1,2-Dichloroethane → Tacrolimus

Participants

Reaction Steps

A mixture of a photocleavable linker (4-{4-[1-(Fmoc-amino)-ethyl]-2-methoxy-5-nitrophenoxy}butyric acid, Fluka) (124 mg, 0.24 mmol), TOYOPEARL resin (TSKgel AF-amino, 600 μl, free amino group (available amino group) was 0.06 mmol), EDC (44 mg, 0.28 mmol), HOBt (39 mg, 0.28 mmol) and DMF (6 ml) was stirred at room temperature for 15 hr. The reaction end point was confirmed by the incapability of visual observation of residual amino group in the ninhydrin reaction. The reaction rate at that time was calculated to be about 88%. After confirmation of the completion of reaction, the resin was washed 5 times with DMF. Thereto was added 20% piperidine-DMF solution (6 ml) and the mixture was stirred at room temperature for 2 hr. The resin was washed 5 times with DMF, and 200 μl thereof was taken and stirred with a mixture of 17-allyl-1,14-dihydroxy-12-{2-[4-(7-carboxy-heptanoyl-oxy)-3-methoxy-cyclohexyl]-1-methyl-vinyl}-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-aza-tricyclo[22.3.1.04,9]octacos-18-ene-2,3,10,16-tetraone (FK506; 77 mg, 0.08 mmol) prepared according to the method described in a reference (Bioconjugate Chemistry, 2003, 14(6), 1222-1230), EDC (14.9 mg, 0.096 mmol), HOBt (12.8 mg, 0.096 mmol) and DMF (1 ml) at room temperature for 20 hours. The reaction end point was confirmed by the incapability of visual observation of residual amino group in the ninhydrin reaction. The reaction rate at that time was calculated to be about 94%. After confirmation of the completion of reaction, the resin was washed 5 times with DMF. Acetic anhydride (200 μl) and DMF (800 μl) were added thereto, and this was followed by stirring at room temperature for 1 hour. Subsequently, the resin was thoroughly washed with DMF, and the obtained resin immobilizing FK506 via photocleavable linker was used for the binding assay described below.

Provenance & Evidence