Synthesis of Trypsin-modulating Oostatic Factor (TMOF) and its Analogues by Solid-phase Peptide Synthesis Using DIC/Oxyma as Coupling Reagent

Trypsin-modulating oostatic factor (TMOF) and two analogues of TMOF have been sucessfully synthesised via solid-phase peptide synthesis (SPPS) method. The synthesis was based on Fmoc strategy and employed chlorotrityl resin as solid support. A combination of N,N-diisopropylcarbodiimide (DIC) and ethyl-2-cyano-2-(hydroxyimino)acetate (oxyma) was proven to be the best coupling reagent in the synthesis. Fmoc-aspartic acid and Fmoc-tyrosine of TMOF were added onto peptidyl resin as t-Bu-protected amino acids. The t-Bu group was removed following the resin cleavage by using TFA cocktail. The t-Bu-free peptides were purified by using reversed-phase flash column chromatography with octadecyl silane (ODS)-functionalized silica as stationary phase. All peptides were characterized by using ESI-MS and their purity were checked by using thin layer chromatography.