Soliseptide A, A Cyclic Hexapeptide Possessing Piperazic Acid Groups from Streptomyces solisilvae HNM30702

Soliseptide A (1), a cyclic hexapeptide possessing piperazic acid groups, together with two known azalomycin derivatives (2 and 3) were isolated from Streptomyces solisilvae HNM30702. Their structures were determined through spectroscopic methods and single crystal X-ray diffraction analysis. Soliseptide A (1) possessed a cyclic hexapeptide core featured with two piperazic acid units rarely discovered in nature, and exhibited weak antibacterial and antiviral activities. Besides, compounds 2 and 3 displayed significant fungicidal effects.