Study On Preparation Of Ligand Resins With Ag~+ And Isolation And Purification Of FK506

The fermentation production of immunosuppressant tacrolimus (FK506) has by-products which were ascomycin (FK520) and dihydro-tacrolimus (2H-FK506), and they have similar structures. It was difficult to remove analogues by chromatography and crystallization. In water-solvent solutions, FK506 was converted into its isomers of tautomer I and II easily. These factors made it difficult for isolation and separation of FK506, and the yield was low. This paper was aimed to develop a new method which can be applied to isolate and purificate FK506 in industrialization.This paper screened out the macroporous adsorption resin of HZM-3 as chromatographic packings by static adsorption and desorption, and optimized these conditions of MPLC. The effect of single chromatography separation was similar to import packings, like XAD1180 and CG161M, and it had good economic performance. But there ware still about 2% of analogues that was unable to remove. In order to completely remove analogues FK520 and 2H-FK506, this paper sulfonated the macroporous adsorption resin of HZM-3 as the ligand substrate, and produced ligand resin by dynamic loading Ag+, which could specifically adsorb FK506. Examining and optimizing ligands density that effected on the properties of adsorption and desorption of FK506, this paper achieved more suitable and economical ligands density of ligand resins with Ag+. Studying on purification performance of FK506 by ligand resins with Ag+, this paper optimized these conditions of MPLC. When sample amount/column volume was 8 mg/mL, and flow rate was 1 BV/h, and methanol/acetic acid ethyl ester was 1/1 as mobile phase, and elution was only 4.5 BV, the purity of FK506 could achieve to above 98.8% without analogues, and the yield was 87%. The final purity of FK506 was 99.6% after crystallization by ethanol. Using ligand resin with Ag+ as chromatography packings of MPLC for isolation and purification of FK506, FK506 and its analogues could be baseline separated, and it could greatly improve the efficiency on isolation and purification of FK506 and yield.Finally, this paper examined the stability of ligand resin with Ag+ in different types and levels of mobile phase and conditions of storage. Enlarging pilot production of FK506 in enterprise, the loss of Ag+ and the quality of FK506 showed that ligand resin with Ag+ had high stability and long service life.The quality of product FK506 accorded with pharmacopoeia standards and enterprise's production requirements.Studying on the performance of isolation and purification of FK506 and the stability of ligand resin with Ag+, it showed that this paper developed ligand resin with Ag+ and separation technology could provide a good way for fast and efficient purification of FK506, and had higher value for industrial application.