New methodology for automated SPOT synthesis of peptides on cellulose using 1,3,5‐triazine derivatives as linkers and as coupling reagents

: Two new rigid bi-aromatic linkers for synthesis of peptide arrays by SPOT methodology were obtained from cellulose treated with 2,4-dichloro-6-methoxy-1,3,5-triazine. Reaction with m-phenylenediamine gave non-cleavable TYPE I linker which enabled attachment of the peptides via resistant to harsh reaction conditions amide, ether, and amine bonds. Reaction with 3-Fmoc-aminobenzoic acid followed by thermal isomerization of the intermediate "superactive" ester producing an amide-like bond gave TYPE II linker that was very stable during peptide synthesis. However, the peptide was cleavable, with fragment of the linker, in the presence of 1 M LiOH solution. The uniform loading of the cellulose and efficient synthesis of the peptide array was achieved by using N-(4,6-dimethoxy-1,3,5-triazin-1-yl)-N-methylmorpholinium 4-toluenesulfonate as the coupling reagent.