The bioconjugates of curcumin, zingerone and [6]-shogaol with low molecular weight chitosan: Synthesis, characterization and in vitro anticancer activity in HepG2 cells

The synthesis of bioconjugates of curcumin, zingerone, and [6]-shogaol with low molecular weight chitosan (LMWC) is presented. The unconjugated forms of these compounds exhibit low water solubility, poor stability, limited bioavailability, and low target specificity, whereas the synthetic conjugates demonstrate improved physical properties. The synthesis was achieved by forming succinates & then reacting with LMWC. They were characterized using FTIR, 1H NMR, UV-Vis spectroscopy, SEM and DLS analysis. The hydrophilicity of bioconjugates was found to be 10.66 mg/mL for C-LMWC, 17.67 mg/mL for Z-LMWC, and 11.59 mg/mL for SLMWC. The bioconjugates exhibited enhanced stability compared to the individual compounds. In vitro release studies indicated a rapid release at pH 5.0 and a slower release at pH 7.4, which is favorable for cancer therapeutic applications. Additionally, the anticancer activity of the bioconjugates was evaluated using a cytotoxicity assay on the liver cancer cell line HepG2, displaying IC50 values of 14.01 mu g/mL for C-LMWC, 82.53 mu g/mL for ZLMWC, and 9.07 mu g/mL for S-LMWC. LMWC is superior to chitosan due to its hydrophilicity & low viscosity. The LMWC conjugates exhibited better solubility, stability and control release of bioactives. The study highlights a better anticancer activity of LMWC-conjugates compared to the native forms.