Start Right Away: Pre-Loaded Resins for Efficient Synthesis
Within the Novabiochem® portfolio, Merck offers a comprehensive range of high-quality supports for solid-phase peptide synthesis (SPPS) based on Wang, 2-chlorotrityl, NovaSyn® TGA, NovaSyn® TGT, HMPB NovaPEG and Trt NovaPEG resins. We provide, among others, resins pre-loaded with N-α-Fmoc-protected and other amino acids, amino aldehydes, amino alcohols, diamines, or amino thiols. Our products are carefully designed to minimize impurities and unwanted side reactions and ensure efficient synthesis processes with high yields.
Fully unprotected peptide acids are cleaved from Wang resins, NovaSyn® TGA, and HMPB NovaPEG by treatment with 95% trifluoroacetic acid (TFA). Hyperacid labile resins such as 2-chlorotrityl, NovaSyn® TGT, and Trt NovaPEG resins are used for the synthesis of either protected or side-chain unprotected peptides by treating with 95% TFA or 20% (trifluoroethanol) TFE in DCM respectively.
For the preparation of peptides containing C-terminal chirally sensitive Cys and His residues, trityl-based resins such as NovaSyn® TGT, Trt NovaPEG or 2-chlorotrityl resins should be used as well. Loading of these resins is free from racemization and dipeptide formation. Furthermore, side-reactions arising from piperidine mediated β-elimination of Cys are much reduced on trityl resins compared to Wang-type resins.
Trityl-based resins are also strongly recommended for the preparation of peptides containing C-terminal Gly, and Pro because dipeptides containing these residues attached to benzyl-based linkers are prone to undergo diketopiperazine formation during Fmoc deprotection, with loss of peptide chains from the support. This side reaction is reduced, if not eliminated, with a trityl resin, owing to the bulk of the linker.
In the table below, you find a listing of Merck pre-loaded resins together with appropriate cleavage reagents.
|95% TFA||20% TFE in DCM|
|Wang resin||Polystyrene- 1% DVB||Peptide acid||-|
|Wang resin LL||Polystyrene- 1% DVB||Peptide acid||-|
|NovaSyn® TGA||PEG-PS||Peptide acid||-|
|NovaSyn® TGT||PEG-PS||Peptide acid||Protected peptide acid|
|HMPB NovaPEG resin||PEG||Peptide acid||Protected peptide acid|
|Trt NovaPEG resin||PEG||Peptide acid||Protected peptide acid|