
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Solid State ◽  
Primary Structure ◽  
Low Molecular Weight ◽  
Aqueous Acetic Acid ◽  
Low Molecular Weight Chitosan ◽  
Backbone Structure ◽  
Γ Ray ◽  
Terminal Chain

ABSTRACTThe present work focuses on the γ-ray irradiation doses and conditions (dry solid state, solid state dispersing in 0.5–2 % aqueous H2O2 solution, solid state dispersing in 1% aqueous acetic acid, and 2% aqueous K2S2O8) to determine the level that the molecular weight of chitosan is lowered significantly without changing its primary structure. Molecular weight of chitosan (105-106 Dalton) is reduced approximately 50% under the γ-ray dose of 20 kGy in the dry solid state. The decrease in molecular weight is enhanced up to 80% when chitosan is suspended in 0.5–2 % aqueous H2O2 solution during γ-ray irradiation. In either condition, the backbone structure of the irradiated product is maintained with little change in the terminal chain. In the cases of (i) chitosan suspended in 2% aqueous K2S2O8 and (ii) chitosan in 1% aqueous acetic acid, chitosans lose their primary structures and physical properties.

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