Novel Glycerophospholipid, Lipo- and N -acyl Amino Acids from Bacteroidetes: Isolation, Structure Elucidation and Bioactivity.

The 'core' metabolome of the Bacteroidetes genus Chitinophaga was recently discovered to consist of only seven metabolites. A structural relationship in terms of shared lipid moieties among four of them was postulated. Here, structure elucidation and characterization via ultra-high resolution mass spectrometry (UHR-MS) and nuclear magnetic resonance (NMR) spectroscopy of those four lipids (two lipoamino acids (LAAs), two lysophosphatidylethanolamines (LPEs)), as well as several other undescribed LAAs and N -acyl amino acids (NAAAs), identified during isolation were carried out. The LAAs represent closely related analogs of the literature-known LAAs, such as the glycine-serine dipeptide lipids 430 ( 2 ) and 654. Most of the here characterized LAAs ( 1 , 5 - 11 ) are members of a so far undescribed glycine-serine-ornithine tripeptide lipid family. Moreover, this study reports three novel NAAAs ( N -(5-methyl)hexanoyl tyrosine ( 14 ) and N -(7-methyl)octanoyl tyrosine ( 15 ) or phenylalanine ( 16 )) from Olivibacter sp. FHG000416, another Bacteroidetes strain initially selected as best in-house producer for isolation of lipid 430. Antimicrobial profiling revealed most isolated LAAs ( 1 - 3 ) and the two LPE 'core' metabolites ( 12 , 13 ) active against the Gram-negative pathogen M. catarrhalis ATCC 25238 and the Gram-positive bacterium M. luteus DSM 20030. For LAA 1 , additional growth inhibition activity against B. subtilis DSM 10 was observed.