2. Articole

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Start date: 2023Subject: search.filters.subject.chitosan

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    Synthesis of chitosan grafted with aminomethyl zinc phthalocyanine for photodynamic therapy [Articol]
    (2025) Robu, Ștefan; Potlog, Tamara; Bulimestru, Ion; Lungu, Ion; Sadohina, Olga; Druța, Alexandrina; Bulmaga, Petru; Guțu, Iacob
    This paper reports the synthesis of a substituted aminomethyl zinc phthalocyanine (AmPcZn) and its covalent grafting onto chitosan via an ethyl chloroformate-mediated reaction. Chitosan-based copolymers containing 10%, 20%, 30%, and 60% (w/w) AmPcZn were successfully obtained. The chemical structure of the synthesized AmPcZn was confirmed by 1H-NMR spectroscopy and elemental analysis, which were consistent with the expected molecular composition. The grafting reaction and structural integrity of the resulting copolymers were investigated using Fourier-transform infrared (FTIR) and UV-Vis spectroscopies. FTIR spectra revealed characteristic amide and carbonyl stretching bands, confirming covalent bond formation between chitosan and AmPcZn. UV-Vis measurements showed a concentration-dependent increase in absorbance and a typical splitting of the Q-band with band at 605 nm and 715 nm, indicating the successful incorporation of the phthalocyanine moiety into the polymeric matrix.
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    Sinteza și cercetarea unor copolimeri din chitosan grefați cu ftalocianină de zinc, pentru scopuri medicinale [Articol]
    (CEP USM, 2024) Popușoi, Ana; Potlog, Tamara; Bulmaga, Petru; Sadohina, Olga; Robu, Ștefan
    In the present work, we describe new copolymers of chitosan grafted with zinc aminomethylphthalocyanine, which was obtained through the mono-(o-carboxybenzamidomethyl) hydrolysis of zinc phthalocyanine at a temperature of 170-175 ℃. Copolymers of aminomethylphthalocyanine with mass contents of 10%, 20%, and 30% of H2nCH2-PCZn were successfully synthesized, and they exhibited good solubility in water and other organic solvents. The chemical structure of the copolymers was proposed through infrared molecular absorption spectroscopy. according to their optical properties in the uV-VIs region, these water-soluble copolymers can be utilized in photodynamic therapy.
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    Synthesis of quercetin functionalized chitosan and determination of antioxidant properties [Articol]
    (2023) Gonța, Maria; Duca, Gheorghe; Sârbu, Elena; Robu, Ștefan; Mocanu, Larisa
    This paper is dedicated to the synthesis of a copolymer with reducing properties obtained by functionalizing chitosan with quercetin and determining the antioxidant activity of the derivatives obtained depending on the molar mass of the polymer. For this purpose, low molecular weight chitosan was obtained by oxidizing commercial chitosan with hydrogen peroxide and further functionalization with quercetin by the covalent grafting method. The functionalization process was performed through the following steps: functionalization of chitosan with ethyl chloroformate to increase the reactivity of the amine group to the hydroxyl group of quercetin and grafting the quercetin molecule to the synthesized intermediate. The comparative antioxidant properties of the composite obtained by grafting technical chitosan with quercetin and by grafting low molecular weight chitosan were studied by the DPPH (2,2-diphenyl-1-picrylhydrazyl radical) method. The obtained results indicate that a decrease in the molecular weight of chitosan contributed to its grafting with quercetin. As a result, the functionalized polymer composite acquired a higher antioxidant activity and can be successfully used to inhibit the oxidation of various organic substrates in the cosmetic, food and pharmaceutical industries.