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.

Polyoxygenated ergostane-type sterols from the liquid culture ofGanoderma applanatum

“…To the best of our knowledge, compound 1 is the first example of a polyoxygenated ergostane congener carrying a unique oxygenation pattern in its structure. Higher fungi (Basidiomycetes) are a rich source of polyoxygenated ergostane steroids, which are often endowed with unprecedented structural features and remarkable bioactivities (Clericuzio et al, 2006;Yang et al, 2009). Because G. applanatum is rarely found in nature and is difficult to obtain, artificial cultivation has been developed as a substitute.…”

“…It was considered interesting to isolate metabolites present in cultures of mycelia obtained from the same fungal material. In fact, very few studies exist on the distribution of secondary metabolites in the fungi and on the comparison of the chemical contents of the fruiting bodies with those of mycelia (Clericuzio et al, 2006). Nowadays, a wide interest in the discovery of new biologically active metabolites from higher fungi is evident.…”

Vulpinic acid contributes to the cytotoxicity of Pulveroboletus ravenelii to human cancer cells by inducing apoptosis

“…[15][16][17][18][19][20] Recent studies successfully identied lead compounds with potential cytotoxic activities against various types of cancer as well as antiantigenic properties from mushrooms. [27][28][29][30][31] For example, cucurbitane triterpenes isolated from Leucopaxillus gentianeus were found to have signicant anti-proliferative activity against human large-cell lung carcinoma cells. 27 Moreover, ergone identied from Fulviformes fastuosus had promising cytotoxic activity against human muscle rhabdomyosarcoma and hepatocellular carcinoma cells by inducing apoptosis.…”

“…[27][28][29][30][31] For example, cucurbitane triterpenes isolated from Leucopaxillus gentianeus were found to have signicant anti-proliferative activity against human large-cell lung carcinoma cells. 27 Moreover, ergone identied from Fulviformes fastuosus had promising cytotoxic activity against human muscle rhabdomyosarcoma and hepatocellular carcinoma cells by inducing apoptosis. 28 A recent study also identied two novel triterpenoids from Naematoloma fasciculare and validated their signicant cytotoxicity against various cancer cell lines, including human lung adenocarcinoma, ovarian carcinoma, melanoma, and colorectal adenocarcinoma cell lines.…”

New Oxidized 4-Oxo Fatty Acids from Hygrophorus Discoxanthus

“…In a search for new prototype (bioactive) agents from higher mushrooms (Basidiomycetes) [1], we were attracted by the species Hygrophorus discoxanthus (Fr.) Rea (fam.…”