First total synthesis of antifungal cyclopeptide tunicyclin d by a solid-phase method

The present study deals with the first total synthesis of a new antifungal cyclic octapeptide, tunicyclin D, cyclo[VNIPPWHG], where all the amino acids are L-configuration, by a two-step solid-phase/solution synthesis strategy. The linear octapeptide was assembled by a solid-phase peptide synthesis (SPPS) method. Subsequently cyclization and deprotection were achieved in solution with high efficiency and reproducibility. The final product was purified by preparative RP-HPLC, and its structure was identified by ESI-MS, (1) H NMR, (13) C NMR, and HR-QTOF-MS.