title: Cucurbitane triterpenes from the fruiting bodies and cultivated mycelia of Leucopaxillus gentianeus.
abstract: A reinvestigation of the fruiting bodies of the mushroom Leucopaxillus gentianeus, allowed the isolation of two minor cucurbitane triterpenes, namely, cucurbitacin D (5) and the new metabolite 16-deoxycucurbitacin B (6). The latter compound lacks an oxygenated substituent at C-16, an unprecedented structural feature among congeners of cucurbitacin B. The cucurbitanes present in the fruiting bodies were compared with those extracted from mycelia grown on the modified Melin-Norkans (MMN) culture medium. Cucurbitacins B (1) and D (5), as well as leucopaxillones A (3) and B (4), were isolated from both sources; in contrast, 16-deoxycucurbitacin B (6) and a mixture of fatty acid esters of cucurbitacin B (2) were absent in the mycelia. A new triterpene, 18-deoxyleucopaxillone A (7), was isolated from the mycelia, but was not detected in the fruiting bodies. The antiproliferative activity of the isolated triterpenes was determined against the NCI-H460 human tumor cell line, in comparison with the antitumor compound topotecan, a well-known topoisomerase I inhibitor.
authors.affiliation: DISAV, Università degli Studi del Piemonte Orientale, Via Bellini 25G, 15100 Alessandria, Italy. marco.clericuzio@mfn.unipmn.it
authors.forename: Marco
authors.initials: M
authors.lastname: Clericuzio
authors.forename: Silvia
authors.initials: S
authors.lastname: Tabasso
authors.forename: Maria Ausilia
authors.initials: MA
authors.lastname: Bianco
authors.forename: Graziella
authors.initials: G
authors.lastname: Pratesi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Beretta
authors.forename: Stella
authors.initials: S
authors.lastname: Tinelli
authors.forename: Franco
authors.initials: F
authors.lastname: Zunino
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vidari
mesh_terms: D000363:Agaricales / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D048690:Fruiting Bodies, Fungal / Q000737:chemistry; D006801:Humans; D015394:Molecular Structure; D025282:Mycelium / Q000737:chemistry; D012384:Rome; D059004:Topoisomerase I Inhibitors; D019772:Topotecan / Q000494:pharmacology; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: C516511:16-deoxycucurbitacin B; D000970:Antineoplastic Agents; D059004:Topoisomerase I Inhibitors; D014315:Triterpenes; C038105:cucurbitacin D; D019772:Topotecan