ABSTRACT
Objective To synthesize the natural cyclopeptide auyuittuqamide A by Fmoc-based solid phase linear synthesis and liquid phase cyclization. Methods Using 2-chlorotriphenylmethyl chloride (CTC) resin as the solid support, 1,3-diisopropylcarbodiimide (DIC) and 1-hydroxybenzotriazole (HOBt) as the condensing agents, 9-fluorenylmethoxycarbonyl (Fmoc) to protect amino acids were assembled in sequence, and then the linear peptide bearing the protected groups was obtained in presence of trifluoroethanol (TFE) cutting reagent. The protected linear peptide was cyclized with the aid of benzotriazole hexafluorophosphate (PyBOP) and 1-hydroxybenzotriazole (HOBt) in dichloromethane (DCM) solution, followed by trifluoroacetic acid (TFA) deprotection to obtain the cyclic peptide, auyuittuqamide A that was purified by preparative HPLC and characterized by HR-MS and 500MHz 1H-NMR. Results The purity of auyuittuqamide A was more than 95% and the total yield was 5.48%. Conclusion This method has simple synthesis steps and high yield. It is the first to establish a fully synthesis method for the natural cyclic peptide auyuittuqamide A, which lays the foundation for further research of auyuittuqamide A.