title: Cristazine, a New Cytotoxic Dioxopiperazine Alkaloid from the Mudflat-Sediment-Derived Fungus Chaetomium cristatum.
abstract: Cristazine (1), a new class of dioxopiperazine alkaloid, along with previously isolated chetomin (2), neoechinulin A (3), and golmaenone (4), were isolated from the mudflat-sediment-derived fungus Chaetomium cristatum. The structure and absolute stereochemistry of 1 was assigned on the basis of NMR, electron impact (EI)-MS, tandem FAB-MS/MS, and circular dichroism (CD) experiments. Compounds 1-4 displayed potent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), with IC50 values of 19, 15, 24, and 20 µM, respectively, which were similar to that of the positive control, ascorbic acid (IC50, 20 µM). Compound 1 also displayed cytotoxic activity against human cervical carcinoma (HeLa) cells, with an IC50 value of 0.5 µM.
authors.affiliation: Department of Chemistry, Pukyong National University.
authors.forename: Keumja
authors.initials: K
authors.lastname: Yun
authors.forename: Trung Thang
authors.initials: TT
authors.lastname: Khong
authors.forename: Alain Simplice
authors.initials: AS
authors.lastname: Leutou
authors.forename: Gun-Do
authors.initials: GD
authors.lastname: Kim
authors.forename: Jongki
authors.initials: J
authors.lastname: Hong
authors.forename: Choong-Hwan
authors.initials: CH
authors.lastname: Lee
authors.forename: Byeng Wha
authors.initials: BW
authors.lastname: Son
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002597:Chaetomium / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D006367:HeLa Cells; D006801:Humans; D008968:Molecular Conformation; D010879:Piperazines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000470:Alkaloids; D010879:Piperazines; C000610326:cristazine