Open AccessSynthesis and Structure Reassignment of Malylglutamate, a Recently Discovered Earthworm Metabolite
Author(s) -
Corey M. Griffith,
Abigail Feceu,
Cynthia K. Larive,
David B. C. Martin
Publication year - 2019
Publication title -
journal of natural products
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.976
H-Index - 139
eISSN - 1520-6025
pISSN - 0163-3864
DOI - 10.1021/acs.jnatprod.8b01083
Subject(s) - earthworm , metabolite , diastereomer , moiety , stereochemistry , chemistry , amide , eisenia fetida , nuclear magnetic resonance spectroscopy , organic chemistry , biology , biochemistry , ecology
Malylglutamate, a newly identified metabolite in earthworms, was synthesized using a traditional peptide coupling approach for assembling the amide from protected malate and glutamate precursors. The proposed structure (1) and a diastereomer were synthesized, but their NMR spectra did not match the natural sample. Further analysis of the natural sample using HMBC spectroscopy suggested an alternative attachment of the malyl moiety, and β-malylglutamate (2) diastereomers were synthesized, L,L-2 and D,D-2. NMR spectra were an excellent match with the natural sample, and chiral-phase chromatography was employed to identify (-)-β-l-malyl-l-glutamate (2) as the isomer native to Eisenia fetida.