Synthetic and pharmacological studies on a natural cyclopeptide from Gypsophila arabica

The present study deals with the synthesis of a novel proline-rich cyclopeptide - gypsin B 7 via coupling of tripeptide units Boc-l-Tyr-l-Phe-l-Pro-OH and Gly-l-Leu-l-Pro-OMe utilizing two different carbodiimides, followed by cyclization of linear polypeptide fragment. Structure elucidation of newly synthesized peptide was done on basis of FT-IR, 1H-NMR, 13C-NMR, ESI-MS/MS data. From biological evaluation, it was concluded that cyclic hexapeptide 7 exhibited potent antidermatophyte activity against pathogenic Microsporum audouinii andTrichophyton mentagrophytes. Also, good bioactivity against pathogenicCandida albicans and gram-negative bacteria, and moderate antihelmintic activity against three species of earthworms was observed for newly synthesized cyclohexapeptide.   Key words: Gypsophila arabica, cyclic hexapeptide, gypsin B, peptide coupling, antimicrobial activity, antihelmintic activity.