title: Arenamides A-C, cytotoxic NFkappaB inhibitors from the marine actinomycete Salinispora arenicola.
abstract: Three new cyclohexadepsipeptides, arenamides A-C (1-3), were isolated from the fermentation broth of a marine bacterial strain identified as Salinispora arenicola. The planar structures of these compounds were assigned by detailed interpretation of NMR and MS/MS spectroscopic data. The absolute configurations of the amino acids, and those of the chiral centers on the side chain, were established by application of the Marfey and modified Mosher methods. The effect of arenamides A and B on NFkappaB activity was studied with stably transfected 293/NFkappaB-Luc human embryonic kidney cells induced by treatment with tumor necrosis factor (TNF). Arenamides A (1) and B (2) blocked TNF-induced activation in a dose- and time-dependent manner with IC(50) values of 3.7 and 1.7 microM, respectively. In addition, the compounds inhibited nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production with lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Moderate cytotoxicity was observed with the human colon carcinoma cell line HCT-116, but no cytotoxic effect was noted with cultured RAW cells. Taken together, these data suggest that the chemoprevention and anti-inflammatory characteristics of arenamides A and B warrant further investigation.
authors.affiliation: Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0204, USA.
authors.forename: Ratnakar N
authors.initials: RN
authors.lastname: Asolkar
authors.forename: Kelle C
authors.initials: KC
authors.lastname: Freel
authors.forename: Paul R
authors.initials: PR
authors.lastname: Jensen
authors.forename: William
authors.initials: W
authors.lastname: Fenical
authors.forename: Tamara P
authors.initials: TP
authors.lastname: Kondratyuk
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Park
authors.forename: John M
authors.initials: JM
authors.lastname: Pezzuto
mesh_terms: D039903:Actinobacteria / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D047630:Depsipeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015232:Dinoprostone / Q000037:antagonists & inhibitors / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D045325:HCT116 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D007668:Kidney / Q000166:cytology / Q000187:drug effects / Q000196:embryology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects; D008386:Marine Biology; D051379:Mice; D015394:Molecular Structure; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D019906:Nuclear Magnetic Resonance, Biomolecular; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D047630:Depsipeptides; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; C548747:arenamide A; C548748:arenamide B; C548749:arenamide C; D009569:Nitric Oxide; D015232:Dinoprostone