Cucurbitane triterpenes from the fruiting bodies and cultivated mycelia of Leucopaxillus gentianeus.
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.
Clericuzio
Marco
M
DISAV, Università degli Studi del Piemonte Orientale, Via Bellini 25G, 15100 Alessandria, Italy. marco.clericuzio@mfn.unipmn.it
Tabasso
Silvia
S
Bianco
Maria Ausilia
MA
Pratesi
Graziella
G
Beretta
Giovanni
G
Tinelli
Stella
S
Zunino
Franco
F
Vidari
Giovanni
G
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
C516511:16-deoxycucurbitacin B; D000970:Antineoplastic Agents; D059004:Topoisomerase I Inhibitors; D014315:Triterpenes; C038105:cucurbitacin D; D019772:Topotecan