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Base resin

Rink Amide resin for C-terminal carboxamides

para-(Rink amide) benzyl ester supports deliver peptides with C-terminal CONH2 after TFA cleavage. Choose AM (aminomethyl) for standard lengths or MBHA (4-methylbenzhydrylamine) when higher swelling and softer aggregation help long or difficult sequences.

All resins

0.3–0.9

mmol/g loading

CONH2

C-terminus

AM / MBHA

support choice

95% TFA

typical cleavage

Fmoc

chemistry

C-terminal amide release

Rink Amide supports attach the growing peptide through a benzyl ester to an aminomethyl (AM) or MBHA handle on polystyrene. Cleavage with concentrated TFA generates the carboxamide C-terminus directly—essential for many bioactive peptides, GPCR ligands, and stability versus free acids.

AM resins resemble standard polystyrene handling; MBHA resins swell more in DCM/DMF and are often favored when sequences aggregate on AM or when MBHA’s hydride handle improves coupling efficiency in longer campaigns.

Typical specifications

Indicative ranges; specify AM vs MBHA on quotation.

Matrix

Polystyrene–DVB (AM or MBHA)

1% DVB common on AM

Linker

Rink amide benzyl ester

Acid-labile to amide

Loading

0.3–0.9 mmol/g

Lower for >30 mer

Mesh

100–200 / 200–400

Match equipment

Swelling

Higher on MBHA vs AM

Check DMF data per lot

Cleavage

TFA + scavengers

Similar cocktails to Wang

Product

C-terminal carboxamide

Not for C-acids

Figures are indicative industry-typical values. Lot- and project-specific data appear on the quotation and certificate of analysis.

Rink Amide AM vs MBHA

Both give C-terminal amides; the choice is often mechanical and sequence-driven.

CriterionRink Amide AMRink Amide MBHA
Sequence lengthDiscovery to ~25–30 residuesLonger or aggregation-prone peptides
Swelling in DMFModerateTypically higher—better resin permeation
HandlingFamiliar polystyrene feelSofter bead; careful frit sizing
First couplingStandard carbodiimide / uroniumSame; pre-loaded Rink common
CleavageTFA cocktailsTFA cocktails; watch scavenger for Trp/Met

Figures are indicative industry-typical values. Lot- and project-specific data appear on the quotation and certificate of analysis.

Indicative cleavage to C-terminal amide

  1. 01

    Wash resin with DCM, then dry briefly.

  2. 02

    Cleavage cocktail: TFA / TIS / H2O (95:2.5:2.5) or EDT-containing recipe for Arg-rich peptides, ~10 mL/g, 1–3 h.

  3. 03

    Collect filtrate; concentrate and precipitate in cold ether.

  4. 04

    Lyophilize from dilute AcOH or TFA and analyze by HPLC and LC-MS.

How teams use Rink Amide

01

Pick AM or MBHA

AM for routine amides; MBHA when prior AM runs show poor coupling yields or severe aggregation.

02

Load C-terminal residue

Esterify first Fmoc-AA or use Pre-loaded Rink Amide AM for documented loading.

03

Fmoc SPPS

Double couples at difficult positions; NMP may help on MBHA for β-sheet motifs.

04

Cleave and prove amide

Confirm [M+H]+ consistent with amide (not acid −18) by HRMS; check for deletion sequences.

What you receive

  • Rink Amide AM or MBHA lot with loading and mesh on COA
  • Clear designation of support type (AM vs MBHA) on documents
  • Storage and moisture protection instructions
  • Optional pre-loaded SKUs cross-referenced
  • Quote by loading band and pack size

Frequently asked questions

No. Many short and medium peptides run perfectly on AM. MBHA is a tool when swelling or aggregation limits AM campaigns.

Related

Pre-loaded Rink Amide AM

C-terminal Fmoc-amino acid loaded on Rink Amide AM support. Start amide-oriented SPPS with qualified loading and avoid first-coupling variability when delivering CONH2 peptides.

View details

Wang Resin

p-Alkoxybenzyl alcohol linker on polystyrene–DVB. The workhorse support for Fmoc SPPS of peptides with a free C-terminal carboxylic acid, cleaved in concentrated TFA with scavengers.

View details

Ethyl & Methyl Indole Resins

Indole-derived linkers on polystyrene enable C-terminal N-ethyl and N-methyl carboxamides after TFA cleavage—motifs common in GnRH analogs such as leuprolide. Chemistry differs from Rink: first coupling to the linker is inefficient under carbodiimide alone; HATU (or similar uronium) is required.

View details

Merrifield & Sieber Amide

Merrifield polystyrene anchors Boc/Bzl peptide synthesis with HF or TFMSA cleavage. Sieber Amide adds a mild-acid–labile linker on aminomethyl resin for Boc-protected C-terminal carboxamides released without HF.

View details
Next step

Ready to specify this for your program?

Share sequence, scale and documentation needs. We reply with indicative specs and a project-specific quotation.