Novel separation procedure for thymopentin

In order to overcome the high operation cost and high pollution shortcomings of the traditional thymopentin (TP5) separation procedure, a novel TP5 separation procedure combining with ion exchange, nanofiltration and crystallization was proposed. The rough TP5 solution was treated by a NH-1 resin ion exchange column at first with a flow rate of 0.1 mL·min^-1, and the most of the impurities were removed by the rinsing solution consisted of NH₄Cl and NaCl. Ammonium solution was used as eluant, and the TP5 recovery of 90.51%, purity of 96.65% can be achieved. Then the eluant with TP5 effusing from the ion exchange column was desalted and concentrated by the help of the SPT-100-150 nanofiltration membrane, and the desalting ratio is 98.21% with the TP5 losing ratio of 1.34%. Finally, the static state crystallization process at low temperature (4°C) was carried out to crystallize the TP5 product, the crystal yield in one-cycle crystallization is 48.35% and the TP5 product purity can reach 99.12%.