Two methods for cleaving peptides from solid-phase resins

solid phase Fmoc After chemically synthesizing peptides, there are many methods of cleavage. Now we will introduce two basic types commonly used by everyone.

Place the dry resin in a shaker flask and add the appropriate amount of scavenger ( Scavengers) Cleaving reagent trifluoroacetic acid ( TFA),10-25ml/g Resin, cover, and shake intermittently at room temperature. Filter the resin with new TFA Wash the resin 2-3 times, combine the filtrate, and dropwise add 8-10 times the volume of glacial ether. Sometimes part of it can be steamed off TFA A crude peptide precipitate was obtained. Diethyl ether can be cooled with ice to improve precipitation efficiency. Finally, collect the precipitated crude peptide.

Applicable resin: king resin or Rink Amide Resin

1% TFA:

will 1 g The polypeptide-hanging resin was added to a solution containing 1% TFA The dichloromethane solution glass shake flask was sealed and shaken for 2 minutes. Use nitrogen to pour the filtrate into another new methanol shake flask containing 10% pyridine. Repeat the above operation 10 times. Use 30 ml DCM, 30ml MeOH Wash the remaining protected peptides on the resin three times sequentially. by TLC or HPLC Check the cleaning residue. Combine all the filtrate and evaporate the solvent under reduced pressure to leave 5% volume. add 40 ml water, and ice-cooled the mixture to aid precipitation. After filtration, wash the product with clean water three times and place it in a vacuum drying box for use. KOH or P2O5 Allow to dry.

Dilute acetic acid:

use AcOH/TFE/DCM (2:2:6) Treat the peptides hanging on the resin with cutting solution for 2 hours, filter the resin, and wash the resin three times with cutting solution. Add 15 times the volume of n-hexane to the mixed filtrate, and rotary evaporate to remove excess acetic acid. Peptide recovery methods are detailed below.

Applicable resin: 2- CTC Resin