title: New Cytotoxic Guaianolides from Centaurea aegyptiaca.
abstract: The ethanol extract of Centaurea aegyptiaca aerial parts afforded two new chlorinated bioactive guaianolides, cenegyptin A (1) and cenegyptin B (2), in addition to four known sesquiterpenes (3 - 6). Their identities were established on the basis of their spectral data. The cytotoxicity (IC50, μM) of compounds 1 - 6 were evaluated against hepatic (HEPG2) and laryngeal (HEP2) carcinoma cell lines in comparison with normal fibroblasts (BHK). Compound 1 showed cytotoxic activity against HEPG2 and HEP2 with IC50 values of 7.2 ± 0.04 and 7.5 ± 0.02, respectively. However, compound 2 exhibited only a limited toxicity against both cell lines.
authors.forename: Hanan G
authors.initials: HG
authors.lastname: Sary
authors.forename: Abdel Nasser B
authors.initials: AN
authors.lastname: Singab
authors.forename: Khaled Y
authors.initials: KY
authors.lastname: Orabi
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D031179:Centaurea / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*
chemical_list: D010936:Plant Extracts; D012717:Sesquiterpenes