Exocellular peptides from Antarctic psychrophile Pseudoalteromonas Haloplanktis.
A novel diketopiperazine, named cyclo-(D-pipecolinyl-L-isoleucine) (DKP 1), and 7 known diketopiperazines were isolated from the cell-free culture supernatant of the Antarctic psychrophilic bacterium Pseudoalteromonas haloplanktis TAC125. Two diketopiperazines containing pipecolinyl moiety were isolated for the first time from a natural source. Two new linear peptides, stable to bacterial proteolytic enzymes, were also characterized. The structures of the isolated compounds were elucidated by means of spectroscopic data (1D-, 2D-NMR, EIMS, FABMS, and ESIMS/MS) and chiral high-performance liquid chromatography. The potential antioxidant activity of the isolated compounds was evaluated by a DPPH free radical scavenging assay.
Mitova
Maya
M
Istituto di Chimica Biomolecole CNR, via Campi Flegrei, 34, I-80078, Pozzuoli, (Napoli), Italy.
Tutino
Maria Luisa
ML
Infusini
Giuseppe
G
Marino
Gennaro
G
De Rosa
Salvatore
S
D000595:Amino Acid Sequence; D000864:Antarctic Regions; D000975:Antioxidants / Q000032:analysis; D001426:Bacterial Proteins / Q000737:chemistry* / Q000145:classification* / Q000302:isolation & purification; D054659:Diketopiperazines; D004121:Dimethyl Sulfoxide; D005285:Fermentation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008968:Molecular Conformation; D010879:Piperazines / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification; D031161:Pseudoalteromonas / Q000737:chemistry* / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*
D000975:Antioxidants; D001426:Bacterial Proteins; D054659:Diketopiperazines; D010879:Piperazines; D004121:Dimethyl Sulfoxide