71847-57-9

Upstream product

• 90-24-4 2-hydroxy-4,6-dimethoxyacetophenone 
• 3535-37-3 3,4-dimethoxybenzoic acid chloride 
• 93-07-2 Veratric acid 
• 71847-56-8 2-acetyl-3,5-dimethoxyphenyl 3,4-dimethoxybenzoate 

Downstream Products

• 855-97-0 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromen-4-one 
• 94303-23-8 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromene-4-thione 
• 491-70-3 2-(3,4-Dihydroxy-phenyl)-5,7-dihydroxy-chromen-4-on 

Relevant academic research and scientific papers

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

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-CO functionality with a 4-CS functionality, and incorporation of electron withdrawing groups at C-4′ 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.

Mild and efficient organocatalytic method for the synthesis of flavones

A convenient and efficient organocatalytic procedure for the selective cyclization of 1,3-diketones to give aromatic substituted 4H-chromen-4-ones under mild reaction conditions using N-triflyl phosphoramide is described. Application of the described conditions is presented in a formal synthesis of (S)-flavanone.

One-Pot Synthesis of Benzopyran-4-ones with Cancer Preventive and Therapeutic Potential

A one-pot synthesis of novel benzopyran-4-ones is described. In a tandem reaction, organobase-catalysed Michael addition of R1COCH2COR2 on chromone-3-carboxylic acid led to decarboxylation and pyran-4-one ring opening of the latter. This was followed by chromone-and/or chromanone ring closure of the resulting Michael adducts when R1 is an ortho-hydroxyaryl group. Antioxidant testing of 14 derivatives identified strong antiradical properties of chromanones 3o-r (2.1-3.1 μmol Trolox equiv./μmol compound in the DPPH assay). Chromanones 3p and 3r and 2-styrylchromone 3k were also most potent in inducing the cytoprotective Keap1-Nrf2 signalling pathway in a reporter gene assay (fivefold induction at concentrations 3 μM). Of the seven compounds evaluated for antiproliferative activities, 3k and 3r were the most active, inhibiting leukaemia K562 cell proliferation by 50 % after 72 h at concentrations of 4.5 and 7.9 μM, whereas normal peripheral blood mononuclear cells were not affected. Chromanones 3p and 3r and 2-styrylchromones 3k potently activate the Nrf2 response in the AREc32 cell line at low micromolar concentrations (C5 3 μM). Compounds 3k and 3r are also the most active in inhibiting cell proliferation by 50 % after 72 h incubation at concentrations of 4.5 and 7.7 μM, whereas normal peripheral blood mononuclear cells were not affected.

Exploring quercetin and luteolin derivatives as antiangiogenic agents

The formation of new blood vessels from the pre-existing vasculature (angiogenesis) is a crucial stage in cancer progression and, indeed, angiogenesis inhibitors are now used as anticancer agents, clinically. Here we have explored the potential of flavonoid derivatives as antiangiogenic agents. Specifically, we have synthesised methoxy and 4-thio derivatives of the natural flavones quercetin and luteolin, two of which (4-thio quercetin and 4-thio luteolin) had never been previously reported. Seven of these compounds showed significant (p 0.05) antiangiogenic activity in an in vitro scratch assay. Their activity ranged from an 86% inhibition of the vascular endothelium growth factor (VEGF)-stimulated migration (observed for methoxyquercetin at 10 μM and for luteolin at 1 μM) to a 36% inhibition (for thiomethoxy quercetin at 10 μM). Western blotting studies showed that most (4 out of 7) compounds inhibited phosphorylation of the VEGF receptor-2 (VEGFR2), suggesting that the antiangiogenic activity was due to an interference with the VEGF/VEGFR2 pathway. Molecular modelling studies looking at the affinity of our compounds towards VEGFR and/or VEGF confirmed this hypothesis, and indeed the compound with the highest antiangiogenic activity (methoxyquercetin) showed the highest affinity towards VEGFR and VEGF. As reports from others have suggested that structurally similar compounds can elicit biological responses via a non-specific, promiscuous membrane perturbation, potential interactions of the active compounds with a model lipid bilayer were assessed via DSC. Luteolin and its derivatives did not perturb the model membrane even at concentrations 10 times higher than the biologically active concentration and only subtle interactions were observed for quercetin and its derivatives. Finally, cytotoxicity assessment of these flavonoid derivatives against MCF-7 breast cancer cells demonstrated also a direct anticancer activity albeit at generally higher concentrations than those required for an antiangiogenic effect (10 fold higher for the methoxy analogues). Taken together these results show promise for flavonoid derivatives as antiangiogenic agents.

Flavonoids with M1 muscarinic acetylcholine receptor binding activity

Muscarinic acetylcholine receptor- Active compounds have potential for the treatment of Alzheimer's disease. In this study, a series of natural and synthetic flavones and flavonols was assayed in vitro for their ability to inhibit radioligand binding at human cloned M1 muscarinic receptors. Several compounds were found to possess competitive binding affinity (K i = 40-110 μM), comparable to that of acetylcholine (Ki = 59 μM). Despite the fact that these compounds lack a positively-charged ammonium group under physiological conditions, molecular modelling studies suggested that they bind to the orthosteric site of the receptor, mainly through non-polar interactions.

Chromenone derivatives useful for the treatment of neurodegenerative diseases

Compounds of general formula (I) and (II) in which R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 and R15 have the meanings given in the specification, are useful in the treatment of neurodegenerative disease.