Figure 2.

Synthesis and characterization of NSC–SS–UA.

Notes: (A) Synthesis of NSC–SS–UA. (B) FT-IR spectra of CS (a); NSC (b); NSC–SS (c); and NSC–SS–UA (d). (C) ¹HNMR spectra of NSC (a); NSC–SS (b); and NSC–SS–UA (c). *Represents a monomer five-membered ring at the end of the long chain.

Abbreviations: CS, chitosan; EDC, 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide; FT-IR, Fourier transform infrared spectroscopy; NHS, N-hydroxysuccinimide; NSC, N-succinyl chitosan; NSC–SS, N-succinyl chitosan–cystamine; NSC–SS–UA, N-succinyl chitosan–cystamine–urocanic acid; ppm, parts per million.