title: A new cytotoxic steroid from co-fermentation of two marine alga-derived micro-organisms.
abstract: Bioactivity-guided chemical investigation of a co-culture of marine-derived micro-organisms has yielded one new steroid, 7β-hydroxycholesterol-1β-carboxylic acid (1) with an unprecedented carboxylic acid group at C-1, together with three known steroidal metabolites (2-4). The chemical structures and stereochemistry of the isolated compounds were unambiguously determined based on extensive 1D, 2D NMR and HR-ESI-MS measurements. The isolated compounds were assessed for their cytotoxic activity against four different human tumour cell lines K562 (leukaemia), HCT116 (colon), A2780 (ovary) and its cisplatin-resistant mutant (A2780 CisR), and they revealed moderate activities with IC50 values ranging from 10.0 to 100.0 μM.
authors.affiliation: a BIO-MAR , Merowingerplatz 1a, D-40225 Düsseldorf , Germany.
authors.forename: Sherif S
authors.initials: SS
authors.lastname: Ebada
authors.forename: Thomas
authors.initials: T
authors.lastname: Fischer
authors.forename: Sarah
authors.initials: S
authors.lastname: Klaßen
authors.forename: Alexandra
authors.initials: A
authors.lastname: Hamacher
authors.forename: Yoen Ok
authors.initials: YO
authors.lastname: Roth
authors.forename: Matthias U
authors.initials: MU
authors.lastname: Kassack
authors.forename: Eckhard H
authors.initials: EH
authors.lastname: Roth
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D005260:Female; D005285:Fermentation; D045325:HCT116 Cells; D006801:Humans; D006888:Hydroxycholesterols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D020014:K562 Cells; D008386:Marine Biology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular
chemical_list: C000593086:7beta-hydroxycholesterol-1beta-carboxylic acid; D000970:Antineoplastic Agents; D006888:Hydroxycholesterols
keywords: Aspergillus; antiproliferative; co-fermentation; marine micro-organisms; steroids