2.2.3. Synthesis of Mel-OCM-chitosan conjugates
Fmoc-Mel-amino acid (2 mmol) was mixed with EDC (383 mg,
2 mmol) in 20 mL N,N-dimethyl formamide (DMF) and reacted at
room temperature for 4 h. Then, NHS (230 mg, 2 mmol) was added
to the above mixture, and the whole mixture was stirred for 6 h at
room temperature to obtain NHS-activated Fmoc-Mel-amino acid.
OCM-chitosan was dissolved in 10 mL distilled water, and NHSactivated
Fmoc-melphalan-amino was added drop-wise to solution
of OCM-chitosan over 30 min. The mixture was reacted at room
temperature for 48 h, and the water of the solution was removed
in vacuo at 50 ◦C with adding suitable amount of toluene several
times. Then the N-Fmoc derivatives of Mel were deprotected with
piperidine.