Exocellular peptides from Antarctic Psychrophile Pseudoalteromonas haloplanktis.

• Main Authors: Mitova M, De Rosa S., TUTINO, MARIA LUISA, INFUSINI, GIUSEPPE, MARINO, GENNARO
• Other Authors: Mitova, M, Tutino, MARIA LUISA, Infusini, Giuseppe, Marino, Gennaro, De Rosa, S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2005
• Subjects: Pseudoalteromonas haloplankti; exocellular peptides; Antarctic; The Antarctic; Antarc*
• Online Access: http://hdl.handle.net/11588/306652

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.