Antioxidant and cytotoxic activities of quinones from Cetraria laevigata

Abstract

Chemical investigation of the extracts obtained from the red thallus tips from Cetraria laevigata resulted in the isolation of five known quinoid pigments identified by FT-IR, UV, NMR, MS methods and by comparison with literature data (skyrin (1), 3-ethyl-2,7-dihydroxynaphthazarin (2), graciliformin (3), cuculoquinone (4) and islandoquinone (5)). An antioxidant capacity of compounds 1–5 were evaluated and compared with quercetin using a lipid peroxidation inhibitory assay and superoxide radical (SOR), nitric oxide radical (NOR), 1,1-diphenyl-2-picrylhydrazine (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) scavenging assays. Compounds 2, 4 and 5 were far more active: they demonstrated the antioxidant capacity in various test assays with the IC₅₀ values 5–409 µM comparable to the flavonoid quercetin. While, the isolated quinones (1–5) exhibited weak cytotoxicity in human cancer cell line A549 assessed by MTT assay.

GRAPHICAL ABSTRACT

Keywords:

• Cetraria laevigata
• naphthoquinones
• anthraquinones
• cytotoxicity
• antioxidant activity

Acknowledgments

Research was performed using the equipment of the Resource Center for Chemical Analysis and Magnetic Resonance Research Center of the Research Park of Saint Petersburg State University.

Author contribution statement

Ilya Prokopiev conceived and designed the experiments, and wrote the article. Igor Sleptsov performed antioxidant assay, Evgeny Serebryakov performed the ESI-MS and NMR analysis, Vladimir Sharoyko performed cytotoxicity assay.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

This work was supported by the frameworks of the state assignment of the Institute for Biological Problems of Cryolithozone, Siberian Branch of the Russian Academy of Sciences (no. АААА-А21-121012190035-9) and the Komarov Botanical Institute of the Russian Academy of Sciences (no. АААА-А18-118032390136-5)