There is renewed focus in the synthesis of non-natural amino acid building blocks (peptidomimetics), but they are often challenging to synthesize and introduce, as they can be expensive and difficult to couple. Microwave heating can be used to overcome some of these difficulties by increasing coupling efficiency and by using less excess of expensive building blocks. We have demonstrated the benefits of a peptide synthesizer with both MAOS and microwave peptide synthesis capability. Synthesis of a non-natural arginine building block was achieved using microwaves in “Organic Synthesis” mode (with magnetic stirring). The system was then easily converted into “Peptide Synthesis” mode (with vortex mixing) where incorporation of the building block into the peptide using microwave heating was accomplished. The semi-automated operation also showed the benefits of being able to manually add a low excess (1.1 eq) of the non-natural arginine building block precursor thereby reducing cost and waste of valuable reagents.
Mupain-1 analogue, cyclo-CPAYS[L-3-(N-amidino-3-piperidyl) alanine]YLDC.