Fmoc protected amino acids linked to TentaGel® S TRT

TentaGel® resins are grafted copolymers consisting of a low crosslinked polystyrene matrix on which polyethylene glycol (PEG or POE) is grafted. The PEG spacer is attached to the matrix via an ethyl ether group which increases stability towards acid treatment and minimizes PEG-leaching. As PEG is a "chameleon type" polymer with hydrophobic and hydrophilic properties, the graft copolymer shows modified physico chemical properties which are highly dominated by the PEG moiety (and no longer by the polystyrene matrix). These graft copolymers are pressure stable and can be used in batch processes as well as under continuous flow conditions. The PEG spacer is in the range of MW 3000 Da.

L 4, L 5, L 6, L 7, L 24, L 25, L 39; see also: General Information.

Residues which are sensitive to racemisation during esterification reactions like His and Cys can be attached to the resin without racemisation. Due to the bulkiness of the trityl group, diketopiperazine formation is suppressed which makes this linker ideal for peptides with C-terminal Pro. This resin is recommended for synthesis of standard peptides up to 40 residues in length.

The sensitivity towards TFA is comparable to the 2-CT linker. Cleavage can be achieved with 50% AcOH in CH₂Cl₂ to liberate protected peptides. For free peptides 95% TFA is afforded.

L 15