Degree Of Deacetylation Research Articles

Deep Chemical and Physico-Chemical Characterization of Antifungal Industrial Chitosans-Biocontrol Applications.

Five different chitosan samples (CHI-1 to CHI-5) from crustacean shells with high deacetylation degrees (>93%) have been deeply characterized from a chemical and physicochemical point of view in order to better understand the impact of some parameters on the bioactivity against two pathogens frequently encountered in vineyards, Plasmopara viticola and Botrytis cinerea. All the samples were analyzed by SEC-MALS, 1H-NMR, elemental analysis, XPS, FTIR, mass spectrometry, pyrolysis, and TGA and their antioxidant activities were measured (DPPH method). Molecular weights were in the order: CHI-4 and CHI-5 (MW >50 kDa) > CHI-3 > CHI-2 and CHI-1 (MW < 20 kDa). CHI-1, CHI-2 and CHI-3 are under their hydrochloride form, CHI-4 and CHI-5 are under their NH2 form, and CHI-3 contains a high amount of a chitosan calcium complex. CHI-2 and CHI-3 showed higher scavenging activity than others. The bioactivity against B. cinerea was molecular weight dependent with an IC50 for CHI-1 = CHI-2 (13 mg/L) ≤ CHI-3 (17 mg/L) < CHI-4 (75 mg/L) < CHI-5 (152 mg/L). The bioactivity on P. viticola zoospores was important, even at a very low concentration for all chitosans (no moving spores between 1 and 0.01 g/L). These results show that even at low concentrations and under hydrochloride form, chitosan could be a good alternative to pesticides.

Trichoderma asperellum as a novel source to prepare chitooligosaccharides by enzymatic hydrolysis and its antimicrobial activity.

Chitooligosaccharides (COS), an important biological functional component, are mainly extracted from marine products, but its raw materials are currently facing challenges such as marine resources pollution and demineralization. This study aimed to explore Trichoderma asperellum as a novel source to prepare COS. The COS were prepared by the enzymatic degradation of chitosan from T. asperellum, and single factor experiment and orthogonal designs were used to optimize the enzymatic conditions for the preparation of COS. The composition of COS was performed by thin-layer chromatography, high-performance liquid chromatography, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The results showed that the degree of deacetylation of T. asperellum chitosan was 87.59%, and its enzymatic hydrolysis yield was 89.37 % under optimized extraction conditions. Moreover, the composition of COS in T. asperellum included chitotriose, chitopentaose, and chitohexaose. Compared with shrimp shells, COS prepared from T. asperellum showed stronger antibacterial properties against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Salmonella bacilli.

Homogeneous preparation of water-soluble products from chitin under alkaline conditions and their cell proliferation in vitro

The purpose of this study was to prepare water-soluble products by homogeneous depolymerization of chitin with H2O2 under alkaline conditions and investigate their potential application in wound healing. For the first time, water-soluble products were successfully prepared using a chitin-NaOH/urea solution; the products were chitosans with molecular weights (Mw) of 3.48–33.5 kDa and degrees of deacetylation (DD) > 0.5. Their Mw, DD and yield were affected by the reaction temperature, reaction time, concentration of H2O2 and chitin DD. The deacetylation and depolymerization of chitin were achieved simultaneously. The depolymerization of chitin was caused by hydrogen abstraction of HO, whereas the deacetylation resulted from the cleavage of amide bonds by HO− and HO2−, although the latter played a more important role. All water-soluble chitosans markedly promoted the proliferation of human skin fibroblast (HSF) cells, but they inhibited the proliferation of human keratinocyte cells. For the proliferation of HSF, a low concentration of chitosans was important. In addition, water-soluble chitosans with an Mw of 3.48–16.4 kDa markedly stimulated the expression of growth factors such as PDGF and TGF-β by macrophages. Water-soluble chitosans could be used as a potential active component in wound dressings.

Influence of chitosan source and degree of deacetylation on antibacterial activity and adsorption of AZO dye from water

Chitosan is one of the most abundant biopolymers in nature with high economic value due to its biocompatibility, biodegradability, lack of toxicity, and antifungal activity. In this study, chitosan was extracted from three different sources: Blaps lethifera (CSB), Pimelia fernandezlopezi (CSP), and Musca domestica (CSM). The ash content (AC), moisture content (MC), fat binding capacity (FBC), water binding capacity (WBC), and deacetylation degree (DD) were determined for the prepared chitosans. The effect of the DD of chitosan on the antibacterial activity of gram (positive/negative) bacteria and the azo dyes (methylene blue, MB) removal from wastewater was also investigated. Chitosan extracts showed good antibacterial activity against Listeria innocua, Bacillus subtiliis, Staphylococcus aureus, Salmonella typhimurium, and Pseudomonas aeruginosa. The MB dye removal of CSB-chitosan, CSP-chitosan, and CSM-chitosan reached 37%, 87%, and 26%, respectively, at a contact time of 2 h, a low initial dye concentration MB of 13 ppm, a solution temperature of 25 °C, and a pH = 7.Graphical

Chitin/chitosan extraction from shrimp shell waste by a completely biotechnological process

Two lactic bacteria were used in sequential co-cultures to demineralize (DM) and deproteinize (DP) shrimp shells (SS) to obtain chitin. During the first 24 h, Lactobacillus delbrueckii performed the DM in a minimal medium containing 100 g/L SS and 50 g/L glucose. Then, three different conditions were assayed to complete DM and perform the DP stage: 1) Bifidobacterium lactis was added with 35 g/L of glucose (Ld-G → Bl-G); 2) only B. lactis was added (Ld-G → Bl); and 3) a 35 g/L pulse of glucose was added, and at 48 h, B. lactis was inoculated (Ld-G → G → Bl). The highest DM (98.63 %) and DP (88 %) were obtained using a glucose pulse in the DM step and controlling the pH value above 6.0 in the DP step. Finally, a deacetylases cocktail produced by Aspergillus niger catalyzed the deacetylation of the resulting chitin. The chitosan samples had a deacetylation degree higher than 78 % and a solubility of 25 % in 1.0 N acetic acid. The deacetylation yield was 74 % after a mild chemical treatment, with a molecular weight of 71.31 KDa. This work reports an entirely biological process to get chitin and chitosan from SS with high yields.

Characteristics and activity of chitosan from mud crab shells on acne bacteria: Staphylococcus aureus, S. epidermidis and Propionibacterium acnes

Abstract. Luthfiyana N, Bija S, Anwar E, Laksmitawati DE, Risalinda GL. 2022. Characteristics and activity of chitosan from mud crab shells on acne bacteria: Staphylococcus aureus, S. epidermidis and Propionibacterium acnes. Biodiversitas 23: 6645-6651. Chitosan is a product of chitin deacetylation, which has the potential to act as acne bacteria. The study aimed to determine the characteristics and activity of chitosan from mud crab shells on acne bacteria, i.e., Staphylococcus aureus FNCC 0047, Staphylococcus epidermidis FNCC 0048 and Propionibacterium acnes ATCC 11827. The research used a descriptive method for analyzing the quality of chitosan and antibacterial activity using analysis of variants at a 95% confidence interval with one factor, while the addition of chitosan as much as 0.25%; 0.5%; 0.75%; and 1% with three replications. The results showed that the value of deacetylation degree (DD) was 76%. The morphology of chitosan shows irregular, wavy, porous shapes and contains several elements: C, O, Ca, and Al. The antibacterial activity of chitosan at concentrations of 0.25%, 0.5%, 0.75%, and 1% showed an inhibition zone of S. aureus (9.5±0.71 mm, 10±0 mm, 11±0 mm, 13.5±0.71 mm), S. epidermidis (9±0 mm, 10±0 mm, 11±0 mm, 12.5±0.71 mm), and P. acnes (28.5±0.7 mm, 28.5±0.7 mm, 31±5.56 mm, 34.5±6.36 mm). The concentration of 1% gives the effectiveness in inhibiting the growth of acne bacteria. This study concludes that chitosan from mud crab shells could be the potential as an anti-acne.

Bionic artificial penile Tunica albuginea

Bionic artificial penile Tunica albuginea

P-sulfonatocalix[8]arene and chitosan based vesicle formation studies by spectroscopic and thermal methods

p-sulfonatocalix [8]arene and chitosan based supramolecular amphiphilic vesicles were formed by electrostatic interaction between anionic character of calixarene and cationic chitosan molecules. UV–visible, fluorescence, dynamic light scattering and thermogravimetric analysis were performed for the characterization of p-SCX8 with chitosan. Increase in absorption and enhancement of fluorescence emission intensity attributed to vesicle formation between both calixarene and chitosan in aqueous media. Results obtained from size distribution curve of dynamic light scattering experiment gives clear evidence for vesicle formation at pH 4.98. Positive zeta potential values obtained from dynamic light scattering experiment gives the evidence for vesicle formation. Thermogravimetric analysis gives quantitative results for purity and stability of the vesicles. From overall studies we can conclude that degree of deacetylation as well as pH 4.98 of the solutions and anionic nature of pSCX8 plays important role in electrostatic interaction of vesicle formation.

The Effects of Partial Deacetylation on the Ultrasonic Mechanical Treatment to Prepare Chitin Nanofibrils

Chitin nanofibrils (ChiNF) were prepared using a partial deacetylation of the chitin-ultrasonic mechanical method. The effects of degree of deacetylation (DD) of chitin on the ultrasonic treatment conditions and structures of the ChiNF were explored via Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), wide angle X-ray diffraction (WAXD) and zeta potential analysis. The results showed that with increasing the DD of chitin, the yields of the ChiNF increased, the average lengths increased, the average diameters were unchanged and the zeta potentials gradually increased. The DD of the ChiNF, however, remained constant in comparison to that of corresponding deacetylated chitin (d-chitin) and, accordingly, the crystallinity indices increased and the grain size was reduced. The ChiNF dispersion, obtained from the optimal process, i.e. deacetylation time of 4 h and ultrasonic treatment time of 1.5 h, was cast into a transparent ChiNF film, and it exhibited enhanced mechanical properties and water-resistance after heat treatment.

Characteristics of crab shells and green mussel shells as potential chitosan material from Karangantu, Banten, Indonesia

Shells are a waste of crab (Portunus pelagicus) and green mussels (Perna viridis) waste in Karangantu. That is a problem for the environment with a large number. One solution is to use it as a raw material for chitosan. This study aims to see the potential of crab shells and green mussel shells as well as raw materials for chitosan biomaterials. This research used shell waste of P. pelagicus and P. viridis (3 replications). The stages of the method of this research include the preparation of raw materials, manufacture of chitosan, and analysis product. Parameters measured in this study include yield, moisture, ash, degree of deacetylation, and viscosity. The results showed that the yield, ash, and viscosity of green mussels shells were higher than that of crab shells, but the moisture and degree of deacetylation were lower. These results indicate that crab shells are better than clam shells, although the yield is lower as a potential for making chitosan from waste in Karangantu.

Effect of chitosan substance on the mechanical properties of paper obtained on the basis of flax cellulose

Chitosan occurs in different molecular weights and degrees of deacetylation. Molecular weight and degree of deacetylation are the main factors affecting particle size, particle formation and aggregation. The use of chitosan improved the dry strength of the paper, especially by adding 1% low molecular weight chitosan. But the increase in concentration reduced its dry strength. This can be explained as follows. The connection must correspond to the distance between the segments between the fibers, because they form an inter-fiber connection area. Even if the water molecule is separated from the organic bond with the fibers or not, a large amount of water destroys the bond state of the paper. These factors are important in the paper industry. Paper-like materials were obtained on the basis of cellulose obtained from the stem of the flax plant. The effect of fibers and adhesives in the composition on the quality indicators of the obtained paper was considered. The effects of chitosan and starch glue were compared. It can be explained that the hydrogen bond on the fiber surface is mainly monopolized by the water molecule, because the fiber forms a macroscopic liquid bridge. The weakness of this bridge indicates the wet tensile strength of the paper.

Physicochemical Properties of Superabsorbent Hydrogels Formed by Polyelectrolytic Complexation of Carboxymethylcellulose-Chitosan at Basic pH

High water consumption during irrigation is one of the main problems in agriculture. The preparation of a material that prolongs the water retention capacity of the soil is important. This article aimed to prepare superabsorbent hydrogels by the complexation of chitosan (CHI), with high degree of deacetylation (DD), and carboxymethylcellulose (CMC), with high degree of substitution (SD). Different parameters (concentration and polymeric solutions addition order, polysaccharides’ ratio, pH) were studied. Morphology, thermal stability, chemical composition, mechanical strength, and swelling kinetics of hydrogels in water were evaluated. A hydrogel formation mechanism was discussed and proposed. Results showed that most samples prepared at acid pH disintegrated during swelling test. The morphology of the hydrogels varied with the pH. It was obtained superabsorbent hydrogels (swelling &gt; 400%) based on CMC (SD = 2.23) and CHI (DD = 92%), at basic pH, with good compression strength, and applicable as soil conditioner. The best sample was the one prepared with CMC:CHI = 1:2, polymeric solutions 1.5% m/v and pH 8.

The Potential Development of Shrimp Shell Waste Into Chitosan Originating from Pacitan Coast, Indonesia

Shrimp is one of the biggest comodities at the Pacitan coast area that was taken its meat to be processed into many food products. This could be due to the accumulation of shrimp shell waste abundantly and has no selling value. The conversion of shrimp shell waste into chitosan is the one breakthrough to increase the value of the shrimp shell waste. The objective of this research is to convert shrimp shell waste into chitosan and characterized the quality of chitosan including the deacetylation degree, crystalinity, and its morphology. This research has successfully isolated chitosan that extracted from shrimp shell waste obtained from Sudimoro coast, Pacitan, Indonesia. Chitosan was isolated through three steps of reaction including deproteination, demineralization, and deacetylation. The chitosan produced had the first deacetylation degree at 75% with the second deacetylation degree at 82% and the total of shrinkage from the raw material is at 84%. The synthesized chitosan also showed the decreasing of its crystalinity and had flakes-type morphology that observed by scanning electron microscopy (SEM).

Copper nanoparticles embedded fungal chitosan as a rational and sustainable bionanozyme with robust laccase activity for catalytic oxidation of phenolic pollutants.

Despite their potential for oxidation of persistent environmental pollutants, the development of rational and sustainable laccase nanozymes with efficient catalytic performance remains a challenge. Herein, fungal-produced chitosan-copper (CsCu) is proposed as a rational and sustainable bionanozyme with intrinsic laccase activity. The CsCu nanozyme was prepared by in situ reduction of copper on chitosan extracted from Irpex sp. isolate AWK2 a native fungus, from traditional fermented foods, yielding a low molecular weight chitosan with a 70% degree of deacetylation. Characterizations of the nanozyme using SEM-EDX, XRD, and XPS confirmed the presence of a multi-oxidation state copper on the chitosan matrix which is consistent with the composition of natural laccase. The laccase memetic activity was investigated using 2,4-DP as a substrate which oxidized to form a reddish-pink color with 4-AP (λmax = 510 nm). The CsCu nanozyme showed 38% higher laccase activity than the pristine Cu NPs at pH 9, indicating enhanced activity in the presence of chitosan structure. Further, CsCu showed significant stability in harsh conditions and exhibited a lower Km (0.26 mM) which is competitive with that reported for natural laccase. Notably, the nanozyme converted 92% of different phenolic substrates in 5 h, signifying a robust performance for environmental remediation purposes.

Extraction and Characterization of Chitin and Chitosan from Tenebrio Molitor Beetles and Investigation of its Antibacterial Effect Against Pseudomonas aeruginosa.

Chitin and chitosan are utilized in many industries such as pharmacy, biotechnology, and medicine. The mealworm beetle, Tenebrio Molitor, is simply breaded and does not require a vast production space. In this study, we extracted chitin and chitosan using two different methods from Tenebrio Molitor adult beetles. Then we studied their physical and chemical properties along with their antibacterial effect. Using two new methods we extracted 13, 3%, and 17.7% chitin from the dry mealworm beetle which was higher than in previous studies. The chitosan yield of the extracted chitin was 78.26% and 76.43%, respectively. The observed FTIR peaks for chitin and chitosan in this study were in accordance with the characteristic peaks. The degree of acetylation of chitin was 95.09% and 92.55% and the degree of deacetylation was 75.84%, and 72.6% from the first and second methods, respectively. The extracted chitosan also showed an antibacterial effect against Pseudomonas aeruginosa. Our study demonstrated that chitin and chitosan extracted from adult mealworm beetles could be considered as a replacement for commercial chitosan and needs further studies.

Deeper inside, the use of chitooligosaccharides, in wound healing process: A computational approach

Chitooligosaccharides (COs) containing up to 10 monomeric units of N-acetyl D-glucosamine and/or D-glucosamine are water-soluble molecules revealing numerous biological activities and low toxicological profiles. Within this study, a computational approach has been used to predict the involvement of the COs having distinct chemical properties (molecular weight, deacetylation degree and acetylation pattern) in all the four wound healing phases: hemostasis, inflammation, proliferation and tissue remodeling. There are predictions, for the investigated COs, regarding their molecular targets and the biological activities that are reliant to the wound healing process. Furthermore, a molecular docking approach was used to assess the interactions of the investigated COs with the myeloid differentiation factor 2 (MD-2), a protein involved in the inflammatory processes. The investigation confirms the functional roles of the investigated COs in wound healing. The molecular targets predicted for the COs containing totally and partially acetylated units are galectins and selectins and those predicted for COs containing totally deacetylated units are fibroblast growing factors, the COs containing 3 units revealing the higher number of molecular targets. All these proteins are involved in mediating immune response, inducing cell division, growth and cell adhesion during the process of wound healing. All the COs containing from 2 to 8 monomeric units are able to interact with the MD-2 protein, the interactions being stronger for the COs containing 6 and 8 monomeric units. The interaction energies increase with the increasing molecular weight and with decreasing deacetylation degree and are reliant on acetylation patterns. Among the investigated COs, the totally acetylated COs containing 6 and 8 N-acetyl glucosamine units can be better inhibitors of the LPS binding to MD-2 protein. Consequently, mixtures of COs with distinct properties should be considered suitable candidates as adjuvants in developing scaffolds for the wound healing process.

Characterization of chitosan extracted from three mushroom species from Edo State, Nigeria

Abstract Chitosan, a biodegradable and nontoxic biopolymer, has applications in a wide range of fields. This study aimed to produce and characterize chitosan from three mushroom species obtained from Edo State, Nigeria. Standard protocols were used to extract and characterize chitosan. Chitosan yield from all three samples differed significantly (p&lt;0.05) with the highest chitosan yield (19.00±0.03 %) from Lenzites betulina. There was no significant difference in the degree of deacetylation of T. versicolor and L. betulina extracted chitosan (82.71 and 83.54 % respectively). Chitosan from Lenzites betulina had significantly higher solubility (79 %), viscosity (1.04 x 10−1 centipoise) and molecular weight (4.70 x 104 Da) than those from the others. The bands of the spectra indicate the presence of NH2, OH, C-O, CH, C-N functional groups. It was observed that the particle distribution was non-homogenous, irregular with the presence of pore for all spectra. The characteristics of chitosan obtained indicate that mushrooms from this locality could serve as an alternate source of chitosan to crustaceans with Lenzites betulina possessing the most promising features.

Direct extraction of chitosan from snail shells by natural deep eutectic solvent

The processes involved to extract chitosan biopolymers from natural resources often employ hazardous chemicals and long processing time. This work provides a sustainable direct extraction method of chitosan from snail shells. Previous attempts using acetogenin in graviola extracts succeeded in the extraction of chitosan from marine shells. However, the slow reaction has prompted the addition of hydrogen bond acceptor solution into the graviola extract. Choline chloride is an excellent hydrogen bond acceptor mixed with acetogenin as hydrogen bond donor to form natural deep eutectic solvent (NADES) for the direct extraction of chitosan. Chitosan obtained from this method has a degree of deacetylation of 91% and a molecular weight of 481 kDa with fiber-like morphology. The direct extraction of chitosan from NADES consisting of choline chloride and acetogenin has proven to extract chitosan with comparable properties to commercial chitosan.

ANTIFUNGAL AND WOUND HEALING ACTIVITIES OF CHITOSAN NANOPARTICLES FROM GREEN MUSSEL SHELL (Perna viridis) AND JERNANG (Daemonorops draco) ETHANOL EXTRACT DRESSING PATCH

The development of chitosan nanoparticles and jernang (Daemonorops draco) as wound medicine materials have received a lot of attention from researchers. In this research the two materials will be combined. The antifungal of the materials determined based on inhibition test of Candida albicans and Malassezia furfur. The wound healing activities determined based on the in vivo wound healing test on Wistar rat (Rattus novergicus). The materials applicated on wound dressing patch. Chitosan was sinthesized from green mussels shell waste (Perna viridis L). The result showed that the yield of chitosan was 64.67% and degree of deacetylation (DD) was 69.53%. Meanwhile, chitosan nanoparticles can be prepared based on ball mill process. The result showed that average of the particles size was 437.6 nm (nanoparticles size is 1-1000 nm). Jernang was obtained by maseration process using ethanol organic solvents technical. The yield was 22.41% and showed positively of alkaloid, saponin, flavonoid and triterpenoid test. F3 has highest activies on antifungal and wound healing test results.

Water Soluble Chitosan from Green Mussel (Perna viridis) Shells and Its Use As Fat-Absorber In Cookies

Green mussel chitin can be converted by H2O2 into water-soluble chitosan (WSC). This can subsequently be utilized for a variety of different purposes, such as a fat binder. This study examines how different H2O2 concentrations (13, 21.5, and 30%) affected the properties of WSC (yield, moisture content, ash content, degree of deacetylation, and solubility in water and acid). Moreover as well as how WSC (8%, 9%, and 10%) affected the hedonic scores, proximate composition, and fat binding capacity of weight-loss cookies. A single factor Completely Randomized Design and single-factor ANOVA were used to analyze the data, followed by Duncan’s additional testing as necessary. The results showed that water-soluble chitosan was impacted by H2O2 concentration in that its yield and ash content decreased, its color changed to a brownish, and its solubility in acid and moisture content all increased. According to De Garmo’s Effectiveness Index Test, 30% H2O2 concentration resulted in the best WSC. The addition of WSC did not affect the hedonic quality, protein, moisture, or carbohydrate contents of the cookies, but it did have an impact on the ash and fat contents. The ability of all cookie samples in all treatments to bind fat in liquified butter and peanut oil validates the use of cookies containing WSC in body weight loss research.