Fmoc固相化学合成中,Fmoc基团在每轮循环中需要被先切割下来,暴露出活性氨基,再接下一个Fmoc保护氨基酸.

切割Fmoc的常规操作如下:

挂在树脂上:

1.用20%的Piperidine in DMF溶液(或者Piperidine/DBU/DMF[2:2:96]溶液)浸泡Fmoc保护的挂在树脂上的多肽3分钟

2.抽干树脂,滤掉切割液,重复上步操作3-4遍.

3.用DMF清洗树脂几遍.

游离多肽:

1.以20%的Piperidine in DCM溶液溶解多肽,反应30min.

2.真空去除DCM

3.用冷乙醚沉淀多肽,再经HPLC纯化.

Peptidyl Resin

1. Place the peptidyl-Resin in a flask and treat with 2% hydrazine monhydrate in DMF (25ml/g). Stopper the flask and leave to stand at rt for 3 min.

2. Filter the resin and repeat the hydrazine treatment two more times. Wash the partially protected resin with DMF.

Free Peptide

1. Dissolve the Fmoc protected peptide with 20% Piperidine in DCM (5mg/ml), stir at rt for 30 min.

2. Remove the DCM with vacuum.

3. Precipitate the deprotected peptide with cool ether and purified with HPLC.