Study on microwave-assisted solid phase synthesis of thymopentin

A microwave-irradiation technique was applied to the solid phase synthesis of thymopentin, and also the influences of coupling reagents, solvents, reactant concentration, reaction time and temperature on the solid phase synthesis yield of thymopentin with microwave irradiation were investigated. Compared with the classical method, the reaction rate of forming peptide bond was increased by over 15 times, and the excessive amount of amino acid was reduced to only one fold from 3 folds of the classical method, therefore the synthetic cost was about 40% reduced by the microwave-assisted technique. The best conditions including solvent, coupling reagent, reactant concentration, reaction time and temperature were pyridine/DMF, O-benzotriazole-N,N,N′,N′- tetramethyl-uronium-hexafluorophosphate (HBTU), 0.113 mmol/L, 4 min and 20 °C, respectively. The yield of thymopentin reached 88.7% under the best conditions.