Quitooligosacáridos bifuncionales: relación entre características químico-físicas y propiedades biológicas

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Sánchez Sánchez, Ángela María (2016) Quitooligosacáridos bifuncionales: relación entre características químico-físicas y propiedades biológicas. [Thesis]

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Abstract

As the degraded products of chitosan, chitooligosaccharides (COS) have recently been produced by several methods, such as enzymatic an acidic hydrolysis. Chitosans are a family of biocompatible and biodegradable biopolymers obtained by N-deacetylation of chitin, the most abundant natural polymer after cellulose, consisting of two monomeric units, N-acetyl-2- amino-2-deoxi-D-glucose (A units) and 2-amino-2-deoxi-D-glucose (D units) linked by β (1→4) links. The degraded products COS, have a smaller molecular weight and therefore have better solubility and lower viscosity under physiological conditions because of shorter chain lengths and free amino groups in D-glucosamine units. The study of COS has been increasing not only because they come from a natural source, but also because of their biological compatibility and effectiveness. There are numerous reports on the biological activities of COS and their potential applications in food industry, pharmacy, agricultural or biomedicine. Nevertheless, in these studies it is difficult to find well defined COS in terms of physicochemical parametres, because these samples are usually poorly characterized. This makes it difficult to compare the results and to understand their mecanism of action. Degradation of the O-glycosidic linkages of chitosan by different methods, results in COS with different numbers and sequences of A and D units as well as different degrees of polymerisation (DP). Over the past few years, several technological approaches have been taken in preparing COS, including acid hydrolysis or enzymatic methods, among others. Therefore, in order to obtain COS with different physicochemical properties, different preparation methods of COS have been developed in this work. Then, the study of the relationship between physicochemical properties of these COS and their biological activities such as natural antioxidants, antibacterial agents, mucoadhesive and anti-inflammatory effects have been studied...


Item Type:Thesis
Additional Information:

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Farmacia, Departamento de Química Física II (Físico-Química Farmacéutica), leída el 14-12-2015

Directors:
Directors
Heras Caballero, Ángeles
Acosta Contreras, Florentina Niuris
López Mengíbar, María Ángeles
Uncontrolled Keywords:Química física
Palabras clave (otros idiomas):Chemistry, physical and theoretical
Subjects:Medical sciences > Pharmacy > Physical chemistry
ID Code:38766
Deposited On:11 Aug 2016 12:58
Last Modified:13 Dec 2018 09:46

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