Callyaerin G, a new cytotoxic cyclic peptide from the marine sponge Callyspongia aerizusa

Sabrin R M Ibrahim,Peter Proksch,Diaa T A Youssef,Gamal A Mohamed,Victor Wray,Ruangelie Edrada-Ebel

doi:10.3998/ark.5550190.0009.c18

Abstract

From the ethyl acetate fraction of the Indonesian sponge Callyspongia aerizusa extract, a new cyclic peptide named callyaerin G was isolated. Its structure was elucidated by extensive 1D and 2D NMR (1H NMR, TOCSY and ROESY) studies and mass spectrometric data (ESI- and FAB-MS). The stereochemistry was determined by Marfey's analysis. Callyaerin G was found to exhibit cytotoxic activity when tested against different cancer cell lines.

Highlights

Sponges belonging to the genus Callyspongia have been reported to yield unusual secondary metabolites with pronounced biological activities
The peptide nature was evident from the 1H NMR spectrum (Table 1), which showed numerous deshielded amide NH resonances and a cluster of α-amino acid methines
Uncommon signals at δH 8.23 (s, NH) and 7.46 (d, J = 13.6 Hz, H-β) in 1H NMR were assigned to formyl glycine (FGly) 7.7

Summary

Introduction

Sponges belonging to the genus Callyspongia have been reported to yield unusual secondary metabolites with pronounced biological activities. The peptide nature was evident from the 1H NMR spectrum (Table 1), which showed numerous deshielded amide NH resonances and a cluster of α-amino acid methines.

Results

Conclusion