Trihydroxyflavone-methyl ether

Some bioactive flavones include aldose reductase inhibitors (apigenin 4 -methyl ether (acacetin), apigenin 7-0-apioside (apiin), 5,7-dihydroxyflavone (chrysin) and luteolin) antiinflammatory 5-LOX inhibitors (5,6,7-trihydroxyflavone (baicalein), 5,6,3, 4 -tetrahydroxy 7-methoxyflavone (pedalitin), 5,3, 4 -trihydroxy 6,7-dimethoxyflavone (cirsiliol, 6-0-methylpedalitin) and flavone) a COX inhibitor (flavone) iodothyronine deiodinase inhibitors (acacetin, chrysin and luteolin) a NADH and succinate dehydrogenase inhibitor (luteolin) millet-derived, goitrogenic inhibitors of thyroid peroxidase (flavone C-glycosides orientin and vitexin) and protein kinase inhibitors (acacetin, apigenin, baicalein, flavone, luteolin, 5,7,3, 4, 5 -pentahydroxyflavone (tricetin) and tricetin 3, 4, 5 -trimethyl ether). 

Acacetin (= Apigenin 4 -methyl ether 5,7,4 -Trihydroxyflavone 4 -methyl ether)... 

Phenolic hydroxyl groups which form part of a strongly chelated ortAo-hydroxycarbonyl or pen-hydroxycarbonyl system (e.g. 8-hydroxynaphthoquinones, 5-hydroxyflavones, 1-hydroxyxanthones) are not normally alkylated by a diazoalkane. Thus the trihydroxyflavone (3) v en treated with diazomethane forms the dimethyl ether (4) [3] and the heartwood xanthone jacareubin (5) similarly methylated gives (6) [4]. 

From alnusin trimethyl ether (3,5,6,7-tetramethoxyflavone) (m.p. 112-112°5) (SM) refluxing in a mixture of 50% potassium hydroxide solution and ethanol for 20 h under nitrogen (50%). SM was prepared by methylation of alnusin (6-methoxy-3,5,7-trihydroxyflavone) (m.p. 239-241°). Alnusin was the main flavonoid isolated from Alnus sieboldiana (Betulaceae) [4971] ... 

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