Novel amphiphilic chitosan derivatives: Synthesis, characterization and micellar solubilization of rotenone

Novel amphiphilic chitosan derivatives N-(octadecanol-1-glycidyl ether)-O-sulfate chitosan (NOSCS) with octadecanol glycidyl ether as hydrophobic groups and sulfate as hydrophilic groups were synthesized successfully. The NOSCS were characterized with 1H NMR, FT-IR, and their critical micellar concentrations (CMCs) were found to be 3.55 × 10−3 to 5.50 × 10−3 mg/mL. The degree of substitution (DS) of octadecanol glycidyl ether grafted on chitosan was ranging from 0.6% to 7.1%. NOSCS could form polymeric micelles with the size of 167.7–214.0 nm by self-assembly in aqueous solution. Rotenone, a water-insoluble botanical insecticide, was entrapped into NOSCS micelles solution by reverse micelle method. And the highest rotenone concentration was up to 26.0 mg/mL, which was much higher than that in water (0.002 mg/mL). Therefore, NOSCS nano micelles may be useful as a prospective carrier for control released agrochemical.