Novel synthesised flavone derivatives provide significant insight into the structural features required for enhanced anti-proliferative activity

Ravishankar, D., Watson, K. A. ORCID: https://orcid.org/0000-0002-9987-8539, Greco, F. and Osborn, H. M. I. ORCID: https://orcid.org/0000-0002-0683-0457 (2016) Novel synthesised flavone derivatives provide significant insight into the structural features required for enhanced anti-proliferative activity. RSC Advances, 6 (69). pp. 64544-64556. ISSN 2046-2069 doi: 10.1039/C6RA11041J

Abstract/Summary

With many cancers showing resistance to current chemotherapies, the search for novel anti-cancer agents is attracting considerable attention. Natural flavonoids have been identified as useful leads in such programmes. However, since an in-depth understanding of the structural requirements for optimum activity is generally lacking, further research is required before the full potential of flavonoids as anti-proliferative agents can be realised. Herein a broad library of 76 methoxy and hydroxy flavones, and their 4-thio analogues, was constructed and their structure-activity relationships for anti-proliferative activity against the breast cancer cell lines MCF-7 (ER+ve), MCF-7/DX (ER+ve, anthracycline resistant) and MDA-MB-231 (ER-ve) were probed. Within this library, 42 compounds were novel, and all compounds were afforded in good yields and > 95% purity. The most promising lead compounds, specifically the novel hydroxy 4-thioflavones 15f and 16f, were further evaluated for their anti-proliferative activities against a broader range of cancer cell lines by the National Cancer Institute (NCI), USA and displayed significant growth inhibition profiles (e.g Compound-15f: MCF-7 (GI50 = 0.18 μM), T-47D (GI50 = 0.03 μM) and MDA-MB-468 (GI50 = 0.47 μM) and compound-16f: MCF-7 (GI50 = 1.46 μM), T-47D (GI50 = 1.27 μM) and MDA-MB-231 (GI50 = 1.81 μM). Overall, 15f and 16f exhibited 7-46 fold greater anti-proliferative potency than the natural flavone chrysin (2d). A systematic structure-activity relationship study against the breast cancer cell lines highlighted that free hydroxyl groups and the B-ring phenyl groups were essential for enhanced anti-proliferative activities. Substitution of the 4-C=O functionality with a 4-C=S functionality, and incorporation of electron withdrawing groups at C4’ of the B-ring phenyl, also enhanced activity. Molecular docking and mechanistic studies suggest that the anti-proliferative effects of flavones 15f and 16f are mediated via ER-independent cleavage of PARP and downregulation of GSK-3β for MCF-7 and MCF-7/DX cell lines. For the MDA-MB-231 cell line, restoration of the wild-type p53 DNA binding activity of mutant p53 tumour suppressor gene was indicated.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/65744
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences > Biomedical Sciences Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Mass Spectrometry (CAF) Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > NMR (CAF) Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Medicinal Chemistry Research Group Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Pharmaceutics Research Group
Publisher	Royal Society of Chemistry
Download/View statistics	View download statistics for this item