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Published on: December 16, 2022
Cyclic heptapeptides from the soil-derived fungus Clonostachys rosea
Nada M Abdel-Wahab1, Harwoko Harwoko2, Werner E G Müller3
1Institute of Pharmaceutical Biology and Biotechnology, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; Department of Pharmacognosy, Faculty of Pharmacy, Minia University, 61519 Minia, Egypt.
Abstract:
Three new cyclic heptapeptides (1-3) together with three known compounds (4-6) were isolated from a solid rice culture of the soil-derived fungus Clonostachys rosea. Fermentation of the fungus on white beans instead of rice afforded a new γ-lactam (7) and a known γ-lactone (8) that were not detected in the former extracts. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR spectra as well as by HRESIMS data. Compounds 1 and 4 exhibited significant cytotoxicity against the L5178Y mouse lymphoma cell line with IC50 values of 4.1 and 0.1 µM, respectively. Compound 4 also displayed cytotoxicity against the A2780 human ovarian cancer cell line with an IC50 value of 3.5 µM. The preliminary structure-activity relationships are discussed.
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