title: Thalassospiramide G, a new γ-amino-acid-bearing peptide from the marine bacterium Thalassospira sp.
abstract: In the chemical investigation of marine unicellular bacteria, a new peptide, thalassospiramide G (1), along with thalassospiramides A and D (2-3), was discovered from a large culture of Thalassospira sp. The structure of thalassospiramide G,  bearing γ-amino acids, such as 4-amino-5-hydroxy-penta-2-enoic acid (AHPEA), 4-amino-3,5-dihydroxy-pentanoic acid (ADPA), and unique 2-amino-1-(1H-indol-3-yl) ethanone (AIEN), was determined via extensive spectroscopic analysis. The absolute configuration of thalassospiramide D (3), including 4-amino-3-hydroxy-5-phenylpentanoic acid (AHPPA), was rigorously determined by 1H-1H coupling constant analysis and chemical derivatization. Thalassospiramides A and D (2-3) inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated mouse macrophage RAW 264.7 cells, with IC(50) values of 16.4 and 4.8 μM, respectively.
authors: Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 151-742, Korea. dongchanoh@snu.ac.kr
authors: Soohyun
authors: S
authors: Um
authors: Yuna
authors: Y
authors: Pyee
authors: Eun-Hee
authors: EH
authors: Kim
authors: Sang Kook
authors: SK
authors: Lee
authors: Jongheon
authors: J
authors: Shin
authors: Dong-Chan
authors: DC
authors: Oh
mesh_terms: D000818:Animals; D002460:Cell Line; D020128:Inhibitory Concentration 50; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D012244:Rhodospirillaceae / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D008070:Lipopolysaccharides; D010455:Peptides; D010456:Peptides, Cyclic; C520245:thalassospiramide A; C520244:thalassospiramide B; D009569:Nitric Oxide