Chitosan functionalization with a series of sulfur‐containing α‐amino acids for the development of drug‐binding abilities

Abstract

Chitosan (Chi; 0.5 g) in 69.66 mM aqueous acetic acid was mixed with 312.4 mM methionine (methi) at 0.01 mL/s to disperse and cause optimum collisions for supporting condensation reactions through ANH 2 of Chi and ACOOH groups of methi. The functionalized chitosan (f-Chi) product with methi developed an amide bond, which was represented as methi-functionalized chitosan [Chi-NHAC(@O)-methi]. Both the 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and Dean-Stark methods were followed for Chi functionalization. Sulfonation with chlorosulfonic acid in a dimethylformamide medium was conducted at 90 8C and 750 rpm with an approximately 72% yield. The Chi-NHAC(@O)-methi was characterized by 1 H-NMR spectroscopy and Fourier transform infrared stretching frequencies. The onset temperature of 280 8C recorded by thermogravimetric analysis/differential scanning calorimetry analysis, confirmed the high stability of the covalent bonds in Chi-NHAC(@O)-methi. The synthesis was repeated with other series members of sulfur (S) atoms containing a-amino acids: homocysteine, ethionine, and propionine. The shielding of terminal ACH 3 was enhanced on elongation of the terminal alkyl chain in the case of propionine. The peak for the ANH 2 of Chi at a d value of 4.73 ppm shifted to 5.36 ppm in Chi-NHAC(@O)-methi because of the involvement of ANH 2 in ANHAC(@O)A. Theoretically, the value of ANH 2 of Chi was 5.11 ppm, with a difference of 0.38 ppm as compared to the experimentally determined value of 4.73 ppm. Additionally, a new peak at a d value of 3.26 ppm also confirmed Chi functionalization.

Preparation and Properties of a Double‐Coated Slow‐Release Urea Fertilizer with Poly(propylene carbonate), a Sodium Polyacrylate Hydroscopicity Resin and Sodium Alginate

“…SPHR was synthesized by solution polymerization using acrylic acid as the monomer, ammonium persulfate and sodium bisulfite as initiator and N-maleyl chitosan as crosslinking agent. [32,33] The reactions were operated under the conditions: monomer concentration 20 wt %, neutralization degree of acrylic acid 50%, initiator concentration 0.2%, cross-linker concentration 1% and 60 8C. Water absorption of the SPHR is 505.7.…”

“…PPC not only exhibits interesting material properties, but also has the additional environmental advantages resulting from their biodegradability. [29,30] Huang et al [31] and Li et al [32] reported PPC and its derivatives were used as controlled drug materials for PPC microcapsules. Microspheres were found to have a certain effect on the controlled release of drug.…”

LSNR:GO template for BSA interaction, photo and sonocatalytic reductions of fluorescent dyes in aqueous solutions

“…Thereby, LGT depicted as the 4𝑓 #𝑒 ~𝐹𝐸 could replace the expensive prisms used for splitting a light for faster photocatalysis of industrial effluents 14 . 𝐿𝑆𝑁𝑅 could also be doped with proteins, chitosan, carbohydrates/cellulose as biotemplet with 4𝑓 #𝑒 ~𝐹𝐸 interface for biophysical applications 15 . 𝐿𝐺𝑇 with 4𝑓 #𝑒 ~𝐹𝐸 an energy simulator could trap a solar radiation for bio and piezoelectric sensors and minimizes a light scattering, and quantum confinements within optoelectronics 3,16 .…”

“…Unlike MOF of transition metals, the lanthanide organic framework (LOF) could create a huge vacancy of applications with higher frequency of recycling and energy storage 17 . The functional edges (FE) and 𝜋 conjugations of 𝐺𝑂 with photon (ℎ𝜈) generates wavefunction (𝜓) in different phases (𝜑) but the 4𝑓 #𝑒 ~𝐹𝐸 interface photocatalyzed a dye in a shorter time with intensified redox cycle (𝑅𝑂𝐶) [14][15][16] . The LSNR and LGT could affect salt bridges, electrostatic, and peptide bonds of protein by generating thermodynamic parameters tuned by 4𝑓 #𝑒 electrons 17,18 .…”

Sewage Polluted Water Treatment via Chitosan: A Review

“…In contrast to the most naturally occurring polysaccharides, which are either anionic or neutral, such as cellulose, starch, or alginate, CS is a polycation. The free amine groups, which are responsible for the polycationic character, bear nonbinding electrons providing donor properties suitable for coupling to electrophiles, for example, for the formation of imines or amides [4,5].…”