Investigation of different natural sources of chitin: influence of the source and deacetylation process on the physicochemical characteristics of chitosan

Rhazi, Mohammed; Desbrires, J; Tolaimate, A.; Alagui, Abdelhakim; Vottero, P.

doi:10.1002/(sici)1097-0126(200004)49:4<337::aid-pi375>3.0.co;2-b

Cited by 120 publications

(61 citation statements)

References 23 publications

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“…13,29,30 In the current study, monoalkyl chitosan derivatives with ethyl, butyl, and hexyl chains were synthesized using this precursor. Initially, TBDMS chitosan was treated with aldehyde in CH 2 Cl 2 to form the imine, which was isolated (to prevent overalkylation) and then reduced with Na(OAc) 3 This procedure gave 100% dialkylation, even with the longer alkyl chains. The initial addition of a large excess of aldehyde and NaBH 4 did not result in full dialkylation, as NaBH 4 also reduces the excess aldehyde present in the medium to an alcohol, thereby preventing further condensation.…”

Section: 1mentioning

confidence: 99%

Impact of Chain Length on Antibacterial Activity and Hemocompatibility of Quaternary N-Alkyl and N,N-Dialkyl Chitosan Derivatives

et al. 2015

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A highly efficient method for chemical modification of chitosan biopolymers by reductive amination to yield N,N-dialkyl chitosan derivatives was developed. The use of 3,6-O-di-tert-butyldimethylsilylchitosan as a precursor enabled the first 100% disubstitution of the amino groups with long alkyl chains. The corresponding mono N-alkyl derivatives were also synthesized, and all the alkyl compounds were then quaternized using an optimized procedure. These well-defined derivatives were studied for antibacterial activity against Gram positive S. aureus, E. faecalis, and Gram negative E. coli, P. aeruginosa, which could be correlated to the length of the alkyl chain, but the order was dependent on the bacterial strain. Toxicity against human red blood cells and human epithelial Caco-2 cells was found to be proportional to the length of the alkyl chain. The most active chitosan derivatives were found to be more selective for killing bacteria than the quaternary ammonium disinfectants cetylpyridinium chloride and benzalkonium chloride, as well as the antimicrobial peptides melittin and LL-37.

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Section: 1mentioning

confidence: 99%

Impact of Chain Length on Antibacterial Activity and Hemocompatibility of Quaternary N-Alkyl and N,N-Dialkyl Chitosan Derivatives

et al. 2015

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“…The DA of both chitin samples was determined by comparing the absorbance of the measured peak (proportional to the DA) to that of the reference peak (independent of the DA). The DA was calculated from the absorbance (A) ratios by using the method of Baxter et al [24] according to the following equation: 13 C cross-polarization magic-angle-spinning (CP/MAS)-NMR spectra were recorded at 125.8 MHz on a Bruker Avance 500 spectrometer with a spinning rate of 10 kHz and using a contact time of 2 ms. A total of 6144 scans were acquired for each run, and measurements were performed at room temperature.…”

Section: Ft-ir Measurementsmentioning

confidence: 99%

“…bartrami [9,10], and Loligo species and cuttlefish (Sepia officinalis) [6,[11][12][13]. The ␥-form is characterized by a mixture of antiparallel and parallel chains and was found in the cocoons of insects [14].…”

Section: Introductionmentioning

confidence: 99%

Isolation and characterization of chitin from bumblebee (Bombus terrestris)

Majtán

Bíliková

Markovič

et al. 2007

International Journal of Biological Macromolecules

133

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“…Chitosan (CS) with a degree of acetylation (DA) of 8, 10% and molecular weight (Mw) of 13, 63 and 125 kDa was prepared following a process already optimized in our previous studies. 31,32 Briefly, purified chitin, extracted from wastes of shrimp, was deacetylated according to the procedure reported by Broussignac 33 which consisted of a treatment at 120°C for 24 h with a solution of potassium hydroxide (50 w/w %) in a mixture of ethanol and monoethyleneglycol. The resulting chitosan samples were then characterized in terms of their DA and Mw.…”

Section: Methodsmentioning

confidence: 99%

Chitosan Nanoparticles as a New Delivery System for the Anti-HIV Drug Zidovudine

Dahmane¹,

Rhazi²,

Taourirte³

2013

Bulletin of the Korean Chemical Society

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Chitosan-based nanoparticles (CSNP) were prepared through ionic cross-linking and gelation of chitosan (CS) by tripolyphosphate (TPP). CS properties such as molecular weight, and preparation conditions were screened and the resulting nanoparticles were examined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained particles were consistently spherical with an overall diameter of approximately 107 ± 20 nm. They were successfully used as a carrier for Zidovudine, an anti-human immunodeficiency virus (HIV) which, to our knowledge, is novel. The encapsulation ability, loading capacity, and controlled release behavior for these CSNP was evaluated. Results indicated that their intrinsic properties were strongly affected by properties inherent to CS such as molecular weight, and by the preparation condition, such as cross-linking density, which depends on the concentration of the cross-linker. In vitro release tests for the entrapped zidovudine showed that the CNNP provided a continuous release that can last upwards 20 h.

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Investigation of different natural sources of chitin: influence of the source and deacetylation process on the physicochemical characteristics of chitosan

Cited by 120 publications

References 23 publications

Impact of Chain Length on Antibacterial Activity and Hemocompatibility of Quaternary N-Alkyl and N,N-Dialkyl Chitosan Derivatives

Impact of Chain Length on Antibacterial Activity and Hemocompatibility of Quaternary N-Alkyl and N,N-Dialkyl Chitosan Derivatives

Isolation and characterization of chitin from bumblebee (Bombus terrestris)

Chitosan Nanoparticles as a New Delivery System for the Anti-HIV Drug Zidovudine

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