Synthesizing Cylic Peptides with Antioxidant Properties using Solid Phase Peptide Synthesis as an Alternative to Natural Product Isolation from Pork

Tetrapeptides Ser-Leu-Tyr-Ala and Tyr-Leu-Tyr-Ala are two derivates that have been successfully isolated from the pork and synthesized using Solid Phase Peptide Synthesis (SPPS) method. Tetrapeptide Gly-Ala-Trp-Ala has also been successfully isolated from the Sardinella aurita fish found in Atlantic Ocean using SPPS. This study aims to synthesize tetrapeptide Ser-Leu-Tyr-Ala, Tyr-Leu-Tyr-Ala and Gly-Ala-Trp-Leu using the SPPS method, and to find the antioxidant properties of the synthesized tetrapeptides using DPPH test. The three tetrapeptides have been synthesized using 2-chlorotritilchloride resin as solid phase, Fmoc group protection, and coupling reagent HBTU/HOBt. HR-TOF-MS with m/z was [M+H]+ 453,23 and [2M+H]+ 905,49 for Ser- Leu-Tyr-Ala, [M+H]+114,61 for Tyr-Leu-Tyr-Ala and [M+H]+ 446,23 for Gly-Ala-Trp-Leu. The antioxidant properties of Ser-Leu-Tyr- Ala had an IC50 value of 11130,04 mg/ml, while the antioxidant properties of Tyr-Leu-Tyr-Ala had an IC50 value of 4319,522 mg/ml. Keywords: solid phase peptide synthesis, antioxidant