Synthesis and characterization of polyampholytic aryl-sulfonated chitosans and their in vitro anticoagulant activity

Abstract

This work firstly aimed to synthesize mono- and di- sulfonic derivatives of chitosan by reductive amination reaction using respectively 2-formyl benzene sulfonic acid and 2,4 formyl benzene sulfonic acid sodium salts. The influence of the reactants molar ratio (R), aryl - substituted amino groups versus chitosan free amino groups, on the degree of substitution (DS) of both sulfonated chitosans was assessed by H NMR, elemental analysis, coupled conductometry-potentiometry analysis and UV spectrometry and FTIR. The influence of pH on sulfonated chitosans' properties in solution were investigated by solubility and zeta potential (ZP) studies, size exclusion chromatography equipped with MALLS detection (SEC-MALLS) and Taylor dispersion analysis (TDA). The polyampholytic character of both series was evidenced and strongly modified the solutions properties compared to chitosan. Then, the anticoagulant properties of mono- and di- sulfonic polymers were investigated by the measurement of the activated partial thromboplastin time (aPTT), Prothrombin-time (PT) and anti-(factor Xa).

Effects of sulfonation on bis‐styrylbiphenyl fluorescent whitening agents for polypropylene

“…The peaks at around 1200 cm −1 and 1180 cm −1 in compounds b and c are attributed to asymmetric and symmetric vibrations of OSO, respectively . The peaks at around 1630 cm −1 are originated from the aromatic CC stretching vibrations of benzene ring . It is envisaged that the structure of the compounds can be confirmed by combining the IR results with those of 1 H‐NMR investigation.…”

“…This is because the sulfonate group is hydrophilic and there is enhanced presence of water molecules with its enrichment . The peaks at around 1200 cm −1 and 1180 cm −1 in compounds b and c are attributed to asymmetric and symmetric vibrations of OSO, respectively . The peaks at around 1630 cm −1 are originated from the aromatic CC stretching vibrations of benzene ring .…”

Modification of Hydroxypropyltrimethyl Ammonium Chitosan with Organic Acid: Synthesis, Characterization, and Antioxidant Activity

“…As for HACCa, the signals at δ 7.25, δ 6.21 ppm are related to the protons of H-h, H-i, respectively. Furthermore, in the range of δ 6.5-7.1 ppm is assigned to the protons on the benzene ring [3]. At the same time, the signal at δ 3.18 ppm which can be assigned to the resonance of hydrogen of trimethyl ammonium groups still exists in the spectra of conjugates of organic acid salt and hydroxypropyltrimethyl ammonium chitosan.…”

“…Compared to HACC, new peaks of the spectra of HACFe appear at 1585, 1546 cm −1 , which were assigned to the characteristic peaks of the benzene ring. As for HACHy, HACSa, HACPc, HACCa, and HACGa, new peaks appear at 1587, 1596, 1596, 1545, and 1552 cm −1 , respectively, can be attributed to the C-C stretching vibration of benzene ring [3,18]. Furthermore, for the spectrum of HACSa, HACCa, HACPc, and HACGa, absorption peaks at 781, 767, 772, 735, 739 cm −1 corresponded to the C-C stretching vibration of the benzene ring [19].…”

“…Reactive oxygen species (ROS), which contains superoxide anion (•O 2 − ), hydrogen peroxide (H 2 O 2 ), hydroxyl radical (•OH), and singlet oxygen ( 1 O 2 ), are produced by normal metabolism in vivo, radiation, and chemical factors [1][2][3]. The constant quantity of ROS is of vital importance to maintain the stability of the intracellular environment.…”