Isolation, characterization, and biological evaluation of secondary metabolites from two Basidiomycetes species: Buglossoporus quercinus and Xylobolus subpileatus
Felegyi Kristóf
Pharmaceutical Sciences
Dr. Zelkó Romána
SE Szemészeti Klinika, Tanterem
2025-01-28 10:30:00
Modern Trends in Pharmaceutical Scientific Research
Dr. Antal István
Ványolós Attila
Dr. Dunkel Petra Zsófia
Dr. Gonda Sándor
Dr. Tóthfalusi László
Dr. Pálla Tamás
Dr. Geösel András
The dissertation presents two comprehensive studies elucidating the chemical constituents and biological activities of fungal species, Buglossoporus quercinus and Xylobolus subpileatus.
From B. quercinus, a series of novel 24-methylene lanostane triterpenes named polyporenic acids N-R (BGS-1–5) were identified alongside seven known polyporenic acids (BGS-6–12). Extensive spectroscopic analyses, including 1D and 2D NMR and HRMS experiments, were employed for structure determination. The antiproliferative activity of isolated fungal metabolites was evaluated in vitro using the MTT assay on Colo 320 human colon adenocarcinoma cells expressing P-glycoprotein (ABCB1). The lanostane triterpenes demonstrated moderate antiproliferative activity with IC50 values ranging from 20.7 to 106.2 μM. Notably, certain fungal metabolites (BGS-3, 5, 8, and 10–12) exhibited the ability to inhibit the efflux pump activity of cancer cells, as highlighted by a P-glycoprotein efflux pump modulatory test on resistant Colo 320 cells. Furthermore, the study investigated drug interactions of triterpenes with doxorubicin using the checkerboard method, revealing synergistic interactions for compounds BGS-3–4 and 7–12.
In the study on Xylobolus subpileatus, a widely distributed crust fungus, mycochemical analysis of its methanol extract led to the isolation of seven compounds (XB-1–7). Among them, compound XB-1, identified as (3β,22E)-3-methoxy-ergosta-4,6,814,22-tetraene, represents a new natural product, while the NMR assignment of its known epimer (XB-2) was revised. Additionally, a benzohydrofuran derivative, fomannoxin (XB-3), and four ergostane-type triterpenes (XB-4–7) were identified. Structure elucidation of these metabolites was conducted using one- and two-dimensional NMR and MS analysis. Evaluation of the isolated compounds (XB-2–7) as well as the chloroform, n-hexane, and methanol extracts of X. subpileatus revealed their inhibitory properties against tyrosinase, AChE and BChE. Fomannoxin (XB-3) exhibited notable antityrosinase activity, while compounds XB-3–4 demonstrated noteworthy AChE inhibitory activity. Regarding BChE inhibition, methanol and chloroform extracts, along with compounds XB-3 and XB-4, displayed significant activity.
