Functionalization of chitosane with carboxyl and organic acids
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CEACÎRU, Mihail; GONTA, Maria; GUŢU, Iacob; CEACÎRU, Cristina; DUCA, Gheorghe. Functionalization of chitosane with carboxyl and organic acids. In: The Environment and the Industry SIMI 2019 Book of abstracts. Ediția a 22-a, Book of abstracts, 26-27 septembrie 2019, București. București, România: National Research and Development Institute for Industrial Ecology ECOIND, 2019, pp. 28-29.
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The Environment and the Industry
Ediția a 22-a, Book of abstracts, 2019
Conferința "The Environment and the Industry"
București, Romania, 26-27 septembrie 2019

Functionalization of chitosane with carboxyl and organic acids


DOI: 10.21698/simi.2019.ab07
Pag. 28-29

Ceacîru Mihail1, Gonta Maria1, Guţu Iacob1, Ceacîru Cristina1, Duca Gheorghe2
 
1 State University of Moldova,
2 Institute of Chemistry
 
Disponibil în IBN: 12 iunie 2020


Rezumat

Introduction

Chitin occupies second place after cellulose and is among the most widespread
biopolymers in nature. Chitosan (made from chitin) is a versatile biopolymer and
therefore its derivatives are used in various fields such as agriculture, food industry,
cosmetics, water treatment and so on. Chitosan is also of interest in the pharmaceutical
field because it is biodegradable, biocompatible and has a low toxicity.
The main objective of this paper was the synthesis of some derivatives of chitosan
functionalized with dihydroxyfumaric acid and ascorbic acid.
Materials and methods
Chitosan – dihydroxyfumaric (Cht-DFH4) was prepared in 3 phase. In first phase
chitosan – diacetyl tartaric anhydride (C) was prepared according to the method
described by Chen et al (2013) with some modifications, following the interaction of
chitosan (B) with diacetyl tartaric anhydride (A). In second phase hydrolysis is carried
out with NaOH (D), and after consumption of the base, the mixture is filtered, washed
with acetone and dried. The obtained copolymer (E) is used to oxidize the step with
the Fenton reagent to obtain the chitosan grafted with dihydroxyfumaric acid (F).
The functionalisation of chitosan was performed according to the figure 1:

Figure 1. The reaction mechanism of chitosan grafting to dihydroxyfumaric acid
Chitosan ascorbate (Cht-AAs) was prepared according to the method described by
Hafsa et al (2014) with some modifications. Weigh out 1.00 g of chitosan and dissolve

in 100 ml of 0.5% acetic acid, shake with the magnetic stirrer until the chitosan solubilizes.

After that, ascorbic acid (1.10 g) is added and the mixture is heated for 3 hours at 100 ° C.

After completion of the reaction time, the mixture is precipitated, filtered, dried under

vacuum.
The mechanism of reaction between chitosan and ascorbic acid is represented in Schemes 2.

Figure 2. Funcționalizarea chitosanului cu acidul ascorbic, raport echimolar, t= 3 h, t= 100 °C
Results and conclusions
The anti-oxidant activity Cht-DFH4 was determined by the DPPH test and it has been established

that the antiradical power of the functionalized copolymer is 2.5 times

higher than pure dihydroxyfumaric acid. These composites are to be used to inhibit the

formation of N-nitrosamines in drug-nitrosation.
The anti-oxidant activity Cht-AAs was determined by the ABTS test and it has been

established that the antiradical activity of the copolymer is 16.7% higher than pure

ascorbic acid at the same concentration of AAs.
Table 1.Total antioxidant activity (ABTS • +) of the composite and pure AAs after

It has been demonstrated a functionalization of chitosan with dihydroxyfumaric acid.

The antiradical

power of the functionalized copolymer was determined. Intermediate and final

compounds have been demonstrated by IR, UV and H1-NMR spectra.
Chitosan was functionalized with dihydroxyfumaric acid and ascorbic acid,

 increasing the antioxidant power of natural reducers.

 



Cuvinte-cheie
antioxidants, chitosan, dihydroxyfumaric acid, Functionalization