Chitin and Chitosan from Animal Sources

Peter, Martin G.

doi:10.1002/3527600035.bpol6015

Cited by 36 publications

(39 citation statements)

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“…Chitin, containing ca. > 40% GlcNac residues (F A >0.4) is insoluble, whereas soluble polymers are named chitosan (Peter 2002a). Chitosan has three types of reactive functional groups, an amino group as well as both primary and secondary hydroxyl groups at the C-2, C-3 and C-6 positions respectively (Furusaki et al 1996).…”

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confidence: 99%

Changes in hyphal morphology due to chitosan treatment in some fungal species

Oliveira

Melo²,

Franco

2012

Braz. arch. biol. technol.

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In this work, changes in the hyphal morphology due to chitosan treatment in some fungal species were studied. Scanning electron microscope (SEM) observations revealed that chitosans with molar fraction of acetyl groups (F A 0.16 and 0.18) and degree of polymerization (DP 1,089 and 1,242) had a direct effect on the morphology of the chitosan-treated fungi, reflecting its potential for causing a delay in the growth ofAlternaria alternata (500 µg × mL -1 ), Botrytis cinerea (1,000 µg × mL -1 ), Penicillium expansum (1,000 µg × mL -1 ) and Rhizopus stolonifer (500 µg × mL -1 ). Mycelial aggregation and structural changes such as excessive branching, swelling of the cell wall and hyphae size reduction were observed in the micrographs.

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Section: Introductionmentioning

confidence: 99%

Changes in hyphal morphology due to chitosan treatment in some fungal species

Oliveira

Melo²,

Franco

2012

Braz. arch. biol. technol.

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“…Keywords Chitosan Á Chitinase Á Fungi Á Oligosaccharides Á Phytopathogens and glucosamine (GlcN = D) residues (for a review, see [1,2]. After the discovery of an antifungal activity of chitosan by Allan and Hadwiger [3], the antimicrobial activity of the polysaccharide has been intensively studied [4,5], e.g.…”

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Growth of Phytopathogenic Fungi in the Presence of Partially Acetylated Chitooligosaccharides

Oliveira

Gueddari²,

Moerschbacher³

et al. 2008

Mycopathologia

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Four phytopathogenic fungi were cultivated up to six days in media containing chitooligosaccharide mixtures differing in average DP and F A . The three different mixtures were named Q3 (which contained oligosaccharides of DP2-DP10, with DP2-DP7 as main components), Q2 (which contained oligosaccharides of DP2-DP12, with DP2-DP10 as main components) and Q1 (which derived from Q2 and contained oligomers of DP5-DP8 with hexamer and a heptamer as the main components). The novel aspect of this work is the description of the effect of mixtures of oligosaccharides with different and known composition on fungal growth rates. The growth rate of Alternaria alternata and Rhizopus stolonifer was initially inhibited by Q3 and Q2 at higher concentrations. Q1 had a growth stimulating effect on these two fungi. Growth of Botrytis cinerea was inhibited by Q3 and Q2, while Q1 had no effect on the growth of this fungus. Growth of Penicillium expansum was only slightly inhibited by higher concentrations of sample Q3, while Q2 and Q1 had no effect. The inhibition of growth rates or their resistance toward chitooligosaccharides correlated with the absence or presence of chitinolytic enzymes in the culture media, respectively.

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“…Diversas pesquisas buscam novos agentes cicatrizantes para o tratamento de lesões cutâneas [7][8][9] , pois embora existam, no mercado, inúmeras opções de curativos e tratamentos para estas lesões, grande parte dos produtos apresenta custo elevado ao paciente. Neste contexto, a quitosana surge como uma alternativa para o tratamento de lesões cutâneas, uma vez que esta é uma aminoglucopirananas, compostas dos monômeros N-acetil-D-glicosamina (GlcNac) e D-glicosamina (GlcN), obtida a partir de resíduos de crustáceos provenientes da indústria pesqueira [10] .…”

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Caracterização química e efeito cicatrizante de quitosana, com baixos valores de massa molar e grau de acetilação, em lesões cutâneas

et al. 2015

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ResumoInúmeras pesquisas buscam fármacos com propriedades cicatrizantes, capazes de reparar lesões cutâneas. O objetivo deste estudo foi caracterizar quimicamente uma quitosana e avaliar seus efeitos cicatrizantes em lesões cutâneas de ratos. A quitosana foi caracterizada quanto à viscosidade, massa molar, grau de acetilação, análise elementar, termogravimetria e espectroscopia na região do infravermelho. As propriedades cicatrizantes da quitosana foram avaliadas, para isso ratos adultos foram submetidos à excisão tecidual e tratados por 21 dias, sendo avaliados parâmetros macroscópicos, semanalmente, e microscópicos, ao final do experimento. A quitosana apresentou viscosidade de 5 mPa s, baixo grau de acetilação (GA=5,9%) e massa molar (132,0 kDa). Por análise elementar observou-se que a composição da quitosana se aproxima da fórmula C 6 H 11 O 4 N, suas principais bandas características foram observadas no espectro de infravermelho e a curva termogravimétrica mostrou que esta apresenta somente duas etapas de decomposição. Não houve diferença significativa na histologia, no 21º dia da lesão, entre os grupos controle e tratado, porém, macroscopicamente, a quitosana promoveu redução de 81,4% da largura das lesões, porcentagem significativamente superior à observada no grupo controle (71,2%), auxiliando a cura de lesões cutâneas, o que reforça seu potencial de aplicação médica. Palavras-chaves: grau de acetilação, análise termogravimétrica, propriedades cicatrizantes, quitosana. AbstractSeveral researches look for drugs with healing properties, capable to cure skin lesions. The objective of this study was to chemically characterize one chitosan and evaluate its healing effects in mice skin lesions. The chitosan was characterized in relation to the viscosity, molar mass, acetylation degree, elementary analysis, thermogravimetry and infrared spectroscopy. To evaluate the healing properties of chitosan mices were submitted to tissue excision and treated during 21 days. The macroscopic parameters were weekly evaluated and the microscopic parameters at the end of the experiment. Chitosan presented viscosity of 5 mPa s, low acetylation degree (GA= 5.9%) and molar mass of 132.0 kDa. By elemental analysis, we observed that the composition of chitosan is similar to the formula C 6 H 11 O 4 N, its main characteristic bands were observed in the infrared spectrum and the thermogravimetric curve showed two decomposition steps. There was no significant difference on the histology between the control and the treated group after the 21 st day of lesion. Macroscopically, chitosan caused the reduction of 81.4% of the lesions width, which is significantly superior to the observed reduction in the control group (71.2%), thus helping the cure of skin lesions. These results reinforces its potential use for medical application.Keywords: degree of acetylation, thermogravimetric analysis, healing properties, chitosan. IntroduçãoA pele reveste quase a totalidade da superfície corpórea e quando um dano tecidual compromete a continuidade des...

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Chitin and Chitosan from Animal Sources

Abstract: Introduction Historical Outline Structure of Chitin and Chitosan Conformation in Solution Crystal Structures Occurrence Physiological Function Detection of Chitin in Animals and Analysis of Chitin and Chitosan Detection of Chitin in Biolo… Show more

Cited by 36 publications

References 279 publications

Changes in hyphal morphology due to chitosan treatment in some fungal species

Changes in hyphal morphology due to chitosan treatment in some fungal species

Growth of Phytopathogenic Fungi in the Presence of Partially Acetylated Chitooligosaccharides

Caracterização química e efeito cicatrizante de quitosana, com baixos valores de massa molar e grau de acetilação, em lesões cutâneas

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