<... is it possible that the s-s bridge, present in cystine derivate in a peptide made using the Fmoc solid phase protocol, breaks down using a solution of piperidine 20% in DMF?...Enrico Millo>
Enrico:
Neither DMF, nor piperidine are able to reduce -S-S- ---> 2-SH.
However, "unsymmetrical" cleavage via beta-elimination promoted by piperidine cannot be excluded:
-Cystine- ---> dehydroalanine + -Cys(SH)-
RNH-CH(C=O...)-CH2-S-S-CH2-CH(NHR')C(O)-... ----> ...>C=CH2 + HSSCH2C(NHR')C(O)-...
Dehydroalanine was shown to scavenge piperidine to give racemic piperidylalanine moiety:
==>RNH-CH(C=O...)-CH2-Pip.
Regards,
Igor Rodionov
Laboratory of Peptide Chemistry
Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry
8 Academy Avenue, Pushchino, Moscow Region
142290, Russian Federation
rodionov@fibkh.serpukhov.su
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