Piperidine
Definition
The base used to remove the Fmoc group, usually as a 20% solution in DMF. It appears once per residue in a standard synthesis, and the by-product it forms is monitored to confirm each deprotection happened.
Terms used in this definition
Other entries this definition refers to.
Where this term comes up
Entries whose definition mentions Piperidine.
What this means for research sourcing
Structure and identity terms are what a certificate of analysis is written in. Every Volta compound ships with its sequence, molecular weight and measured purity, so these terms map directly onto the specification on the product page.
Related Terms in Chemistry & Structure
Resin
The insoluble polymer bead the chain is assembled on in solid-phase synthesis. Anchoring the chain to it is what lets excess reagents and by-products be washed away at every step, which is the entire advantage of the method.
Wang Resin
A resin whose linker releases the chain as a free carboxylic acid at the C-terminus. The choice of resin decides the C-terminal form, which is why it is picked before the first residue is attached.
Rink Amide Resin
A resin whose linker releases the chain as a C-terminal amide. Many research peptides are amidated at the C-terminus, and this is the usual way that is achieved.
Aspartimide Formation
A side reaction at aspartic acid where the side chain cyclises onto the backbone, generating a family of related impurities. Certain neighbouring residues make it much more likely, and it is one of the main reasons a sequence proves hard to synthesise cleanly.
Epimerisation
Loss of stereochemistry at one centre, converting an L-residue to its D-form during synthesis. The product has the same mass and often a very similar retention time, so it is an impurity ordinary purity testing can miss.
Racemisation
Loss of stereochemical purity toward an equal mixture of both forms. Activation chemistry is where peptides are most at risk, which is why coupling additives that suppress it are standard rather than optional.
Pseudoproline
A reversibly modified serine or threonine dipeptide that disrupts chain aggregation during synthesis and reverts at cleavage. It is one of the standard tools for a sequence that otherwise fails partway through.
Native Chemical Ligation
Joining two unprotected peptide fragments in solution through a cysteine at the junction, forming a normal peptide bond. It is how chains too long for stepwise synthesis are assembled.