Concise synthesis of polymethoxyflavone sudachitin and its derivatives, and biological evaluations

Expression and functional analysis of the nobiletin biosynthesis-related gene CitOMT in citrus fruit

“…To investigate the enzymatic function of CitOMT from Ponkan mandarin, the purified recombinant protein was tested for its reaction with several flavonoids: 3′-hydroxyflavanone, 4′-hydroxyflavone, naringenin, and hesperidin as flavanones, 3′,4′-dihydroxyflavone, 3′,5,6,7,8-pentamethoxy-4′-hydroxyflavone 49 , 3′,4′,5,7-tetrahydroxyflavone, 7-hydroxyflavone and 7,8-dihydroxyflavone as flavones, and daidzein as an isoflavone, in the presence of S-adenosyl-l-methionine (SAM) as methyl donor. The reaction mixture consisted of 10 mM substrate, 500 mM SAM, 20 mM Tris-HCl (pH 7.0), 10% glycerol (v/v), 5 mM DTT, and 0.5 mg of purified CitOMT yielding a total volume of 500 μL.…”

Practical Synthesis of Polymethylated Flavones: Nobiletin and Its Desmethyl Derivatives

“…By means of a similar strategy for the desmethylation and flavone synthesis, efficient syntheses of sudatichin ( 36 ) and desmethylnobiletin derivatives 37 – 39 were accomplished, as shown in Figure .…”

“…There have been few pharmacodynamic studies of dietary flavonoids using labeled synthetic compounds, even though several flavonoids are known to have beneficial effects both in vitro and in vivo. 16 Thus, we investigated the conversion of modified acetophenones and acylbenzotriazoles into desmethyl derivatives of nobiletin (Scheme 5). After the coupling of 4 and 22 12 afforded β-diketone 23, acidic cyclization of 23 gave flavone 24.…”

“…5-Desmethylnobiletin (27) has already been converted into chemical probes labeled with 11 C for positron emission tomography 10 with fluorescein (TokyoGreen) for visualizing the biodistribution or with biotin for identification of binding proteins. 14 By means of a similar strategy for the desmethylation and flavone synthesis, efficient syntheses of sudatichin (36) and desmethylnobiletin derivatives 37−39 15 were accomplished, 16 as shown in Figure 2.…”

Recent advances in the synthesis of 4H-chromen-4-ones (2012 − 2021)

“…168 Polymethoxy-4H-chromen-4-ones have been prepared by condensation of 2 0 -hydroxyacetophenone derivatives and acylbenzotriazoles in the presence of lithium bis(trimethylsilyl)amide (LiHMDS) in dry THF at À78 to 0 °C, followed by cyclodehydration promoted by p-PTSA in toluene at 80 °C. 169 Scheme 18…”