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<P>Dear all,</P>
<P>I’m trying to synthetize a very long peptide (80 aa), with stepwise manual
Fmoc chemistry (with acetylation post coupling), but altough I have made double
coupling, using HATU, DIPEA, sim collidine in NMP at 35-40°C, the yield has
strongly decreased obtaining already at the 61st aa. only the 20%. Resin: Rink
MBHA 0.5mmole/g</P>
<P>I have found a lot of truncated and acetilated peptides. I also made an
attempt with convergent synthesis but without success.</P>
<P>Does anybody know any other attention or trick that I can use to improve the
synthesis of such a very long peptide?</P>
<P>Thanks a lot</P>
<P>Enrico Millo</P>
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