Pholiols A-D and other triterpenes from Pholiota populnea and their activity against colon carcinoma

Pholiota populnea (Pers.) Kuyper & Tjall.-Beuk. (Strophariaceae) is a saprophytic or sometimes parasitic mushroom species, which grows on poplars, willow and birch. The detailed phytochemical analysis of the hexane phase of P. populnea led to the isolation of four new lanostane diesters, named pholiols A-D (1–4), together with tetrahydroxy-squlene (5), ergosterol and 3β-hydroxyergosta-7,22-diene. The isolation was carried out by flash chromatography and HPLC, the structures were elucidated using extensive spectroscopic analyses. All compounds were isolated for the first time from this mushroom. The isolated fungal metabolites were investigated for antiproliferative activity against Colo205, Colo320 colon adenocarcinoma and non-tumoral MRC-5 cell lines. Combination with doxorubicin and efflux pump inhibitory activity of the compounds on Colo 320 cells were also assayed.

Among the tested compounds only ergosterol (5) showed antiproliferative activity against all cell lines with no tumour cell selectivity. P-glycoprotein efflux pump modulatory test on resistant Colo 320 cells indicated that pholiol A (1) and B (2), and 5 have the capacity to inhibit the efflux-pump over-expressed in the cells. Very strong synergism with doxorubicin was observed for linear triterpene 5. Our results indicate that P. populnea is a promising source for finding new terpene metabolites with significant chemo-sensitizing activity on cancer cells.

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Artikel online veröffentlicht:
13. Dezember 2021