Resolution Fast Atom Bombardment Research Articles

Gamakamide-E, a Strongly Bitter Tasting Cyclic Peptide with a Hydantoin Structure from Cultured Oysters Crassostrea gigas

A new cyclic peptide (six-membered amino acid), gamakamide-E (L-Leu-L-Met (SO)-L-Me-Phe-L-Leu-D-Lys-L-Phe), was isolated as a strongly bitter tasting compound from cultured oysters, Crassostrea gigas. The molecular formula of C 43 H 61 N 7 O 8 S was deduced from high resolution fast atom bom bardment mass spectrometry (HR FAB-MS) ([M + H] + m/z 836.4356 △= -2.4 mmu). Its unique structure including a hydantoin structure was firstly elucidated by nuclear magnetic resonance (NMR) analysis. Stereo chemistries of constituent amino acids were determined by chiral high performanced liquid chromatography analysis of natural and synthesized peptides.