Two excised from the solid phase resin polypeptide!

After Fmoc solid-phase peptide synthesis chemistry , there are a lot of cutting methods , we now introduce two basic types commonly used .

1 , acid method ( commonly TFA)
The dry resin is placed in a shake flask, containing an appropriate amount of scavenger (Scavengers) cleavage agents trifluoroacetic acid (TFA) ,10-25ml / g resin , cover , intermittent rotary shaken at room temperature. Filtration resin , the resin was washed with TFA new 2-3 times , the combined filtrate was added dropwise to an ice 8-10 times the volume of diethyl ether . TFA can sometimes get partially evaporated and precipitated crude peptide . Ether can assist with ice cooling to increase precipitation efficiency . Finally , collect the precipitated crude peptide .

Applicable resin : Wang resin or Rink Amide resin

2 , weak law ( TFA or diluted acetic acid )
1% TFA:
1g of the polypeptide linked to the resin was added a dichloromethane solution containing a glass flask containing 1% TFA , and the shock two minutes after sealing with nitrogen gas and the filtrate into another hydraulic new shake flask containing methanol containing 10% pyridine repeat the operation 10 times. With 30ml DCM, 30ml MeOH wash the residue in the sequence of protected polypeptide resin three times. TLC or HPLC to check the cleaning residue situation . All combined filtrate and evaporate the solvent remaining 5% by volume . 40ml of water added , and the mixture was cooled with ice to assist precipitation. After filtration, cleaning products with water three times , dried in a vacuum oven with KOH or P2O5.
Dilute acetic acid :
With AcOH / TFE / DCM (2:2:6) was treated cutting polypeptide linked to the resin for 2 hours the resin was filtered and the resin was washed three times with a cutter . The filtrate was mixed with 15 volumes of n-hexane , rotary evaporated to remove excess acetic acid. Peptide recovery methods described below .

Applicable resin :2-CTC resin