Wang Resin is a classical acid-labile solid support used in Fmoc solid-phase peptide synthesis to prepare peptides with a C-terminal carboxylic acid. The linker contains a benzyl-alcohol-type hydroxyl functionality to which the first protected amino acid is attached through an ester linkage.

Unlike highly acid-labile 2-Chlorotrityl Chloride Resin, Wang-linked peptides are normally released under relatively strong TFA-based cleavage conditions. This makes Wang Resin particularly suitable for routine synthesis when the intended final product is a fully deprotected peptide acid rather than a side-chain-protected peptide fragment.

Product Information

Wang Resin for Peptide Acids

Wang Resin is one of the standard solid supports for preparing peptide-COOH products by Fmoc-SPPS. The C-terminal protected amino acid is esterified onto the resin linker, after which the sequence is extended through standard Fmoc deprotection and coupling cycles.

During final TFA cleavage, the peptide is released from the resin as a C-terminal carboxylic acid while conventional acid-labile side-chain protecting groups are typically removed in the same operation.

First Amino Acid Loading

Loading the first amino acid onto Wang Resin is an important process step because esterification conditions can influence substitution level and, for some residues, stereochemical integrity.

For stereochemically sensitive C-terminal amino acids or demanding synthesis programs, researchers may choose a preloaded Wang resin whose substitution and chiral identity have already been characterized. When unloaded Wang Resin is used, first-residue loading and final substitution should be controlled analytically.

Wang Resin vs 2-Chlorotrityl Chloride Resin

Both Wang Resin and 2-Chlorotrityl Chloride Resin are used to generate peptide acids.

Wang Resin generally requires stronger acidic conditions for cleavage and is well suited to routine preparation of fully deprotected peptide acids. 2-CTC is much more acid-labile and is often selected when protected peptide fragments must be isolated before final global deprotection.

Wang Resin vs Rink Amide Resin

The required peptide C-terminus is the most important distinction. Wang Resin produces peptide-COOH, whereas Rink Amide AM Resin produces peptide-CONH₂.

Researchers should therefore select the resin based on the exact terminal chemistry specified for the target peptide rather than treating these supports as interchangeable.

Applications

Wang Resin is used for routine Fmoc-SPPS of peptide acids, peptide libraries, modified peptides, synthetic standards and research peptides intended for downstream biochemical, cellular or in vivo studies.

The resin itself is a synthesis support and is removed during cleavage and purification; it is not intended as a direct biological assay reagent.

Purchasing and QC Considerations

Important procurement parameters include resin loading in mmol/g, bead or mesh size, degree of crosslinking, swelling behavior and lot-to-lot consistency.

Commercial products described as “Wang Resin” can be supplied in multiple physical specifications. Therefore, CAS identity alone should not be used to infer loading or mesh. These values should be taken from the current Certificate of Analysis.

For guidance on evaluating loading alongside sequence, support and solvent conditions, see Peptide Resin Loading in SPPS: How to Choose the Right Loading.

Product Documents

A Material Safety Data Sheet (MSDS) is available for this product to support laboratory handling, storage and safety assessment.

MSDS_Wang-Resin_AS3023

Certificates of Analysis (COAs) are batch-specific. Please contact us to request the COA for your product, and we will provide it by email.

Frequently Asked Questions

What type of peptide does Wang Resin produce?

Wang Resin normally produces peptides with a free C-terminal carboxylic acid.

Is Wang Resin compatible with Fmoc-SPPS?

Yes. It is one of the classical resin systems used for Fmoc solid-phase peptide synthesis.

What is the main difference between Wang and Rink Amide Resin?

Wang Resin produces peptide acids, whereas Rink Amide Resin produces C-terminal peptide amides.

What is the difference between Wang Resin and 2-CTC Resin?

Both generate peptide acids, but 2-CTC is substantially more acid-labile and is better suited to mild cleavage of protected peptide fragments.

Should loading capacity be assumed from the CAS number?

No. Loading capacity and mesh size are product- and lot-specific specifications and should be confirmed from the COA.

Related Technical Resources

Browse the complete Peptide Synthesis Resins selection.

For complete synthesis and purification of peptide acids, see our Chemical Peptide Synthesis service.

Research Use Only.